mirror of https://github.com/status-im/timbre.git
303 lines
14 KiB
Markdown
303 lines
14 KiB
Markdown
**[API docs][]** | **[CHANGELOG][]** | [other Clojure libs][] | [Twitter][] | [contact/contrib](#contact--contributing) | current [Break Version][]:
|
|
|
|
```clojure
|
|
[com.taoensso/timbre "3.4.0"]
|
|
```
|
|
|
|
# Timbre, a (sane) Clojure logging & profiling library
|
|
|
|
Logging with Java can be maddeningly, unnecessarily hard. Particularly if all you want is something *simple that works out-the-box*. Timbre brings functional, Clojure-y goodness to all your logging needs. **No XML!**
|
|
|
|
## What's in the box™?
|
|
* [Logs as Clojure values](https://github.com/ptaoussanis/timbre/tree/dev#redis-carmine-appender-v3) (v3+).
|
|
* Small, uncomplicated **all-Clojure** library.
|
|
* **Super-simple map-based config**: no arcane XML or properties files!
|
|
* **Low overhead** with dynamic logging level.
|
|
* **No overhead** with compile-time logging level. (v2.6+)
|
|
* Flexible **fn-centric appender model** with **middleware**.
|
|
* Sensible built-in appenders including simple **email appender**.
|
|
* Tunable **rate limit** and **asynchronous** logging support.
|
|
* Robust **namespace filtering**.
|
|
* [tools.logging](https://github.com/clojure/tools.logging) support (optional, useful when integrating with legacy logging systems).
|
|
* Dead-simple, logging-level-aware **logging profiler**.
|
|
|
|
## 3rd-party tools, appenders, etc.
|
|
* [log-config](https://github.com/palletops/log-config) by [Hugo Duncan](https://github.com/hugoduncan) - library to help manage Timbre logging config.
|
|
* Suggestions welcome!
|
|
|
|
## Getting started
|
|
|
|
### Dependencies
|
|
|
|
Add the necessary dependency to your [Leiningen][] `project.clj` and use the supplied ns-import helper:
|
|
|
|
```clojure
|
|
[com.taoensso/timbre "3.4.0"] ; project.clj
|
|
|
|
(ns my-app (:require [taoensso.timbre :as timbre])) ; Your ns
|
|
(timbre/refer-timbre) ; Provides useful Timbre aliases in this ns
|
|
```
|
|
|
|
The `refer-timbre` call is a convenience fn that executes:
|
|
```clojure
|
|
(require '[taoensso.timbre :as timbre
|
|
:refer (log trace debug info warn error fatal report
|
|
logf tracef debugf infof warnf errorf fatalf reportf
|
|
spy logged-future with-log-level with-logging-config
|
|
sometimes)])
|
|
(require '[taoensso.timbre.profiling :as profiling
|
|
:refer (pspy pspy* profile defnp p p*)])
|
|
```
|
|
|
|
### Logging
|
|
|
|
By default, Timbre gives you basic print output to `*out*`/`*err*` at a `debug` logging level:
|
|
|
|
```clojure
|
|
(info "This will print") => nil
|
|
%> 2012-May-28 17:26:11:444 +0700 localhost INFO [my-app] - This will print
|
|
|
|
(spy :info (* 5 4 3 2 1)) => 120
|
|
%> 2012-May-28 17:26:14:138 +0700 localhost INFO [my-app] - (* 5 4 3 2 1) 120
|
|
|
|
(trace "This won't print due to insufficient logging level") => nil
|
|
```
|
|
|
|
First-argument exceptions generate a nicely cleaned-up stack trace using [io.aviso.exception](https://github.com/AvisoNovate/pretty):
|
|
|
|
```clojure
|
|
(info (Exception. "Oh noes") "arg1" "arg2")
|
|
%> 2012-May-28 17:35:16:132 +0700 localhost INFO [my-app] - arg1 arg2
|
|
java.lang.Exception: Oh noes
|
|
NO_SOURCE_FILE:1 my-app/eval6409
|
|
Compiler.java:6511 clojure.lang.Compiler.eval
|
|
<...>
|
|
```
|
|
|
|
### Configuration
|
|
|
|
This is the biggest win over Java logging utilities IMO. Here's `timbre/example-config` (also Timbre's default config):
|
|
|
|
```clojure
|
|
(def example-config
|
|
"APPENDERS
|
|
An appender is a map with keys:
|
|
:doc ; (Optional) string.
