Docker: Instalasi di Ubuntu 22.04
Sumber: https://www.digitalocean.com/community/tutorials/how-to-install-and-use-docker-on-ubuntu-22-04
Step 1 Install Docker
sudo apt update sudo apt install apt-transport-https ca-certificates curl software-properties-common
Add GPG Key Docker Repo & Sources List
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt update
Pastikan instal dari docker repo bukan ubuntu repo
sudo apt install docker-ce apt-cache policy docker-ce
Output
docker-ce: Installed: 5:24.0.2-1~ubuntu.22.04~jammy Candidate: 5:24.0.2-1~ubuntu.22.04~jammy Version table: ...
Cek status
sudo systemctl status docker
Output
● docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: active (running) since Mon 2023-07-03 06:52:31 UTC; 1min 13s ago
TriggeredBy: ● docker.socket
Docs: https://docs.docker.com
Main PID: 4145 (dockerd)
Tasks: 10
Memory: 27.1M
CPU: 791ms
CGroup: /system.slice/docker.service
└─4145 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
Jul 03 06:52:23 server2204 systemd[1]: Starting Docker Application Container Engine...
Jul 03 06:52:23 server2204 dockerd[4145]: time="2023-07-03T06:52:23.888013536Z" level=info msg="Starting up"
Jul 03 06:52:23 server2204 dockerd[4145]: time="2023-07-03T06:52:23.889350329Z" level=info msg="detected 127.0.0.53 names>
Jul 03 06:52:26 server2204 dockerd[4145]: time="2023-07-03T06:52:26.571125282Z" level=info msg="Loading containers: start>
Jul 03 06:52:29 server2204 dockerd[4145]: time="2023-07-03T06:52:29.337682161Z" level=info msg="Loading containers: done."
Jul 03 06:52:29 server2204 dockerd[4145]: time="2023-07-03T06:52:29.802304747Z" level=info msg="Docker daemon" commit=659>
Jul 03 06:52:29 server2204 dockerd[4145]: time="2023-07-03T06:52:29.802663028Z" level=info msg="Daemon has completed init>
Jul 03 06:52:31 server2204 dockerd[4145]: time="2023-07-03T06:52:31.321360076Z" level=info msg="API listen on /run/docker>
Jul 03 06:52:31 server2204 systemd[1]: Started Docker Application Container Engine.
Step 2 — Executing the Docker Command Without Sudo (Optional)
By default, the docker command can only be run the root user or by a user in the docker group, which is automatically created during Docker’s installation process. If you attempt to run the docker command without prefixing it with sudo or without being in the docker group, you’ll get an output like this:
Output docker: Cannot connect to the Docker daemon. Is the docker daemon running on this host?. See 'docker run --help'. If you want to avoid typing sudo whenever you run the docker command, add your username to the docker group:
sudo usermod -aG docker ${USER} To apply the new group membership, log out of the server and back in, or type the following:
su - ${USER} You will be prompted to enter your user’s password to continue.
Confirm that your user is now added to the docker group by typing:
groups Output sammy sudo docker If you need to add a user to the docker group that you’re not logged in as, declare that username explicitly using:
sudo usermod -aG docker username The rest of this article assumes you are running the docker command as a user in the docker group. If you choose not to, please prepend the commands with sudo.
Let’s explore the docker command next.
Step 3 — Using the Docker Command
Using docker consists of passing it a chain of options and commands followed by arguments. The syntax takes this form:
docker [option] [command] [arguments]
To view all available subcommands, type:
docker
As of Docker version 20.10.14, the complete list of available subcommands includes:
Output
attach Attach local standard input, output, and error streams to a running container build Build an image from a Dockerfile commit Create a new image from a container's changes cp Copy files/folders between a container and the local filesystem create Create a new container diff Inspect changes to files or directories on a container's filesystem events Get real time events from the server exec Run a command in a running container export Export a container's filesystem as a tar archive history Show the history of an image images List images import Import the contents from a tarball to create a filesystem image info Display system-wide information inspect Return low-level information on Docker objects kill Kill one or more running containers load Load an image from a tar archive or STDIN login Log in to a Docker registry logout Log out from a Docker registry logs Fetch the logs of a container pause Pause all processes within one or more containers port List port mappings or a specific mapping for the container ps List containers pull Pull an image or a repository from a registry push Push an image or a repository to a registry rename Rename a container restart Restart one or more containers rm Remove one or more containers rmi Remove one or more images run Run a command in a new container save Save one or more images to a tar archive (streamed to STDOUT by default) search Search the Docker Hub for images start Start one or more stopped containers stats Display a live stream of container(s) resource usage statistics stop Stop one or more running containers tag Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE top Display the running processes of a container unpause Unpause all processes within one or more containers update Update configuration of one or more containers version Show the Docker version information wait Block until one or more containers stop, then print their exit codes
To view the options available to a specific command, type:
docker docker-subcommand --help
To view system-wide information about Docker, use:
docker info
Let’s explore some of these commands. We’ll start by working with images.
