nerdctl VS Docker Compose

nerdctl CLI for containerd (Docker replacement) Feels like Docker. But lighter. And hipster-approved.

If you are unfamiliar with the concept of containers and docker images, I suggest you have a look at docker. It will be leveraged here to start the Spark server for the tests; it's important to mention there are other opensource alternatives like podman or nerdctl to allow containerization.

NERDCTL_VERSION=2.0.3 wget https://github.com/containerd/nerdctl/releases/download/v2.0.3/nerdctl-$NERDCTL_VERSION-linux-arm64.tar.gz tar -xzvf nerdctl-$NERDCTL_VERSION-linux-arm64.tar.gz -C /sbin CNI_VERSION wget https://github.com/containernetworking/plugins/releases/download/v1.6.2/cni-plugins-linux-arm64-vCNI_VERSION.tgz mkdir -p /opt/cni/bin tar -xzvf cni-plugins-linux-arm64-vCNI_VERSION.tgz -C /opt/cni/bin

Here's a script that left me in awe the first time I saw it:

https://github.com/containerd/nerdctl/blob/main/extras/rootl...

I have since copied this pattern for many scripts: logging functions, grouping all global vars and constants at the top and creating subcommands using shift.

Rancher Desktop allows you to choose between the Moby engine (offered by Continered) and the dockerd engine (offered by Docker) for building, pushing, and running containers. Compared with Docker Desktop, which provides Docker CLI as a CLI tool, Rancher provides both kubectl and nerdctl for managing Kubernetes and containers, respectively.

What about the docker-cli? colima also ships with a docker-compatible cli to interact with containerd called nerdctl. We can execute the same docker cli commands like:

Using nerdctl: https://github.com/containerd/nerdctl

I'd really disagree that compose files are somehow one-shot, or blindly modified. To the contrary, really, we have them checked in with the source code. Upon deployment to the cluster, the (running) services will be intelligently updated or replaced (in a rolling manner, causing zero downtime). LXC might be more elegant, but I have no idea what simple, file-based format I could use to let engineers describe the environment their app should run in without compose.

I need something that even junior devs can start up with a single command, that can be placed in the VCS along with the code, and that will not require deep Linux knowledge to get running. Open for suggestions here, really.

Now since Kubernetes works off of containerd I'll be taking a different approach on handling container builds by using nerdctl and the buildkit that comes bundled with it. I'll do this on the amd64 control plane node since it's beefier than my Raspberry Pi workers for handling builds and build related services. Go ahead and download and unpack the latest nerdctl release as of writing (make sure to check the release page in case there's a new one):

That's why nerdctl, their cli binary, is so well named.

sudo mkdir -p /usr/libexec/docker/cli-plugins # docker compose cd /tmp && \ wget -O docker-compose https://github.com/docker/compose/releases/download/v2.38.2/docker-compose-linux-riscv64 && \ chmod +x docker-compose && \ sudo mv docker-compose /usr/libexec/docker/cli-plugins && \ wget -O docker-buildx https://github.com/docker/buildx/releases/download/v0.26.1/buildx-v0.26.1.linux-riscv64 && \ chmod +x docker-buildx && \ sudo mv docker-buildx /usr/libexec/docker/cli-plugins

sudo curl -L "https://github.com/docker/compose/releases/download/1.29.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose sudo chmod +x /usr/local/bin/docker-compose

Step 4:Install Docker Compose: Now we install Docker Compose using the command: sudo curl -L "https://github.com/docker/compose/releases/latest/download/docker-compose-$(uname -s)-$(uname -m)" \ -o /usr/local/bin/docker-compose

$ sudo yum install docker git -y $ sudo systemctl enable --now docker $ # Attention: You need IPv4 to download from GitHub! $ sudo curl -L \ "https://github.com/docker/compose/releases/latest/download/docker-compose-$(uname -s)-$(uname -m)" \ -o /usr/local/bin/docker-compose $ sudo chmod +x /usr/local/bin/docker-compose $ sudo usermod -aG docker $(whoami) # Log in to the instance again

[ec2-user]$ sudo yum update -y [ec2-user]$ sudo yum install -y docker [ec2-user]$ sudo service docker start [ec2-user]$ sudo curl -L https://github.com/docker/compose/releases/latest/download/docker-compose-$(uname -s)-$(uname -m) -o /usr/local/bin/docker-compose [ec2-user]$ sudo chmod +x /usr/local/bin/docker-compose [ec2-user]$ docker --version Docker version 20.10.23, build 7155243 [ec2-user]$ docker-compose --version Docker Compose version v2.18.1

If you're a fan of compose files, then you can use Docker's own compose application [1] with Podman [2]. It seems that the compose cli controls the engine using its socket. Both podman and docker engines have the almost same API. I'm using this approach since podman-compose didn't work as expected for me. Docker-compose is usually installed as a plugin for the docker client. However, I use it as a standalone application for use with Podman. In addition, I prefer using docker 'contexts' instead of the DOCKER_HOST environment variable to set up the integration.

Another relevant project is podlet [3]. It can be used to convert compose files, podman/docker command or a running object to a set of quadlet files. Also, note that if plain quadlets aren't powerful enough for you, quadlets [4] and plain podman [5] also support running a limited set of kubernetes manifests.

[1] https://github.com/docker/compose

[2] https://docs.podman.io/en/latest/markdown/podman-system-serv...

[3] https://github.com/containers/podlet

[4] https://docs.podman.io/en/latest/markdown/podman-systemd.uni...

[5] https://docs.podman.io/en/latest/markdown/podman-kube-play.1...

name: CD Pipeline on: push: branches: [main] jobs: deploy: runs-on: ubuntu-latest steps: - name: Checkout repository uses: actions/checkout@v3 - name: Deploy via SSH uses: appleboy/ssh-action@master with: host: ${{ secrets.SSH_HOST }} username: ${{ secrets.SSH_USERNAME }} key: ${{ secrets.SSH_PRIVATE_KEY }} script: | # Update package index and install dependencies sudo apt-get update -y sudo apt-get install -y apt-transport-https ca-certificates curl software-properties-common # Add Docker's official GPG key curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add - sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" # Install Docker sudo apt-get update -y sudo apt-get install -y docker-ce docker-ce-cli containerd.io # Add the SSH user to the Docker group sudo usermod -aG docker ${{ secrets.SSH_USERNAME }} # Install Docker Compose sudo curl -L "https://github.com/docker/compose/releases/download/v2.20.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose sudo chmod +x /usr/local/bin/docker-compose # Verify installations docker --version docker-compose --version # Navigate to the project directory and deploy cd /home/ubuntu/ git clone cd fastapi-book-project/ git pull docker-compose up -d --build