From 7c7add8dc143a48bf5805174f7189cbb84fb1b84 Mon Sep 17 00:00:00 2001
From: Cyril Rohr <cyril.rohr@gmail.com>
Date: Sat, 26 May 2018 16:22:41 +0200
Subject: [PATCH] Enable s3 transport scheme

---
 .gitignore       |  1 +
 README.md        |  9 +++++++++
 config.go        |  5 +++++
 download.go      |  6 ++++++
 keepalive_old.go |  7 -------
 s3transport.go   | 32 ++++++++++++++++++++++++++++++++
 shutdown_old.go  | 11 -----------
 7 files changed, 53 insertions(+), 18 deletions(-)
 delete mode 100644 keepalive_old.go
 create mode 100644 s3transport.go
 delete mode 100644 shutdown_old.go

diff --git a/.gitignore b/.gitignore
index a22238de..001cf9c2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
+*.swp
 imgproxy
 tmp/
diff --git a/README.md b/README.md
index c2e37e34..5d0b27ac 100644
--- a/README.md
+++ b/README.md
@@ -145,6 +145,7 @@ $ xxd -g 2 -l 64 -p /dev/random | tr -d '\n'
 * `IMGPROXY_MAX_CLIENTS` — the maximum number of simultaneous active connections. Default: `IMGPROXY_CONCURRENCY * 10`;
 * `IMGPROXY_TTL` — duration in seconds sent in `Expires` and `Cache-Control: max-age` headers. Default: `3600` (1 hour);
 * `IMGPROXY_USE_ETAG` — when true, enables using [ETag](https://en.wikipedia.org/wiki/HTTP_ETag) header for the cache control. Default: false;
+* `IMGPROXY_USE_S3` — when true, enables fetching the images from an `s3` source. See [Serving files from S3](#serving-files-from-s3). Default: false.
 * `IMGPROXY_LOCAL_FILESYSTEM_ROOT` — root of the local filesystem. See [Serving local files](#serving-local-files). Keep empty to disable serving of local files.
 
 #### Security
@@ -229,6 +230,14 @@ imgproxy can process files from your local filesystem. To use this feature do th
 1. Set `IMGPROXY_LOCAL_FILESYSTEM_ROOT` to your images directory path.
 2. Use `local:///path/to/image.jpg` as the source image url.
 
+## Serving files from S3
+
+imgproxy can process files from S3 buckets. To use this feature do the following:
+
+1. Set `IMGPROXY_USE_S3` to `true`.
+2. Ensure you pass `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY` as environment variables. Other authentication mechanisms supported by the AWS sdk (environment, session, or instance role credentials) are also supported. The credentials need to be able to read from any of the `bucket_name` variables given in the source URLs (see below).
+3. Use `s3://%bucket_name/%object_key` as the source image url
+
 ## Source image formats support
 
 imgproxy supports only the most popular image formats of the moment: PNG, JPEG, GIF and WebP.
diff --git a/config.go b/config.go
index 1be29560..ac25a473 100644
--- a/config.go
+++ b/config.go
@@ -99,6 +99,8 @@ type config struct {
 
 	LocalFileSystemRoot string
 
+	S3Enabled bool
+
 	ETagEnabled   bool
 	ETagSignature []byte
 
@@ -117,6 +119,7 @@ var conf = config{
 	Quality:          80,
 	GZipCompression:  5,
 	ETagEnabled:      false,
+	S3Enabled:        false,
 }
 
 func init() {
@@ -155,6 +158,8 @@ func init() {
 
 	strEnvConfig(&conf.LocalFileSystemRoot, "IMGPROXY_LOCAL_FILESYSTEM_ROOT")
 
+	boolEnvConfig(&conf.S3Enabled, "IMGPROXY_USE_S3")
+
 	boolEnvConfig(&conf.ETagEnabled, "IMGPROXY_USE_ETAG")
 
 	strEnvConfig(&conf.BaseURL, "IMGPROXY_BASE_URL")
diff --git a/download.go b/download.go
index df0622ad..7da1d963 100644
--- a/download.go
+++ b/download.go
@@ -15,6 +15,8 @@ import (
 	_ "image/jpeg"
 	_ "image/png"
 
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/s3"
 	_ "golang.org/x/image/webp"
 )
 
@@ -62,6 +64,10 @@ func initDownloading() {
 	if conf.LocalFileSystemRoot != "" {
 		transport.RegisterProtocol("local", http.NewFileTransport(http.Dir(conf.LocalFileSystemRoot)))
 	}
+	if conf.S3Enabled {
+		svc := s3.New(session.New())
+		transport.RegisterProtocol("s3", NewS3Transport(svc))
+	}
 	downloadClient = &http.Client{
 		Timeout:   time.Duration(conf.DownloadTimeout) * time.Second,
 		Transport: transport,
diff --git a/keepalive_old.go b/keepalive_old.go
deleted file mode 100644
index 71915966..00000000
--- a/keepalive_old.go
+++ /dev/null
@@ -1,7 +0,0 @@
-// +build !go1.7
-
-package main
-
-func keepAlive(i interface{}) {
-	// Dummy function. Do nothing
-}
diff --git a/s3transport.go b/s3transport.go
new file mode 100644
index 00000000..45f24477
--- /dev/null
+++ b/s3transport.go
@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/service/s3"
+	http "net/http"
+)
+
+// s3Transport implements RoundTripper for the 's3' protocol.
+type s3Transport struct {
+	svc *s3.S3
+}
+
+func NewS3Transport(svc *s3.S3) http.RoundTripper {
+	return s3Transport{svc}
+}
+
+func (t s3Transport) RoundTrip(req *http.Request) (resp *http.Response, err error) {
+	input := &s3.GetObjectInput{
+		Bucket: aws.String(req.URL.Host),
+		Key:    aws.String(req.URL.Path),
+	}
+	s3req, _ := t.svc.GetObjectRequest(input)
+
+	s3err := s3req.Send()
+	if s3err == nil { // resp is now filled
+		return s3req.HTTPResponse, nil
+	}
+	fmt.Println("s3 error", s3err)
+	return nil, s3err
+}
diff --git a/shutdown_old.go b/shutdown_old.go
deleted file mode 100644
index cbb5c0f5..00000000
--- a/shutdown_old.go
+++ /dev/null
@@ -1,11 +0,0 @@
-// +build !go1.8
-
-package main
-
-import (
-	"net/http"
-)
-
-func shutdownServer(_ *http.Server) {
-	// Nothing we can do here
-}