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      How To Build a GraphQL API With Golang to Upload Files to DigitalOcean Spaces


      The author selected the Diversity in Tech Fund to receive a donation as part of the Write for DOnations program.

      Introduction

      For many applications, one desirable feature is the user’s ability to upload a profile image. However, building this feature can be a challenge for developers new to GraphQL, which has no built-in support for file uploads.

      In this tutorial, you will learn to upload images to a third-party storage service directly from your backend application. You will build a GraphQL API that uses an S3-compatible AWS GO SDK from a Go backend application to upload images to DigitalOcean Spaces, which is a highly scalable object storage service. The Go back-end application will expose a GraphQL API and store user data in a PotsgreSQL database provided by DigitalOcean’s Managed Databases service.

      By the end of this tutorial, you will have built a GraphQL API using Golang that can receive a media file from a multipart HTTP request and upload the file to a bucket within DigitalOcean Spaces.

      Prerequisites

      To follow this tutorial, you will need:

      • A DigitalOcean account. If you do not have one, sign up for a new account. You will use DigitalOcean’s Spaces and Managed Databases in this tutorial.

      • A DigitalOcean Space with Access Key and Access Secret, which you can create by following the tutorial, How To Create A DigitalOcean Space and API Key. You can also see product documentation for How to Manage Administrative Access to Spaces.

      • Go installed on your local machine, which you can do by following our series, How to Install and Set Up a Local Programming Environment for Go. This tutorial used Go version 1.17.1.

      • Basic knowledge of Golang, which you can gain from our How To Code in Go series. The tutorial, How To Write Your First Program In Go, provides a good introduction to the Golang programming language.

      • An understanding of GraphQL, which you can find in our tutorial, An Introduction To GraphQL.

      Step 1 — Bootstrapping a Golang GraphQL API

      In this step, you will use the Gqlgen library to bootstrap the GraphQL API. Gqlgen is a Go library for building GraphQL APIs. Two important features that Gqglen provides are a schema-first approach and code generation. With a schema-first approach, you first define the data model for the API using the GraphQL Schema Definition Language (SDL). Then you generate the boilerplate code for the API from the defined schema. Using the code generation feature, you do not need to manually create the query and mutation resolvers for the API as they are automatically generated.

      To get started, execute the command below to install gqlgen:

      • go install github.com/99designs/gqlgen@latest

      Next, create a project directory named digitalocean to store the files for this project:

      Change into the digitalocean project directory:

      From your project directory, run the following command to create a go.mod file that manages the modules within the digitalocean project:

      Next, using nano or your favorite text editor, create a file named tools.go within the project directory:

      Add the following lines into the tools.go file as a tool for the project:

      // +build tools
      
       package tools
      
       import _ "github.com/99designs/gqlgen" 
      

      Next, execute the tidy command to install the gqlgen dependency introduced within the tools.go file:

      Finally, using the installed Gqlgen library, generate the boilerplate files needed for the GraphQL API:

      Running the gqlgen command above generates a server.go file for running the GraphQL server and a graph directory containing a schema.graphqls file that contains the Schema Definitions for the GraphQL API.

      In this step, you used the Gqlgen library to bootstrap the GraphQL API. Next, you’ll define the schema of the GraphQL application.

      Step 2 — Defining the GraphQL Application Schema

      In this step, you will define the schema of the GraphQL application by modifying the schema.graphqls file that was automatically generated when you ran the gqlgen init command. In this file, you will define a User, Query, and Mutation types.

      Navigate to the graph directory and open the schema.graphqls file, which defines the schema of the GraphQL application. Replace the boilerplate schema with the following code block, which defines the User type with a Query to retrieve all user data and a Mutation to insert data:

      schema.graphqls

      
      scalar Upload
      
      type User {
        id: ID!
        fullName: String!
        email: String!
        img_uri: String!
        DateCreated: String!
      }
      
      type Query {
        users: [User]!
      }
      
      input NewUser {
        fullName: String!
        email: String!
        img_uri: String
        DateCreated: String
      }
      
      input ProfileImage {
        userId: String
        file: Upload
      }
      
      type Mutation {
        createUser(input: NewUser!): User!
        uploadProfileImage(input: ProfileImage!): Boolean!
      }
      

      The code block defines two Mutation types and a single Query type for retrieving all users. A mutation is used to insert or mutate existing data in a GraphQL application, while a query is used to fetch data, similar to the GET HTTP verb in a REST API.

      The schema in the code block above used the GraphQL Schema Definition Language to define a Mutation containing the CreateUser type, which accepts the NewUser input as a parameter and returns a single user. It also contains the uploadProfileImage type, which accepts the ProfileImage and returns a boolean value to indicate the status of the success upload operation.

      Note: Gqlgen automatically defines the Upload scalar type, and it defines the properties of a file. To use it, you only need to declare it at the top of the schema file, as it was done in the code block above.

      At this point, you have defined the structure of the data model for the application. The next step is to generate the schema’s query and the mutation resolver functions using Gqlgen’s code generation feature.

      Step 3 — Generating the Application Resolvers

      In this step, you will use Gqlgen’s code generation feature to automatically generate the GraphQL resolvers based on the schema that you created in the previous step. A resolver is a function that resolves or returns a value for a GraphQL field. This value could be an object or a scalar type such as a string, number, or even a boolean.

      The Gqlgen package is based on a schema-first approach. A time-saving feature of Gqlgen is its ability to generate your application’s resolvers based on your defined schema in the schema.graphqls file. With this feature, you do not need to manually write the resolver boilerplate code, which means you can focus on implementing the defined resolvers.

      To use the code generation feature, execute the command below in the project directory to generate the GraphQL API model files and resolvers:

      A few things will happen after executing the gqlgen command. Two validation errors relating to the schema.resolvers.go file will be printed out, some new files will be generated, and your project will have a new folder structure.