Step 4 — Working with Docker Images
Docker containers are built from Docker images. By default, Docker pulls these images from Docker Hub, a Docker registry managed by Docker, the company behind the Docker project. Anyone can host their Docker images on Docker Hub, so most applications and Linux distributions you’ll need will have images hosted there.
To check whether you can access and download images from Docker Hub, type:
docker run hello-world The output will indicate that Docker in working correctly:
Output Unable to find image 'hello-world:latest' locally latest: Pulling from library/hello-world 2db29710123e: Pull complete Digest: sha256:bfea6278a0a267fad2634554f4f0c6f31981eea41c553fdf5a83e95a41d40c38 Status: Downloaded newer image for hello-world:latest
Hello from Docker! This message shows that your installation appears to be working correctly.
...
Docker was initially unable to find the hello-world image locally, so it downloaded the image from Docker Hub, which is the default repository. Once the image downloaded, Docker created a container from the image and the application within the container executed, displaying the message.
You can search for images available on Docker Hub by using the docker command with the search subcommand. For example, to search for the Ubuntu image, type:
docker search ubuntu The script will crawl Docker Hub and return a listing of all images whose name matches the search string. In this case, the output will be similar to this:
Output NAME DESCRIPTION STARS OFFICIAL AUTOMATED ubuntu Ubuntu is a Debian-based Linux operating sys… 14048 [OK] websphere-liberty WebSphere Liberty multi-architecture images … 283 [OK] ubuntu-upstart DEPRECATED, as is Upstart (find other proces… 112 [OK] neurodebian NeuroDebian provides neuroscience research s… 88 [OK] open-liberty Open Liberty multi-architecture images based… 51 [OK] ...
In the OFFICIAL column, OK indicates an image built and supported by the company behind the project. Once you’ve identified the image that you would like to use, you can download it to your computer using the pull subcommand.
Execute the following command to download the official ubuntu image to your computer:
docker pull ubuntu You’ll see the following output:
Output Using default tag: latest latest: Pulling from library/ubuntu e0b25ef51634: Pull complete Digest: sha256:9101220a875cee98b016668342c489ff0674f247f6ca20dfc91b91c0f28581ae Status: Downloaded newer image for ubuntu:latest docker.io/library/ubuntu:latest After an image has been downloaded, you can then run a container using the downloaded image with the run subcommand. As you saw with the hello-world example, if an image has not been downloaded when docker is executed with the run subcommand, the Docker client will first download the image, then run a container using it.
To see the images that have been downloaded to your computer, type:
docker images The output will look similar to the following:
Output REPOSITORY TAG IMAGE ID CREATED SIZE ubuntu latest 1d622ef86b13 3 weeks ago 73.9MB hello-world latest bf756fb1ae65 4 months ago 13.3kB As you’ll see later in this tutorial, images that you use to run containers can be modified and used to generate new images, which may then be uploaded (pushed is the technical term) to Docker Hub or other Docker registries.
Let’s look at how to run containers in more detail.
Step 5 — Running a Docker Container
The hello-world container you ran in the previous step is an example of a container that runs and exits after emitting a test message. Containers can be much more useful than that, and they can be interactive. After all, they are similar to virtual machines, only more resource-friendly.
As an example, let’s run a container using the latest image of Ubuntu. The combination of the -i and -t switches gives you interactive shell access into the container:
docker run -it ubuntu
Your command prompt should change to reflect the fact that you’re now working inside the container and should take this form:
Output
root@d9b100f2f636:/#
Note the container id in the command prompt. In this example, it is d9b100f2f636. You’ll need that container ID later to identify the container when you want to remove it.
Now you can run any command inside the container. For example, let’s update the package database inside the container. You don’t need to prefix any command with sudo, because you’re operating inside the container as the root user:
apt update
Then install any application in it. Let’s install Node.js:
apt install nodejs
This installs Node.js in the container from the official Ubuntu repository. When the installation finishes, verify that Node.js is installed:
node -v
You’ll see the version number displayed in your terminal:
Output v12.22.9 Any changes you make inside the container only apply to that container.
To exit the container, type exit at the prompt.
Let’s look at managing the containers on our system next.
Step 6 — Managing Docker Containers
After using Docker for a while, you’ll have many active (running) and inactive containers on your computer. To view the active ones, use:
docker ps You will see output similar to the following:
Output CONTAINER ID IMAGE COMMAND CREATED
In this tutorial, you started two containers; one from the hello-world image and another from the ubuntu image. Both containers are no longer running, but they still exist on your system.
