How to check if the docker engine and a docker container are running?

Question

In a script, I need to check:

a) Is the docker engine running?
b) Given a container name, is that docker container running?

[the initial wording of this

Answer 1

List all containers:

docker container ls -a

ls = list
-a = all

Check the column "status"

Answer 2

I ended up using

docker info

to check with a bash script if docker engine is running.

Answer 3

You can also check if a particular docker container is running or not using following command:

docker inspect postgres | grep "Running"

This command will check if for example my postgres container is running or not and will return output as "Running": true

Hope this helps.

Answer 4

you can check docker state using: systemctl is-active docker

➜  ~  systemctl is-active docker
active

you can use it as:

➜  ~  if [ "$(systemctl is-active docker)" = "active" ]; then echo "is alive :)" ; fi
is alive :)

➜  ~  sudo systemctl stop docker

➜  ~  if [ "$(systemctl is-active docker)" = "active" ]; then echo "is alive :)" ; fi
 * empty response *

Answer 5

docker ps -a

You can see all docker containers whether it is alive or dead.

Answer 6

on a Mac you might see the image:

if you right click on the docker icon then you see:

alternatively:

docker ps

and

docker run hello-world