|
|
@@ -1,511 +0,0 @@
|
|
|
-# Logrus <img src="http://i.imgur.com/hTeVwmJ.png" width="40" height="40" alt=":walrus:" class="emoji" title=":walrus:"/> [](https://travis-ci.org/sirupsen/logrus) [](https://godoc.org/github.com/sirupsen/logrus)
|
|
|
-
|
|
|
-Logrus is a structured logger for Go (golang), completely API compatible with
|
|
|
-the standard library logger.
|
|
|
-
|
|
|
-**Seeing weird case-sensitive problems?** It's in the past been possible to
|
|
|
-import Logrus as both upper- and lower-case. Due to the Go package environment,
|
|
|
-this caused issues in the community and we needed a standard. Some environments
|
|
|
-experienced problems with the upper-case variant, so the lower-case was decided.
|
|
|
-Everything using `logrus` will need to use the lower-case:
|
|
|
-`github.com/sirupsen/logrus`. Any package that isn't, should be changed.
|
|
|
-
|
|
|
-To fix Glide, see [these
|
|
|
-comments](https://github.com/sirupsen/logrus/issues/553#issuecomment-306591437).
|
|
|
-For an in-depth explanation of the casing issue, see [this
|
|
|
-comment](https://github.com/sirupsen/logrus/issues/570#issuecomment-313933276).
|
|
|
-
|
|
|
-**Are you interested in assisting in maintaining Logrus?** Currently I have a
|
|
|
-lot of obligations, and I am unable to provide Logrus with the maintainership it
|
|
|
-needs. If you'd like to help, please reach out to me at `simon at author's
|
|
|
-username dot com`.
|
|
|
-
|
|
|
-Nicely color-coded in development (when a TTY is attached, otherwise just
|
|
|
-plain text):
|
|
|
-
|
|
|
-
|
|
|
-
|
|
|
-With `log.SetFormatter(&log.JSONFormatter{})`, for easy parsing by logstash
|
|
|
-or Splunk:
|
|
|
-
|
|
|
-```json
|
|
|
-{"animal":"walrus","level":"info","msg":"A group of walrus emerges from the
|
|
|
-ocean","size":10,"time":"2014-03-10 19:57:38.562264131 -0400 EDT"}
|
|
|
-
|
|
|
-{"level":"warning","msg":"The group's number increased tremendously!",
|
|
|
-"number":122,"omg":true,"time":"2014-03-10 19:57:38.562471297 -0400 EDT"}
|
|
|
-
|
|
|
-{"animal":"walrus","level":"info","msg":"A giant walrus appears!",
|
|
|
-"size":10,"time":"2014-03-10 19:57:38.562500591 -0400 EDT"}
|
|
|
-
|
|
|
-{"animal":"walrus","level":"info","msg":"Tremendously sized cow enters the ocean.",
|
|
|
-"size":9,"time":"2014-03-10 19:57:38.562527896 -0400 EDT"}
|
|
|
-
|
|
|
-{"level":"fatal","msg":"The ice breaks!","number":100,"omg":true,
|
|
|
-"time":"2014-03-10 19:57:38.562543128 -0400 EDT"}
|
|
|
-```
|
|
|
-
|
|
|
-With the default `log.SetFormatter(&log.TextFormatter{})` when a TTY is not
|
|
|
-attached, the output is compatible with the
|
|
|
-[logfmt](http://godoc.org/github.com/kr/logfmt) format:
|
|
|
-
|
|
|
-```text
|
|
|
-time="2015-03-26T01:27:38-04:00" level=debug msg="Started observing beach" animal=walrus number=8
|
|
|
-time="2015-03-26T01:27:38-04:00" level=info msg="A group of walrus emerges from the ocean" animal=walrus size=10
|
|
|
-time="2015-03-26T01:27:38-04:00" level=warning msg="The group's number increased tremendously!" number=122 omg=true
|
|
|
-time="2015-03-26T01:27:38-04:00" level=debug msg="Temperature changes" temperature=-4
|
|
|
-time="2015-03-26T01:27:38-04:00" level=panic msg="It's over 9000!" animal=orca size=9009
|
|
|
-time="2015-03-26T01:27:38-04:00" level=fatal msg="The ice breaks!" err=&{0x2082280c0 map[animal:orca size:9009] 2015-03-26 01:27:38.441574009 -0400 EDT panic It's over 9000!} number=100 omg=true
|
|
|
-exit status 1
|
|
|
-```
|
|
|
-
|
|
|
-#### Case-sensitivity
|
|
|
-
|
|
|
-The organization's name was changed to lower-case--and this will not be changed
|
|
|
-back. If you are getting import conflicts due to case sensitivity, please use
|
|
|
-the lower-case import: `github.com/sirupsen/logrus`.
