Mastering nerdctl & containerd: Image Packaging and Docker‑Compose‑Style Orchestration

Introduction

Containerization is reshaping software development and operations. Containerd, a lightweight Docker alternative, offers an efficient runtime and supports image packaging and Docker‑Compose‑like orchestration when paired with the Docker‑compatible CLI tool nerdctl.

nerdctl Introduction

Docker CLI compatibility – familiar commands work without learning new syntax.

Docker Compose support – can run multi‑container apps using Compose files.

Rootless mode – non‑root users can run containers for added flexibility and security.

Advanced features – image encryption (ocicrypt), P2P distribution (IPFS), signing and verification (cosign) not present in Docker.

nerdctl Installation

Besides containerd, install the following components:

CNI plugins – required for

nerdctl run

. Use version 1.1.0 or newer.

BuildKit (optional) – needed for

nerdctl build

. Use version 0.11.0 or newer.

RootlessKit and slirp4netns (optional) – for rootless mode. Recommended versions: RootlessKit ≥ v0.10.0 (prefer v2.0.0), slirp4netns ≥ v0.4.0 (prefer v1.1.7).

<code># Download nerdctl package
curl -SLO https://github.com/containerd/nerdctl/releases/download/v1.7.6/nerdctl-1.7.6-linux-amd64.tar.gz

# Extract and install
mkdir -p /tmp/nerdctl
tar xf nerdctl-1.7.6-linux-amd64.tar.gz -C /tmp/nerdctl
sudo cp /tmp/nerdctl/nerdctl /usr/bin
rm -rf /tmp/nerdctl</code>

Install CNI plugins (skip if a Kubernetes network plugin is already present):

<code># Download CNI plugins
curl -SLO https://github.com/containernetworking/plugins/releases/download/v1.5.1/cni-plugins-linux-amd64-v1.5.1.tgz

# Install binaries
sudo mkdir -p /opt/cni/bin
sudo tar xvf cni-plugins-linux-amd64-v1.5.1.tgz -C /opt/cni/bin/</code>

Install BuildKit for image building:

<code># Download BuildKit
curl -SLO https://github.com/moby/buildkit/releases/download/v0.15.0/buildkit-v0.15.0.linux-amd64.tar.gz

# Extract and install
mkdir -p /tmp/buildkit
tar xvf buildkit-v0.15.0.linux-amd64.tar.gz -C /tmp/buildkit
sudo cp /tmp/buildkit/bin/* /usr/local/bin
rm -rf /tmp/buildkit

# Create systemd service files
cat <<-EOF | sudo tee /lib/systemd/system/buildkitd.service > /dev/null
[Unit]
Description=BuildKit
Documentation=https://github.com/moby/buildkit
After=buildkit.socket

[Service]
ExecStart=/usr/local/bin/buildkitd --oci-worker=false --containerd-worker=true

[Install]
WantedBy=multi-user.target
EOF

cat <<-EOF | sudo tee /lib/systemd/system/buildkit.socket > /dev/null
[Unit]
Description=BuildKit
Documentation=https://github.com/moby/buildkit

[Socket]
ListenStream=%t/buildkit/buildkitd.sock

[Install]
WantedBy=sockets.target
EOF

# Enable and start BuildKit
sudo systemctl daemon-reload
sudo systemctl enable --now buildkitd.service</code>

Verification and Simple Usage

Validate the installation by running a container:

<code>sudo nerdctl run --rm docker.1panel.live/library/hello-world</code>

Build a custom image using a Dockerfile:

<code># Create Dockerfile
cat >> Dockerfile <<EOF
FROM docker.1panel.live/library/hello-world
EOF

# Build the image
sudo nerdctl build -t jiaxzeng/hello-world:v1 .

# List the built image
sudo nerdctl images jiaxzeng/hello-world:v1</code>

Conclusion

Containerd is a key component of the cloud‑native ecosystem, offering a lightweight, high‑performance runtime. Combined with tools like nerdctl, it enables image packaging and Docker‑Compose‑style orchestration, making it a foundational technology for modern application development.