Solve the puzzle

Image sources and updates

The creation script uses an existing local image when available. Otherwise it first pulls ghcr.io/oneclickvirt/docker:<system>, then tries an architecture-specific tag and the GitHub Release archive. See the creation guide for download and setup commands.

The central CNB build repository also builds openEuler container images daily. To pull one separately:

docker pull docker.cnb.cool/oneclickvirt/virtualization-images/docker:openeuler-22.03

See CNB container artifacts for the published tags. On an X86_64 host, create a container directly after installing the runtime:

install -d -m 700 /opt/oneclickvirt/docker-openeuler
(umask 077; printf 'ROOT_PASSWORD=%s\n' "$(openssl rand -base64 24)" > /opt/oneclickvirt/docker-openeuler/root.env)
docker run -d --name docker-openeuler --restart unless-stopped \
  --cpus 1 --memory 512m -p 25001:22 \
  --env-file /opt/oneclickvirt/docker-openeuler/root.env \
  docker.cnb.cool/oneclickvirt/virtualization-images/docker:openeuler-22.03

Connect to the host on SSH port 25001 as root; the generated password is in /opt/oneclickvirt/docker-openeuler/root.env. Choose another container name and port if these are already in use. This example provides IPv4 port mapping; use the provisioning instructions for the project's IPv6 network setup.

This CNB image uses the build runner's architecture; the tag is not multi-architecture. The existing creation script does not switch to this address automatically. GitHub Releases and GHCR remain maintained by their existing workflow. Pulling a new image does not update existing containers; back up their data and configuration before arranging a replacement.

NDP responder on CNB

The CNB source mirror synchronizes the public GitHub main branch hourly. Container artifacts are tested, built and published on source updates and a daily schedule. The latest tag supports Linux amd64 and ARM64; explicit amd64 and arm64 tags are also available.

docker pull docker.cnb.cool/oneclickvirt/ndpresponder/ndpresponder:latest
docker run --rm docker.cnb.cool/oneclickvirt/ndpresponder/ndpresponder:latest --help

For a standalone responder serving a specific IPv6 address, replace the example Ethernet uplink eth0 and assigned address 2001:db8::2/128 before running:

docker run -d --name ndpresponder-cnb --restart unless-stopped \
  --network host --cap-drop ALL --cap-add NET_RAW --cap-add NET_ADMIN \
  docker.cnb.cool/oneclickvirt/ndpresponder/ndpresponder:latest \
  --ifname eth0 --subnet 2001:db8::2/128

This command proxies only the explicit address; it does not configure routes or container addresses. Do not start another responder alongside one already managed by the installer. Docker network tracking uses -N and containerd CNI lease tracking uses -C, with the corresponding API or lease-directory mounts. Installer image sources keep their existing defaults. To use the CNB source during a fallback build, first set export NDPRESPONDER_SOURCE_URL=https://cnb.cool/oneclickvirt/ndpresponder.git.

SSH reports a changed host key after recreating a container

New images no longer contain shared SSH host keys. Each new container generates its own keys on first startup. Restarting the same container retains its keys; deleting and recreating it generates new ones.

Check the container's ED25519 public key fingerprint from the host, replacing test-direct with its actual name:

docker exec test-direct ssh-keygen -lf /etc/ssh/ssh_host_ed25519_key.pub

Compare the fingerprint when connecting. Update the old record saved on your client only after confirming that it belongs to your recreated container. Updating an image does not automatically replace passwords or host keys inside existing containers.

Common Docker Commands

Check real-time resource usage of a specific container

docker stats <container_name>

Enter a specific container

docker exec -it <container_name> /bin/bash

Clean Docker cache, remove unused resources including images, containers, networks, etc.

docker system prune -a

Uninstall all Docker images and containers

docker rm -f $(docker ps -aq); docker rmi $(docker images -aq)

View logs of a specific container

docker logs <container_name_or_ID>

View overall disk usage of Docker

docker system df

List all containers

docker ps -a

List all images

docker images

Remove a specific container

docker rm -f <container_name_or_ID>

Remove a specific image

docker rmi <image_name_or_ID>