|
|
|
-
|
|
|
-#### Example
|
|
|
-
|
|
|
-The simplest way to use Logrus is simply the package-level exported logger:
|
|
|
-
|
|
|
-```go
|
|
|
-package main
|
|
|
-
|
|
|
-import (
|
|
|
- log "github.com/sirupsen/logrus"
|
|
|
-)
|
|
|
-
|
|
|
-func main() {
|
|
|
- log.WithFields(log.Fields{
|
|
|
- "animal": "walrus",
|
|
|
- }).Info("A walrus appears")
|
|
|
-}
|
|
|
-```
|
|
|
-
|
|
|
-Note that it's completely api-compatible with the stdlib logger, so you can
|
|
|
-replace your `log` imports everywhere with `log "github.com/sirupsen/logrus"`
|
|
|
-and you'll now have the flexibility of Logrus. You can customize it all you
|
|
|
-want:
|
|
|
-
|
|
|
-```go
|
|
|
-package main
|
|
|
-
|
|
|
-import (
|
|
|
- "os"
|
|
|
- log "github.com/sirupsen/logrus"
|
|
|
-)
|
|
|
-
|
|
|
-func init() {
|
|
|
- // Log as JSON instead of the default ASCII formatter.
|
|
|
- log.SetFormatter(&log.JSONFormatter{})
|
|
|
-
|
|
|
- // Output to stdout instead of the default stderr
|
|
|
- // Can be any io.Writer, see below for File example
|
|
|
- log.SetOutput(os.Stdout)
|
|
|
-
|
|
|
- // Only log the warning severity or above.
|
|
|
- log.SetLevel(log.WarnLevel)
|
|
|
-}
|
|
|
-
|
|
|
-func main() {
|
|
|
- log.WithFields(log.Fields{
|
|
|
- "animal": "walrus",
|
|
|
- "size": 10,
|
|
|
- }).Info("A group of walrus emerges from the ocean")
|
|
|
-
|
|
|
- log.WithFields(log.Fields{
|
|
|
- "omg": true,
|
|
|
- "number": 122,
|
|
|
- }).Warn("The group's number increased tremendously!")
|
|
|
-
|
|
|
- log.WithFields(log.Fields{
|
|
|
- "omg": true,
|
|
|
- "number": 100,
|
|
|
- }).Fatal("The ice breaks!")
|
|
|
-
|
|
|
- // A common pattern is to re-use fields between logging statements by re-using
|
|
|
- // the logrus.Entry returned from WithFields()
|
|
|
- contextLogger := log.WithFields(log.Fields{
|
|
|
- "common": "this is a common field",
|
|
|
- "other": "I also should be logged always",
|
|
|
- })
|
|
|
-
|
|
|
- contextLogger.Info("I'll be logged with common and other field")
|
|
|
- contextLogger.Info("Me too")
|
|
|
-}
|
|
|
-```
|
|
|
-
|
|
|
-For more advanced usage such as logging to multiple locations from the same
|
|
|
-application, you can also create an instance of the `logrus` Logger:
|
|
|
-
|
|
|
-```go
|
|
|
-package main
|
|
|
-
|
|
|
-import (
|
|
|
- "os"
|
|
|
- "github.com/sirupsen/logrus"
|
|
|
-)
|
|
|
-
|
|
|
-// Create a new instance of the logger. You can have any number of instances.
|
|
|
-var log = logrus.New()
|
|
|
-
|
|
|
-func main() {
|
|
|
- // The API for setting attributes is a little different than the package level
|
|
|
- // exported logger. See Godoc.
