Docker Image
This article explains how to use the official Fluentd Docker image, maintained by Treasure Data, Inc.
Please download and install Docker from here:
Then, download Fluentd edge-debian's (edge-debian means latest version of Fluentd) image by docker pull command:
$ docker pull fluent/fluentd:edge-debian
Debian and Alpine Linux version is available for Fluentd image. Debian version is recommended officially since it has jemalloc support. However, the Alpine image is smaller.
To make the test simple, create the example config below at $(pwd)/tmp/fluentd.conf. This example accepts records from http, and outputs to stdout.
# $(pwd)/tmp/fluentd.conf<source>@type httpport 9880bind 0.0.0.0</source><match **>@type stdout</match>
Finally, you can run Fluentd with docker run command:
$ docker run -p 9880:9880 -v $(pwd)/tmp:/fluentd/etc fluent/fluentd:edge-debian -c /fluentd/etc/fluentd.conf2021-03-16 09:11:32 +0000 [info]: parsing config file is succeeded path="/fluentd/etc/fluentd.conf"2021-03-16 09:11:32 +0000 [info]: gem 'fluentd' version '1.11.5'2021-03-16 09:11:32 +0000 [warn]: define <match fluent.**> to capture fluentd logs in top level is deprecated. Use <label @FLUENT_LOG> instead2021-03-16 09:11:32 +0000 [info]: using configuration file: <ROOT><source>@type httpport 9880bind "0.0.0.0"</source><match **>@type stdout</match></ROOT>2021-03-16 09:11:32 +0000 [info]: starting fluentd-1.11.5 pid=7 ruby="2.6.6"2021-03-16 09:11:32 +0000 [info]: spawn command to main: cmdline=["/usr/local/bin/ruby", "-Eascii-8bit:ascii-8bit", "/usr/local/bundle/bin/fluentd", "-c", "/fluentd/etc/fluentd.conf", "-p", "/fluentd/plugins", "--under-supervisor"]2021-03-16 09:11:33 +0000 [info]: adding match pattern="**" type="stdout"2021-03-16 09:11:33 +0000 [info]: adding source type="http"2021-03-16 09:11:33 +0000 [warn]: #0 define <match fluent.**> to capture fluentd logs in top level is deprecated. Use <label @FLUENT_LOG> instead2021-03-16 09:11:33 +0000 [info]: #0 starting fluentd worker pid=16 ppid=7 worker=02021-03-16 09:11:33 +0000 [info]: #0 fluentd worker is now running worker=02021-03-16 09:11:33.025408358 +0000 fluent.info: {"pid":16,"ppid":7,"worker":0,"message":"starting fluentd worker pid=16 ppid=7 worker=0"}2021-03-16 09:11:33.026503372 +0000 fluent.info: {"worker":0,"message":"fluentd worker is now running worker=0"}
Use curl command to post sample logs via HTTP like this:
$ curl -X POST -d 'json={"json":"message"}' http://127.0.0.1:9880/sample.test
Use docker ps command to retrieve container ID and use docker logs command to check the specific container's log like this:
$ docker ps -aCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES775a8e192f2b fluent/fluentd:edge-debian "tini -- /bin/entryp…" About a minute ago Up About a minute 5140/tcp, 24224/tcp, 0.0.0.0:9880->9880/tcp tender_leakey$ docker logs 775a8e192f2b | tail -n 12021-03-16 09:12:15.257351750 +0000 sample.test: {"json":"message"}
Now, you know how to use Fluentd via Docker.
Here are some Docker related resources for Fluentd:
Also, refer to the following tutorials to learn how to collect data from various data sources:
Basic Configuration
If this article is incorrect or outdated, or omits critical information, please let us know. Fluentd is an open-source project under Cloud Native Computing Foundation (CNCF). All components are available under the Apache 2 License.
