Documentation
¶
Overview ¶
Package log implements logging analogous to the Google-internal C++ INFO/ERROR/V setup. It provides functions Info, Warning, Error, Fatal, plus formatting variants such as Infof. It also provides V-style logging and adaptions for use as a structured logging engine.
Basic examples:
log.Info("Prepare to repel boarders")
log.Fatal("Initialization failed", err)
// Log with context.
log.Infoc(context, "client error: %s", err)
See the documentation for the V function for an explanation of these examples:
if log.V(2) {
log.Info("Starting transaction...")
}
Log output is buffered and written periodically using Flush. Programs should call Flush before exiting to guarantee all log output is written.
By default, all log statements write to files in a temporary directory. This package provides several flags that modify this behavior. These are provided via the pflags library; see InitFlags.
--logtostderr=true Logs are written to standard error instead of to files. --alsologtostderr=INFO Logs are written to standard error as well as to files. --log-dir="" Log files will be written to this directory instead of the default temporary directory. Other flags provide aids to debugging. --log-backtrace-at="" When set to a file and line number holding a logging statement, such as -log_backtrace_at=gopherflakes.go:234 a stack trace will be written to the Info log whenever execution hits that statement. (Unlike with --vmodule, the ".go" must be present.) --verbosity=0 Enable V-leveled logging at the specified level. --vmodule="" The syntax of the argument is a comma-separated list of pattern=N, where pattern is a literal file name (minus the ".go" suffix) or "glob" pattern and N is a V level. For instance, -vmodule=gopher*=3 sets the V level to 3 in all Go files whose names begin "gopher".
Index ¶
- Variables
- func Add(ctx context.Context, kvs ...interface{}) context.Context
- func DirSet() bool
- func DisableLogFileOutput()
- func EnableLogFileOutput(dir string)
- func Error(args ...interface{})
- func Errorc(ctx context.Context, format string, args ...interface{})
- func Errorf(format string, args ...interface{})
- func ErrorfDepth(depth int, format string, args ...interface{})
- func Fatal(args ...interface{})
- func FatalOnPanic()
- func Fatalc(ctx context.Context, format string, args ...interface{})
- func Fatalf(format string, args ...interface{})
- func FatalfDepth(depth int, format string, args ...interface{})
- func Flush()
- func GetLogReader(filename string, restricted bool) (io.ReadCloser, error)
- func Info(args ...interface{})
- func Infoc(ctx context.Context, format string, args ...interface{})
- func Infof(format string, args ...interface{})
- func InfofDepth(depth int, format string, args ...interface{})
- func NewStdLogger(severity Severity) *stdLog.Logger
- func Trace(ctx context.Context, msg string)
- func V(level level) bool
- func VDepth(level level, depth int) bool
- func Warning(args ...interface{})
- func Warningc(ctx context.Context, format string, args ...interface{})
- func Warningf(format string, args ...interface{})
- func WarningfDepth(depth int, format string, args ...interface{})
- type Entry
- type EntryDecoder
- type FileDetails
- type FileInfo
- type Severity
Constants ¶
This section is empty.
Variables ¶
var ( // NodeID is a context key identifying a node ID. NodeID = nodeIDField{} // StoreID is a context key identifying a store ID. StoreID = storeIDField{} // RangeID is a context key identifying a range ID. RangeID = rangeIDField{} )
var MaxSize uint64 = 1024 * 1024 * 10
MaxSize is the maximum size of a log file in bytes.
var Stats struct {
Info, Warning, Error outputStats
}
Stats tracks the number of lines of output and number of bytes per severity level. Values must be read with atomic.LoadInt64.
Functions ¶
func Add ¶
Add takes a context and an additional even number of arguments, interpreted as key-value pairs. These are added on top of the supplied context and the resulting context returned.
func DirSet ¶
func DirSet() bool
DirSet returns true of the log directory has been changed from its default.
func DisableLogFileOutput ¶
func DisableLogFileOutput()
DisableLogFileOutput turns off logging. For unittesting only.
func EnableLogFileOutput ¶
func EnableLogFileOutput(dir string)
EnableLogFileOutput turns on logging using the specified directory. For unittesting only.
func Error ¶
func Error(args ...interface{})
Error logs to the ERROR, WARNING, and INFO logs. Arguments are handled in the manner of fmt.Print; a newline is appended.
func Errorc ¶
Errorc logs to the ERROR, WARNING, and INFO logs. It extracts values from Field keys specified in this package and logs them along with the given message and any additional pairs specified as consecutive elements in kvs.
func Errorf ¶
func Errorf(format string, args ...interface{})
Errorf logs to the ERROR, WARNING, and INFO logs. Don't use it; use Error Info or Errorc instead. Arguments are handled in the manner of fmt.Printf; a newline is appended if missing.
func ErrorfDepth ¶
ErrorfDepth logs to the ERROR, WARNING, and INFO logs, offsetting the caller's stack frame by 'depth'. Passing an empty string for `format` causes this method to naturally format `args`.
func Fatal ¶
func Fatal(args ...interface{})
Fatal logs to the INFO, WARNING, ERROR, and FATAL logs, including a stack trace of all running goroutines, then calls os.Exit(255). Arguments are handled in the manner of fmt.Print; a newline is appended.
func FatalOnPanic ¶
func FatalOnPanic()
FatalOnPanic recovers from a panic and exits the process with a Fatal log. This is useful for avoiding a panic being caught through a CGo exported function or preventing HTTP handlers from recovering panics and ignoring them.
func Fatalc ¶
Fatalc logs to the INFO, WARNING, ERROR, and FATAL logs, including a stack trace of all running goroutines, then calls os.Exit(255). It extracts values from the context using the Field keys specified in this package and logs them along with the given message and any additional pairs specified as consecutive elements in kvs.
