For Docker overview and setup docker locally refer Setup-Docker-and-build-docker-image. In this post I will spawn a container(with an image built in this post) and will run most commonly used docker commands like starting a container, stopping/removing container and publish images to remote repository.
1. List all locally stored images
n0r0082@m-c02z31rnlvdt ~ % docker images REPOSITORY TAG IMAGE ID CREATED SIZE nodejsapp latest 25b6a2a39b88 17 hours ago 993MB zytham/nodejsapp latest 25b6a2a39b88 17 hours ago 993MB busybox latest beae173ccac6 4 weeks ago 1.24MB
2. Running the container image - run a new container
n0r0082@m-c02z31rnlvdt ~ % docker run --name nodeapp-container -p 8080:8080 -d nodejsapp 15d4656ca3571431b39080b68757f26a698cab34e78797627b4852247353ba5c
- Above command tells Docker to run a new container called nodeapp-container from the nodejsapp image.
- The container will be detached from the console (-d flag), which means it will run in the background.
- Port 8080 on the local machine will be mapped to port 8080 inside the container (-p 8080:8080 option)
3. List of all running containers
n0r0082@m-c02z31rnlvdt ~ % docker ps CONTAINER ID IMAGE COMMAND CREATED ... STATUS PORTS NAMES 15d4656ca357 nodejsapp "node app.js" ... 3 minutes ago Up 3 minutes 0.0.0.0:8080->8080/tcp, :::8080->8080/tcp nodeapp-container
4. List of all active and Inactive containers
n0r0082@m-c02z31rnlvdt ~ % docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 15d4656ca357 nodejsapp "node app.js" 4 minutes ago Up 4 minutes 0.0.0.0:8080->8080/tcp, :::8080->8080/tcp nodeapp-container 7a14bc1d20aa zytham/nodejsapp "node app.js" 12 hours ago Exited (137) 12 hours ago laughing_faraday f88dc3ad15fb busybox "echo 'Hello world'" 21 hours ago Exited (0) 21 hours ago modest_galois
- with "-a" option we can see all inactive containers.
5. Get additional details a running container:
n0r0082@m-c02z31rnlvdt ~ % docker inspect nodeapp-container
[
{
"Id": "15d4656ca3571431b39080b68757f26a698cab34e78797627b4852247353ba5c",
"Created": "2022-01-30T12:48:20.3601401Z",
"Path": "node",
"Args": [
"app.js"
],
"State": {
"Status": "running",
"Running": true,
"Paused": false,
"Restarting": false,
"OOMKilled": false,
"Dead": false,
"Pid": 2824,
"ExitCode": 0,
"Error": "",
"StartedAt": "2022-01-30T12:48:20.7424185Z",
"FinishedAt": "0001-01-01T00:00:00Z"
},
"Image": "sha256:25b6a2a39b887274d463589aabff2428bb5fbed3be3126a6057b4561fad93178",
...
...
"LogPath": "......-json.log",
"Name": "/nodeapp-container",
"RestartCount": 0,
"Driver": "overlay2",
"Platform": "linux",
...
"HostConfig": {
"Binds": null,
"ContainerIDFile": "",
"LogConfig": {
"Type": "json-file",
"Config": {}
},
"NetworkMode": "default",
"PortBindings": {
"8080/tcp": [
{
"HostIp": "",
"HostPort": "8080"
}
]
},
...
....
},
"GraphDriver": {
"Data": {
...
},
"Name": "overlay2"
},
"Mounts": [],
"Config": {
"Hostname": "15d4656ca357",
"Domainname": "",
"User": "",
...
"ExposedPorts": {
"8080/tcp": {}
},
....
},
"NetworkSettings": {
"Bridge": "",
"SandboxID": "e51097e9d2d54fcc30d97452926dd5e79dc7df3b1c0e8434b92fe92857aaf8eb",
"HairpinMode": false,
"LinkLocalIPv6Address": "",
"LinkLocalIPv6PrefixLen": 0,
"Ports": {
"8080/tcp": [
{
"HostIp": "0.0.0.0",
"HostPort": "8080"
},
{
"HostIp": "::",
"HostPort": "8080"
}
]
},
..
"MacAddress": "02:42:ac:11:00:02",
"Networks": {
"bridge": {
"IPAMConfig": null,
"Links": null,
"Aliases": null,
"NetworkID": "7e67c344180d1bfe713c168fc80c06284e07f39329ea140a1cdd1610be2e72a9",
"EndpointID": "2a8a3cf1046ecbc0f9c5b3eefaf252a2526a84a126b362237b10756055e2e9ee",
"Gateway": "172.17.0.1",
"IPAddress": "172.17.0.2"
....
}
}
}
}
]
6. Running a shell inside an existing container:
In order to explore environment details inside container, we need a bash shell in container. Running docker container internals explains in detail how to open a bash terminal in container and run commands inside it.
7. Stopping a container:
n0r0082@m-c02z31rnlvdt ~ % docker stop nodeapp-container nodeapp-container
- To stop running app or container, above command tells Docker to stop the nodeapp-container container.
- It will stop the main process running in the container and consequently stop the container. At this point we have stopped container but the container itself still exists and we can see it with command "docker ps -a"
n0r0082@m-c02z31rnlvdt ~ % docker stop nodeapp-container nodeapp-container n0r0082@m-c02z31rnlvdt ~ % docker ps -a CONTAINER ID IMAGE COMMAND CREATED .. STATUS PORTS NAMES 15d4656ca357 nodejsapp "node app.js" 28 minutes ago ... Exited (137) 4 minutes ago nodeapp-container 7a14bc1d20aa zytham/nodejsapp "node app.js" 13 hours ago ... Exited (137) 12 hours ago laughing_faraday f88dc3ad15fb busybox "echo 'Hello world'" 22 hours ago ... Exited (0) 22 hours ago modest_galois
8. Removing a container:
n0r0082@m-c02z31rnlvdt ~ % docker rm nodeapp-container
nodeapp-container
n0r0082@m-c02z31rnlvdt ~ % docker ps -a
CONTAINER ID IMAGE COMMAND CREATED
... STATUS PORTS NAMES
7a14bc1d20aa zytham/nodejsapp "node app.js"
.... 13 hours ago Exited (137) 13 hours ago laughing_faraday
f88dc3ad15fb busybox "echo 'Hello world'"
.... 22 hours ago Exited (0) 22 hours ago modest_galois
n0r0082@m-c02z31rnlvdt ~ %
- With command "rm" container is removed.
- With "ps -a" we can see its not listing as inactive container.
9. Pushing the image to an image registry
Setup-Docker-and-build-docker-image explains in details how to publish locally created image to remote repository.10. Build container image(docker image):
Container images are composed of layers, which can be shared and reused across multiple images.
Setup-Docker-and-build-docker-image explains in details how to create container image from scratch and use it spawn container.
Reference: Kubernetes in Action By Marko Lukša