Support separate S3 serving endpoint (#91)

* Add s3 serving endpoint config. Fixes #90

* Move CDN endpoint generation to GenerateRemotePlaylist

* Include HLS path

* Add docs and config

* Prefer sprintf to string concatenation

* Use config method

* gofmt

config/config.go

@@ -81,6 +81,7 @@ type files struct {
 type s3 struct {
 	Enabled         bool   `yaml:"enabled"`
 	Endpoint        string `yaml:"endpoint"`
+	ServingEndpoint string `yaml:"servingEndpoint"`
 	AccessKey       string `yaml:"accessKey"`
 	Secret          string `yaml:"secret"`
 	Bucket          string `yaml:"bucket"`

core/storageproviders/s3Storage.go

@@ -2,6 +2,7 @@ package storageproviders
 
 import (
 	"bufio"
+	"fmt"
 	"os"
 	"strings"
 
@@ -22,6 +23,7 @@ type S3Storage struct {
 	host string
 
 	s3Endpoint        string
+	s3ServingEndpoint string
 	s3Region          string
 	s3Bucket          string
 	s3AccessKey       string
@@ -34,6 +36,7 @@ func (s *S3Storage) Setup() error {
 	log.Trace("Setting up S3 for external storage of video...")
 
 	s.s3Endpoint = config.Config.S3.Endpoint
+	s.s3ServingEndpoint = config.Config.S3.ServingEndpoint
 	s.s3Region = config.Config.S3.Region
 	s.s3Bucket = config.Config.S3.Bucket
 	s.s3AccessKey = config.Config.S3.AccessKey
@@ -90,6 +93,8 @@ func (s *S3Storage) GenerateRemotePlaylist(playlist string, variant models.Varia
 			fullRemotePath := variant.GetSegmentForFilename(line)
 			if fullRemotePath == nil {
 				line = ""
+			} else if s.s3ServingEndpoint != "" {
+				line = fmt.Sprintf("%s/%s/%s", s.s3ServingEndpoint, config.Config.GetPrivateHLSSavePath(), fullRemotePath.RelativeUploadPath)
 			} else {
 				line = fullRemotePath.RemoteID
 			}

doc/S3.md

@@ -110,6 +110,10 @@ You should expire old segments on your S3 bucket.  [Here are some instructions o
 
 * Ugh.  CORS.  [You will need to enable CORS on your bucket](https://docs.aws.amazon.com/AmazonS3/latest/dev/cors.html#how-do-i-enable-cors) so the web player can access the video.
 
+### CDN
+
+AWS (and other S3 compatible providers) offer a feature to change the HTTP host to support CDNs. You can configure Owncast to serve media files from this host by setting the `s3.servingEndpoint` config to your CDNed host.
+
 
 ## [Wasabi cloud storage](https://wasabi.com/content-delivery/)
 

doc/config-example-full.yaml

@@ -70,6 +70,7 @@ files:
 s3:
   enabled: false
   endpoint: https://s3.us-west-2.amazonaws.com
+  servingEndpoint: https://yourcdn.example
   accessKey: ABC12342069
   secret: lolomgqwtf49583949
   region: us-west-2