|
|
|
- log.Out = os.Stdout
|
|
|
-
|
|
|
- // You could set this to any `io.Writer` such as a file
|
|
|
- // file, err := os.OpenFile("logrus.log", os.O_CREATE|os.O_WRONLY, 0666)
|
|
|
- // if err == nil {
|
|
|
- // log.Out = file
|
|
|
- // } else {
|
|
|
- // log.Info("Failed to log to file, using default stderr")
|
|
|
- // }
|
|
|
-
|
|
|
- log.WithFields(logrus.Fields{
|
|
|
- "animal": "walrus",
|
|
|
- "size": 10,
|
|
|
- }).Info("A group of walrus emerges from the ocean")
|
|
|
-}
|
|
|
-```
|
|
|
-
|
|
|
-#### Fields
|
|
|
-
|
|
|
-Logrus encourages careful, structured logging through logging fields instead of
|
|
|
-long, unparseable error messages. For example, instead of: `log.Fatalf("Failed
|
|
|
-to send event %s to topic %s with key %d")`, you should log the much more
|
|
|
-discoverable:
|
|
|
-
|
|
|
-```go
|
|
|
-log.WithFields(log.Fields{
|
|
|
- "event": event,
|
|
|
- "topic": topic,
|
|
|
- "key": key,
|
|
|
-}).Fatal("Failed to send event")
|
|
|
-```
|
|
|
-
|
|
|
-We've found this API forces you to think about logging in a way that produces
|
|
|
-much more useful logging messages. We've been in countless situations where just
|
|
|
-a single added field to a log statement that was already there would've saved us
|
|
|
-hours. The `WithFields` call is optional.
|
|
|
-
|
|
|
-In general, with Logrus using any of the `printf`-family functions should be
|
|
|
-seen as a hint you should add a field, however, you can still use the
|
|
|
-`printf`-family functions with Logrus.
|
|
|
-
|
|
|
-#### Default Fields
|
|
|
-
|
|
|
-Often it's helpful to have fields _always_ attached to log statements in an
|
|
|
-application or parts of one. For example, you may want to always log the
|
|
|
-`request_id` and `user_ip` in the context of a request. Instead of writing
|
|
|
-`log.WithFields(log.Fields{"request_id": request_id, "user_ip": user_ip})` on
|
|
|
-every line, you can create a `logrus.Entry` to pass around instead:
|
|
|
-
|
|
|
-```go
|
|
|
-requestLogger := log.WithFields(log.Fields{"request_id": request_id, "user_ip": user_ip})
|
|
|
-requestLogger.Info("something happened on that request") # will log request_id and user_ip
|
|
|
-requestLogger.Warn("something not great happened")
|
|
|
-```
|
|
|
-
|
|
|
-#### Hooks
|
|
|
-
|
|
|
-You can add hooks for logging levels. For example to send errors to an exception
|
|
|
-tracking service on `Error`, `Fatal` and `Panic`, info to StatsD or log to
|
|
|
-multiple places simultaneously, e.g. syslog.
|
|
|
-
|
|
|
-Logrus comes with [built-in hooks](hooks/). Add those, or your custom hook, in
|
|
|
-`init`:
|
|
|
-
|
|
|
-```go
|
|
|
-import (
|
|
|
- log "github.com/sirupsen/logrus"
|
|
|
- "gopkg.in/gemnasium/logrus-airbrake-hook.v2" // the package is named "airbrake"
|
|
|
- logrus_syslog "github.com/sirupsen/logrus/hooks/syslog"
|
|
|
- "log/syslog"
|
|
|
-)
|
|
|
-
|
|
|
-func init() {
|
|
|
-
|
|
|
- // Use the Airbrake hook to report errors that have Error severity or above to
|
|
|
- // an exception tracker. You can create custom hooks, see the Hooks section.
