package logging import ( "fmt" "io" "path/filepath" "time" "github.com/hashicorp/go-hclog" gsyslog "github.com/hashicorp/go-syslog" "github.com/mitchellh/cli" ) // Config is used to set up logging. type Config struct { // LogLevel is the minimum level to be logged. LogLevel string // LogJSON controls outputing logs in a JSON format. LogJSON bool // Name is the name the returned logger will use to prefix log lines. Name string // EnableSyslog controls forwarding to syslog. EnableSyslog bool // SyslogFacility is the destination for syslog forwarding. SyslogFacility string //LogFilePath is the path to write the logs to the user specified file. LogFilePath string //LogRotateDuration is the user specified time to rotate logs LogRotateDuration time.Duration //LogRotateBytes is the user specified byte limit to rotate logs LogRotateBytes int //LogRotateMaxFiles is the maximum number of past archived log files to keep LogRotateMaxFiles int } const ( // defaultRotateDuration is the default time taken by the agent to rotate logs defaultRotateDuration = 24 * time.Hour ) var ( logRotateDuration time.Duration logRotateBytes int ) // Setup is used to perform setup of several logging objects: // // * A hclog.Logger is used to perform filtering by log level and write to io.Writer. // * A GatedWriter is used to buffer logs until startup UI operations are // complete. After this is flushed then logs flow directly to output // destinations. // * An io.Writer is provided as the sink for all logs to flow to. // // The provided ui object will get any log messages related to setting up // logging itself, and will also be hooked up to the gated logger. The final bool // parameter indicates if logging was set up successfully. func Setup(config *Config, ui cli.Ui) (hclog.InterceptLogger, *GatedWriter, io.Writer, bool) { // The gated writer buffers logs at startup and holds until it's flushed. logGate := &GatedWriter{ Writer: &cli.UiWriter{Ui: ui}, } if !ValidateLogLevel(config.LogLevel) { ui.Error(fmt.Sprintf( "Invalid log level: %s. Valid log levels are: %v", config.LogLevel, allowedLogLevels)) return nil, nil, nil, false } // Set up syslog if it's enabled. var syslog io.Writer if config.EnableSyslog { retries := 12 delay := 5 * time.Second for i := 0; i <= retries; i++ { l, err := gsyslog.NewLogger(gsyslog.LOG_NOTICE, config.SyslogFacility, "consul") if err == nil { syslog = &SyslogWrapper{l} break } ui.Error(fmt.Sprintf("Syslog setup error: %v", err)) if i == retries { timeout := time.Duration(retries) * delay ui.Error(fmt.Sprintf("Syslog setup did not succeed within timeout (%s).", timeout.String())) return nil, nil, nil, false } ui.Error(fmt.Sprintf("Retrying syslog setup in %s...", delay.String())) time.Sleep(delay) } } writers := []io.Writer{logGate} var logOutput io.Writer if syslog != nil { writers = append(writers, syslog) } // Create a file logger if the user has specified the path to the log file if config.LogFilePath != "" { dir, fileName := filepath.Split(config.LogFilePath) // If a path is provided but has no fileName a default is provided. if fileName == "" { fileName = "consul.log" } // Try to enter the user specified log rotation duration first if config.LogRotateDuration != 0 { logRotateDuration = config.LogRotateDuration } else { // Default to 24 hrs if no rotation period is specified logRotateDuration = defaultRotateDuration } // User specified byte limit for log rotation if one is provided if config.LogRotateBytes != 0 { logRotateBytes = config.LogRotateBytes } logFile := &LogFile{ fileName: fileName, logPath: dir, duration: logRotateDuration, MaxBytes: logRotateBytes, MaxFiles: config.LogRotateMaxFiles, } writers = append(writers, logFile) } logOutput = io.MultiWriter(writers...) logger := hclog.NewInterceptLogger(&hclog.LoggerOptions{ Level: LevelFromString(config.LogLevel), Name: config.Name, Output: logOutput, JSONFormat: config.LogJSON, }) return logger, logGate, logOutput, true }