# Go Cheatsheet - Upload file to digitalocean space

## Install packages:

```bash
go get github.com/aws/aws-sdk-go
go get github.com/gabriel-vasile/mimetype
```

## Files

In `main.go`

```go
package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"s3upload/s3client"
	"time"

	"github.com/gabriel-vasile/mimetype"
)

func main() {
	if len(os.Args) < 2 {
		log.Fatalln("Missing file path argument")
	}
	filePath := os.Args[1]
	fileContent, _ := ioutil.ReadFile(filePath)
	mimeType := mimetype.Detect(fileContent)
	uploadPath := fmt.Sprintf(
		"test/%d%s",
		time.Now().UnixNano(),
		mimeType.Extension(),
	)

	url, err := s3client.UploadFileFromBytes(
		fileContent,
		uploadPath,
		mimeType.String(),
		"public-read",
	)
	if err != nil {
		log.Fatalln(err)
	}
	log.Println(url)
}
```

Create a folder `s3client` and add a `s3client.go` file:

```go
package s3client

import (
	"bytes"
	"fmt"
	"log"

	"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"
)

const (
	KEY        string = "<key>"
	SECRET     string = "<secret>"
	ENDPOINT   string = "nyc3.digitaloceanspaces.com"
	REGION     string = "nyc3"
	BUCKET     string = "<bucket>"
	URL_PREFIX string = "<file's url prefix, could be your custom domain>"
)

var (
	Client *s3.S3
)

func UploadFileFromBytes(
	fileContent []byte,
	uploadPath string,
	mimeType string,
	acl string,
) (string, error) {
	object := s3.PutObjectInput{
		Bucket:      aws.String(BUCKET),
		Key:         aws.String(uploadPath),
		Body:        bytes.NewReader(fileContent),
		ACL:         aws.String(acl),
		ContentType: aws.String(mimeType),
	}
	_, err := Client.PutObject(&object)
	if err != nil {
		return "", err
	}
	publicUrl := fmt.Sprintf("%s/%s", URL_PREFIX, uploadPath)
	return publicUrl, nil
}

func init() {
	s3Cred := credentials.NewStaticCredentials(KEY, SECRET, "")
	s3Config := &aws.Config{
		Credentials: s3Cred,
		Endpoint:    aws.String(ENDPOINT),
		Region:      aws.String(REGION),
	}
	sess, err := session.NewSession(s3Config)
	if err != nil {
		log.Fatalln("Failed to create s3 session")
	}
	Client = s3.New(sess)
}
```

## Reference

* https://docs.digitalocean.com/products/spaces/resources/s3-sdk-examples/
* https://github.com/thenomemac/digitalocean_spaces_golang_aws_sdk_example/blob/master/main.go