snapenv: Include snap application environment state (#16016)

3v1n0 · olivercalder · web-flow · commit 409deb4a9bc9 · 2026-06-02T07:34:42.000+02:00
* snapenv: Include snap application environment state When running an application of a snap is complicated to get some per-app state values such as its name, desktop file and common IDs, but these are actually important to make the application to be able to identify itself properly in a desktop environment. As per this, expose the application information as env variables. Related to: https://bugs.launchpad.net/ubuntu/+source/snapd/+bug/2125222 * tests: add snap env check for app with common id and desktop file Signed-off-by: Oliver Calder <oliver.calder@canonical.com> --------- Signed-off-by: Oliver Calder <oliver.calder@canonical.com> Co-authored-by: Oliver Calder <oliver.calder@canonical.com>
diff --git a/cmd/snap/cmd_run.go b/cmd/snap/cmd_run.go
@@ -1679,7 +1679,7 @@ func (x *cmdRun) runSnapConfine(info *snap.Info, runner runnable, beforeExec fun
 		return err
 	}
 
-	snapenv.ExtendEnvForRun(env, info, runner.Component(), opts)
+	snapenv.ExtendEnvForRun(env, info, runner.App(), runner.Component(), opts)
 
 	if len(xauthPath) > 0 {
 		// Environment is not nil here because it comes from
diff --git a/snap/snapenv/snapenv.go b/snap/snapenv/snapenv.go
@@ -49,19 +49,25 @@ var userCurrent = user.Current
 //
 // It ensures all SNAP_* override any pre-existing environment
 // variables.
-func ExtendEnvForRun(env osutil.Environment, info *snap.Info, component *snap.ComponentInfo, opts *dirs.SnapDirOptions) {
+func ExtendEnvForRun(env osutil.Environment, info *snap.Info, app *snap.AppInfo, component *snap.ComponentInfo, opts *dirs.SnapDirOptions) {
 	// Set various SNAP_ environment variables as well as some non-SNAP variables,
 	// depending on snap confinement mode. Note that this does not include environment
 	// set by snap-exec.
-	for k, v := range snapEnv(info, component, opts) {
+	for k, v := range snapEnv(info, app, component, opts) {
 		env[k] = v
 	}
 }
 
-func snapEnv(info *snap.Info, component *snap.ComponentInfo, opts *dirs.SnapDirOptions) osutil.Environment {
+func snapEnv(info *snap.Info, app *snap.AppInfo, component *snap.ComponentInfo, opts *dirs.SnapDirOptions) osutil.Environment {
 	// Environment variables with basic properties of a snap.
 	env := basicEnv(info)
 
+	if app != nil {
+		for k, v := range appEnv(info, app) {
+			env[k] = v
+		}
+	}
+
 	if component != nil {
 		for k, v := range componentEnv(info, component) {
 			env[k] = v
@@ -137,6 +143,26 @@ func basicEnv(info *snap.Info) osutil.Environment {
 		logger.Noticef("cannot determine existence of save data directory for snap %q: %v",
 			info.InstanceName(), err)
 	}
+
+	return env
+}
+
+// appEnv returns the app-level environment variables for a snap.
+func appEnv(info *snap.Info, app *snap.AppInfo) osutil.Environment {
+	env := osutil.Environment{
+		"SNAP_APP_NAME": app.Name,
+	}
+
+	if app.CommonID != "" {
+		env["SNAP_APP_COMMON_ID"] = app.CommonID
+	}
+	if df := app.DesktopFile(); df != "" && osutil.FileExists(df) {
+		env["SNAP_APP_DESKTOP_FILE"] = df
+	}
+	if app.BusName != "" {
+		env["SNAP_APP_BUS_NAME"] = app.BusName
+	}
+
 	return env
 }
 
