Running Flatcar Container Linux on EC2

The current AMIs for all Flatcar Container Linux channels and EC2 regions are listed below and updated frequently. Using CloudFormation is the easiest way to launch a cluster, but it is also possible to follow the manual steps at the end of the article. Questions can be directed to the Flatcar Container Linux IRC channel or user mailing list.

Choosing a channel

Flatcar 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 Flatcar Container Linux 2345.0.0.

View as json feed
EC2 Region AMI Type AMI ID CloudFormation
ap-northeast-1 PV ami-042882fb8720c9ef3 Launch Stack
HVM ami-0776caec522fae21d Launch Stack
ap-northeast-2 PV Launch Stack
HVM ami-0318eb49b2abd920c Launch Stack
ap-south-1 PV Launch Stack
HVM ami-023814c46ec4f5362 Launch Stack
ap-southeast-1 PV ami-06f520e398bf3b19c Launch Stack
HVM ami-028d2972600696ef2 Launch Stack
ap-southeast-2 PV ami-0a13f70d0d2bfd454 Launch Stack
HVM ami-08f522e029a6d0067 Launch Stack
ca-central-1 PV Launch Stack
HVM ami-00b7030cbb20dd37d Launch Stack
eu-central-1 PV ami-0f498ecd5a9fd4377 Launch Stack
HVM ami-062ac79c71b297e6e Launch Stack
eu-west-1 PV ami-07efb846d9ef2f4c8 Launch Stack
HVM ami-0e4e59e8798cd2f13 Launch Stack
eu-west-2 PV Launch Stack
HVM ami-07112805d2291fd35 Launch Stack
eu-west-3 PV Launch Stack
HVM ami-014a6cf7d29622f5e Launch Stack
sa-east-1 PV ami-02ddd330ca37ea3f2 Launch Stack
HVM ami-0b8d66e51967375c6 Launch Stack
us-east-1 PV ami-0be7abb81ace3b264 Launch Stack
HVM ami-02f56e4181b59a06b Launch Stack
us-east-2 PV Launch Stack
HVM ami-014697306d4905b08 Launch Stack
us-west-1 PV ami-0daec4967e71b126c Launch Stack
HVM ami-0654d80d88a8941e3 Launch Stack
us-west-2 PV ami-0b9a6d176b92f60b2 Launch Stack
HVM ami-0a9fb7d18e76b88a2 Launch Stack

The Edge channel includes bleeding-edge features with the newest versions of the Linux kernel, systemd and other core packages. Can be highly unstable. The current version is Flatcar Container Linux 2303.99.1.

EC2 Region AMI Type AMI ID CloudFormation
ap-northeast-1 PV ami-0a225b44263c9a79d Launch Stack
HVM ami-0cab8597f9076b50e Launch Stack
ap-northeast-2 PV Launch Stack
HVM ami-07e87cf6d11183294 Launch Stack
ap-south-1 PV Launch Stack
HVM ami-01a81541e8d1cf8da Launch Stack
ap-southeast-1 PV ami-0cce6a6b15e7decd0 Launch Stack
HVM ami-0206bdb5257e1845e Launch Stack
ap-southeast-2 PV ami-0607ec3bb00e2bde0 Launch Stack
HVM ami-09b27c734c32a6db1 Launch Stack
ca-central-1 PV Launch Stack
HVM ami-0c205201523b0606d Launch Stack
eu-central-1 PV ami-036f138b8072de257 Launch Stack
HVM ami-0f1c15a49ae6d8fe3 Launch Stack
eu-west-1 PV ami-006d8fdd653d584db Launch Stack
HVM ami-0f9e34273bb0afda7 Launch Stack
eu-west-2 PV Launch Stack
HVM ami-05e31ec2838a93abd Launch Stack
eu-west-3 PV Launch Stack
HVM ami-05ce072c91dcd6102 Launch Stack
sa-east-1 PV ami-00f91bb98d45774b8 Launch Stack
HVM ami-02529617073f95be0 Launch Stack
us-east-1 PV ami-06e8626855b5f0d11 Launch Stack
HVM ami-0554144a991ee2596 Launch Stack
us-east-2 PV Launch Stack
HVM ami-0f30f83383480619e Launch Stack
us-west-1 PV ami-014b15dddf268702f Launch Stack
HVM ami-08d8586877a385fe2 Launch Stack
us-west-2 PV ami-0b66a05acb08a27e5 Launch Stack
HVM ami-0022415280a6c08b6 Launch Stack

The Stable channel should be used by production clusters. Versions of Flatcar Container Linux are battle-tested within the Beta and Alpha channels before being promoted. The current version is Flatcar Container Linux 2303.3.0.