|
|
|
- log.AddHook(airbrake.NewHook(123, "xyz", "production"))
|
|
|
-
|
|
|
- hook, err := logrus_syslog.NewSyslogHook("udp", "localhost:514", syslog.LOG_INFO, "")
|
|
|
- if err != nil {
|
|
|
- log.Error("Unable to connect to local syslog daemon")
|
|
|
- } else {
|
|
|
- log.AddHook(hook)
|
|
|
- }
|
|
|
-}
|
|
|
-```
|
|
|
-Note: Syslog hook also support connecting to local syslog (Ex. "/dev/log" or "/var/run/syslog" or "/var/run/log"). For the detail, please check the [syslog hook README](hooks/syslog/README.md).
|
|
|
-
|
|
|
-| Hook | Description |
|
|
|
-| ----- | ----------- |
|
|
|
-| [Airbrake "legacy"](https://github.com/gemnasium/logrus-airbrake-legacy-hook) | Send errors to an exception tracking service compatible with the Airbrake API V2. Uses [`airbrake-go`](https://github.com/tobi/airbrake-go) behind the scenes. |
|
|
|
-| [Airbrake](https://github.com/gemnasium/logrus-airbrake-hook) | Send errors to the Airbrake API V3. Uses the official [`gobrake`](https://github.com/airbrake/gobrake) behind the scenes. |
|
|
|
-| [Amazon Kinesis](https://github.com/evalphobia/logrus_kinesis) | Hook for logging to [Amazon Kinesis](https://aws.amazon.com/kinesis/) |
|
|
|
-| [Amqp-Hook](https://github.com/vladoatanasov/logrus_amqp) | Hook for logging to Amqp broker (Like RabbitMQ) |
|
|
|
-| [Application Insights](https://github.com/jjcollinge/logrus-appinsights) | Hook for logging to [Application Insights](https://azure.microsoft.com/en-us/services/application-insights/)
|
|
|
-| [AzureTableHook](https://github.com/kpfaulkner/azuretablehook/) | Hook for logging to Azure Table Storage|
|
|
|
-| [Bugsnag](https://github.com/Shopify/logrus-bugsnag/blob/master/bugsnag.go) | Send errors to the Bugsnag exception tracking service. |
|
|
|
-| [DeferPanic](https://github.com/deferpanic/dp-logrus) | Hook for logging to DeferPanic |
|
|
|
-| [Discordrus](https://github.com/kz/discordrus) | Hook for logging to [Discord](https://discordapp.com/) |
|
|
|
-| [ElasticSearch](https://github.com/sohlich/elogrus) | Hook for logging to ElasticSearch|
|
|
|
-| [Firehose](https://github.com/beaubrewer/logrus_firehose) | Hook for logging to [Amazon Firehose](https://aws.amazon.com/kinesis/firehose/)
|
|
|
-| [Fluentd](https://github.com/evalphobia/logrus_fluent) | Hook for logging to fluentd |
|
|
|
-| [Go-Slack](https://github.com/multiplay/go-slack) | Hook for logging to [Slack](https://slack.com) |
|
|
|
-| [Graylog](https://github.com/gemnasium/logrus-graylog-hook) | Hook for logging to [Graylog](http://graylog2.org/) |
|
|
|
-| [Hiprus](https://github.com/nubo/hiprus) | Send errors to a channel in hipchat. |
|
|
|
-| [Honeybadger](https://github.com/agonzalezro/logrus_honeybadger) | Hook for sending exceptions to Honeybadger |
|
|
|
-| [InfluxDB](https://github.com/Abramovic/logrus_influxdb) | Hook for logging to influxdb |
|
|
|
-| [Influxus](http://github.com/vlad-doru/influxus) | Hook for concurrently logging to [InfluxDB](http://influxdata.com/) |
|
|
|
-| [Journalhook](https://github.com/wercker/journalhook) | Hook for logging to `systemd-journald` |
|
|
|
-| [KafkaLogrus](https://github.com/tracer0tong/kafkalogrus) | Hook for logging to Kafka |
|
|
|
-| [Kafka REST Proxy](https://github.com/Nordstrom/logrus-kafka-rest-proxy) | Hook for logging to [Kafka REST Proxy](https://docs.confluent.io/current/kafka-rest/docs) |
|
|
|
-| [LFShook](https://github.com/rifflock/lfshook) | Hook for logging to the local filesystem |
|
|
|
-| [Logbeat](https://github.com/macandmia/logbeat) | Hook for logging to [Opbeat](https://opbeat.com/) |
|
|
|
-| [Logentries](https://github.com/jcftang/logentriesrus) | Hook for logging to [Logentries](https://logentries.com/) |
|
|
|