|
|
:min-level ; (Optional) keyword, or nil (no minimum level).
|
|
:enabled? ; (Optional).
|
|
:async? ; (Optional) dispatch using agent (good for slow appenders).
|
|
:rate-limit ; (Optional) [ncalls-limit window-ms].
|
|
:fmt-output-opts ; (Optional) extra opts passed to `fmt-output-fn`.
|
|
:fn ; (fn [appender-args-map]), with keys described below.
|
|
|
|
An appender's fn takes a single map with keys:
|
|
:level ; Keyword.
|
|
:error? ; Is level an 'error' level?.
|
|
:throwable ; java.lang.Throwable.
|
|
:args ; Raw logging macro args (as given to `info`, etc.).
|
|
:message ; Stringified logging macro args, or nil.
|
|
:output ; Output of `fmt-output-fn`, used by built-in appenders
|
|
; as final, formatted appender output. Appenders may (but
|
|
; are not obligated to) use this as their output.
|
|
:ap-config ; Contents of config's :shared-appender-config key.
|
|
:profile-stats ; From `profile` macro.
|
|
:instant ; java.util.Date.
|
|
:timestamp ; String generated from :timestamp-pattern, :timestamp-locale.
|
|
:hostname ; String.
|
|
:ns ; String.
|
|
;; Waiting on http://dev.clojure.org/jira/browse/CLJ-865:
|
|
:file ; String.
|
|
:line ; Integer.
|
|
|
|
MIDDLEWARE
|
|
Middleware are fns (applied right-to-left) that transform the map
|
|
dispatched to appender fns. If any middleware returns nil, no dispatching
|
|
will occur (i.e. the event will be filtered).
|
|
|
|
The `example-config` code contains further settings and details.
|
|
See also `set-config!`, `merge-config!`, `set-level!`."
|
|
|
|
{;;; Control log filtering by namespace patterns (e.g. ["my-app.*"]).
|
|
;;; Useful for turning off logging in noisy libraries, etc.
|
|
:ns-whitelist []
|
|
:ns-blacklist []
|
|
|
|
;; Fns (applied right-to-left) to transform/filter appender fn args.
|
|
;; Useful for obfuscating credentials, pattern filtering, etc.
|
|
:middleware []
|
|
|
|
;;; Control :timestamp format
|
|
:timestamp-pattern "yyyy-MMM-dd HH:mm:ss ZZ" ; SimpleDateFormat pattern
|
|
:timestamp-locale nil ; A Locale object, or nil
|
|
|
|
;; Output formatter used by built-in appenders. Custom appenders may (but are
|
|
;; not required to use) its output (:output). Extra per-appender opts can be
|
|
;; supplied as an optional second (map) arg.
|
|
:fmt-output-fn
|
|
(fn [{:keys [level throwable message timestamp hostname ns]}
|
|
;; Any extra appender-specific opts:
|
|
& [{:keys [nofonts?] :as appender-fmt-output-opts}]]
|
|
;; <timestamp> <hostname> <LEVEL> [<ns>] - <message> <throwable>
|
|
(format "%s %s %s [%s] - %s%s"
|
|
timestamp hostname (-> level name str/upper-case) ns (or message "")
|
|
(or (stacktrace throwable "\n" (when nofonts? {})) "")))
|
|
|
|
:shared-appender-config {} ; Provided to all appenders via :ap-config key
|
|
:appenders
|
|
{:standard-out
|
|
{:doc "Prints to *out*/*err*. Enabled by default."
|
|
:min-level nil :enabled? true :async? false :rate-limit nil
|
|
:fn (fn [{:keys [error? output]}] ; Use any appender args
|
|
(binding [*out* (if error? *err* *out*)]
|
|
(str-println output)))}
|
|
|
|
:spit
|
|
{:doc "Spits to `(:spit-filename :shared-appender-config)` file."
|
|
:min-level nil :enabled? false :async? false :rate-limit nil
|
|
:fn (fn [{:keys [ap-config output]}] ; Use any appender args
|
|
(when-let [filename (:spit-filename ap-config)]
|
|
(try (spit filename output :append true)
|
|
(catch java.io.IOException _))))}}})
|
|
```
|
|
|
|
A few things to note:
|
|
|
|
* Appenders are trivial to write & configure - **they're just fns**. It's Timbre's job to dispatch useful args to appenders when appropriate, it's their job to do something interesting with them.