View as json feed
EC2 Region AMI Type AMI ID CloudFormation
ap-northeast-1 PV ami-04780edd546cae9cd Launch Stack
HVM ami-06f0f6d1803cebc00 Launch Stack
ap-northeast-2 PV Launch Stack
HVM ami-04ca85723ec15146f Launch Stack
ap-south-1 PV Launch Stack
HVM ami-0fde66e0672da3c77 Launch Stack
ap-southeast-1 PV ami-0e78a19e3f3365321 Launch Stack
HVM ami-080daf9ba3a611f10 Launch Stack
ap-southeast-2 PV ami-0024f469584b6c1c6 Launch Stack
HVM ami-0814264bec66c0993 Launch Stack
ca-central-1 PV Launch Stack
HVM ami-03cc5c255029bfab3 Launch Stack
eu-central-1 PV ami-0859b89207e60d132 Launch Stack
HVM ami-0d5a49659dec77965 Launch Stack
eu-west-1 PV ami-0019c44517ab9a7c5 Launch Stack
HVM ami-0f86251689411749d Launch Stack
eu-west-2 PV Launch Stack
HVM ami-09071fd99e4d52356 Launch Stack
eu-west-3 PV Launch Stack
HVM ami-0331176a89635da0c Launch Stack
sa-east-1 PV ami-007f393679d20744e Launch Stack
HVM ami-061e80c52825921a4 Launch Stack
us-east-1 PV ami-0cd41626c2d7e7fef Launch Stack
HVM ami-0bec30eaca6325366 Launch Stack
us-east-2 PV Launch Stack
HVM ami-05596993ab3e27a8f Launch Stack
us-west-1 PV ami-0dead7c23e8ca29fc Launch Stack
HVM ami-01a92755bd145f1f0 Launch Stack
us-west-2 PV ami-0f42a6681c43973eb Launch Stack
HVM ami-0448d339360a2373d Launch Stack

CloudFormation will launch a cluster of Flatcar Container Linux machines with a security and autoscaling group.

Container Linux Configs

Flatcar Container Linux allows you to configure machine parameters, configure networking, launch systemd units on startup, and more via Container Linux Configs. These configs are then transpiled into Ignition configs and given to booting machines. Head over to the docs to learn about the supported features.

You can provide a raw Ignition config to Flatcar Container Linux via the Amazon web console or via the EC2 API.

As an example, this Container Linux Config will configure and start etcd:

etcd:
  # All options get passed as command line flags to etcd.
  # Any information inside curly braces comes from the machine at boot time.

  # multi_region and multi_cloud deployments need to use {PUBLIC_IPV4}
  advertise_client_urls:       "http://{PRIVATE_IPV4}:2379"
  initial_advertise_peer_urls: "http://{PRIVATE_IPV4}: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"
  listen_peer_urls:            "http://{PRIVATE_IPV4}:2380"
  # 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>"

Instance storage

Ephemeral disks and additional EBS volumes attached to instances can be mounted with a .mount unit. Amazon's block storage devices are attached differently depending on the instance type. Here's the Container Linux Config to format and mount the first ephemeral disk, xvdb, on most instance types:

storage:
  filesystems:
    - mount:
        device: /dev/xvdb
        format: ext4
        wipe_filesystem: true

systemd:
  units:
    - name: media-ephemeral.mount
      enable: true
      contents: |
        [Mount]
        What=/dev/xvdb
        Where=/media/ephemeral
        Type=ext4

        [Install]
        RequiredBy=local-fs.target

For more information about mounting storage, Amazon's own documentation is the best source. You can also read about mounting storage on Flatcar Container Linux.

Adding more machines

To add more instances to the cluster, just launch more with the same Container Linux Config, the appropriate security group and the AMI for that region. New instances will join the cluster regardless of region if the security groups are configured correctly.

SSH to your instances

Flatcar Container Linux is set up to be a little more secure than other cloud images. By default, it uses the core user instead of root and doesn't use a password for authentication. You'll need to add an SSH key(s) via the AWS console or add keys/passwords via your Container Linux Config in order to log in.

To connect to an instance after it's created, run:

ssh core@<ip address>

Multiple clusters

If you would like to create multiple clusters you will need to change the "Stack Name". You can find the direct template file on S3.

Manual setup

TL;DR: launch three instances of ami-0be7abb81ace3b264 in us-east-1 with a security group that has open port 22, 2379, 2380, 4001, and 7001 and the same "User Data" of each host. SSH uses the core user and you have etcd and Docker to play with.

Creating the security group

You need open port 2379, 2380, 7001 and 4001 between servers in the etcd cluster. Step by step instructions below.

This step is only needed once

First we need to create a security group to allow Flatcar Container Linux instances to communicate with one another.

  1. Go to the security group page in the EC2 console.
  2. Click "Create Security Group"
    • Name: flatcar-testing
    • Description: Flatcar Container Linux instances
    • VPC: No VPC
    • Click: "Yes, Create"
  3. In the details of the security group, click the Inbound tab
  4. First, create a security group rule for SSH
    • Create a new rule: SSH
    • Source: 0.0.0.0/0
    • Click: "Add Rule"
  5. Add two security group rules for etcd communication
    • Create a new rule: Custom TCP rule
    • Port range: 2379
    • Source: type "flatcar-testing" until your security group auto-completes. Should be something like "sg-8d4feabc"
    • Click: "Add Rule"
    • Repeat this process for port range 2380, 4001 and 7001 as well
  6. Click "Apply Rule Changes"

Launching a test cluster

We will be launching three instances, with a few parameters in the User Data, and selecting our security group.

