docker - docker 容器中的 microk8s

Question

对于我的代码的自动测试，我想添加一个 microk8s在我的 docker-compose 设置中进行测试。因此，我想在 docker 环境中安装 microk8s

我使用 web 中的以下命令在 docker 容器中运行 snap

FROM ubuntu:18.04

ENV container docker
ENV PATH /snap/bin:$PATH
ADD snap /usr/local/bin/snap
RUN apt-get update
RUN apt-get install -y snapd squashfuse fuse
RUN systemctl enable snapd
STOPSIGNAL SIGRTMIN+3
CMD [ "/sbin/init" ]

快照脚本

!/bin/sh -e

while ! kill -0 $(pidof snapd) 2>/dev/null; do
  echo "Waiting for snapd to start."
  sleep 1
done

/usr/bin/snap $@

和 build docker

docker build -t snapd .

并运行

 docker run --name=snapd -ti -d --tmpfs /run --tmpfs /run/lock --tmpfs /tmp --privileged -v /lib/modules:/lib/modules:ro snapd

到这里一切都很好。

但是，如果尝试通过 snap 安装 microk8s，它会失败

snap install microk8s --classic --channel=1.18/stable
2020-04-27T14:22:39Z INFO Waiting for restart...
error: cannot perform the following tasks:
- Run install hook of "microk8s" snap if present (run hook "install": execv failed: Permission denied)

检查快照 systemctl status snapd.service给我

Apr 27 15:14:32 8985fc7fc5cb snapd[489]: helpers.go:961: cannot retrieve info for snap "microk8s": cannot find installed snap "microk8s" at revision 1341: missing file /sn
ap/microk8s/1341/meta/snap.yaml
Apr 27 15:14:33 8985fc7fc5cb snapd[489]: helpers.go:105: error trying to compare the snap system key: system-key versions not comparable
Apr 27 15:14:33 8985fc7fc5cb snapd[489]: helpers.go:961: cannot retrieve info for snap "microk8s": cannot find installed snap "microk8s" at revision 1341: missing file /sn
ap/microk8s/1341/meta/snap.yaml
Apr 27 15:14:33 8985fc7fc5cb systemd[1]: Started Snappy daemon.
Apr 27 15:15:08 8985fc7fc5cb snapd[489]: handlers.go:495: Reported install problem for "microk8s" as e11fe0c4-8899-11ea-a8e2-fa163ee63de6 OOPSID

Answer 1

我发现(对我来说)有点令人满意的答案是使用 k3s
A German description can be found here

关键是以下docker-compose.yml

version: '3'
services:
  server:
    image: rancher/k3s:v0.8.1
    command: server --disable-agent
    environment:
    - K3S_CLUSTER_SECRET=somethingtotallyrandom
    - K3S_KUBECONFIG_OUTPUT=/output/kubeconfig.yaml
    - K3S_KUBECONFIG_MODE=666
    volumes:
    - k3s-server:/var/lib/rancher/k3s
    # get the kubeconfig file
    - .:/output
    ports:
    - 6443:6443

  node:
    image: rancher/k3s:v0.8.1
    tmpfs:
    - /run
    - /var/run
    privileged: true
    environment:
    - K3S_URL=https://server:6443
    - K3S_CLUSTER_SECRET=somethingtotallyrandom
    ports:
      - 31000-32000:31000-32000

  worker:
    image: rancher/k3s:v0.8.1
    tmpfs:
    - /run
    - /var/run
    privileged: true
    environment:
    - K3S_URL=https://server:6443
    - K3S_CLUSTER_SECRET=somethingtotallyrandom

volumes:
  k3s-server: {}