      Execute the tree command to view the new files added to your project.

      tree *
      

      The current directory structure will look similar to this:

      Output

      go.mod go.sum gqlgen.yml graph ├── db.go ├── generated │   └── generated.go ├── model │   └── models_gen.go ├── resolver.go ├── schema.graphqls └── schema.resolvers.go server.go tmp ├── build-errors.log └── main tools.go 2 directories, 8 files

      Among the project files, one important file is schema.resolvers.go. It contains methods that implement the Mutation and Query types previously defined in the schema.graphqls file.

      To fix the validation errors, delete the CreateTodo and Todos methods at the bottom of the schema.resolvers.go file. Gqlgen moved the methods to the bottom of the file because the type definitions were changed in the schema.graphqls file.

      schema.resolvers.go

      
      package graph
      
      // This file will be automatically regenerated based on the schema, any resolver implementations
      // will be copied through when generating and any unknown code will be moved to the end.
      
      import (
          "context"
          "digitalocean/graph/generated"
          "digitalocean/graph/model"
          "fmt"
      )
      
      func (r *mutationResolver) CreateUser(ctx context.Context, input model.NewUser) (*model.User, error) {
          panic(fmt.Errorf("not implemented"))
      }
      
      func (r *mutationResolver) UploadProfileImage(ctx context.Context, input model.ProfileImage) (bool, error) {
          panic(fmt.Errorf("not implemented"))
      }
      
      func (r *queryResolver) User(ctx context.Context) (*model.User, error) {
          panic(fmt.Errorf("not implemented"))
      }
      
      // Mutation returns generated.MutationResolver implementation.
      func (r *Resolver) Mutation() generated.MutationResolver { return &mutationResolver{r} }
      
      // Query returns generated.QueryResolver implementation.
      func (r *Resolver) Query() generated.QueryResolver { return &queryResolver{r} }
      
      type mutationResolver struct{ *Resolver }
      type queryResolver struct{ *Resolver }
      
      // !!! WARNING !!!
      // The code below was going to be deleted when updating resolvers. It has been copied here so you have
      // one last chance to move it out of harms way if you want. There are two reasons this happens:
      //  - When renaming or deleting a resolver the old code will be put in here. You can safely delete
      //    it when you're done.
      //  - You have helper methods in this file. Move them out to keep these resolver files clean.
      
      func (r *mutationResolver) CreateTodo(ctx context.Context, input model.NewTodo) (*model.Todo, error) {
       panic(fmt.Errorf("not implemented"))
      }
      func (r *queryResolver) Todos(ctx context.Context) ([]*model.Todo, error) {
       panic(fmt.Errorf("not implemented"))
      }
      

      As defined in the schema.graphqls file, Gqlgen’s code generator created two mutations and one query resolver method. These resolvers serve the following purposes:

      • CreateUser: This mutation resolver inserts a new user record into the connected Postgres database.

      • UploadProfileImage: This mutation resolver uploads a media file received from a multipart HTTP request and uploads the file to a bucket within DigitalOcean Spaces. After the file upload, the URL of the uploaded file is inserted into the img_uri field of the previously created user.

      • Users: This query resolver queries the database for all existing users and returns them as the query result.

      Going through the methods generated from the Mutation and Query types, you would observe that they cause a panic with a not implemented error when executed. This indicates that they are still auto-generated boilerplate code. Later in this tutorial, you will return to the schema.resolver.go file to implement these generated methods.

      At this point, you generated the resolvers for this application based on the content of the schema.graphqls file. You will now use the Managed Databases service to create a database that will store the data passed to the mutation resolvers to create a user.

      Step 4 — Provisioning and Using a Managed Database Instance on DigitalOcean

      In this step, you will use the DigitalOcean console to access the Managed Databases service and create a PostgreSQL database to store data from this application. After the database has been created, you will securely store the details in a .env file.

      Although the application will not store images directly in a database, it still needs a database to insert each user‘s record. The stored record will then contain links to the uploaded files.

      A user’s record will consist of a Fullname, email, dateCreated, and an img_uri field of String data type. The img_uri field contains the URL pointing to an image file uploaded by a user through this GraphQL API and stored within a bucket on DigitalOcean Spaces.

      Using your DigitalOcean dashboard, navigate to the Databases section of the console to create a new database cluster, and select PostgreSQL from the list of databases offered. Leave all other settings at their default values and create this cluster using the button at the bottom.

      Digitalocean database cluster

      The database cluster creation process will take a few minutes before it is completed.

      After creating the cluster, follow the Getting Started steps on the database cluster page to set up the cluster for use.

      At the second step of the Getting Started guide, click the Continue, I’ll do this later text to proceed. By default, the database cluster is open to all connections.

      Note: In a production-ready scenario, the Add Trusted Sources input field at the second step should only contain trusted IP addresses, such as the IP Address of the DigitalOcean Droplet running the application. During development, you can alternatively add the IP address of your development machine to the Add Trusted Sources input field.

      Click the Allow these inbound sources button to save and proceed to the next step.

      At the next step, the connection details of the cluster are displayed. You can also find the cluster credentials by clicking the Actions dropdown, then selecting the Connection details option.

      Digitalocean database cluster credentials

      In this screenshot, the gray box at right shows the connection credentials of the created demo cluster.

      You will securely store these cluster credentials as environment variables. In the digitalocean project directory, create a .env file and add your cluster credentials in the following format, making sure to replace the highlighted placeholder content with your own credentials:

      .env

      
       DB_PASSWORD=YOUR_DB_PASSWORD
       DB_PORT=PORT
       DB_NAME=YOUR_DATABASE_NAME
       DB_ADDR=HOST
       DB_USER=USERNAME
      

      With the connection details securely stored in the .env file, the next step will be to retrieve these credentials and connect the database cluster to your project.

      Before proceeding, you will need a database driver to work with Golang’s native SQL package when connecting to the Postgres database. go-pg is a Golang library for translating ORM (object-relational mapping) queries into SQL Queries for a Postgres database. godotenv is a Golang library for loading environment credential from a .env file into your application. Lastly, go.uuid generates a UUID (universally unique identifier) for each user’s record that will be inserted into the database.