  1. Open the quick launch wizard to boot ami-0be7abb81ace3b264.
  2. On the second page of the wizard, launch 3 servers to test our clustering
    • Number of instances: 3
    • Click "Continue"
  3. Next, we need to specify a discovery URL, which contains a unique token that allows us to find other hosts in our cluster. If you're launching your first machine, generate one at https://discovery.etcd.io/new?size=3, configure the `?size=` to your initial cluster size and add it to the metadata. You should re-use this key for each machine in the cluster.
  4. Use ct to convert the following configuration into an Ignition config, and back in the EC2 dashboard, paste it into the "User Data" field. wzxhzdk:3
    • Paste configuration into "User Data"
    • "Continue"
  5. Storage Configuration
    • "Continue"
  6. Tags
    • "Continue"
  7. Create Key Pair
    • Choose a key of your choice, it will be added in addition to the one in the gist.
    • "Continue"
  8. Choose one or more of your existing Security Groups
    • "flatcar-testing" as above.
    • "Continue"
  9. Launch!

We will be launching three instances, with a few parameters in the User Data, and selecting our security group.

  1. Open the quick launch wizard to boot ami-08ce1119d91c9e989.
  2. On the second page of the wizard, launch 3 servers to test our clustering
    • Number of instances: 3
    • Click "Continue"
  3. Next, we need to specify a discovery URL, which contains a unique token that allows us to find other hosts in our cluster. If you're launching your first machine, generate one at https://discovery.etcd.io/new?size=3, configure the `?size=` to your initial cluster size and add it to the metadata. You should re-use this key for each machine in the cluster.
  4. Use ct to convert the following configuration into an Ignition config, and back in the EC2 dashboard, paste it into the "User Data" field. wzxhzdk:4
    • Paste configuration into "User Data"
    • "Continue"
  5. Storage Configuration
    • "Continue"
  6. Tags
    • "Continue"
  7. Create Key Pair
    • Choose a key of your choice, it will be added in addition to the one in the gist.
    • "Continue"
  8. Choose one or more of your existing Security Groups
    • "flatcar-testing" as above.
    • "Continue"
  9. Launch!

We will be launching three instances, with a few parameters in the User Data, and selecting our security group.

  1. Open the quick launch wizard to boot ami-0cd41626c2d7e7fef.
  2. On the second page of the wizard, launch 3 servers to test our clustering
    • Number of instances: 3
    • Click "Continue"
  3. Next, we need to specify a discovery URL, which contains a unique token that allows us to find other hosts in our cluster. If you're launching your first machine, generate one at https://discovery.etcd.io/new?size=3, configure the `?size=` to your initial cluster size and add it to the metadata. You should re-use this key for each machine in the cluster.
  4. Use ct to convert the following configuration into an Ignition config, and back in the EC2 dashboard, paste it into the "User Data" field. wzxhzdk:5
    • Paste configuration into "User Data"
    • "Continue"
  5. Storage Configuration
    • "Continue"
  6. Tags
    • "Continue"
  7. Create Key Pair
    • Choose a key of your choice, it will be added in addition to the one in the gist.
    • "Continue"
  8. Choose one or more of your existing Security Groups
    • "flatcar-testing" as above.
    • "Continue"
  9. Launch!

Installation from a VMDK image

One of the possible ways of installation is to import the generated VMDK Flatcar image as a snapshot. The image file will be in https://${CHANNEL}.release.flatcar-linux.net/amd64-usr/${VERSION}/flatcar_production_ami_vmdk_image.vmdk.bz2. Make sure you download the signature (it's available in https://${CHANNEL}.release.flatcar-linux.net/amd64-usr/${VERSION}/flatcar_production_ami_vmdk_image.vmdk.bz2.sig) and check it before proceeding.

$ wget https://alpha.release.flatcar-linux.net/amd64-usr/current/flatcar_production_ami_vmdk_image.vmdk.bz2
$ wget https://alpha.release.flatcar-linux.net/amd64-usr/current/flatcar_production_ami_vmdk_image.vmdk.bz2.sig
$ gpg --verify flatcar_production_ami_vmdk_image.vmdk.bz2.sig
gpg: assuming signed data in 'flatcar_production_ami_vmdk_image.vmdk.bz2'
gpg: Signature made Thu 15 Mar 2018 10:27:57 AM CET
gpg:                using RSA key A621F1DA96C93C639506832D603443A1D0FC498C
gpg: Good signature from "Flatcar Buildbot (Official Builds) <buildbot@flatcar-linux.org>" [ultimate]

Then, follow the instructions in Importing a Disk as a Snapshot Using VM Import/Export. You'll need to upload the uncompressed vmdk file to S3.

After the snapshot is imported, you can go to "Snapshots" in the EC2 dashboard, and generate an AMI image from it. To make it work, use /dev/sda2 as the "Root device name" and you probably want to select "Hardware-assisted virtualization" as "Virtualization type".

In the future we'll upload AMIs directly during the build process so this will be much easier.

Using Flatcar Container Linux

Now that you have a machine booted it is time to play around. Check out the Flatcar Container Linux Quickstart guide or dig into more specific topics.