How to check if docker is running or not

Question

I am new to docker. I am writing a simple script for docker. I need to check whether docker is running or not. Is there a command to check with container name

Answer 1

Sometimes you don't know the full container name, in this case this is what worked for me:

if [ $(docker ps | grep keyword | wc -l) -gt 0 ]
then 
    echo "Running!"
else
    echo "Not running!"
    exit 1
fi

We list all the running container processes (docker ps -a would show us also not running ones, but that's not what I needed), we search for a specific word (grep part) and simply count the lines of the result (wc -l), if it's greater than 0 it means we found some running containers which names contain our keyword.

Answer 2

List all containers:

docker container ls -a

ls = list
-a = all

Check the column "status"

Answer 3

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

Answer 4

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 5

For OS X users (Mojave 10.14.3)

Here is what i use in my Bash script to test if Docker is running or not

# Check if docker is running
docker_state=$(docker info >/dev/null 2>&1)
if [[ $? -ne 0 ]]; then
    echo "Docker does not seem to be running, run it first and retry"
    exit 1
fi

Answer 6

You can check with this command systemctl status docker it will show the status of the docker. If you want to start you can use systemctl start docker instead of systemctl you can try also with service, service docker status and service docker start respectively.