To view all containers — active and inactive, run docker ps with the -a switch:
docker ps -a You’ll see output similar to this:
Output CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 1c08a7a0d0e4 ubuntu "bash" About a minute ago Exited (0) 7 seconds ago dazzling_taussig 587000e49d53 hello-world "/hello" 5 minutes ago Exited (0) 5 minutes ago adoring_kowalevski To view the latest container you created, pass it the -l switch:
docker ps -l Output CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 1c08a7a0d0e4 ubuntu "bash" 3 minutes ago Exited (0) 2 minutes ago dazzling_taussig To start a stopped container, use docker start, followed by the container ID or the container’s name. Let’s start the Ubuntu-based container with the ID of 1c08a7a0d0e4:
docker start 1c08a7a0d0e4 The container will start, and you can use docker ps to see its status:
Output CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 1c08a7a0d0e4 ubuntu "bash" 6 minutes ago Up 8 seconds dazzling_taussig To stop a running container, use docker stop, followed by the container ID or name. This time, we’ll use the name that Docker assigned the container, which is dazzling_taussig:
docker stop dazzling_taussig Once you’ve decided you no longer need a container anymore, remove it with the docker rm command, again using either the container ID or the name. Use the docker ps -a command to find the container ID or name for the container associated with the hello-world image and remove it.
docker rm adoring_kowalevski You can start a new container and give it a name using the --name switch. You can also use the --rm switch to create a container that removes itself when it’s stopped. See the docker run help command for more information on these options and others.
Containers can be turned into images which you can use to build new containers. Let’s look at how that works.
Step 7 — Committing Changes in a Container to a Docker Image When you start up a Docker image, you can create, modify, and delete files just like you can with a virtual machine. The changes that you make will only apply to that container. You can start and stop it, but once you destroy it with the docker rm command, the changes will be lost for good.
This section shows you how to save the state of a container as a new Docker image.
After installing Node.js inside the Ubuntu container, you now have a container running off an image, but the container is different from the image you used to create it. But you might want to reuse this Node.js container as the basis for new images later.
Then commit the changes to a new Docker image instance using the following command.
docker commit -m "What you did to the image" -a "Author Name" container_id repository/new_image_name The -m switch is for the commit message that helps you and others know what changes you made, while -a is used to specify the author. The container_id is the one you noted earlier in the tutorial when you started the interactive Docker session. Unless you created additional repositories on Docker Hub, the repository is usually your Docker Hub username.
For example, for the user sammy, with the container ID of d9b100f2f636, the command would be:
docker commit -m "added Node.js" -a "sammy" d9b100f2f636 sammy/ubuntu-nodejs When you commit an image, the new image is saved locally on your computer. Later in this tutorial, you’ll learn how to push an image to a Docker registry like Docker Hub so others can access it.
Listing the Docker images again will show the new image, as well as the old one that it was derived from:
docker images You’ll see output like this:
Output REPOSITORY TAG IMAGE ID CREATED SIZE sammy/ubuntu-nodejs latest 7c1f35226ca6 7 seconds ago 179MB ...
In this example, ubuntu-nodejs is the new image, which was derived from the existing ubuntu image from Docker Hub. The size difference reflects the changes that were made. And in this example, the change was that NodeJS was installed. So next time you need to run a container using Ubuntu with NodeJS pre-installed, you can just use the new image.
You can also build Images from a Dockerfile, which lets you automate the installation of software in a new image. However, that’s outside the scope of this tutorial.
Now let’s share the new image with others so they can create containers from it.
Step 8 — Pushing Docker Images to a Docker Repository The next logical step after creating a new image from an existing image is to share it with a select few of your friends, the whole world on Docker Hub, or other Docker registry that you have access to. To push an image to Docker Hub or any other Docker registry, you must have an account there.
To push your image, first log into Docker Hub.
docker login -u docker-registry-username You’ll be prompted to authenticate using your Docker Hub password. If you specified the correct password, authentication should succeed.
Note: If your Docker registry username is different from the local username you used to create the image, you will have to tag your image with your registry username. For the example given in the last step, you would type:
docker tag sammy/ubuntu-nodejs docker-registry-username/ubuntu-nodejs Then you may push your own image using:
docker push docker-registry-username/docker-image-name To push the ubuntu-nodejs image to the sammy repository, the command would be:
docker push sammy/ubuntu-nodejs The process may take some time to complete as it uploads the images, but when completed, the output will look like this:
Output The push refers to a repository [docker.io/sammy/ubuntu-nodejs] e3fbbfb44187: Pushed 5f70bf18a086: Pushed a3b5c80a4eba: Pushed 7f18b442972b: Pushed 3ce512daaf78: Pushed 7aae4540b42d: Pushed
...
After pushing an image to a registry, it should be listed on your account’s dashboard, like that show in the image below.
New Docker image listing on Docker Hub
If a push attempt results in an error of this sort, then you likely did not log in:
Output The push refers to a repository [docker.io/sammy/ubuntu-nodejs] e3fbbfb44187: Preparing 5f70bf18a086: Preparing a3b5c80a4eba: Preparing 7f18b442972b: Preparing 3ce512daaf78: Preparing 7aae4540b42d: Waiting unauthorized: authentication required Log in with docker login and repeat the push attempt. Then verify that it exists on your Docker Hub repository page.
You can now use docker pull sammy/ubuntu-nodejs to pull the image to a new machine and use it to run a new container.