diff --git a/snap/snapenv/snapenv_test.go b/snap/snapenv/snapenv_test.go
@@ -63,6 +63,35 @@ var mockSnapInfo = &snap.Info{
 		Revision: snap.R(17),
 	},
 }
+var mockSnapInfoWithDesktopFile = func() *snap.Info {
+	mi := *mockSnapInfo
+	mi.Plugs = map[string]*snap.PlugInfo{
+		"desktop": {
+			Snap:      &mi,
+			Interface: "desktop",
+			Name:      "desktop",
+			Attrs: map[string]any{
+				"desktop-file-ids": []any{"io.snapcraft.foo.bar.desktop"},
+			},
+		},
+	}
+	return &mi
+}()
+var mockAppInfo = &snap.AppInfo{
+	Snap:     mockSnapInfo,
+	Name:     "bar",
+	CommonID: "io.snapcraft.foo.bar",
+	BusName:  "io.snapcraft.foo.bar.bus",
+}
+var mockAppInfoWithDesktopFile = func() *snap.AppInfo {
+	mai := *mockAppInfo
+	mai.Snap = mockSnapInfoWithDesktopFile
+	return &mai
+}()
+var mockAppInfoMinimal = &snap.AppInfo{
+	Snap: mockSnapInfo,
+	Name: "bar",
+}
 var mockComponentInfo = &snap.ComponentInfo{
 	Component: naming.ComponentRef{
 		SnapName:      "foo",
@@ -94,6 +123,10 @@ var mockClassicSnapInfo = &snap.Info{
 func (s *HTestSuite) SetUpTest(c *C) {
 	s.BaseTest.SetUpTest(c)
 	s.BaseTest.AddCleanup(snap.MockSanitizePlugsSlots(func(snapInfo *snap.Info) {}))
+
+	defaultDesktopFilesDir := dirs.SnapDesktopFilesDir
+	dirs.SnapDesktopFilesDir = c.MkDir()
+	s.BaseTest.AddCleanup(func() { dirs.SnapDesktopFilesDir = defaultDesktopFilesDir })
 }
 
 func (s *HTestSuite) TearDownTest(c *C) {
@@ -160,6 +193,47 @@ func (ts *HTestSuite) TestBasicWithSources(c *C) {
 	})
 }
 
+func (ts *HTestSuite) TestAppEnvironment(c *C) {
+	env := appEnv(mockSnapInfo, mockAppInfo)
+	c.Assert(env, DeepEquals, osutil.Environment{
+		"SNAP_APP_NAME":      "bar",
+		"SNAP_APP_COMMON_ID": "io.snapcraft.foo.bar",
+		"SNAP_APP_BUS_NAME":  "io.snapcraft.foo.bar.bus",
+	})
+}
+
+func (ts *HTestSuite) testAppDesktopFileEnvironment(c *C, appInfo *snap.AppInfo, desktopFileName string) {
+	desktopFilePath := filepath.Join(dirs.SnapDesktopFilesDir, desktopFileName)
+	desktopFile := fmt.Sprintf(`[Desktop Entry]
+Exec=%s
+X-SnapInstanceName=%s
+X-SnapAppName=%s
+`, appInfo.Command, appInfo.Snap.InstanceName(), appInfo.Name)
+	c.Assert(os.WriteFile(desktopFilePath, []byte(desktopFile), 0644), IsNil)
+
+	c.Assert(appInfo.DesktopFile(), Equals, desktopFilePath)
+
+	env := appEnv(appInfo.Snap, appInfo)
+	c.Assert(env, DeepEquals, osutil.Environment{
+		"SNAP_APP_NAME":         appInfo.Name,
+		"SNAP_APP_COMMON_ID":    appInfo.CommonID,
+		"SNAP_APP_BUS_NAME":     appInfo.BusName,
+		"SNAP_APP_DESKTOP_FILE": appInfo.DesktopFile(),
+	})
+}
+
+func (ts *HTestSuite) TestAppWithFallbackDesktopFileIDEnvironment(c *C) {
+	ts.testAppDesktopFileEnvironment(c, mockAppInfo, "foo_bar.desktop")
+}
+
+func (ts *HTestSuite) TestAppWithDesktopFileIDEnvironment(c *C) {
+	ts.testAppDesktopFileEnvironment(c, mockAppInfoWithDesktopFile, "io.snapcraft.foo.bar.desktop")
+}
+
+func (ts *HTestSuite) TestAppWithDesktopFileIDUsingFallbackDesktopFileEnvironment(c *C) {
+	ts.testAppDesktopFileEnvironment(c, mockAppInfoWithDesktopFile, "foo_bar.desktop")
+}
+
 func (ts *HTestSuite) TestSaveDataEnvironmentNotPresent(c *C) {
 	dirs.SetRootDir(c.MkDir())
 	ts.AddCleanup(func() { dirs.SetRootDir("") })
@@ -236,7 +310,7 @@ func (s *HTestSuite) TestSnapRunSnapExecEnv(c *C) {
 			os.Setenv("HOME", "")
 		}
 
