Use correct path to snap binary

docs/content/doc/advanced/environment-variables.en-us.md

@@ -41,6 +41,7 @@ For documentation about each of the variables available, refer to the
 ## Gitea files
 
 - `GITEA_WORK_DIR`: Absolute path of working directory.
+- `GITEA_APP_PATH`: Absolute path of gitea binary. (This is usually automatically detected and should therefore be only set in limited circumstances.)
 - `GITEA_CUSTOM`: Gitea uses `GITEA_WORK_DIR`/custom folder by default. Use this variable
   to change _custom_ directory.
 - `GOGS_WORK_DIR`: Deprecated, use `GITEA_WORK_DIR`
@@ -51,6 +52,8 @@ For documentation about each of the variables available, refer to the
 - `USER`: System user that Gitea will run as. Used for some repository access strings.
 - `USERNAME`: if no `USER` found, Gitea will use `USERNAME`
 - `HOME`: User home directory path. The `USERPROFILE` environment variable is used in Windows.
+- `SNAP`: Path to directory that snap uses to store Gitea's configuration. Snap defaults to using `$GITEA_APP_PATH`.
+- `SNAP_REVISION`: If Gitea is installed using snap, revision number of snap in use.
 
 ### Only on Windows
 

docs/content/doc/installation/from-source.en-us.md

@@ -159,6 +159,7 @@ using the `LDFLAGS` environment variable for `make`. The appropriate settings ar
 - To set the `CustomPath` use `LDFLAGS="-X \"code.gitea.io/gitea/modules/setting.CustomPath=custom-path\""`
 - For `CustomConf` you should use `-X \"code.gitea.io/gitea/modules/setting.CustomConf=conf.ini\"`
 - For `AppWorkPath` you should use `-X \"code.gitea.io/gitea/modules/setting.AppWorkPath=working-path\"`
+- For `AppPath` you should use `-X \"code.gitea.io/gitea/modules/setting.AppPath=/path/to/gitea/binary\"`
 - For `StaticRootPath` you should use `-X \"code.gitea.io/gitea/modules/setting.StaticRootPath=static-root-path\"`
 - To change the default PID file location use `-X \"code.gitea.io/gitea/modules/setting.PIDFile=/run/gitea.pid\"`
 

modules/setting/setting.go

@@ -431,7 +431,14 @@ func IsProd() bool {
 }
 
 func getAppPath() (string, error) {
-	var appPath string
+	appPath := AppPath
+	if giteaAppPath, ok := os.LookupEnv("GITEA_APP_PATH"); ok {
+		appPath = giteaAppPath
+	}
+	if appPath != "" {
+		return appPath, nil
+	}
+
 	var err error
 	if IsWindows && filepath.IsAbs(os.Args[0]) {
 		appPath = filepath.Clean(os.Args[0])
@@ -446,9 +453,24 @@ func getAppPath() (string, error) {
 	if err != nil {
 		return "", err
 	}
+
 	// Note: we don't use path.Dir here because it does not handle case
 	//	which path starts with two "/" in Windows: "//psf/Home/..."
-	return strings.ReplaceAll(appPath, "\\", "/"), err
+	appPath = strings.ReplaceAll(appPath, "\\", "/")
+
+	// Fix issue 16209: When running in a snap and repositories are
+	// created, paths in the hooks include the snap revision. But as new
+	// revisions come out the older revisions are eventually deleted, and
+	// the hooks begin to fail.
+	// The code below replaces the snap revision with "current", which
+	// is a link to the current snap revision.
+	snapPath := os.Getenv("SNAP")
+	if snapPath != "" && strings.HasPrefix(appPath, snapPath) {
+		revision := os.Getenv("SNAP_REVISION")
+		appPath = strings.Replace(appPath, revision, "current", 1)
+	}
+
+	return appPath, nil
 }
 
 func getWorkPath(appPath string) string {

snap/snapcraft.yaml

@@ -45,7 +45,7 @@ parts:
     source: .
     stage-packages: [ git, sqlite3, openssh-client ]
     build-packages: [ git, libpam0g-dev, libsqlite3-dev]
-    build-snaps: [ go, node/14/stable ]
+    build-snaps: [ go, node/16/stable ]
     build-environment:
       - LDFLAGS: ""
     override-pull: |