|
|
* Being 'just fns', appenders have basically limitless potential: write to your database, send a message over the network, check some other state (e.g. environment config) before making a choice, etc.
|
|
|
|
The **logging level** may be set:
|
|
* At compile-time: (`TIMBRE_LOG_LEVEL` environment variable).
|
|
* Via an atom: `(timbre/set-level! <level>)`. (Usual method).
|
|
* Via dynamic thread-level binding: `(timbre/with-log-level <level> ...)`.
|
|
|
|
A compile-time level offers _zero-overhead_ performance since it'll cause insufficient logging calls to disappear completely at compile-time. Usually you won't need/want to bother: Timbre offers very decent performance with runtime level checks (~15msecs/10k checks on my Macbook Air).
|
|
|
|
For common-case ease-of-use, **all logging utils use a global atom for their config**. This is configurable with `timbre/set-config!`, `timbre/merge-config!`. The lower-level `log` and `logf` macros also take an optional first-arg config map for greater flexibility (e.g. **during testing**).
|
|
|
|
### Built-in appenders
|
|
|
|
#### Redis ([Carmine](https://github.com/ptaoussanis/carmine)) appender (v3+)
|
|
|
|
```clojure
|
|
;; [com.taoensso/carmine "2.4.0"] ; Add to project.clj deps
|
|
;; (:require [taoensso.timbre.appenders (carmine :as car-appender)]) ; Add to ns
|
|
|
|
(timbre/set-config! [:appenders :carmine] (car-appender/make-carmine-appender))
|
|
```
|
|
|
|
This gives us a high-performance Redis appender:
|
|
* **All raw logging args are preserved** in serialized form (**even Throwables!**).
|
|
* Only the most recent instance of each **unique entry** is kept (hash fn used to determine uniqueness is configurable).
|
|
* Configurable number of entries to keep per logging level.
|
|
* **Log is just a value**: a vector of Clojure maps: **query+manipulate with standard seq fns**: group-by hostname, sort/filter by ns & severity, explore exception stacktraces, filter by raw arguments, etc. **Datomic and `core.logic`** also offer interesting opportunities here.
|
|
|
|
A simple query utility is provided: `car-appender/query-entries`.
|
|
|
|
#### Email ([Postal](https://github.com/drewr/postal)) appender
|
|
|
|
```clojure
|
|
;; [com.draines/postal "1.9.2"] ; Add to project.clj deps
|
|
;; (:require [taoensso.timbre.appenders (postal :as postal-appender)]) ; Add to ns
|
|
|
|
(timbre/set-config! [:appenders :postal]
|
|
(postal-appender/make-postal-appender
|
|
{:enabled? true
|
|
:rate-limit [1 60000] ; 1 msg / 60,000 msecs (1 min)
|
|
:async? true ; Don't block waiting for email to send
|
|
}
|
|
{:postal-config
|
|
^{:host "mail.isp.net" :user "jsmith" :pass "sekrat!!1"}
|
|
{:from "me@draines.com" :to "foo@example.com"}}))
|
|
```
|
|
|
|
#### File appender
|
|
|
|
```clojure
|
|
(timbre/set-config! [:appenders :spit :enabled?] true)
|
|
(timbre/set-config! [:shared-appender-config :spit-filename] "/path/my-file.log")
|
|
```
|
|
|
|
#### Other included appenders
|
|
|
|
A number of 3rd-party appenders are included out-the-box for: Android, IRC, sockets, MongoDB, and rotating files. These are all located in the `taoensso.timbre.appenders.x` namespaces - **please see the relevant docstrings for details**.
|
|
|
|
Thanks to their respective authors! Just give me a shout if you've got an appender you'd like to have added.
|
|
|
|
## Profiling
|
|
|
|
The usual recommendation for Clojure profiling is: use a good **JVM profiler** like [YourKit](http://www.yourkit.com/), [JProfiler](http://www.ej-technologies.com/products/jprofiler/overview.html), or [VisualVM](http://docs.oracle.com/javase/6/docs/technotes/guides/visualvm/index.html).
|
|
|
|
And these certainly do the job. But as with many Java tools, they can be a little hairy and often heavy-handed - especially when applied to Clojure. Timbre includes an alternative.
