Linux sysadmin notes dump

diagnosing an app running on docker containers

Check a local connection with an HTTP header and time out after 60 seconds.

$ curl -v --max-time 60 http://127.0.0.1:9890/ -H "Host: bitwarden.han.com"
*   Trying 127.0.0.1:9890...
* Established connection to 127.0.0.1 (127.0.0.1 port 9890) from 127.0.0.1 port 47858
* using HTTP/1.x
> GET / HTTP/1.1
> Host: bitwarden.han.com
> User-Agent: curl/8.17.0
> Accept: */*
>
* Request completely sent off
* Operation timed out after 60002 milliseconds with 0 bytes received
* closing connection #0
curl: (28) Operation timed out after 60002 milliseconds with 0 bytes received

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Reset all of Docker state including containers, images, volumes, and networks.

$ sudo systemctl stop docker
$ docker network prune -f
$ docker system prune -a -f --volumes
$ sudo systemctl start docker

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Stop all currently running Docker containers

$ docker stop $(docker ps -q)

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