      Execute this command to install these:

      • go get github.com/go-pg/pg/v10 github.com/joho/godotenv github.com/satori/go.uuid

      Next, navigate to the graph directory and create a db.go file. You will gradually put together the code within the file to connect with the Postgres database created in the Managed Databases cluster.

      First, add the content of the code block into the db.go file. This function (createSchema) creates a user table in the Postgres database immediately after a connection to the database has been established.

      db.go

      package graph
      
      import (
          "github.com/go-pg/pg/v10"
          "github.com/go-pg/pg/v10/orm"
          "digitalocean/graph/model"
      )
      
      func createSchema(db *pg.DB) error {
          for _, models := range []interface{}{(*model.User)(nil)}{
              if err := db.Model(models).CreateTable(&orm.CreateTableOptions{
                  IfNotExists: true,
              }); err != nil {
                  panic(err)
              }
          }
      
          return nil
      }
      

      Using the IfNotExists option passed to the CreateTable method from go-pg, the createSchema function only inserts a new table into the database if the table does not exist. You can understand this process as a simplified form of seeding a newly created database. Rather than creating the Tables manually through the psql client or GUI, the createSchema function takes care of the table creation.

      Next, add the content of the code block below into the db.go file to establish a connection to the Postgres database and execute the createSchema function above when a connection has been established successfully:

      db.go

      
      import (
            // ...
      
               "fmt" 
               "os" 
          )
      
      func Connect() *pg.DB {
          DB_PASSWORD := os.Getenv("DB_PASSWORD")
          DB_PORT := os.Getenv("DB_PORT")
          DB_NAME := os.Getenv("DB_NAME")
          DB_ADDR := os.Getenv("DB_ADDR")
          DB_USER := os.Getenv("DB_USER")
      
          connStr := fmt.Sprintf(
              "postgresql://%v:%v@%v:%v/%v?sslmode=require",
              DB_USER, DB_PASSWORD, DB_ADDR, DB_PORT, DB_NAME )
      
          opt, err := pg.ParseURL(connStr); if err != nil {
            panic(err)
            }
      
          db := pg.Connect(opt)
      
          if schemaErr := createSchema(db); schemaErr != nil {
              panic(schemaErr)
          }
      
          if _, DBStatus := db.Exec("SELECT 1"); DBStatus != nil {
              panic("PostgreSQL is down")
          }
      
          return db 
      }
      

      When executed, the exported Connect function in the code block above establishes a connection to a Postgres database using go-pg. This is done through the following operations:

      • First, the database credentials you stored in the root .env file are retrieved. Then, a variable is created to store a string formatted with the retrieved credentials. This variable will be used as a connection URI when connecting with the database.

      • Next, the created connection string is parsed to see if the formatted credentials are valid. If valid, the connection string is passed into the connect method as an argument to establish a connection.

      To use the exported Connect function, you will need to add the function to the server.go file, so it will be executed when the application is started. Then the connection can be stored in the DB field within the Resolver struct.

      To use the previously created Connect function from the graph package immediately after the application is started, and to load the credentials from the .env file into the application, open the server.go file in your preferred code editor and add the lines highlighted below:

      Note: Make sure to replace the existing srv variable in the server.go file with the srv variable highlighted below.

      server.go

       package main
      
      import (
        "log"
        "net/http"
        "os"
        "digitalocean/graph"
        "digitalocean/graph/generated"
      
        "github.com/99designs/gqlgen/graphql/handler"
        "github.com/99designs/gqlgen/graphql/playground"
       "github.com/joho/godotenv"
      )
      
      const defaultPort = "8080"
      
      func main() {
           err := godotenv.Load(); if err != nil {
           log.Fatal("Error loading .env file")
          } 
      
        // ...
      
           Database := graph.Connect()
           srv := handler.NewDefaultServer(
                   generated.NewExecutableSchema(
                           generated.Config{
                               Resolvers: &graph.Resolver{
                                   DB: Database,
                               },
                           }),
               )
      
        // ...
      }
      

      In this code snippet, you loaded the credentials stored in the .env through the Load() function. You called the Connect function from the db package and also created the Resolver object with the database connection stored in the DB field. (The stored database connection will be accessed by the resolvers later in this tutorial.)

      Currently, the boilerplate Resolver struct in the resolver.go file does not contain the DB field where you stored the database connection in the code above. You will need to create the DB field.

      In the graph directory, open the resolver.go file and modify the Resolver struct to have a DB field with a go-pg pointer as its type, as shown below:

      resolver.go

      package graph
      
      import "github.com/go-pg/pg/v10"
      
      // This file will not be regenerated automatically.
      //
      // It serves as dependency injection for your app, add any dependencies you require here.
      
      type Resolver struct {
          DB *pg.DB
      }
      

      Now a database connection will be established each time the entry server.go file is run and the go-pg package can be used as an ORM to perform operations on the database from the resolver functions.

      In this step, you created a PostgreSQL database using the Managed Database service on DigitalOcean. You also created a db.go file with a Connect function to establish a connection to the PostgreSQL database when the application is started. Next, you will implement the generated resolvers to store data in the PostgreSQL database.

      Step 5 — Implementing the Generated Resolvers

      In this step, you will implement the methods in the schema.resolvers.go file, which serves as the mutation and query resolvers. The implemented mutation resolvers will create a user and upload the user’s profile image, while the query resolver will retrieve all stored user details.

      Implementing the Mutation Resolver Methods

      In the schema.graphqls file, two mutation resolvers were generated. One with the purpose of inserting the user’s record, while the other handles the profile image uploads. However, these mutations have not yet been implemented as they are boilerplate code.