-		env := snapEnv(info, nil, nil)
+		env := snapEnv(info, mockAppInfo, nil, nil)
 		c.Assert(env, DeepEquals, osutil.Environment{
 			"SNAP":               fmt.Sprintf("%s/snapname/42", dirs.CoreSnapMountDir),
 			"SNAP_COMMON":        "/var/snap/snapname/common",
@@ -256,6 +330,9 @@ func (s *HTestSuite) TestSnapRunSnapExecEnv(c *C) {
 			"SNAP_REAL_HOME":     usr.HomeDir,
 			"SNAP_UID":           fmt.Sprint(sys.Getuid()),
 			"SNAP_EUID":          fmt.Sprint(sys.Geteuid()),
+			"SNAP_APP_COMMON_ID": "io.snapcraft.foo.bar",
+			"SNAP_APP_BUS_NAME":  "io.snapcraft.foo.bar.bus",
+			"SNAP_APP_NAME":      "bar",
 		})
 	}
 }
@@ -279,7 +356,7 @@ func (s *HTestSuite) TestParallelInstallSnapRunSnapExecEnv(c *C) {
 			os.Setenv("HOME", "")
 		}
 
-		env := snapEnv(info, nil, nil)
+		env := snapEnv(info, mockAppInfoMinimal, nil, nil)
 		c.Check(env, DeepEquals, osutil.Environment{
 			// Those are mapped to snap-specific directories by
 			// mount namespace setup
@@ -303,6 +380,7 @@ func (s *HTestSuite) TestParallelInstallSnapRunSnapExecEnv(c *C) {
 			"SNAP_REAL_HOME":   usr.HomeDir,
 			"SNAP_UID":         fmt.Sprint(sys.Getuid()),
 			"SNAP_EUID":        fmt.Sprint(sys.Geteuid()),
+			"SNAP_APP_NAME":    "bar",
 		})
 	}
 }
@@ -355,23 +433,29 @@ func (ts *HTestSuite) TestParallelInstallUserForClassicConfinement(c *C) {
 func (s *HTestSuite) TestExtendEnvForRunForNonClassic(c *C) {
 	env := osutil.Environment{"TMPDIR": "/var/tmp"}
 
-	ExtendEnvForRun(env, mockSnapInfo, nil, nil)
+	ExtendEnvForRun(env, mockSnapInfo, mockAppInfo, nil, nil)
 
 	c.Assert(env["SNAP_NAME"], Equals, "foo")
 	c.Assert(env["SNAP_COMMON"], Equals, "/var/snap/foo/common")
 	c.Assert(env["SNAP_DATA"], Equals, "/var/snap/foo/17")
+	c.Assert(env["SNAP_APP_NAME"], Equals, "bar")
+	c.Assert(env["SNAP_APP_COMMON_ID"], Equals, "io.snapcraft.foo.bar")
+	c.Assert(env["SNAP_APP_BUS_NAME"], Equals, "io.snapcraft.foo.bar.bus")
 
 	c.Assert(env["TMPDIR"], Equals, "/var/tmp")
 }
 
 func (s *HTestSuite) TestExtendEnvForRunForClassic(c *C) {
 	env := osutil.Environment{"TMPDIR": "/var/tmp"}
 