|
|
|
|
Wrap forms that you'd like to profile with the `p` macro and give them a name:
|
|
|
|
```clojure
|
|
(defn my-fn
|
|
[]
|
|
(let [nums (vec (range 1000))]
|
|
(+ (p :fast-sleep (Thread/sleep 1) 10)
|
|
(p :slow-sleep (Thread/sleep 2) 32)
|
|
(p :add (reduce + nums))
|
|
(p :sub (reduce - nums))
|
|
(p :mult (reduce * nums))
|
|
(p :div (reduce / nums)))))
|
|
|
|
(my-fn) => 42
|
|
```
|
|
|
|
The `profile` macro can now be used to log times for any wrapped forms:
|
|
|
|
```clojure
|
|
(profile :info :Arithmetic (dotimes [n 100] (my-fn))) => "Done!"
|
|
%> 2012-Jul-03 20:46:17 +0700 localhost INFO [my-app] - Profiling my-app/Arithmetic
|
|
Name Calls Min Max MAD Mean Total% Total
|
|
my-app/slow-sleep 100 2ms 2ms 31μs 2ms 57 231ms
|
|
my-app/fast-sleep 100 1ms 1ms 27μs 1ms 29 118ms
|
|
my-app/add 100 44μs 2ms 46μs 100μs 2 10ms
|
|
my-app/sub 100 42μs 564μs 26μs 72μs 2 7ms
|
|
my-app/div 100 54μs 191μs 17μs 71μs 2 7ms
|
|
my-app/mult 100 31μs 165μs 11μs 44μs 1 4ms
|
|
Unaccounted 6 26ms
|
|
Total 100 405ms
|
|
```
|
|
|
|
You can also use the `defnp` macro to conveniently wrap whole fns.
|
|
|
|
It's important to note that Timbre profiling is fully **logging-level aware**: if the level is insufficient, you *won't pay for profiling* (there is a minimal dynamic-var deref cost). Likewise, normal namespace filtering applies. (Performance characteristics for both checks are inherited from Timbre itself).
|
|
|
|
And since `p` and `profile` **always return their body's result** regardless of whether profiling actually happens or not, it becomes feasible to use profiling more often as part of your normal workflow: just *leave profiling code in production as you do for logging code*.
|
|
|
|
A simple **sampling profiler** is also available: `taoensso.timbre.profiling/sampling-profile`.
|
|
|
|
## This project supports the CDS and  goals
|
|
|
|
* [CDS][], the **Clojure Documentation Site**, is a **contributer-friendly** community project aimed at producing top-notch, **beginner-friendly** Clojure tutorials and documentation. Awesome resource.
|
|
|
|
* [ClojureWerkz][] is a growing collection of open-source, **batteries-included Clojure libraries** that emphasise modern targets, great documentation, and thorough testing. They've got a ton of great stuff, check 'em out!
|
|
|
|
## Contact & contributing
|
|
|
|
`lein start-dev` to get a (headless) development repl that you can connect to with [Cider][] (Emacs) or your IDE.
|
|
|
|
Please use the project's GitHub [issues page][] for project questions/comments/suggestions/whatever **(pull requests welcome!)**. Am very open to ideas if you have any!
|
|
|
|
Otherwise reach me (Peter Taoussanis) at [taoensso.com][] or on [Twitter][]. Cheers!
|
|
|
|
## License
|
|
|
|
Copyright © 2012-2014 Peter Taoussanis. Distributed under the [Eclipse Public License][], the same as Clojure.
|
|
|
|
|
|
[API docs]: http://ptaoussanis.github.io/timbre/
|
|
[CHANGELOG]: https://github.com/ptaoussanis/timbre/releases
|
|
[other Clojure libs]: https://www.taoensso.com/clojure
|
|
[taoensso.com]: https://www.taoensso.com
|
|
[Twitter]: https://twitter.com/ptaoussanis
|
|
[issues page]: https://github.com/ptaoussanis/timbre/issues
|
|
[commit history]: https://github.com/ptaoussanis/timbre/commits/master
|
|
[Break Version]: https://github.com/ptaoussanis/encore/blob/master/BREAK-VERSIONING.md
|
|
[Leiningen]: http://leiningen.org/
|
|
[Cider]: https://github.com/clojure-emacs/cider
|
|
[CDS]: http://clojure-doc.org/
|
|
[ClojureWerkz]: http://clojurewerkz.org/
|
|
[Eclipse Public License]: https://raw2.github.com/ptaoussanis/timbre/master/LICENSE |