      Open the schema.resolvers.go file. Modify the imports and the CreateUser mutation with the highlighted lines to insert a new row containing the user details input into the database:

      schema.resolvers.go

      package graph
      
      import (
        "context"
        "fmt"
         "time" 
      
        "digitalocean/graph/generated"
        "digitalocean/graph/model"
        "github.com/satori/go.uuid" 
      )
      
      func (r *mutationResolver) CreateUser(ctx context.Context, input model.NewUser) (*model.User, error) {
           user := model.User{ 
               ID:          fmt.Sprintf("%v", uuid.NewV4()), 
               FullName:    input.FullName, 
               Email:       input.Email, 
               ImgURI:      "https://bit.ly/3mCSn2i", 
               DateCreated: time.Now().Format("01-02-2006"), 
           } 
      
           _, err := r.DB.Model(&user).Insert(); if err != nil { 
               return nil, fmt.Errorf("error inserting user: %v", err) 
           } 
      
           return &user, nil 
      }
      
      

      In the CreateUser mutation, there are two things to note about the user rows inserted. First, each row that is inserted is given a UUID. Second, the ImgURI field in each row has a placeholder image URL as the default value. This will be the default value for all records and will be updated when a user uploads a new image.

      Next, you will test the application that has been built at this point. From the project directory, run the server.go file with the following command:

      Now, navigate to http://localhost:8080 through your web browser to access the GraphQL playground built-in to your GraphQL API. Paste the GraphQL Mutation in the code block below into the playground editor to insert a new user record.

      graphql

      
      mutation createUser {
        createUser(
          input: {
            email: "johndoe@gmail.com"
            fullName: "John Doe"
          }
        ) {
          id
        }
      }
      

      The output in the right pane will look similar to this:

      A create user mutation on the GraphQL Playround

      You executed the CreateUser mutation to create a test user with the name of John Doe, and the id of the newly inserted user record was returned as a result of the mutation.

      Note: Copy the id value returned from the executed GraphQL query. You will use the id when uploading a profile image for the test user created above.

      At this point, you have the second UploadProfileImage mutation resolver function left to implement. But before you implement this function, you need to implement the query resolver first. This is because each upload is linked to a specific user, which is why you retrieved the ID of a specific user before uploading an image.

      Implementing the Query Resolver Method

      As defined in the schema.resolvers.graphqls file, one query resolver was generated to retrieve all created users. Similar to the previous mutation resolvers methods, you also need to implement the query resolver method.

      Open scheme.resolvers.go and modify the generated Users query resolver with the highlighted lines. The new code within the Users method below will query the Postgres database for all user rows and return the result.

      schema.resolvers.go

      package graph
      
      func (r *queryResolver) Users(ctx context.Context) ([]*model.User, error) {
        var users []*model.User
      
        err := r.DB.Model(&users).Select()
          if err != nil {
           return nil, err
          } 
      
        return users, nil 
      }
      

      Within the Users resolver function above, fetching all records within the user table is made possible by using go-pg’s select method on the User model without passing the WHERE or LIMIT clause into the query.

      Note: For a bigger application where many records will be returned from the query, it is important to consider paginating the data returned for improved performance.

      To test this query resolver from your browser, navigate to http://localhost:8080 to access the GraphQL playground. Paste the GraphQL Query below into the playground editor to fetch all created user records.

      graphql

      
      query fetchUsers {
        users {
            fullName
            id
            img_uri
        }
      }
      

      The output in the right pane will look similar to this:

      Query result GraphQL playground

      In the returned results, you can see that a users object with an array value was returned. For now, only the previously created user was returned in the users array because that it is the only record in the table. More users will be returned in the users array if you execute the createUser mutation with new details. You can also observe that the img_uri field in the returned data has the hardcoded fallback image URL.

      At this point, you have now implemented both the CreateUser mutation and the User query. Everything is in place for you to receive images from the second UploadProfileImage resolver and upload the received image to a bucket with DigitalOcean Spaces using an S3 compatible AWS-GO SDK.

      Step 6 — Uploading Images to DigitalOcean Spaces

      In this step, you will use the powerful API within the second UploadProfileImage mutation to upload an image to your Space.

      To begin, navigate to the Spaces section of your DigitalOcean console, where you will create a new bucket for storing the uploaded files from your backend application.

      Click the Create New Space button. Leave the settings at their default values and specify a unique name for the new Space:

      Digitalocean spaces

      After a new Space has been created, navigate to the settings tab and copy the Space’s endpoint, name, and region. Add these to the .env file within the GraphQL project in this format:

      .env

      SPACE_ENDPOINT=BUCKET_ENDPOINT
      DO_SPACE_REGION=DO_SPACE_REGION
      DO_SPACE_NAME=DO_SPACE_NAME
      

      As an example, the following screenshot shows the Setting tab, and highlights the name, region, and endpoint details of the demo space (Victory-space):

      Victory-space endpoint, name, and region

      As part of the prerequisites, you created a Space Access key and Secret key for your Space. Paste in your Access and Secret keys into the .env file within the GraphQL application in the following format:

      .env

      ACCESS_KEY=YOUR_SPACE_ACCESS_KEY
      SECRET_KEY=YOUR_SPACE_SECRET_KEY
      

      At this point, you will need to use the CTRL + C key combination to stop the GraphQL server, and execute the command below to restart the GraphQL application with the new credentials loaded into the application.

      Now that your Space credentials are loaded into the application, you will create the upload logic in the UploadProfileImage mutation resolver. The first step will be to add and configure the aws-sdk-go SDK to connect to your DigitalOcean Space.

      One way to programmatically perform operations on your bucket within Spaces is through the use of compatible AWS SDKs. The AWS Go SDK is a development kit that provides a set of libraries to be used by Go developers. The libraries provided by the SDK can be used by a Go written application when performing operations with AWS resources such as file transfers to S3 buckets.

      The DigitalOcean Spaces documentation provides a list of operations you can perform on the Spaces API using an AWS SDK. We will use the aws-sdk-go SDK to connect to the your DigitalOcean Space.

      Execute the go get command to install the aws-sdk-go SDK into the application:

      • go get github.com/aws/aws-sdk-go

      Over the next few code blocks, you will gradually put together the upload logic in the UploadProfileImage mutation resolver.

