Add config option MediaDownloadPath (#443)

* Add config option MediaUploadPath

MediaDownloadPath can be used instead of MediaServerUpload, for when your
webserver is on the same system as matterbridge and matterbridge has
write access to the serve dir.

* Limit length of hash in MediaServer urls to 8chars

Full SHA256 is unnecessary for uniqueness.
Also; if a file has the same first 8 charachters of the SHA256 hash,
it's still not a problem, as long as the filename is not the same.

4 files changed, 87 insertions, 38 deletions

diff --git a/bridge/config/config.go b/bridge/config/config.go
index 1627adc2..351e6cad 100644
--- a/bridge/config/config.go
+++ b/bridge/config/config.go
@@ -2,14 +2,15 @@ package config
 
 import (
 	"bytes"
-	"github.com/fsnotify/fsnotify"
-	log "github.com/sirupsen/logrus"
-	"github.com/spf13/viper"
-	prefixed "github.com/x-cray/logrus-prefixed-formatter"
 	"os"
 	"strings"
 	"sync"
 	"time"
+
+	"github.com/fsnotify/fsnotify"
+	log "github.com/sirupsen/logrus"
+	"github.com/spf13/viper"
+	prefixed "github.com/x-cray/logrus-prefixed-formatter"
 )
 
 const (
@@ -76,6 +77,7 @@ type Protocol struct {
 	MediaDownloadSize      int    // all protocols
 	MediaServerDownload    string
 	MediaServerUpload      string
+	MediaDownloadPath      string     // Basically MediaServerUpload, but instead of uploading it, just write it to a file on the same server.
 	MessageDelay           int        // IRC, time in millisecond to wait between messages
 	MessageFormat          string     // telegram
 	MessageLength          int        // IRC, max length of a message allowed
diff --git a/gateway/gateway.go b/gateway/gateway.go
index eb5bbe92..b926912a 100644
--- a/gateway/gateway.go
+++ b/gateway/gateway.go
@@ -3,6 +3,10 @@ package gateway
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+
 	"github.com/42wim/matterbridge/bridge"
 	"github.com/42wim/matterbridge/bridge/api"
 	"github.com/42wim/matterbridge/bridge/config"
@@ -18,16 +22,16 @@ import (
 	"github.com/42wim/matterbridge/bridge/telegram"
 	"github.com/42wim/matterbridge/bridge/xmpp"
 	"github.com/42wim/matterbridge/bridge/zulip"
+	"github.com/hashicorp/golang-lru"
 	log "github.com/sirupsen/logrus"
 	//	"github.com/davecgh/go-spew/spew"
 	"crypto/sha1"
-	"github.com/hashicorp/golang-lru"
-	"github.com/peterhellberg/emojilib"
-	"net/http"
 	"path/filepath"
 	"regexp"
 	"strings"
 	"time"
+
+	"github.com/peterhellberg/emojilib"
 )
 
 type Gateway struct {
@@ -411,46 +415,83 @@ func (gw *Gateway) modifyMessage(msg *config.Message) {
 	}
 }
 
+// handleFiles uploads or places all files on the given msg to the MediaServer and
+// adds the new URL of the file on the MediaServer onto the given msg.
 func (gw *Gateway) handleFiles(msg *config.Message) {
 	reg := regexp.MustCompile("[^a-zA-Z0-9]+")
-	// if we don't have a attachfield or we don't have a mediaserver configured return
-	if msg.Extra == nil || gw.Config.General.MediaServerUpload == "" {
+
+	// If we don't have a attachfield or we don't have a mediaserver configured return
+	if msg.Extra == nil || (gw.Config.General.MediaServerUpload == "" && gw.Config.General.MediaDownloadPath == "") {
 		return
 	}
 
