[AMLII-2036] Add check for readonly file systems (#29320)

Co-authored-by: Jen Gilbert <[email protected]>

pkg/logs/launchers/integration/launcher.go

@@ -45,9 +45,9 @@ type Launcher struct {
 func NewLauncher(sources *sources.LogSources, integrationsLogsComp integrations.Component) *Launcher {
 	runPath := filepath.Join(pkgConfig.Datadog().GetString("logs_config.run_path"), "integrations")
 	err := os.MkdirAll(runPath, 0755)
+
 	if err != nil {
-		ddLog.Warn("Unable to make integrations logs directory: ", err)
-		return nil
+		ddLog.Warn("Unable to create integrations logs directory:", err)
 	}
 
 	return &Launcher{
@@ -76,6 +76,7 @@ func (s *Launcher) run() {
 	for {
 		select {
 		case cfg := <-s.addedConfigs:
+
 			sources, err := ad.CreateSources(cfg.Config)
 			if err != nil {
 				ddLog.Warn("Failed to create source ", err)

pkg/logs/launchers/integration/launcher_test.go

@@ -144,3 +144,31 @@ func (suite *LauncherTestSuite) TestIntegrationLogFilePath() {
 func TestLauncherTestSuite(t *testing.T) {
 	suite.Run(t, new(LauncherTestSuite))
 }
+
+// TestReadyOnlyFileSystem ensures the launcher doesn't panic in a read-only
+// file system. There will be errors but it should handle them gracefully.
+func TestReadyOnlyFileSystem(t *testing.T) {
+	readOnlyDir := filepath.Join(t.TempDir(), "readonly")
+	err := os.Mkdir(readOnlyDir, 0444)
+	assert.Nil(t, err, "Unable to make tempdir readonly")
+
+	pkgConfig.Datadog().SetWithoutSource("logs_config.run_path", readOnlyDir)
+
+	integrationsComp := integrationsmock.Mock()
+	s := NewLauncher(sources.NewLogSources(), integrationsComp)
+
+	// Check the launcher doesn't block on receiving channels
+	mockConf := &integration.Config{}
+	mockConf.Provider = "container"
+	mockConf.LogsConfig = integration.Data(`[{"type": "integration", "source": "foo", "service": "bar"}]`)
+	id := "123456789"
+
+	s.Start(nil, nil, nil, nil)
+	integrationsComp.RegisterIntegration(id, *mockConf)
+
+	logSample := "hello world"
+	integrationsComp.SendLog(logSample, id)
+
+	// send a second log to make sure the launcher isn't blocking
+	integrationsComp.SendLog(logSample, id)
+}

releasenotes/notes/fix-panic-on-readonly-filesystems-1012ba761aa70aaa.yaml

@@ -0,0 +1,12 @@
+# Each section from every release note are combined when the
+# CHANGELOG.rst is rendered. So the text needs to be worded so that
+# it does not depend on any information only available in another
+# section. This may mean repeating some details, but each section
+# must be readable independently of the other.
+#
+# Each section note must be formatted as reStructuredText.
+---
+fixes:
+  - |
+    Fixes a panic caused by running the Agent on readonly filesystems. The
+    Agent will now return integration launchers and handle memory gracefully.