      First, open the schema.resolvers.go file. Add the highlighted lines to configure the AWS SDK with the stored credentials and establish a connection with your DigitalOcean Space:

      Note: The code within the code block below is incomplete, as you are gradually putting the upload logic together. You will complete the code in the subsequent code blocks.

      schema.resolvers.go

      package graph
      
      import (
         ...
      
         "os"
      
         "github.com/aws/aws-sdk-go/aws"
         "github.com/aws/aws-sdk-go/aws/credentials"
         "github.com/aws/aws-sdk-go/aws/session"
         "github.com/aws/aws-sdk-go/service/s3"
      )
      
      func (r *mutationResolver) UploadProfileImage(ctx context.Context, input model.ProfileImage) (bool, error) {
      
       SpaceRegion := os.Getenv("DO_SPACE_REGION")
       accessKey := os.Getenv("ACCESS_KEY")
       secretKey := os.Getenv("SECRET_KEY")
      
       s3Config := &aws.Config{
           Credentials: credentials.NewStaticCredentials(accessKey, secretKey, ""),
           Endpoint:    aws.String(os.Getenv("SPACE_ENDPOINT")),
           Region:      aws.String(SpaceRegion),
       }
      
       newSession := session.New(s3Config)
       s3Client := s3.New(newSession)
      
      }
      

      Now that the SDK is configured, the next step is to upload the file sent in the multipart HTTP request.

      One way to handle files sent is to read the content from the multipart request, temporarily save the content to a new file in memory, upload the temporary file using the aws-SDK-go library, and then delete it after an upload. Using this approach, a client application such as a web application consuming this GraphQL API still uses the same GraphQL endpoint to perform file uploads, rather than using a third party API to upload files.

      To achieve this, add the highlighted lines to the existing code within the UploadProfileImage mutation resolver in the schema.resolvers.go file:

      schema.resolvers.go

      
      package graph
      
      import (
         ...
      
         "io/ioutil"
         "bytes"
      
      )
      
      func (r *mutationResolver) UploadProfileImage(ctx context.Context, input model.ProfileImage) (bool, error) {
      ...
      
      SpaceName := os.Getenv("DO_SPACE_NAME")
      
      ...
      
      
        userFileName := fmt.Sprintf("%v-%v", input.UserID, input.File.Filename)
        stream, readErr := ioutil.ReadAll(input.File.File)
       if readErr != nil {
           fmt.Printf("error from file %v", readErr)
       }
      
       fileErr := ioutil.WriteFile(userFileName, stream, 0644); if fileErr != nil {
           fmt.Printf("file err %v", fileErr)
       }
      
       file, openErr := os.Open(userFileName); if openErr != nil {
           fmt.Printf("Error opening file: %v", openErr)
       }
      
       defer file.Close()
      
       buffer := make([]byte, input.File.Size)
      
      _, _ = file.Read(buffer)
      
       fileBytes := bytes.NewReader(buffer)
      
       object := s3.PutObjectInput{
           Bucket: aws.String(SpaceName),
           Key:    aws.String(userFileName),
           Body:   fileBytes,
           ACL:    aws.String("public-read"),
       }
      
       if _, uploadErr := s3Client.PutObject(&object); uploadErr != nil {
           return false, fmt.Errorf("error uploading file: %v", uploadErr)
       }
      
       _ = os.Remove(userFileName)
      
      
      return true, nil
      }
      

      Using the ReadAll method from the io package in the code block above, you first read the content of the file added to the multipart request sent to the GraphQL API, and then a temporary file is created to dump this content into.

      Next, using the PutObjectInput struct, you created the structure of the file to be uploaded by specifying the Bucket, Key, ACL, and Body field to be the content of the temporarily stored file.

      Note: The Access Control List (ACL) field in the PutObjectInput struct has a public-read value to make all uploaded files available for viewing over the internet. You can remove this field if your application requires that uploaded data be kept private.

      After creating the PutObjectInput struct, the PutObject method is used to make a PUT operation, sending the values of the PutObjectInput struct to the bucket. If there is an error, a false boolean value and an error message are returned, ending the execution of the resolver function and the mutation in general.

      To test the upload mutation resolver, you can use an image of Sammy the Shark, DigitalOcean’s mascot. Use the wget command to download an image of Sammy:

      • wget https://html.sammy-codes.com/images/small-profile.jpeg

      Next, execute the cURL command below to make an HTTP request to the GraphQL API to upload Sammy’s image, which has been added to the request form body.

      Note: If you are on a Windows Operating System, it is recommended that you execute the cURL commands using the Git Bash shell due to the backslash escapes.

      • curl localhost:8080/query -F operations="{ "query": "mutation uploadProfileImage($image: Upload! $userId : String!) { uploadProfileImage(input: { file: $image userId : $userId}) }", "variables": { "image": null, "userId" : "12345" } }" -F map='{ "0": ["variables.image"] }' -F 0=@small-profile.jpeg

      Note: We are using a random userId value in the request above because the process of updating a user’s record has not yet been implemented.

      The output will look similar to this, indicating that the file upload was successful:

      Output

      {"data": { "uploadProfileImage": true }}

      In the Spaces section of the DigitalOcean console, you will find the image uploaded from your terminal:

      A bucket within Digitalocean showing a list of uploaded files

      At this point, file uploads within the application are working; however, the files are linked to the user who performed the upload. The goal of each file upload is to have the file uploaded into a storage bucket and then linked back to a user by updating the img_uri field of the user.

      Open the resolver.go file in the graph directory and add the code block below. It contains two methods: one to retrieve a user from the database by a specified field, and the other function to update the record of a user.

      resolver.go

      
      import (
      ...
      
        "digitalocean/graph/model"
        "fmt"
      )
      
      ...
      
      func (r *mutationResolver) GetUserByField(field, value string) (*model.User, error) {
          user := model.User{}
      
          err := r.DB.Model(&user).Where(fmt.Sprintf("%v = ?", field), value).First()
      
          return &user, err
      }
      
      
      func (r *mutationResolver) UpdateUser(user *model.User) (*model.User, error) {
          _, err := r.DB.Model(user).Where("id = ?", user.ID).Update()
          return user, err
      }
      
      

      The first GetUserByField function above accepts a field and value argument, both of a string type. Using go-pg’s ORM, it executes a query on the database, fetching data from the user table with a WHERE clause.

