How to colorize logs for docker container

Question

I have container which in logs sometimes write key word which is for me important, and I want to highlight this word in color in my terminal, but also important is still see all content logs in real time (--follow). I just tried command

docker logs -f my_app --tail=100 | grep --color -E '^myWord'

but not working.

So exist some way to do this ?

Can you be more specific about "not working"? You might also be interested in this one: https://stackoverflow.com/questions/7161821/how-to-grep-a-continuous-stream — gesellix, Sep 02 '17 at 15:10
after execute above command I see only cursor event in logs will appire keyWord — Mbded, Sep 03 '17 at 08:36

spiilmusic · Answer 1 · 2022-08-06T20:05:25.160

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I use ccze. as @aimless said, grc is the great utility also. It easy to install by sudo apt install ccze for debian/ubuntu-like OS

But if you want to colorize stderr, you need to redirect stderr output to stdout. For example:

docker logs -f my-app 2>&1 | ccze -m ansi

arg -m ansi helps if you want to scroll output normally

UPD: ccze can be very slow. If you encounter this, try running ccze with the nolookups option: ccze -o nolookups. originally answered - https://unix.stackexchange.com/a/461390/83391

edited Aug 06 '22 at 20:05

answered Jan 14 '19 at 14:27

spiilmusic

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Here is a function version of it `dockerlogscolor() { docker logs $@ 2>&1 | ccze -m ansi ; }` for easy usage: `dockerlogscolor -f my-app` – cya Sep 21 '21 at 22:32
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it's very slow. without `| ccze` logs are printed in a second. with it, I wait for minute or longer. it depends on logs amount. – naXa stands with Ukraine Aug 02 '22 at 10:37
@naXastandswithUkraine try with option `-o nolookups` – spiilmusic Aug 06 '22 at 19:59

score 10 · Answer 2 · answered Apr 13 '18 at 01:29

Try this.

docker logs -f my_app --tail=100 | grep --color=always -E '^myWord'

Note the "--color=always" argument.

Another option would be to use something like https://github.com/jlinoff/colorize. I wrote it to specifically address situations like this. For example it has the ability to specify different colors for each pattern (see the help for details).

Here is an example of how to use it for your case.

$ curl -L https://github.com/jlinoff/colorize/releases/download/v0.8.1/colorize-linux-amd64 --out colorize
$ chmod a+x colorize
$ ./colorize -h
$ docker logs -f my_app --tail=100 | ./colorize '^myWord'
$ # really make it standout.
$ docker logs -f my_app --tail=100 | ./colorize -c red+greenB+bold '^myWord'

score 1 · Answer 3 · answered Apr 13 '18 at 16:39

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try grc. Follow the instruction to install and just pipe the logs output:

docker logs -app | grc

answered Apr 13 '18 at 16:39

aimless

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Generic Colouriser 1.9 grc [options] command [args] Options:") -e --stderr redirect stderr. If this option is selected, do not automatically redirect stdout -s --stdout redirect stdout, even if -e is selected -c name --config=name use name as configuration file for grcat --colour=word word is one of: on, off, auto – Vladimir Nov 25 '20 at 08:09

How to colorize logs for docker container

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