-| [Logentrus](https://github.com/puddingfactory/logentrus) | Hook for logging to [Logentries](https://logentries.com/) |
|
|
|
-| [Logmatic.io](https://github.com/logmatic/logmatic-go) | Hook for logging to [Logmatic.io](http://logmatic.io/) |
|
|
|
-| [Logrusly](https://github.com/sebest/logrusly) | Send logs to [Loggly](https://www.loggly.com/) |
|
|
|
-| [Logstash](https://github.com/bshuster-repo/logrus-logstash-hook) | Hook for logging to [Logstash](https://www.elastic.co/products/logstash) |
|
|
|
-| [Mail](https://github.com/zbindenren/logrus_mail) | Hook for sending exceptions via mail |
|
|
|
-| [Mattermost](https://github.com/shuLhan/mattermost-integration/tree/master/hooks/logrus) | Hook for logging to [Mattermost](https://mattermost.com/) |
|
|
|
-| [Mongodb](https://github.com/weekface/mgorus) | Hook for logging to mongodb |
|
|
|
-| [NATS-Hook](https://github.com/rybit/nats_logrus_hook) | Hook for logging to [NATS](https://nats.io) |
|
|
|
-| [Octokit](https://github.com/dorajistyle/logrus-octokit-hook) | Hook for logging to github via octokit |
|
|
|
-| [Papertrail](https://github.com/polds/logrus-papertrail-hook) | Send errors to the [Papertrail](https://papertrailapp.com) hosted logging service via UDP. |
|
|
|
-| [PostgreSQL](https://github.com/gemnasium/logrus-postgresql-hook) | Send logs to [PostgreSQL](http://postgresql.org) |
|
|
|
-| [Promrus](https://github.com/weaveworks/promrus) | Expose number of log messages as [Prometheus](https://prometheus.io/) metrics |
|
|
|
-| [Pushover](https://github.com/toorop/logrus_pushover) | Send error via [Pushover](https://pushover.net) |
|
|
|
-| [Raygun](https://github.com/squirkle/logrus-raygun-hook) | Hook for logging to [Raygun.io](http://raygun.io/) |
|
|
|
-| [Redis-Hook](https://github.com/rogierlommers/logrus-redis-hook) | Hook for logging to a ELK stack (through Redis) |
|
|
|
-| [Rollrus](https://github.com/heroku/rollrus) | Hook for sending errors to rollbar |
|
|
|
-| [Scribe](https://github.com/sagar8192/logrus-scribe-hook) | Hook for logging to [Scribe](https://github.com/facebookarchive/scribe)|
|
|
|
-| [Sentry](https://github.com/evalphobia/logrus_sentry) | Send errors to the Sentry error logging and aggregation service. |
|
|
|
-| [Slackrus](https://github.com/johntdyer/slackrus) | Hook for Slack chat. |
|
|
|
-| [Stackdriver](https://github.com/knq/sdhook) | Hook for logging to [Google Stackdriver](https://cloud.google.com/logging/) |
|
|
|
-| [Sumorus](https://github.com/doublefree/sumorus) | Hook for logging to [SumoLogic](https://www.sumologic.com/)|
|
|
|
-| [Syslog](https://github.com/sirupsen/logrus/blob/master/hooks/syslog/syslog.go) | Send errors to remote syslog server. Uses standard library `log/syslog` behind the scenes. |
|
|
|
-| [Syslog TLS](https://github.com/shinji62/logrus-syslog-ng) | Send errors to remote syslog server with TLS support. |
|
|
|
-| [Telegram](https://github.com/rossmcdonald/telegram_hook) | Hook for logging errors to [Telegram](https://telegram.org/) |
|
|
|
-| [TraceView](https://github.com/evalphobia/logrus_appneta) | Hook for logging to [AppNeta TraceView](https://www.appneta.com/products/traceview/) |
|
|
|
-| [Typetalk](https://github.com/dragon3/logrus-typetalk-hook) | Hook for logging to [Typetalk](https://www.typetalk.in/) |
|
|
|
-| [logz.io](https://github.com/ripcurld00d/logrus-logzio-hook) | Hook for logging to [logz.io](https://logz.io), a Log as a Service using Logstash |
|
|
|
-| [SQS-Hook](https://github.com/tsarpaul/logrus_sqs) | Hook for logging to [Amazon Simple Queue Service (SQS)](https://aws.amazon.com/sqs/) |
|
|
|
-
|
|
|
-#### Level logging
|
|
|
-
|
|
|
-Logrus has six logging levels: Debug, Info, Warning, Error, Fatal and Panic.