-	ExtendEnvForRun(env, mockClassicSnapInfo, nil, nil)
+	ExtendEnvForRun(env, mockClassicSnapInfo, mockAppInfoMinimal, nil, nil)
 
 	c.Assert(env["SNAP_NAME"], Equals, "foo")
 	c.Assert(env["SNAP_COMMON"], Equals, "/var/snap/foo/common")
 	c.Assert(env["SNAP_DATA"], Equals, "/var/snap/foo/17")
+	c.Assert(env["SNAP_APP_NAME"], Equals, "bar")
+	c.Assert(func() bool { _, ok := env["SNAP_APP_COMMON_ID"]; return ok }(), Equals, false)
+	c.Assert(func() bool { _, ok := env["SNAP_APP_BUS_NAME"]; return ok }(), Equals, false)
 
 	c.Assert(env["TMPDIR"], Equals, "/var/tmp")
 }
@@ -392,15 +476,15 @@ func checkEnvWithComp(c *C, env osutil.Environment, compVersion string) {
 func (s *HTestSuite) TestExtendEnvForRunWithComponent(c *C) {
 	env := osutil.Environment{"TMPDIR": "/var/tmp"}
 
-	ExtendEnvForRun(env, mockSnapInfo, mockComponentInfo, nil)
+	ExtendEnvForRun(env, mockSnapInfo, nil, mockComponentInfo, nil)
 	compVersion := "1.1"
 	checkEnvWithComp(c, env, compVersion)
 }
 
 func (s *HTestSuite) TestExtendEnvForRunWithComponentNoVersion(c *C) {
 	env := osutil.Environment{"TMPDIR": "/var/tmp"}
 
-	ExtendEnvForRun(env, mockSnapInfo, mockComponentInfoNoVersion, nil)
+	ExtendEnvForRun(env, mockSnapInfo, nil, mockComponentInfoNoVersion, nil)
 	// Same as snap in this case
 	compVersion := "1.0"
 	checkEnvWithComp(c, env, compVersion)
@@ -425,7 +509,7 @@ func (s *HTestSuite) TestHiddenDirEnv(c *C) {
 		{dir: dirs.HiddenSnapDataHomeDir, opts: &dirs.SnapDirOptions{HiddenSnapDataDir: true}},
 		{dir: dirs.HiddenSnapDataHomeDir, opts: &dirs.SnapDirOptions{HiddenSnapDataDir: true, MigratedToExposedHome: true}}} {
 		env := osutil.Environment{}
-		ExtendEnvForRun(env, mockSnapInfo, nil, t.opts)
+		ExtendEnvForRun(env, mockSnapInfo, mockAppInfo, nil, t.opts)
 
 		c.Check(env["SNAP_USER_COMMON"], Equals, filepath.Join(testDir, t.dir, mockSnapInfo.SuggestedName, "common"))
 		c.Check(env["SNAP_USER_DATA"], DeepEquals, filepath.Join(testDir, t.dir, mockSnapInfo.SuggestedName, mockSnapInfo.Revision.String()))
diff --git a/tests/main/snap-env/task.yaml b/tests/main/snap-env/task.yaml
@@ -20,6 +20,7 @@ prepare: |
         snap set system experimental.parallel-instances=true
     fi
     "$TESTSTOOLS"/snaps-state install-local-as test-snapd-tools "$NAME"
+    "$TESTSTOOLS"/snaps-state install-local test-snapd-desktop-file-ids
 