      The second UpdateUser function in the code block uses go-pg to execute an UPDATE statement to update a record in the user table. Using the where method, a WHERE clause with a condition is added to the UPDATE statement to update only the row having the same ID passed into the function.

      Now you can use the two methods in the UploadProfileImage mutation. Add the content of the highlighted code block below to the UploadProfileImage mutation within the schema.resolvers.go file. This will retrieve a specific row from the user table and update the img_uri field in the user’s record after the file has been uploaded.

      Note: Place the highlighted code at the line above the existing return statement within the UploadProfileImage mutation.

      schema.resolvers.go

      
      package graph
      
      
      func (r *mutationResolver) UploadProfileImage(ctx context.Context, input model.ProfileImage) (bool, error) {
        _ = os.Remove(userFileName)
      
       
          user, userErr := r.GetUserByField("ID", *input.UserID)
        
           if userErr != nil {
               return false, fmt.Errorf("error getting user: %v", userErr)
           }
        
         fileUrl := fmt.Sprintf("https://%v.%v.digitaloceanspaces.com/%v", SpaceName, SpaceRegion, userFileName)
        
           user.ImgURI = fileUrl
        
           if _, err := r.UpdateUser(user); err != nil {
               return false, fmt.Errorf("err updating user: %v", err)
           }
        
      
        return true, nil
      }
      

      From the new code added to the schema.resolvers.go file, an ID string and the user’s ID are passed to the GetUserByField helper function to retrieve the record of the user executing the mutation.

      A new variable is then created and given the value of a string formatted to have the link of the recently uploaded file in the format of https://BUCKET_NAME.SPACE_REGION.digitaloceanspaces.com/USER_ID-FILE_NAME. The ImgURI field in the retrieved user model was reassigned the value of the formatted string as a link to the uploaded file.

      Paste the curl command below into your terminal, and replace the highlighted USER_ID placeholder in the command with the userId of the user created through the GraphQL playground in a previous step. Make sure the userId is wrapped in quotation marks so that the terminal can encode the value properly.

      • curl localhost:8080/query -F operations="{ "query": "mutation uploadProfileImage($image: Upload! $userId : String!) { uploadProfileImage(input: { file: $image userId : $userId}) }", "variables": { "image": null, "userId" : "USER_ID" } }" -F map='{ "0": ["variables.image"] }' -F 0=@small-profile.jpeg

      The output will look similar to this:

      Output

      {"data": { "uploadProfileImage": true }}

      To further confirm that the user’s img_uri was updated, you can use the fetchUsers query from the GraphQL playground in the browser to retrieve the user’s details. If the update was successful, you will see that the default placeholder URL of https://bit.ly/3mCSn2i in the img_uri field has been updated to the value of the uploaded image.

      The output in the right pane will look similar to this:

      A query mutation to retrieve an updated user record using the GraphQL Playground

      In the returned results, the img_uri in the first user object returned from the query has a value that corresponds to a file upload to a bucket within DigitalOcean Spaces. The link in the img_uri field is made up of the bucket endpoint, the user’s ID, and lastly, the filename.

      To test the permission of the uploaded file set through the ACL option, you can open the img_uri link in your browser. Due to the default Metadata on the uploaded image, it will automatically download to your computer as an image file. You can open the file to view the image.

      Downloaded view of the uploaded file

      The image at the img_uri link will be the same image that was uploaded from the command line, indicating that the methods in the resolver.go file were executed correctly, and the entire file upload logic in the UploadProfileImage mutation works as expected.

      In this step, you uploaded an image into a DigitalOcean Space by using the AWS SDK for Go from the UploadProfileImage mutation resolver.

      Conclusion

      In this tutorial, you performed a file upload to a created bucket on a DigitalOcean Space using the AWS SDK for Golang from a mutation resolver in a GraphQL application.

      As a next step, you could deploy the application built within this tutorial. The Go Dev Guide provides a beginner-friendly guide on how to deploy a Golang application to DigitalOcean’s App Platform, which is a fully managed solution for building, deploying, and managing your applications from various programming languages.



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      How to Fix the “Upload: Failed to Write File to Disk” Error in WordPress (3 Ways)


      Are you encountering the “Upload: Failed to write file to disk” error message when uploading files in WordPress? Whether you’re trying to add images or videos to your site, this message can be very frustrating, as it prevents you from sharing your amazing visuals with your audience.

      Fortunately, you can troubleshoot this issue by following a few simple steps. In some cases, you’ll just need to contact your web host to get it fixed.

      In this post, we’ll take a closer look at the “Upload: Failed to write file to disk” error and its main causes. We’ll then show you three simple ways to fix this problem. Let’s get started!

      What Causes the “Upload: Failed to Write File to Disk” Error in WordPress

      The “Upload: Failed to Write File to Disk” error message typically comes up when you’re trying to upload media files to your WordPress site. There are a few possible causes, the most common one being incorrect file permissions.

      Every file and folder on your WordPress site comes with a set of permissions. These are controlled by the web server and determine which site users can access and edit your files and folders. Thus, if the permissions are incorrect, you may be unable to perform certain actions on your site, such as uploading images to your media library.

      However, this error could also be caused by other issues, including a full WordPress temporary folder. It’s also possible that you’ve reached the disk space limit provided with your hosting plan.

      Next, we’ll take a closer look at these possible causes. We’ll also walk you through a solution for each scenario.

      Skip the Stress

      Avoid troubleshooting when you sign up for DreamPress. Our friendly WordPress experts are available 24/7 to help solve website problems — big or small.

