CRI-Oのソースを表示

[[Category:仮想化]]
CRI-O は、[[Kubernetes]] Container RuntimeInterface の [[Wikipedia:Open_Container_Initiative|OCI]] ベースの実装です。

そのため、Kubernetes クラスタのノードで使用できるコンテナランタイムの 1 つです。

== インストール ==

{{pkg|cri-o}} パッケージを[[インストール]]します。

このパッケージは、{{ic|overlay}} と {{ic|br_netfilter}} モジュールをロードするようにシステムをセットアップし、以下の [[sysctl]] オプションを設定します。

  net.bridge.bridge-nf-call-iptables = 1
  net.bridge.bridge-nf-call-ip6tables = 1
  net.ipv4.ip_forward = 1

CRI-O を再起動せずに使用するには、モジュールを[[カーネルモジュール#手動でモジュールを扱う|ロード]]し、それに応じてsysctlの値を[[Sysctl#Configuration|設定]]することを確認してください。

== Configuration ==

CRI-O is configured via {{ic|/etc/crio/crio.conf}} or via drop-in configuration files in {{ic|/etc/crio/crio.conf.d/}}.

=== Network ===

CRI-O can make use of container networking as provided by {{pkg|cni-plugins}}.

Copy one of the examples from {{ic|/usr/share/doc/cri-o/examples/cni/}} to {{ic|/etc/cni/net.d}} and modify it as needed.

{{Warning|The {{pkg|cri-o}} package installs the {{ic|10-crio-bridge.conf}} and {{ic|99-loopback.conf}} examples to {{ic|/etc/cni/net.d}} by default (as {{ic|100-crio-bridge.conf}} and {{ic|199-crio-loopback.conf}} respectively). This may conflict with Kubernetes cluster network fabrics (weave, flannel, calico, etc) and require manual deletion to resolve this (e.g. [https://github.com/cri-o/cri-o/issues/2411 #2411] [https://github.com/cri-o/cri-o/issues/2885 #2885]).}}

=== Storage ===

By default CRI-O makes use of the {{ic|overlay}} driver as its {{ic|storage_driver}} for the container storage in {{ic|/var/lib/containers/storage/}}. However, it can also be configured to use [[btrfs]] or [[ZFS]] natively by changing the {{ic|driver}} in {{ic|/etc/containers/storage}}:

  sed -i 's/driver = ""/driver = "btrfs"/' /etc/containers/storage.conf

== Running ==

[[Start]] and [[enable]] the {{ic|crio.service}} [[systemd]] unit.

== Testing ==

Use {{ic|crio-status}} like this:

  # crio-status info
  cgroup driver: systemd
  storage driver: vfs
  storage root: /var/lib/containers/storage
  default GID mappings (format <container>:<host>:<size>):
    0:0:4294967295
  default UID mappings (format <container>:<host>:<size>):
    0:0:4294967295

and:

  # crio-status config
  ...

Now [[Install]] the {{pkg|crictl}} package, and see e.g. https://kubernetes.io/docs/tasks/debug-application-cluster/crictl/ or https://github.com/kubernetes-sigs/cri-tools/blob/master/docs/crictl.md, or simply:

  source <(crictl completion bash)

  crictl pull index.docker.io/busybox
  crictl pull quay.io/prometheus/busybox
  crictl images

  curl -O https://raw.githubusercontent.com/kubernetes-sigs/cri-tools/master/docs/examples/podsandbox-config.yaml
  curl -O https://raw.githubusercontent.com/kubernetes-sigs/cri-tools/master/docs/examples/container-config.yaml
  crictl run container-config.yaml podsandbox-config.yaml

  crictl logs $(crictl ps --last 1 --output yaml | yq -r .containers[0].id)
  crictl exec -it $(crictl ps --last 1 --output yaml | yq -r .containers[0].id) /bin/sh

  crictl rm -af
  crictl rmp -af

Note how Docker Hub is not hard-coded, so specify container registry explicitly. (See also https://github.com/kubernetes-sigs/cri-tools/pull/718.)

== See also ==

* [https://github.com/cri-o/cri-o CRI-O on Github] - CRI-O repository on Github
* [https://cri-o.io CRI-O Website] - The official CRI-O website