add minio support via http

README.md

@@ -114,6 +114,11 @@ enabled using the `-cache` flag.  It supports the following values:
    environmental variables be set. (Additional methods of loading credentials
    are documented in the [aws-sdk-go session
    package](https://docs.aws.amazon.com/sdk-for-go/api/aws/session/)).
+ - http (Minio) URL (e.g. `http://endpoint/region/bucket/optional-path-prefix`) - will cache
+   images on Minio S3.  This requires `AWS_ACCESS_KEY_ID` and `AWS_SECRET_KEY`
+   environmental variables be set. (Additional methods of loading credentials
+   are documented in the [aws-sdk-go session
+   package](https://docs.aws.amazon.com/sdk-for-go/api/aws/session/)).
  - gcs URL (e.g. `gcs://bucket-name/optional-path-prefix`) - will cache images
    on Google Cloud Storage. Authentication is documented in Google's
    [Application Default Credentials

cmd/imageproxy/main.go

@@ -36,6 +36,7 @@ import (
 	"github.com/peterbourgon/diskv"
 	"willnorris.com/go/imageproxy"
 	"willnorris.com/go/imageproxy/internal/gcscache"
+	"willnorris.com/go/imageproxy/internal/miniocache"
 	"willnorris.com/go/imageproxy/internal/s3cache"
 )
 
@@ -153,6 +154,8 @@ func parseCache(c string) (imageproxy.Cache, error) {
 		return rediscache.NewWithClient(conn), nil
 	case "s3":
 		return s3cache.New(u.String())
+	case "http":
+		return miniocache.New(u.String())
 	case "file":
 		fallthrough
 	default:

internal/miniocache/miniocache.go

@@ -0,0 +1,120 @@
+// Package miniocache provides an httpcache.Cache implementation that stores
+// cached values on Minio S3.
+package miniocache
+
+import (
+	"bytes"
+	"crypto/md5"
+	"encoding/hex"
+	"io"
+	"io/ioutil"
+	"log"
+	"net/url"
+	"path"
+	"strings"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/awserr"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/s3"
+)
+
+type cache struct {
+	*s3.S3
+	bucket, prefix string
+}
+
+func (c *cache) Get(key string) ([]byte, bool) {
+	key = path.Join(c.prefix, keyToFilename(key))
+	input := &s3.GetObjectInput{
+		Bucket: &c.bucket,
+		Key:    &key,
+	}
+
+	resp, err := c.GetObject(input)
+	if err != nil {
+		if aerr, ok := err.(awserr.Error); ok && aerr.Code() != "NoSuchKey" {
+			log.Printf("error fetching from minio: %v", aerr)
+		}
+		return nil, false
+	}
+
+	value, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		log.Printf("error reading minio response body: %v", err)
+		return nil, false
+	}
+
+	return value, true
+}
+func (c *cache) Set(key string, value []byte) {
+	key = path.Join(c.prefix, keyToFilename(key))
+	input := &s3.PutObjectInput{
+		Body:   aws.ReadSeekCloser(bytes.NewReader(value)),
+		Bucket: &c.bucket,
+		Key:    &key,
+	}
+
+	_, err := c.PutObject(input)
+	if err != nil {
+		log.Printf("error writing to minio: %v", err)
+	}
+}
+func (c *cache) Delete(key string) {
+	key = path.Join(c.prefix, keyToFilename(key))
+	input := &s3.DeleteObjectInput{
+		Bucket: &c.bucket,
+		Key:    &key,
+	}
+
+	_, err := c.DeleteObject(input)
+	if err != nil {
+		log.Printf("error deleting from minio: %v", err)
+	}
+}
+
+func keyToFilename(key string) string {
+	h := md5.New()
+	io.WriteString(h, key)
+	return hex.EncodeToString(h.Sum(nil))
+}
+
+// New constructs a cache configured using the provided URL string.  URL should
+// be of the form: "http://endpoint/region/bucket/optional-path-prefix".  Credentials
+// should be specified using one of the mechanisms supported by aws-sdk-go (see
+// https://docs.aws.amazon.com/sdk-for-go/api/aws/session/).
+func New(s string) (*cache, error) {
+	u, err := url.Parse(s)
+	if err != nil {
+		return nil, err
+	}
+
+	endpoint := u.Host
+	path := strings.SplitN(strings.TrimPrefix(u.Path, "/"), "/", 2)
+	region := path[0]
+	bucket := path[1]
+
+	var prefix string
+	if len(path) > 1 {
+		prefix = path[2]
+	}
+
+	// Configure to use Minio Server
+	s3Config := &aws.Config{
+		Endpoint:         aws.String(endpoint),
+		Region:           aws.String(region),
+		DisableSSL:       aws.Bool(true),
+		S3ForcePathStyle: aws.Bool(true),
+	}
+
+	sess, err := session.NewSession(s3Config)
+	if err != nil {
+		return nil, err
+	}
+
+	return &cache{
+		S3:     s3.New(sess),
+		bucket: bucket,
+		prefix: prefix,
+	}, nil
+}