      How to Fix the “Upload: Failed to Write File to Disk” Error in WordPress (3 Ways)

      Now, let’s look at three easy ways to fix this disk error in WordPress. As always, we recommend that you perform a backup of your site before proceeding. That way, if something goes wrong, you can restore your site to an earlier version.

      1. Change the File Permissions

      As we mentioned earlier, the “Upload: Failed to write file to disk” error is likely caused by incorrect file permissions. If you want to check these permissions, you can contact your hosting provider and ask them if they can do it for you. Alternatively, you can do this yourself by accessing your site’s root directory.

      First, you’ll need to connect to your site via a Secure File Transfer Protocol (SFTP) client such as FileZilla. You can also access your site’s directory through the file manager in your hosting account.

      If you have a DreamHost account, start by navigating to Websites > Files in the sidebar. Then locate your domain and click on the Manage Files button.

      Accessing your site in DreamHost

      This will take you to the file manager. To access your site’s directory, you can open the folder labeled with your domain name. Inside, locate the wp-content folder and right-click on it.

      Next, select File permissions.

      Locating the wp-content folder in your site’s root directory.

      In the pop-up window, go to the Numeric value field and enter “755” or “750” in the corresponding box. Next, you can select the Recurse into subdirectories and Apply to directories only options and click on OK.

      Changing the file permissions of your subdirectories in FileZilla.

      You have now set the correct file permissions for all subdirectories inside the wp-content folder. This includes the uploads folder, which is where your uploaded media files are stored.

      However, you’ll also need to set the correct permissions for the files within those folders. To do this, you can right-click on the wp-content folder again and select File permissions.

      In the Numeric value field, type in “644”. Then select the Recurse into subdirectories and Apply to files only options, and click on OK.

      Changing the file permissions of your files in FileZilla.

      Don’t worry if you’re still unable to upload files to your site after checking your file permissions. There are a couple of other things you can do to resolve the issue.

      2. Empty the WordPress Temporary Folder

      If changing the file permissions doesn’t solve the problem, you may need to empty your temporary folder. WordPress processes your media uploads in PHP. This means that your images are first saved in a temporary folder on your web server before being transferred to your uploads folder.

      If the temporary folder is full, WordPress won’t be able to write your files to disk until you’ve emptied it. Unfortunately, you cannot access this temporary directory via SFTP.  However, you can simply contact your hosting provider and ask them to empty the folder for you, and then check to see if the error has been resolved. If you have sudo users, you could ask them to clear your temporary folder.

      Alternatively, you can try to resolve this issue by defining a new location for WordPress to store your media (instead of the temporary folder). First, you’ll need to connect to your site via an SFTP client or the file manager. Then locate the wp-config.php file, right-click on it, and select View/Edit.

      Editing the wp-config.php file in FileZilla.

      Next, you’ll need to paste in the following code right before the line that reads “That’s all, stop editing! Happy publishing”:

      define(‘WP_TEMP_DIR’, dirname(__FILE__) . ‘/wp-content/temp/’);

      Save your changes, then navigate to the wp-content folder, open it, and create a new folder inside it called temp.

      Creating a temp folder inside the wp-content folder.

      When you’re done, you can return to your website and try to upload an image. If the file disk error was caused by the temporary folder, the issue should now be resolved.

      3. Upgrade Your Hosting Plan

      The disk error could also be a sign that you’ve outgrown your current hosting plan. For example, if you’ve been adding a lot of content to your site, including media files, new pages, and plugins, you might have used up all the disk space available in your account.

      Your web host may be able to tell you how much disk space you have left. If you’re a DreamHost client, you can check your disk usage by logging into your hosting account and navigating to Billing & Account > Disk Usage in the side menu.

      Checking your disk usage in your DreamHost account.

      If you’ve reached your disk space limit, you might need to upgrade to a more advanced hosting plan. This will give your site more room to grow. We recommend getting in touch with your hosting provider to discuss the possibility of switching to a higher plan.

      Additional WordPress Error Articles

      Do you want to learn how to resolve other technical issues on your site? We’ve put together several tutorials to help you troubleshoot the most common WordPress errors:

      If you’re looking for more information about running a WordPress site, make sure to check out our WordPress Tutorials. This is a collection of guides designed to help you navigate the WordPress dashboard like an expert.

      Take Your WordPress Website to the Next Level

      Whether you need help navigating file permission issues, choosing a web hosting provider, or finding the best plugin, we can help! Subscribe to our monthly digest so you never miss an article.

      Fix the “Upload: Failed to Write File to Disk” Error

      The “Upload: Failed to write file to disk” error message prevents you from uploading files such as images and videos to your WordPress site. Incorrect file permissions on your site normally cause this error. However, you may also be seeing this message because you’ve used all the disk space offered with your hosting plan.

      In this article, we looked at three simple ways to fix this common WordPress error:

      1. Change the file permissions of your WordPress site using an SFTP client like FileZilla.
      2. Empty the WordPress temporary folder by getting in touch with your web host.
      3. Upgrade your hosting plan to access more disk space.

      At DreamHost, we provide 24/7 expert support to help you efficiently resolve technical issues. We also offer reliable managed WordPress hosting solutions to help you grow your business while also making it easy for you to upgrade to an advanced plan as your site grows.



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      Common WordPress Image Upload Issues and How to Fix Them (5 Methods)


      Since about 65% of people are visual learners, images are an important part of any website. And when you’re regularly uploading images for your WordPress website, it’s natural to run into the occasion error message.

      Fortunately, there are ways to diagnose even the vaguest image upload issue. By running through a checklist of common fixes, you should have no problems adding beautiful, eye-catching visuals to your website.

      In this article, we’ll look at why image-related errors can be tricky to diagnose. We’ll then share five solutions to try the next time the WordPress Media Library doesn’t want to cooperate with your creative vision. Let’s get started!

      An Introduction to WordPress Image Errors (And Why They’re a Problem)

      Beautiful, eye-catching images are a crucial part of almost any website. If you’re running an e-commerce store, product images are particularly important for driving sales, as they enable people to see what they’re purchasing. Maybe that explains why on average, images make up almost 17% of a web page’s total weight.

