Home server, how to get all container logs forwarded to the host

General Discussions
1

I have a small home server, where I run about 8 containers. I don’t use docker-compose, I just run all containers using the docker run-command. So far so good; I can easily fetch (or tail) logs from inside the containers by doing this: docker logs -f <container-name>.

But now I want to go one step further: I want to have all the containers logs to be available on the host-system. And I can’t figure out how to do this. For example, take this docker run command:: docker run --name rogier alpine ping 127.0.0.1. The typical output of this container is this:

64 bytes from 127.0.0.1: seq=0 ttl=64 time=0.053 ms
64 bytes from 127.0.0.1: seq=1 ttl=64 time=0.133 ms
64 bytes from 127.0.0.1: seq=2 ttl=64 time=0.132 ms

Ideally, what I want now, is a file on the host (/var/log/containers/rogier) where all output from inside the container is stored. Is something like this possible?

2

With 8 containers, why not?

If all your containers are designed well and log to stdout you could simply redirect this output to logfiles.

3

Well, I don’t use compose because everything already works fine and -for some reason- I don’t like it :slight_smile:. And about redirecting to stdout; this indeed is possible, but this feels a bit “stupid” to me. Isn’t there a better solution?

I’m reading about logdrivers; now what if I do this:

docker run --rm=true --log-driver=syslog --log-opt syslog-address=tcp://:5000 --name rogier alpine ping 127.0.0.1

Will this do the same? As in: sending all containers logs (which usually go to stdout) to the remote syslog server (running on the host on :5000)?

4

You could write the logs to a file located in a mounted volume. Make sure those files don’t grow to large. For this, make sure you rotate the files maybe every 100MB. If you have a high rate of log output then this might not be a good solution specially running 8. You should clarify more about the nature of these logs and what you want to do with them.

Kf

5

Acualy, you can set the default logging driver in the daemon.json:

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