|
|
|
-
|
|
|
-```go
|
|
|
-log.Debug("Useful debugging information.")
|
|
|
-log.Info("Something noteworthy happened!")
|
|
|
-log.Warn("You should probably take a look at this.")
|
|
|
-log.Error("Something failed but I'm not quitting.")
|
|
|
-// Calls os.Exit(1) after logging
|
|
|
-log.Fatal("Bye.")
|
|
|
-// Calls panic() after logging
|
|
|
-log.Panic("I'm bailing.")
|
|
|
-```
|
|
|
-
|
|
|
-You can set the logging level on a `Logger`, then it will only log entries with
|
|
|
-that severity or anything above it:
|
|
|
-
|
|
|
-```go
|
|
|
-// Will log anything that is info or above (warn, error, fatal, panic). Default.
|
|
|
-log.SetLevel(log.InfoLevel)
|
|
|
-```
|
|
|
-
|
|
|
-It may be useful to set `log.Level = logrus.DebugLevel` in a debug or verbose
|
|
|
-environment if your application has that.
|
|
|
-
|
|
|
-#### Entries
|
|
|
-
|
|
|
-Besides the fields added with `WithField` or `WithFields` some fields are
|
|
|
-automatically added to all logging events:
|
|
|
-
|
|
|
-1. `time`. The timestamp when the entry was created.
|
|
|
-2. `msg`. The logging message passed to `{Info,Warn,Error,Fatal,Panic}` after
|
|
|
- the `AddFields` call. E.g. `Failed to send event.`
|
|
|
-3. `level`. The logging level. E.g. `info`.
|
|
|
-
|
|
|
-#### Environments
|
|
|
-
|
|
|
-Logrus has no notion of environment.
|
|
|
-
|
|
|
-If you wish for hooks and formatters to only be used in specific environments,
|
|
|
-you should handle that yourself. For example, if your application has a global
|
|
|
-variable `Environment`, which is a string representation of the environment you
|
|
|
-could do:
|
|
|
-
|
|
|
-```go
|
|
|
-import (
|
|
|
- log "github.com/sirupsen/logrus"
|
|
|
-)
|
|
|
-
|
|
|
-init() {
|
|
|
- // do something here to set environment depending on an environment variable
|
|
|
- // or command-line flag
|
|
|
- if Environment == "production" {
|
|
|
- log.SetFormatter(&log.JSONFormatter{})
|
|
|
- } else {
|
|
|
- // The TextFormatter is default, you don't actually have to do this.
|
|
|
- log.SetFormatter(&log.TextFormatter{})
|
|
|
- }
|
|
|
-}
|
|
|
-```
|
|
|
-
|
|
|
-This configuration is how `logrus` was intended to be used, but JSON in
|
|
|
-production is mostly only useful if you do log aggregation with tools like
|
|
|
-Splunk or Logstash.
|
|
|
-
|
|
|
-#### Formatters
|
|
|
-
|
|
|
-The built-in logging formatters are:
|
|
|
-
|
|
|
-* `logrus.TextFormatter`. Logs the event in colors if stdout is a tty, otherwise
|
|
|
- without colors.
|
|
|
- * *Note:* to force colored output when there is no TTY, set the `ForceColors`
|
|
|
- field to `true`. To force no colored output even if there is a TTY set the
|
|
|
- `DisableColors` field to `true`. For Windows, see
|
|
|
- [github.com/mattn/go-colorable](https://github.com/mattn/go-colorable).
