docker¶

podman

exec as other user (e.G. root)¶

with docker exec (where ac0 is the container id):

docker exec -it -u root ac0 sh

or with docker-compose (znc is the container name):

docker-compose exec -u root znc sh

docker logs¶

the default json log can become pretty large if you're running a container for weeks. there are multiple options for logging, to simply use syslog globally for all containers:

create or edit /etc/docker/daemon.json:

{
  "log-driver": "syslog"
}

or like this:

{
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "10m",
    "max-file": "3"
  }
}

changes in the daemon.json only apply to new containers, not existing.

docker cleanup¶

get rid of exited containers:

docker rm $(docker ps -aq -f status=exited)

get rid of unused images:

docker rmi $(docker images -a|grep none|awk {'print $3'})

ipv6¶

this will never end

enable ipv6 in docker container¶

I just want my nginx or traefik container to be available from the outside, man. Since I couldn't find anything meaningful out there on the interwebs I assume something is dangerously wrong with my config, but it works.

docker-compose.yaml example (from mailcow):

networks:
  proxynet:
    name: awesomenet
    driver: bridge
    enable_ipv6: true
    ipam:
      driver: default
      config:
        - subnet: fd4d:6169:6c63:6f77::/64

more docker ipv6 stuff¶

this is for your /etc/docker/daemon.json file. it might not exist.

{
  "ipv6": true,
  "fixed-cidr-v6": "fd00:dead:beef:c0::/80",
  "experimental": true,
  "ip6tables": true
}