Support setting CONTAINER_LOG_PATH via an environment variable (#1773)

* Support CONTAINER_LOG_PATH.

Signed-off-by: Josh Baird <[email protected]>

* Lint fixes.

Signed-off-by: Josh Baird <[email protected]>

* Update comments.

Signed-off-by: Josh Baird <[email protected]>

* Abstract into function.

Signed-off-by: Josh Baird <[email protected]>

* Handle errors in test.

Signed-off-by: Josh Baird <[email protected]>

* Remove AI agent comments

They don't add value

Signed-off-by: Marco Franssen <[email protected]>

---------

Signed-off-by: Josh Baird <[email protected]>
Signed-off-by: Marco Franssen <[email protected]>
Co-authored-by: Marco Franssen <[email protected]>

Author: joshuabaird

cmd/fluent-manager/main.go

@@ -230,9 +230,7 @@ func main() {
 		}
 	}
 
-	if envs, err := godotenv.Read("/fluent-operator/fluent-bit.env"); err == nil {
-		logPath = envs["CONTAINER_ROOT_DIR"] + "/containers"
-	}
+	logPath = getContainerLogPath("/fluent-operator/fluent-bit.env")
 
 	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrlOpts)
 	if err != nil {
@@ -325,3 +323,20 @@ func main() {
 		os.Exit(1)
 	}
 }
+
+// getContainerLogPath determines the container log path for FluentBit.
+func getContainerLogPath(envFilePath string) string {
+	var logPath string
+
+	if envLogPath := os.Getenv("CONTAINER_LOG_PATH"); envLogPath != "" {
+		logPath = envLogPath
+	} else if envs, err := godotenv.Read(envFilePath); err == nil {
+		logPath = envs["CONTAINER_ROOT_DIR"] + "/containers"
+	}
+
+	if logPath == "" {
+		logPath = "/var/log/containers"
+	}
+
+	return logPath
+}

cmd/fluent-manager/main_test.go

@@ -0,0 +1,119 @@
+/*
+Copyright 2021.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestGetContainerLogPath(t *testing.T) {
+	tests := []struct {
+		name           string
+		envValue       string
+		setupEnvFile   bool
+		envFileContent string
+		expectedPath   string
+	}{
+		{
+			name:         "returns path from CONTAINER_LOG_PATH environment variable",
+			envValue:     "/custom/log/path",
+			setupEnvFile: false,
+			expectedPath: "/custom/log/path",
+		},
+		{
+			name:           "returns path from fluent-bit.env file when env var not set",
+			envValue:       "",
+			setupEnvFile:   true,
+			envFileContent: "CONTAINER_ROOT_DIR=/var/lib/docker",
+			expectedPath:   "/var/lib/docker/containers",
+		},
+		{
+			name:           "returns path with different CONTAINER_ROOT_DIR",
+			envValue:       "",
+			setupEnvFile:   true,
+			envFileContent: "CONTAINER_ROOT_DIR=/custom/container/root",
+			expectedPath:   "/custom/container/root/containers",
+		},
+		{
+			name:         "returns default path when neither env var nor file is available",
+			envValue:     "",
+			setupEnvFile: false,
+			expectedPath: "/var/log/containers",
+		},
+		{
+			name:           "prefers env var over file when both are set",
+			envValue:       "/priority/path",
+			setupEnvFile:   true,
+			envFileContent: "CONTAINER_ROOT_DIR=/var/lib/docker",
+			expectedPath:   "/priority/path",
+		},
+		{
+			name:           "handles env file with multiple variables",
+			envValue:       "",
+			setupEnvFile:   true,
+			envFileContent: "OTHER_VAR=value\nCONTAINER_ROOT_DIR=/multi/var/test\nANOTHER_VAR=other",
+			expectedPath:   "/multi/var/test/containers",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			originalEnv := os.Getenv("CONTAINER_LOG_PATH")
+			defer func() {
+				if originalEnv != "" {
+					if err := os.Setenv("CONTAINER_LOG_PATH", originalEnv); err != nil {
+						t.Errorf("Failed to restore CONTAINER_LOG_PATH: %v", err)
+					}
+				} else {
+					if err := os.Unsetenv("CONTAINER_LOG_PATH"); err != nil {
+						t.Errorf("Failed to unset CONTAINER_LOG_PATH: %v", err)
+					}
+				}
+			}()
+
+			if tt.envValue != "" {
+				if err := os.Setenv("CONTAINER_LOG_PATH", tt.envValue); err != nil {
+					t.Fatalf("Failed to set CONTAINER_LOG_PATH: %v", err)
+				}
+			} else {
+				if err := os.Unsetenv("CONTAINER_LOG_PATH"); err != nil {
+					t.Fatalf("Failed to unset CONTAINER_LOG_PATH: %v", err)
+				}
+			}
+
+			var envFilePath string
+			if tt.setupEnvFile {
+				tempDir := t.TempDir()
+				envFilePath = filepath.Join(tempDir, "fluent-bit.env")
+
+				err := os.WriteFile(envFilePath, []byte(tt.envFileContent), 0644)
+				if err != nil {
+					t.Fatalf("Failed to create test env file: %v", err)
+				}
+			} else {
+				envFilePath = "/non/existent/path/fluent-bit.env"
+			}
+
+			result := getContainerLogPath(envFilePath)
+			if result != tt.expectedPath {
+				t.Errorf("getContainerLogPath() = %q, want %q", result, tt.expectedPath)
+			}
+		})
+	}
+}