Pre-Flight Checks

Docker

Let’s check to make sure docker and other components are installed and working correctly. First, check to make sure docker is installed.

1docker --version

You should see the installed Docker Engine or Docker Desktop version.

Docker version <current>, build <hash>

Now, let’s make sure we are able to run the busybox container.

docker run busybox echo "hello, world!"

The command above simply echos hello, world! back to the console.

Swarm

Initialization

Initialize swarm.

1docker swarm init

You should see an output as follows.

Swarm initialized: current node (muo6bizx5z19kny0gswqm8jq4) is now a manager.

To add a worker to this swarm, run the following command:

    docker swarm join --token SWMTKN-1-3qo8eradxo3oy2tjzc0odurhumk4nlpt9eoeg2gq5dwl2sh88o-bc6fpa8qeh5bsn3l0kdfip2qf 10.0.2.15:2377

To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

Service creation

Now let’s create a toy service. This service uses the current alpine container to ping the Google domain name server 8.8.8.8.

docker service create --name demo alpine:latest ping 8.8.8.8

The output should look like the following.

av2o3juacixl7zwr36wd10zzg
overall progress: 1 out of 1 tasks
1/1: running
verify: Service converged

To see which services are running.

docker service ps demo

To see the logs of a service.

docker service logs demo

To stop the service.

docker service rm demo