This guide will walk you through the installation of CRI-O Container Runtime on Ubuntu 22.04|20.04|18.04. CRI-O is an OCI-based implementation of Kubernetes Container Runtime Interface (CRI) designed to provide an integration path between OCI conformant runtimes and the kubelet.
CRI-O is created to provide following core functionalities:
- Support multiple image formats including the existing Docker image format
- Support for multiple means to download images including trust & image verification
- Container image management (managing image layers, overlay filesystems, etc)
- Container process lifecycle management
- Monitoring and logging required to satisfy the CRI
- Resource isolation as required by the CRI
The libraries used by CRI-O are:
- Runtime: runc (or any OCI runtime-spec implementation) and oci runtime tools
- Images: Image management using containers/image
- Storage: Storage and management of image layers using containers/storage
- Networking: Networking support through use of CNI
Install CRI-O Container Runtime on Ubuntu 22.04|20.04|18.04
We will use pre-built binary packages to install CRI-O container runtime. Follow the steps below to install CRI-O Container Runtime on Ubuntu 22.04|20.04|18.04.
Step 1: Update System
Ensure your Ubuntu system is updated. If you’re afraid this could break your system you can skip.
sudo apt update && sudo apt upgradeIt is recommended to reboot your system to ensure it is running on updated version.
sudo systemctl rebootStep 2: Add CRI-O Kubic repository
Add the Kubic repository which host binary packages for Debian based systems. If using CRI-O with Kubernetes, install the version matching Kubernetes version you’ll setup.
If your Kubernetes version is 1.23, install CRI-O version 1.23. We’ll start by adding the APT repository which contains CRI-O packages:
Ubuntu 22.04/20.04:
OS=xUbuntu_20.04
CRIO_VERSION=1.23
echo "deb https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable/$OS/ /"|sudo tee /etc/apt/sources.list.d/devel:kubic:libcontainers:stable.list
echo "deb http://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable:/cri-o:/$CRIO_VERSION/$OS/ /"|sudo tee /etc/apt/sources.list.d/devel:kubic:libcontainers:stable:cri-o:$CRIO_VERSION.listUbuntu 18.04:
OS=xUbuntu_18.04
CRIO_VERSION=1.23
echo "deb https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable/$OS/ /"|sudo tee /etc/apt/sources.list.d/devel:kubic:libcontainers:stable.list
echo "deb http://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable:/cri-o:/$CRIO_VERSION/$OS/ /"|sudo tee /etc/apt/sources.list.d/devel:kubic:libcontainers:stable:cri-o:$CRIO_VERSION.listOnce the repository is added to your system, import GPG key:
curl -L https://download.opensuse.org/repositories/devel:kubic:libcontainers:stable:cri-o:$CRIO_VERSION/$OS/Release.key | sudo apt-key add -
curl -L https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable/$OS/Release.key | sudo apt-key add -Step 3: Install CRI-O on Ubuntu22.04|20.04|18.04
When repository is added, update apt cache and install CRI-O on Ubuntu.
sudo apt update
sudo apt install cri-o cri-o-runcAccept installation prompt with y key.
The following additional packages will be installed:
conmon containers-common
Suggested packages:
cri-o-runc | runc containernetworking-plugins
The following NEW packages will be installed:
conmon containers-common cri-o
0 upgraded, 3 newly installed, 0 to remove and 94 not upgraded.
Need to get 20.2 MB of archives.
After this operation, 99.4 MB of additional disk space will be used.
Do you want to continue? [Y/n] yChecking the version of CRI-O installed on Ubuntu:
$ apt show cri-o
Package: cri-o
Version: 1.23.0~0
Priority: optional
Section: devel
Maintainer: Peter Hunt
Installed-Size: 98.3 MB
Depends: libgpgme11, libseccomp2, conmon, containers-common (>= 0.1.27), tzdata
Suggests: cri-o-runc | runc (>= 1.0.0), containernetworking-plugins
Replaces: cri-o-1.19, cri-o-1.20, cri-o-1.21
Homepage: https://github.com/cri-o/cri-o
Download-Size: 19.9 MB Start and enable crio service:
sudo systemctl enable crio.service
sudo systemctl start crio.serviceService status can be checked with the command:
$ systemctl status crio
● crio.service - Container Runtime Interface for OCI (CRI-O)
Loaded: loaded (/lib/systemd/system/crio.service; enabled; vendor preset: enabled)
Active: active (running) since Sun 2020-06-07 20:16:50 CEST; 37s ago
Docs: https://github.com/cri-o/cri-o
Main PID: 2461 (crio)
Tasks: 13
Memory: 7.7M
CGroup: /system.slice/crio.service
└─2461 /usr/bin/crio
Jun 07 20:16:50 ubuntu systemd[1]: Starting Container Runtime Interface for OCI (CRI-O)...
Jun 07 20:16:50 ubuntu systemd[1]: Started Container Runtime Interface for OCI (CRI-O).Step 4: Using CRI-O on Ubuntu22.04|20.04|18.04
The command line tool crioctl can be installed through cri-tools package.
sudo apt install cri-toolsCheck existence of crictl command:
$ sudo crictl info
"status":
"conditions": [
"type": "RuntimeReady",
"status": true,
"reason": "",
"message": ""
,
"type": "NetworkReady",
"status": false,
"reason": "NetworkPluginNotReady",
"message": "Network plugin returns error: Missing CNI default network"
]
Pull a test image:
$ sudo crictl pull nginx
Image is up to date for docker.io/library/[email protected]:c870bf53de0357813af37b9500cb1c2ff9fb4c00120d5fe1d75c21591293c34d
$ sudo crictl pull hello-world
Image is up to date for docker.io/library/[email protected]:6a65f928fb91fcfbc963f7aa6d57c8eeb426ad9a20c7ee045538ef34847f44f1
$ sudo crictl pull busybox
Image is up to date for docker.io/library/[email protected]:95cf004f559831017cdf4628aaf1bb30133677be8702a8c5f2994629f637a209
List available images:
$ sudo crictl images
IMAGE TAG IMAGE ID SIZE
docker.io/library/alpine latest a24bb4013296f 5.85MB
docker.io/library/busybox latest 1c35c44120825 1.44MB
docker.io/library/hello-world latest bf756fb1ae65a 20kB
docker.io/library/nginx latest 4392e5dad77db 136MBCreate pod sandbox config file:
cat >nginx.json<net-pod.json< Run the pod
sudo crictl runp net-pod.json
sudo crictl create nginx.json net-pod.json
sudo crictl ps -aEnjoy using CRI-O on Ubuntu with Kubernetes.
