address comments and add tests

pkg/logs/launchers/integration/launcher.go

@@ -79,6 +79,10 @@ func NewLauncher(sources *sources.LogSources, integrationsLogsComp integrations.
 			ddLog.Warn("Unable to compute integrations logs max disk usage, falling back to integrations_logs_total_usage setting:", err)
 			maxDiskUsage = logsTotalUsageSetting
 		}
+
+		if maxDiskUsage == 0 {
+			ddLog.Warn("No space available to store logs. Logs from integrations will be dropped. Please allocate space for logs to be stored.")
+		}
 	}
 
 	return &Launcher{
@@ -197,14 +201,14 @@ func (s *Launcher) receiveLogs(log integrations.IntegrationLog) {
 	for s.combinedUsageSize+logSize > s.combinedUsageMax {
 		leastRecentlyModifiedFile := s.getLeastRecentlyModifiedFile()
 		if leastRecentlyModifiedFile == nil {
-			ddLog.Warn("Could not determine least recently modified file, skipping writing log to file.")
+			ddLog.Error("Could not determine least recently modified file, skipping writing log to file.")
 			return
 		}
 
 		err := s.deleteFile(leastRecentlyModifiedFile)
 		if err != nil {
 			ddLog.Error("Error deleting log file:", err)
-			continue
+			return
 		}
 
 		file, err := os.Create(leastRecentlyModifiedFile.filename)
@@ -387,7 +391,7 @@ func (s *Launcher) scanInitialFiles(dir string) error {
 		leastRecentlyModifiedFile := s.getLeastRecentlyModifiedFile()
 
 		if leastRecentlyModifiedFile == nil {
-			ddLog.Warn("getLeastRecentlyModifiedFile returned nil.")
+			ddLog.Error("Could not determine least recently modified file")
 			return errors.New("getLeastRecentlyModifiedFile returned nil when trying to delete files")
 		}
 

pkg/logs/launchers/integration/launcher_test.go

@@ -68,7 +68,6 @@ func (suite *LauncherTestSuite) TestFileCreation() {
 }
 
 func (suite *LauncherTestSuite) TestSendLog() {
-
 	mockConf := &integration.Config{}
 	mockConf.Provider = "container"
 	mockConf.LogsConfig = integration.Data(`[{"type": "integration", "source": "foo", "service": "bar"}]`)
@@ -99,6 +98,90 @@ func (suite *LauncherTestSuite) TestSendLog() {
 	assert.Equal(suite.T(), expectedPath, <-filepathChan)
 }
 
+// TestNegativeCombinedUsageMax ensures errors in combinedUsageMax don't result
+// in panics from `deleteFile`
+func (suite *LauncherTestSuite) TestNegativeCombinedUsageMax() {
+	suite.s.combinedUsageMax = -1
+	err := suite.s.scanInitialFiles(suite.s.runPath)
+	assert.NotNil(suite.T(), err)
+}
+
+// TestZeroCombinedUsageMax ensures the launcher won't panic when
+// combinedUsageMax is zero. Realistically the launcher would never run receiveLogs since there is a check for
+func (suite *LauncherTestSuite) TestZeroCombinedUsageMaxFileCreated() {
+	suite.s.combinedUsageMax = 0
+
+	filename := "sample_integration_123.log"
+	filepath := filepath.Join(suite.s.runPath, filename)
+	file, err := os.Create(filepath)
+	assert.Nil(suite.T(), err)
+
+	file.Close()
+
+	suite.s.Start(nil, nil, nil, nil)
+
+	integrationLog := integrations.IntegrationLog{
+		Log:           "sample log",
+		IntegrationID: "sample_integration:123",
+	}
+
+	suite.s.receiveLogs(integrationLog)
+}
+
+func (suite *LauncherTestSuite) TestZeroCombinedUsageMaxFileNotCreated() {
+	suite.s.combinedUsageMax = 0
+
+	suite.s.Start(nil, nil, nil, nil)
+
+	integrationLog := integrations.IntegrationLog{
+		Log:           "sample log",
+		IntegrationID: "sample_integration:123",
+	}
+
+	suite.s.receiveLogs(integrationLog)
+}
+
+func (suite *LauncherTestSuite) TestSmallCombinedUsageMax() {
+	suite.s.combinedUsageMax = 10
+
+	filename := "sample_integration_123.log"
+	filepath := filepath.Join(suite.s.runPath, filename)
+	file, err := os.Create(filepath)
+	assert.Nil(suite.T(), err)
+
+	file.Close()
+
+	suite.s.Start(nil, nil, nil, nil)
+
+	// Launcher should write this log
+	writtenLog := "sample"
+	integrationLog := integrations.IntegrationLog{
+		Log:           writtenLog,
+		IntegrationID: "sample_integration:123",
+	}
+	suite.s.receiveLogs(integrationLog)
+	fileStat, err := os.Stat(filepath)
+	assert.Nil(suite.T(), err)
+	assert.Equal(suite.T(), fileStat.Size(), int64(len(writtenLog)+1))
+
+	// Launcher should delete file for this log
+	unwrittenLog := "sample log two"
+	integrationLogTwo := integrations.IntegrationLog{
+		Log:           unwrittenLog,
+		IntegrationID: "sample_integration:123",
+	}
+	suite.s.receiveLogs(integrationLogTwo)
+
+	_, err = os.Stat(filepath)
+	assert.True(suite.T(), os.IsNotExist(err))
+
+	// Remake the file
+	suite.s.receiveLogs(integrationLog)
+	fileStat, err = os.Stat(filepath)
+	assert.Nil(suite.T(), err)
+	assert.Equal(suite.T(), fileStat.Size(), int64(len(writtenLog)+1))
+}
+
 func (suite *LauncherTestSuite) TestWriteLogToFile() {
 	logText := "hello world"
 	err := suite.s.writeLogToFileFunction(suite.testPath, logText)
@@ -156,14 +239,6 @@ func (suite *LauncherTestSuite) TestDeleteFile() {
 	assert.True(suite.T(), os.IsNotExist(err))
 }
 
-// TestNegativeCombinedUsageMax ensures errors in combinedUsageMax don't result
-// in panics from `deleteFile`
-func (suite *LauncherTestSuite) TestNegativeCombinedUsageMax() {
-	suite.s.combinedUsageMax = -1
-	err := suite.s.scanInitialFiles(suite.s.runPath)
-	assert.NotNil(suite.T(), err)
-}
-
 // TestIntegrationLogFilePath ensures the filepath for the logs files are correct
 func (suite *LauncherTestSuite) TestIntegrationLogFilePath() {
 	id := "123456789"