func Fatalf ¶
func Fatalf(format string, args ...interface{})
Fatalf logs to the INFO, WARNING, ERROR, and FATAL logs, including a stack trace of all running goroutines, then calls os.Exit(255). Arguments are handled in the manner of fmt.Printf; a newline is appended.
func FatalfDepth ¶
FatalfDepth logs to the INFO, WARNING, ERROR, and FATAL logs, including a stack trace of all running goroutines, then calls os.Exit(255), offsetting the caller's stack frame by 'depth'. Passing an empty string for `format` causes this method to naturally format `args`.
func GetLogReader ¶
func GetLogReader(filename string, restricted bool) (io.ReadCloser, error)
GetLogReader returns a reader for the specified filename. In restricted mode, the filename must be the base name of a file in this process's log directory (this is safe for cases when the filename comes from external sources, such as the admin UI via HTTP). In unrestricted mode any path is allowed, with the added feature that relative paths will be searched in both the current directory and this process's log directory.
func Info ¶
func Info(args ...interface{})
Info logs to the INFO log. Arguments are handled in the manner of fmt.Print; a newline is appended.
func Infoc ¶
Infoc logs to the WARNING and INFO logs. It extracts values from the context using the Field keys specified in this package and logs them along with the given message and any additional pairs specified as consecutive elements in kvs.
func Infof ¶
func Infof(format string, args ...interface{})
Infof logs to the INFO log. Don't use it; use Info or Infoc instead. Arguments are handled in the manner of fmt.Printf; a newline is appended if missing.
func InfofDepth ¶
InfofDepth logs to the INFO log, offsetting the caller's stack frame by 'depth'. Passing an empty string for `format` causes this method to naturally format `args`.
func NewStdLogger ¶
NewStdLogger creates a *stdLog.Logger that forwards messages to the Google logs for the specified severity.
func Trace ¶
Trace looks for an opentracing.Trace in the context and logs the given message to it on success.
func V ¶
func V(level level) bool
V returns true if the logging verbosity is set to the specified level or higher.
func Warning ¶
func Warning(args ...interface{})
Warning logs to the WARNING and INFO logs. Warningf logs to the WARNING and INFO logs. Don't use it; use Warning or Arguments are handled in the manner of fmt.Print; a newline is appended.
func Warningc ¶
Warningc logs to the WARNING and INFO logs. It extracts values from the context using the Field keys specified in this package and logs them along with the given message and any additional pairs specified as consecutive elements in kvs.
func Warningf ¶
func Warningf(format string, args ...interface{})
Warningf logs to the WARNING and INFO logs. Don't use it; use Warning or Warningc instead. Arguments are handled in the manner of fmt.Printf; a newline is appended if missing.
func WarningfDepth ¶
WarningfDepth logs to the WARNING and INFO logs, offsetting the caller's stack frame by 'depth'. Passing an empty string for `format` causes this method to naturally format `args`.
Types ¶
type Entry ¶
type Entry struct {
Severity int `json:"severity"` // Log message severity.
Time int64 `json:"time"` // Time, measured in nanoseconds since the epoch.
File string `json:"file"` // File which generated log statement.
Line int `json:"line"` // Line in file which generated log statement.
// TODO(pmattis): The json output should be called `message` as well. Need to
// fix the UI.
Message string `json:"format"` // Log message.
}
Entry represents a cockroach structured log entry.
func FetchEntriesFromFiles ¶
func FetchEntriesFromFiles(severity Severity, startTimestamp, endTimestamp int64, maxEntries int, pattern *regexp.Regexp) ([]Entry, error)
FetchEntriesFromFiles fetches all available log entires on disk that match the log 'severity' (or worse) and are between the 'startTimestamp' and 'endTimestamp'. It will stop reading new files if the number of entries exceeds 'maxEntries'. Log entries are further filtered by the regexp 'pattern' if provided. The logs entries are returned in reverse chronological order.
type EntryDecoder ¶
type EntryDecoder struct {
// contains filtered or unexported fields
}
EntryDecoder reads successive encoded log entries from the input buffer. Each entry is preceded by a single big-ending uint32 describing the next entry's length.
func NewEntryDecoder ¶
func NewEntryDecoder(in io.Reader) *EntryDecoder
NewEntryDecoder creates a new instance of EntryDecoder.
func (*EntryDecoder) Decode ¶
func (d *EntryDecoder) Decode(entry *Entry) error
Decode decodes the next log entry into the provided protobuf message.
type FileDetails ¶
type FileDetails struct {
Program string
Host string
UserName string
Severity Severity
Time time.Time
PID uint
}
A FileDetails holds all of the particulars that can be parsed by the name of a log file.
type FileInfo ¶
type FileInfo struct {
Name string // base name
SizeBytes int64
ModTimeNanos int64 // most recent mode time in unix nanos
Details FileDetails
}
A FileInfo holds the filename and size of a log file.
func ListLogFiles ¶
ListLogFiles returns a slice of FileInfo structs for each log file on the local node, in any of the configured log directories.
type Severity ¶
type Severity int32 // sync/atomic int32
Severity identifies the sort of log: info, warning etc. It also implements the flag.Value interface. The -stderrthreshold flag is of type Severity and should be modified only through the flag.Value interface. The values match the corresponding constants in C++.
These constants identify the log levels in order of increasing Severity. A message written to a high-Severity log file is also written to each lower-Severity log file.
func SeverityByName ¶
SeverityByName attempts to parse the passed in string into a severity. (i.e. ERROR, INFO). If it succeeds, the returned bool is set to true.
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