|
|
|
- * All options are listed in the [generated docs](https://godoc.org/github.com/sirupsen/logrus#TextFormatter).
|
|
|
-* `logrus.JSONFormatter`. Logs fields as JSON.
|
|
|
- * All options are listed in the [generated docs](https://godoc.org/github.com/sirupsen/logrus#JSONFormatter).
|
|
|
-
|
|
|
-Third party logging formatters:
|
|
|
-
|
|
|
-* [`FluentdFormatter`](https://github.com/joonix/log). Formats entries that can be parsed by Kubernetes and Google Container Engine.
|
|
|
-* [`logstash`](https://github.com/bshuster-repo/logrus-logstash-hook). Logs fields as [Logstash](http://logstash.net) Events.
|
|
|
-* [`prefixed`](https://github.com/x-cray/logrus-prefixed-formatter). Displays log entry source along with alternative layout.
|
|
|
-* [`zalgo`](https://github.com/aybabtme/logzalgo). Invoking the P͉̫o̳̼̊w̖͈̰͎e̬͔̭͂r͚̼̹̲ ̫͓͉̳͈ō̠͕͖̚f̝͍̠ ͕̲̞͖͑Z̖̫̤̫ͪa͉̬͈̗l͖͎g̳̥o̰̥̅!̣͔̲̻͊̄ ̙̘̦̹̦.
|
|
|
-
|
|
|
-You can define your formatter by implementing the `Formatter` interface,
|
|
|
-requiring a `Format` method. `Format` takes an `*Entry`. `entry.Data` is a
|
|
|
-`Fields` type (`map[string]interface{}`) with all your fields as well as the
|
|
|
-default ones (see Entries section above):
|
|
|
-
|
|
|
-```go
|
|
|
-type MyJSONFormatter struct {
|
|
|
-}
|
|
|
-
|
|
|
-log.SetFormatter(new(MyJSONFormatter))
|
|
|
-
|
|
|
-func (f *MyJSONFormatter) Format(entry *Entry) ([]byte, error) {
|
|
|
- // Note this doesn't include Time, Level and Message which are available on
|
|
|
- // the Entry. Consult `godoc` on information about those fields or read the
|
|
|
- // source of the official loggers.
|
|
|
- serialized, err := json.Marshal(entry.Data)
|
|
|
- if err != nil {
|
|
|
- return nil, fmt.Errorf("Failed to marshal fields to JSON, %v", err)
|
|
|
- }
|
|
|
- return append(serialized, '\n'), nil
|
|
|
-}
|
|
|
-```
|
|
|
-
|
|
|
-#### Logger as an `io.Writer`
|
|
|
-
|
|
|
-Logrus can be transformed into an `io.Writer`. That writer is the end of an `io.Pipe` and it is your responsibility to close it.
|
|
|
-
|
|
|
-```go
|
|
|
-w := logger.Writer()
|
|
|
-defer w.Close()
|
|
|
-
|
|
|
-srv := http.Server{
|
|
|
- // create a stdlib log.Logger that writes to
|
|
|
- // logrus.Logger.
|
|
|
- ErrorLog: log.New(w, "", 0),
|
|
|
-}
|
|
|
-```
|
|
|
-
|
|
|
-Each line written to that writer will be printed the usual way, using formatters
|
|
|
-and hooks. The level for those entries is `info`.
|
|
|
-
|
|
|
-This means that we can override the standard library logger easily:
|
|
|
-
|
|
|
-```go
|
|
|
-logger := logrus.New()
|
|
|
-logger.Formatter = &logrus.JSONFormatter{}
|
|
|
-
|
|
|
-// Use logrus for standard log output
|
|
|
-// Note that `log` here references stdlib's log
|
|
|
-// Not logrus imported under the name `log`.
|
|
|
-log.SetOutput(logger.Writer())
|
|
|
-```
|
|
|
-
|
|
|
-#### Rotation
|
|
|
-
|
|
|
-Log rotation is not provided with Logrus. Log rotation should be done by an
|
|
|
-external program (like `logrotate(8)`) that can compress and delete old log
|
|
|
-entries. It should not be a feature of the application-level logger.