-	// if we actually have files, start uploading them to the mediaserver
-	if len(msg.Extra["file"]) > 0 {
-		client := &http.Client{
-			Timeout: time.Second * 5,
-		}
-		for i, f := range msg.Extra["file"] {
-			fi := f.(config.FileInfo)
-			ext := filepath.Ext(fi.Name)
-			fi.Name = fi.Name[0 : len(fi.Name)-len(ext)]
-			fi.Name = reg.ReplaceAllString(fi.Name, "_")
-			fi.Name = fi.Name + ext
-			sha1sum := fmt.Sprintf("%x", sha1.Sum(*fi.Data))
-			reader := bytes.NewReader(*fi.Data)
+	// If we don't have files, nothing to upload.
+	if len(msg.Extra["file"]) == 0 {
+		return
+	}
+
+	client := &http.Client{
+		Timeout: time.Second * 5,
+	}
+
+	for i, f := range msg.Extra["file"] {
+		fi := f.(config.FileInfo)
+		ext := filepath.Ext(fi.Name)
+		fi.Name = fi.Name[0 : len(fi.Name)-len(ext)]
+		fi.Name = reg.ReplaceAllString(fi.Name, "_")
+		fi.Name = fi.Name + ext
+
+		sha1sum := fmt.Sprintf("%x", sha1.Sum(*fi.Data))[:8]
+
+		if gw.Config.General.MediaServerUpload != "" {
+			// Use MediaServerUpload. Upload using a PUT HTTP request and basicauth.
+
 			url := gw.Config.General.MediaServerUpload + "/" + sha1sum + "/" + fi.Name
-			durl := gw.Config.General.MediaServerDownload + "/" + sha1sum + "/" + fi.Name
-			extra := msg.Extra["file"][i].(config.FileInfo)
-			extra.URL = durl
-			req, err := http.NewRequest("PUT", url, reader)
+
+			req, err := http.NewRequest("PUT", url, bytes.NewReader(*fi.Data))
 			if err != nil {
-				flog.Errorf("mediaserver upload failed: %#v", err)
+				flog.Errorf("mediaserver upload failed, could not create request: %#v", err)
 				continue
 			}
+
+			flog.Debugf("mediaserver upload url: %s", url)
+
 			req.Header.Set("Content-Type", "binary/octet-stream")
 			_, err = client.Do(req)
 			if err != nil {
-				flog.Errorf("mediaserver upload failed: %#v", err)
+				flog.Errorf("mediaserver upload failed, could not Do request: %#v", err)
+				continue
+			}
+		} else {
+			// Use MediaServerPath. Place the file on the current filesystem.
+
+			dir := gw.Config.General.MediaDownloadPath + "/" + sha1sum
+			err := os.Mkdir(dir, os.ModePerm)
+			if err != nil && !os.IsExist(err) {
+				flog.Errorf("mediaserver path failed, could not mkdir: %s %#v", err, err)
+				continue
+			}
+
+			path := dir + "/" + fi.Name
+			flog.Debugf("mediaserver path placing file: %s", path)
+
+			err = ioutil.WriteFile(path, *fi.Data, os.ModePerm)
+			if err != nil {
+				flog.Errorf("mediaserver path failed, could not writefile: %s %#v", err, err)
 				continue
 			}
-			flog.Debugf("mediaserver download URL = %s", durl)
-			// we uploaded the file successfully. Add the SHA
-			extra.SHA = sha1sum
-			msg.Extra["file"][i] = extra
 		}
+
+		// Download URL.
+		durl := gw.Config.General.MediaServerDownload + "/" + sha1sum + "/" + fi.Name
+
+		flog.Debugf("mediaserver download URL = %s", durl)
+
+		// We uploaded/placed the file successfully. Add the SHA and URL.
+		extra := msg.Extra["file"][i].(config.FileInfo)
+		extra.URL = durl
+		extra.SHA = sha1sum
+		msg.Extra["file"][i] = extra
 	}
 }
 
diff --git a/matterbridge.go b/matterbridge.go
index f05a745b..df138028 100644
--- a/matterbridge.go
+++ b/matterbridge.go
@@ -3,13 +3,14 @@ package main
 import (
 	"flag"
 	"fmt"
+	"os"
+	"strings"
+
 	"github.com/42wim/matterbridge/bridge/config"
 	"github.com/42wim/matterbridge/gateway"
 	"github.com/google/gops/agent"
 	log "github.com/sirupsen/logrus"
 	prefixed "github.com/x-cray/logrus-prefixed-formatter"
-	"os"
-	"strings"
 )
 
 var (
diff --git a/matterbridge.toml.sample b/matterbridge.toml.sample
index 6f81baf6..1bc4f3b4 100644
--- a/matterbridge.toml.sample
+++ b/matterbridge.toml.sample
@@ -1306,10 +1306,13 @@ RemoteNickFormat="[{PROTOCOL}] <{NICK}> "
 StripNick=false
 
 
-#MediaServerUpload and MediaServerDownload are used for uploading images/files/video to
-#a remote "mediaserver" (a webserver like caddy for example).
-#When configured images/files uploaded on bridges like mattermost,slack, telegram will be downloaded
-#and uploaded again to MediaServerUpload URL
+#MediaServerUpload (or MediaDownloadPath) and MediaServerDownload are used for uploading
+#images/files/video to a remote "mediaserver" (a webserver like caddy for example).
+#When configured images/files uploaded on bridges like mattermost, slack, telegram will be
+#downloaded and uploaded again to MediaServerUpload URL
+#MediaDownloadPath is the filesystem path where the media file will be placed, instead of uploaded,
+#for if Matterbridge has write access to the directory your webserver is serving.
+#It is an alternative to MediaServerUpload.
 #The MediaServerDownload will be used so that bridges without native uploading support:
 #gitter, irc and xmpp will be shown links to the files on MediaServerDownload
 #
@@ -1317,6 +1320,8 @@ StripNick=false
 #OPTIONAL (default empty)
 MediaServerUpload="https://user:pass@yourserver.com/upload"
 #OPTIONAL (default empty)
+MediaDownloadPath="/srv/http/yourserver.com/public/download"
+#OPTIONAL (default empty)
 MediaServerDownload="https://youserver.com/download"
 
 #MediaDownloadSize is the maximum size of attachments, videos, images