      The WordPress media library upload screen.

      However, uploading images to WordPress isn’t always straightforward. Sometimes, this popular Content Management System (CMS) may display a failure to upload error. These issues are notoriously difficult to diagnose, as they’re triggered by a wide range of factors. That can make it difficult to know where to start to address the problem.

      The good news? We can walk you through the steps we take to take to identify and fix image upload issues in WordPress.

      We’ll Fix Your Image Upload Issue

      Avoid troubleshooting when you sign up for DreamPress. Our friendly WordPress experts are available 24/7 to help solve website problems — big or small.

      Common WordPress Image Upload Errors and How to Fix Them (5 Methods)

      Nothing is more frustrating than having your workflow interrupted by a vague error message. Here are five ways to fix upload errors, so you can get back to adding striking visuals to your website.

      1. Rename, Resize, and Re-Upload the Image

      If you’re only encountering issues with a specific image, you can start by taking a look at the file’s name. If you’re using special characters ($, *, &, #) or accent letters (ñ, á, é), these can cause issues with the WordPress uploader.

      The image may also be too large — both in terms of dimensions and file size. You can change an image’s dimensions using your favorite editing program. If you’re trying to upload a particularly high-resolution graphic, you can reduce the size without impacting the quality using a compression tool such as TinyPNG.

      The TinyPNG plugin upload screen.

      If you regularly encounter issues due to file size, then WordPress’ limit may be set too low. You can raise the limit by adding code to your site’s php.ini file:

      upload_max_filesize = 128M
      
      post_max_size = 128M
      
      max_execution_time = 300

      If your site doesn’t already contain a php.ini file, you can create it inside the PHP folder for the current PHP version your site is running.  Then, simply add the above code at the end of the file.

      2. Increase the Memory Limit

      When you try to upload an image, you may encounter the WordPress HTTP error. This can sometimes be caused by low server resources or unusual traffic. For this reason, it’s always worth waiting a few minutes and then attempting to re-upload the image.

      If the issue doesn’t resolve itself, then you may be exceeding the WordPress memory limit. You can increase the amount of memory that PHP has to use on your server by connecting to your site over SFTP.

      Next, open your wp-config file. You can then add the following, which will increase the limit to 256MB:

      define( 'WP_MEMORY_LIMIT', '256M' );

      If this doesn’t resolve your issue, your problem may be related to threading. WordPress processes images using either the GD Library or Imagick module, depending on which one is available.

      Imagick was designed to use multiple threads in order to accelerate image processing.  However, some shared hosting providers limit Imagick’s ability to use multiple threads, which can result in an HTTP error. You can often resolve this issue by adding the following to your .htaccess file:

      SetEnv MAGICK_THREAD_LIMIT 1.

      3. Deactivate Your Plugins

      Third-party software can sometimes interfere with your image uploads. If you’re using any plugins, it’s always worth deactivating each one in turn and testing to see whether this resolves your image upload issue.

      Deactivating plugins in the WordPress dashboard

      If a plugin is to blame, you can double-check to make sure you’re running the latest version. If you’ve fallen behind on your updates, you may be struggling with a problem that’s already been addressed.

      If you’re running the latest version, we recommend contacting the plugin’s developer to ensure that they’re aware of the issue. This can also be an opportunity to ask whether they plan to solve this problem in their next release. If the plugin is critical to your site and no fix is forthcoming, it may be time to look for an alternative solution.

      4. Clear the Cache

      If you’re using a caching plugin, then clearing the cache may be enough to resolve your image upload errors. It’s important to note, however, that it is incredibly rare for the cache to prevent a file upload, so we’re including this fix out of an abundance of caution.

      If you think that caching could be causing the error, the steps you take will depend on your chosen caching solution. For example, if you’re using the W3 Total Cache plugin, you can clear the cache by selecting Performance > Purge All Caches from the WordPress toolbar.

      Purging all caches in the WordPress dashboard Appearance menu.

      If you’re unsure how to clear the cache in your specific tool, the plugin’s Settings menu is often a good place to start. You can also check the developer’s official documentation for more details.

      5. Try the Browser Uploader

      If you’ve tried all of the above fixes and are still encountering problems, you can use your browser’s built-in file uploader. Unlike WordPress’ image uploader, the browser uploader doesn’t support multiple file selection or drag and drop. However, it can be a useful workaround when you need to upload an image quickly.

      To access the native image uploader, navigate to Media > Add New. You can then select the browser uploader link.

      Selecting the ‘browser uploader’ link in the WordPress native image uploader.

      Next, click on Choose file. This launches the familiar file selection dialog, where you can upload the image as normal. If this workaround succeeds, we recommend trying to upload an image using WordPress’ standard image uploader afterward, to see whether this has resolved your problem.

      Take Your WordPress Site to the Next Level

      Whether you need help tweaking directory permissions, choosing a WordPress theme, or finding the uploads folder, we can help! Subscribe to our monthly email newsletter so you never miss an article.

      Additional WordPress Error Tutorials

      Once you’ve solved your image upload error, the adventure isn’t over. There’s always more to learn about WordPress! We’ve put together several tutorials to help you troubleshoot other common WordPress errors:

      Want more information on managing a WordPress site? Check out our WordPress Tutorials, a collection of guides designed to help you navigate the WordPress dashboard like an expert.

      WordPress Images Made Easy  

      Visuals are crucial for catching (and holding) the visitor’s attention, but image upload errors are frustratingly common. By following some simple steps, we’re confident that you can get your site back on track — even when the error message itself doesn’t provide much information.

      Let’s recap five ways to resolve common WordPress image upload issues:

      1. Rename, resize, and re-upload the image.
      2. Increase the memory limit.
      3. Deactivate your plugins.
      4. Clear the cache.
      5. Try the browser uploader.

      Are you tired of handling WordPress errors with no help? All of our DreamPress hosting packages include 24/7 customer support as a standard option. Regardless of the problem, our expert team will be on hand to help you get back on track!



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