|
|
|
-
|
|
|
-#### Tools
|
|
|
-
|
|
|
-| Tool | Description |
|
|
|
-| ---- | ----------- |
|
|
|
-|[Logrus Mate](https://github.com/gogap/logrus_mate)|Logrus mate is a tool for Logrus to manage loggers, you can initial logger's level, hook and formatter by config file, the logger will generated with different config at different environment.|
|
|
|
-|[Logrus Viper Helper](https://github.com/heirko/go-contrib/tree/master/logrusHelper)|An Helper around Logrus to wrap with spf13/Viper to load configuration with fangs! And to simplify Logrus configuration use some behavior of [Logrus Mate](https://github.com/gogap/logrus_mate). [sample](https://github.com/heirko/iris-contrib/blob/master/middleware/logrus-logger/example) |
|
|
|
-
|
|
|
-#### Testing
|
|
|
-
|
|
|
-Logrus has a built in facility for asserting the presence of log messages. This is implemented through the `test` hook and provides:
|
|
|
-
|
|
|
-* decorators for existing logger (`test.NewLocal` and `test.NewGlobal`) which basically just add the `test` hook
|
|
|
-* a test logger (`test.NewNullLogger`) that just records log messages (and does not output any):
|
|
|
-
|
|
|
-```go
|
|
|
-import(
|
|
|
- "github.com/sirupsen/logrus"
|
|
|
- "github.com/sirupsen/logrus/hooks/test"
|
|
|
- "github.com/stretchr/testify/assert"
|
|
|
- "testing"
|
|
|
-)
|
|
|
-
|
|
|
-func TestSomething(t*testing.T){
|
|
|
- logger, hook := test.NewNullLogger()
|
|
|
- logger.Error("Helloerror")
|
|
|
-
|
|
|
- assert.Equal(t, 1, len(hook.Entries))
|
|
|
- assert.Equal(t, logrus.ErrorLevel, hook.LastEntry().Level)
|
|
|
- assert.Equal(t, "Helloerror", hook.LastEntry().Message)
|
|
|
-
|
|
|
- hook.Reset()
|
|
|
- assert.Nil(t, hook.LastEntry())
|
|
|
-}
|
|
|
-```
|
|
|
-
|
|
|
-#### Fatal handlers
|
|
|
-
|
|
|
-Logrus can register one or more functions that will be called when any `fatal`
|
|
|
-level message is logged. The registered handlers will be executed before
|
|
|
-logrus performs a `os.Exit(1)`. This behavior may be helpful if callers need
|
|
|
-to gracefully shutdown. Unlike a `panic("Something went wrong...")` call which can be intercepted with a deferred `recover` a call to `os.Exit(1)` can not be intercepted.
|
|
|
-
|
|
|
-```
|
|
|
-...
|
|
|
-handler := func() {
|
|
|
- // gracefully shutdown something...
|
|
|
-}
|
|
|
-logrus.RegisterExitHandler(handler)
|
|
|
-...
|
|
|
-```
|
|
|
-
|
|
|
-#### Thread safety
|
|
|
-
|
|
|
-By default Logger is protected by mutex for concurrent writes, this mutex is invoked when calling hooks and writing logs.
|
|
|
-If you are sure such locking is not needed, you can call logger.SetNoLock() to disable the locking.
|
|
|
-
|
|
|
-Situation when locking is not needed includes:
|
|
|
-
|
|
|
-* You have no hooks registered, or hooks calling is already thread-safe.
|
|
|
-
|
|
|
-* Writing to logger.Out is already thread-safe, for example:
|
|
|
-
|
|
|
- 1) logger.Out is protected by locks.
|
|
|
-
|
|
|
- 2) logger.Out is a os.File handler opened with `O_APPEND` flag, and every write is smaller than 4k. (This allow multi-thread/multi-process writing)
|
|
|
-
|
|
|
- (Refer to http://www.notthewizard.com/2014/06/17/are-files-appends-really-atomic/)
|
Jackson Tian