 restore: |
     if [[ "$SPREAD_VARIANT" == "parallel" ]]; then
@@ -57,6 +58,7 @@ execute: |
     MATCH "^SNAP_CONTEXT=$CTX"                                            < snap-vars.txt
     # parallel-installs: $SNAP_NAME is always _the_ snap name
     MATCH '^SNAP_NAME=test-snapd-tools$'                                  < snap-vars.txt
+    MATCH '^SNAP_APP_NAME=env$'                                           < snap-vars.txt
     # parallel-install: name of a particular instance
     MATCH "^SNAP_INSTANCE_NAME=$NAME$"                                    < snap-vars.txt
     # parallel-installs: empty if none is set
@@ -67,11 +69,11 @@ execute: |
     # if on UC20+, then we should see an additional variable (SNAP_SAVE_DATA)
     if [[ "$SPREAD_SYSTEM" == ubuntu-core-2* ]]; then
         MATCH "^SNAP_SAVE_DATA=/var/lib/snapd/save/snap/$NAME$"           < snap-vars.txt
-        # 18 variables are expected on ubuntu-core
-        test "$(wc -l < snap-vars.txt)" -eq 18 || { cat snap-vars.txt; exit 1; }
+        # 19 variables are expected on ubuntu-core
+        test "$(wc -l < snap-vars.txt)" -eq 19 || { cat snap-vars.txt; exit 1; }
     else
-        # 17 variables are expected on non ubuntu-core
-        test "$(wc -l < snap-vars.txt)" -eq 17 || { cat snap-vars.txt; exit 1; }
+        # 18 variables are expected on non ubuntu-core
+        test "$(wc -l < snap-vars.txt)" -eq 18 || { cat snap-vars.txt; exit 1; }
     fi
 
     echo "Ensure that XDG environment variables are what we expect"
@@ -99,3 +101,19 @@ execute: |
     # parallel-installs: $HOME is set to instance specific path
     MATCH "^HOME=/root/snap/$NAME/x1$"                                                                      < misc-vars.txt
     test "$(wc -l < misc-vars.txt)" -eq 4 || { cat misc-vars.txt; exit 1; }
+
+    echo "Collect SNAP environment variables for snap with desktop metadata"
+    echo env | snap run --shell test-snapd-desktop-file-ids.cmd | grep -E '^SNAP_' | sort > snap-vars-desktop.txt
+    echo "Ensure that SNAP environment variables are what we expect"
+    MATCH '^SNAP_NAME=test-snapd-desktop-file-ids$' < snap-vars-desktop.txt
+    MATCH '^SNAP_APP_NAME=cmd$' < snap-vars-desktop.txt
+    MATCH '^SNAP_APP_COMMON_ID=org.example.Foo$' < snap-vars-desktop.txt
+    MATCH '^SNAP_APP_DESKTOP_FILE=/var/lib/snapd/desktop/applications/org.example.Foo.desktop$' < snap-vars-desktop.txt
+    # if on UC20+, then we should see an additional variable (SNAP_SAVE_DATA)
+    if [[ "$SPREAD_SYSTEM" == ubuntu-core-2* ]]; then
+        # 21 variables are expected on ubuntu-core
+        test "$(wc -l < snap-vars-desktop.txt)" -eq 21 || { cat snap-vars-desktop.txt; exit 1; }
+    else
+        # 20 variables are expected on non ubuntu-core
+        test "$(wc -l < snap-vars-desktop.txt)" -eq 20 || { cat snap-vars-desktop.txt; exit 1; }
+    fi

Original file line number	Diff line number	Diff line change
`@@ -1679,7 +1679,7 @@ func (x cmdRun) runSnapConfine(info snap.Info, runner runnable, beforeExec fun`
`1679`	`1679`	`return err`
`1680`	`1680`	`}`
`1681`	`1681`
`1682`		`- snapenv.ExtendEnvForRun(env, info, runner.Component(), opts)`
	`1682`	`+ snapenv.ExtendEnvForRun(env, info, runner.App(), runner.Component(), opts)`
`1683`	`1683`
`1684`	`1684`	`if len(xauthPath) > 0 {`
`1685`	`1685`	`// Environment is not nil here because it comes from`