Documentation
¶
Index ¶
- Constants
- Variables
- func GetRuntimeFields() map[string]interface{}
- func InitRuntimeFields(environment string, customEnvFields map[string]string)
- func ValidateTemplate(template string) error
- type CustomLogEntry
- type CustomTemplate
- type Format
- type Formatter
- type JSONFormatter
- type Level
- type LogEntry
- type RuntimeFields
- type TimestampFormat
Constants ¶
const ( PlaceholderTimestamp = "{{timestamp}}" PlaceholderLevel = "{{level}}" PlaceholderLogger = "{{logger}}" PlaceholderMessage = "{{message}}" PlaceholderCaller = "{{caller}}" PlaceholderFields = "{{fields}}" PlaceholderSource = "{{source}}" PlaceholderTraceID = "{{trace_id}}" PlaceholderSpanID = "{{span_id}}" // Runtime fields PlaceholderHostname = "{{hostname}}" PlaceholderPID = "{{pid}}" PlaceholderGoroutine = "{{goroutine}}" PlaceholderEnv = "{{env}}" )
Supported placeholders
const ( LevelDebug = logcastle.LevelDebug LevelInfo = logcastle.LevelInfo LevelWarn = logcastle.LevelWarn LevelError = logcastle.LevelError LevelFatal = logcastle.LevelFatal )
Variables ¶
var ValidPlaceholders = []string{ PlaceholderTimestamp, PlaceholderLevel, PlaceholderLogger, PlaceholderMessage, PlaceholderCaller, PlaceholderFields, PlaceholderSource, PlaceholderTraceID, PlaceholderSpanID, PlaceholderHostname, PlaceholderPID, PlaceholderGoroutine, PlaceholderEnv, }
ValidPlaceholders lists all valid placeholders
Functions ¶
func GetRuntimeFields ¶
func GetRuntimeFields() map[string]interface{}
GetRuntimeFields returns current runtime information as a map. Includes hostname, PID, environment, goroutine count, and custom env fields.
func InitRuntimeFields ¶
InitRuntimeFields initializes global runtime context for all logs. Call once at app startup. environment: "prod"/"dev"/etc, customEnvFields: datacenter, region, etc.
func ValidateTemplate ¶
ValidateTemplate validates a template string Checks for: - Required placeholder presence (at least timestamp and message) - Invalid placeholder syntax - Unknown placeholders
Types ¶
type CustomLogEntry ¶
type CustomLogEntry struct {
Timestamp time.Time
Level string
Logger string
Message string
Caller string
Fields map[string]interface{}
TraceID string
SpanID string
Source string
}
CustomLogEntry represents a log entry for JSON custom formatter
type CustomTemplate ¶
type CustomTemplate struct {
// contains filtered or unexported fields
}
CustomTemplate represents a compiled custom log format template
func CompileTemplate ¶
func CompileTemplate(template string) (*CustomTemplate, error)
CompileTemplate compiles a custom template string into an executable template Returns an error if the template contains invalid placeholders or syntax
func (*CustomTemplate) Execute ¶
func (ct *CustomTemplate) Execute(entry *LogEntry) string
Execute executes the template with the given log entry
type Formatter ¶
type Formatter struct {
// contains filtered or unexported fields
}
Formatter formats log entries to the desired output format
func NewCustomFormatter ¶
NewCustomFormatter creates a formatter with a custom template The template is validated at creation time
func NewFormatter ¶
NewFormatter creates a new formatter with the specified format
func NewFormatterWithTimestamp ¶
func NewFormatterWithTimestamp(format Format, tsFormat TimestampFormat, customTsFormat string) *Formatter
NewFormatterWithTimestamp creates a formatter with custom timestamp format
type JSONFormatter ¶
type JSONFormatter struct {
// FieldOrder specifies the order of fields in JSON output for readability.
// Empty = default alphabetical. Example: ["timestamp", "level", "message"]
FieldOrder []string
// GlobalFields are automatically added to every log entry.
// Use for service name, version, region, etc. Thread-safe updates via SetGlobalField.
GlobalFields map[string]interface{}
// IncludeRuntimeFields adds hostname, PID, etc. to logs
IncludeRuntimeFields bool
// TimestampFormat for formatting timestamps
TimestampFormat string
// PrettyPrint enables indented JSON output
PrettyPrint bool
// contains filtered or unexported fields
}
JSONFormatter provides customizable JSON formatting with global fields and field ordering. Thread-safe. Supports runtime fields, custom field order, and pretty printing.
func NewJSONFormatter ¶
func NewJSONFormatter() *JSONFormatter
NewJSONFormatter creates a JSON formatter with sensible defaults. Default field order: timestamp, level, message. Call SetGlobalField to add metadata.
func (*JSONFormatter) Format ¶
func (f *JSONFormatter) Format(entry *CustomLogEntry) []byte
Format formats a log entry as customizable JSON with global and runtime fields. Returns newline-terminated JSON bytes. Honors FieldOrder if set.
func (*JSONFormatter) RemoveGlobalField ¶
func (f *JSONFormatter) RemoveGlobalField(key string)
RemoveGlobalField removes a global field
func (*JSONFormatter) SetGlobalField ¶
func (f *JSONFormatter) SetGlobalField(key string, value interface{})
SetGlobalField adds or updates a global field that appears in all logs. Thread-safe. Example: f.SetGlobalField("service", "api-gateway")
func (*JSONFormatter) SetGlobalFields ¶
func (f *JSONFormatter) SetGlobalFields(fields map[string]interface{})
SetGlobalFields sets multiple global fields at once
type RuntimeFields ¶
type RuntimeFields struct {
// contains filtered or unexported fields
}
RuntimeFields provides access to runtime and environment information for log enrichment. Collects hostname, PID, environment name, and custom fields once at startup.
type TimestampFormat ¶
type TimestampFormat string
TimestampFormat represents timestamp formatting options
const ( TimestampFormatRFC3339Nano TimestampFormat = "rfc3339nano" TimestampFormatRFC3339 TimestampFormat = "rfc3339" TimestampFormatRFC3339Millis TimestampFormat = "rfc3339milli" TimestampFormatUnix TimestampFormat = "unix" TimestampFormatUnixMilli TimestampFormat = "unixmilli" TimestampFormatUnixNano TimestampFormat = "unixnano" TimestampFormatDateTime TimestampFormat = "datetime" TimestampFormatCustom TimestampFormat = "custom" )
Source Files