There is a simple installer that will destroy everything on the given target disk and install Container Linux. Essentially it downloads an image, verifies it with gpg, and then copies it bit for bit to disk. An installation requires at least 8 GB of usable space on the device.
The script is self-contained and located on GitHub here and can be run from any Linux distribution. You cannot normally install Container Linux to the same device that is currently booted. However, the Container Linux ISO or any Linux liveCD will allow Container Linux to install to a non-active device.
If you boot Container Linux via PXE, the install script is already installed. By default the install script will attempt to install the same version and channel that was PXE-booted:
coreos-install -d /dev/sda -i ignition.json
ignition.json
should include user information (especially an SSH key) generated from a Container Linux Config, or you will not be able to log into your Container Linux instance.
If you are installing on VMware, pass -o vmware_raw
to install the VMware-specific image:
coreos-install -d /dev/sda -i ignition.json -o vmware_raw
Container Linux is designed to be updated automatically with different schedules per channel. You can disable this feature, although we don't recommend it. Read the release notes for specific features and bug fixes.
The Alpha channel closely tracks master and is released frequently. The newest versions of system libraries and utilities will be available for testing. The current version is Container Linux {{site.alpha-channel}}.
If you want to ensure you are installing the latest alpha version, use the -C
option:
coreos-install -d /dev/sda -C alpha
The Beta channel consists of promoted Alpha releases. The current version is Container Linux {{site.beta-channel}}.
If you want to ensure you are installing the latest beta version, use the -C
option:
coreos-install -d /dev/sda -C beta
The Stable channel should be used by production clusters. Versions of Container Linux are battle-tested within the Beta and Alpha channels before being promoted. The current version is Container Linux {{site.stable-channel}}.
If you want to ensure you are installing the latest stable version, use the -C
option:
coreos-install -d /dev/sda -C stable
For reference here are the rest of the coreos-install
options:
-d DEVICE Install Container Linux to the given device.
-V VERSION Version to install (e.g. current)
-B BOARD Container Linux board to use
-C CHANNEL Release channel to use (e.g. beta)
-o OEM OEM type to install (e.g. ami)
-c CLOUD Insert a cloud-init config to be executed on boot.
-i IGNITION Insert an Ignition config to be executed on boot.
-b BASEURL URL to the image mirror (overrides BOARD)
-k KEYFILE Override default GPG key for verifying image signature
-f IMAGE Install unverified local image file to disk instead of fetching
-n Copy generated network units to the root partition.
-v Super verbose, for debugging.
By default there isn't a password or any other way to log into a fresh Container Linux system. The easiest way to configure accounts, add systemd units, and more is via Container Linux Configs. Jump over to the docs to learn about the supported features.
After using the Container Linux Config Transpiler to produce an Ignition config, the installation script will process your ignition.json
file specified with the -i
flag and use it when the installation is booted.
A Container Linux Config that specifies an SSH key for the core
user but doesn't use any other parameters looks like:
passwd:
users:
- name: core
ssh_authorized_keys:
- ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDGdByTgSVHq.......
Note: The {PRIVATE_IPV4}
and {PUBLIC_IPV4}
substitution variables referenced in other documents are not supported on libvirt.
To start the installation script with a reference to our Ignition config, run:
coreos-install -d /dev/sda -C stable -i ~/ignition.json
This example will configure Container Linux components: etcd and flannel. You have to substitute <PEER_ADDRESS>
to your host's IP or DNS address.
passwd:
users:
- name: core
ssh_authorized_keys:
- ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDGdByTgSVHq.......
etcd:
# generate a new token for each unique cluster from https://discovery.etcd.io/new?size=3
# specify the initial size of your cluster with ?size=X
discovery: https://discovery.etcd.io/<token>
advertise_client_urls: http://<PEER_ADDRESS>:2379,http://<PEER_ADDRESS>:4001
initial_advertise_peer_urls: http://<PEER_ADDRESS>:2380
# listen on both the official ports and the legacy ports
# legacy ports can be omitted if your application doesn't depend on them
listen_client_urls: http://0.0.0.0:2379,http://0.0.0.0:4001
listen_peer_urls: http://<PEER_ADDRESS>:2380
systemd:
units:
- name: flanneld.service
enable: true
dropins:
- name: 50-network-config.conf
contents: |
[Service]
ExecStartPre=/usr/bin/etcdctl set /coreos.com/network/config '{"Network":"10.1.0.0/16", "Backend": {"Type": "vxlan"}}'
Now that you have a machine booted it is time to play around. Check out the Container Linux Quickstart guide or dig into more specific topics.