Running Flatcar Linux on EC2

The current AMIs for all Flatcar 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 Linux IRC channel or user mailing list.

Choosing a channel

Flatcar 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 Linux 2234.0.0.

View as json feed
EC2 Region AMI Type AMI ID CloudFormation
ap-northeast-1 PV ami-0b64f8fb2adeba947 Launch Stack
HVM ami-0a18283f5e3a43d8e Launch Stack
ap-northeast-2 PV Launch Stack
HVM ami-07e9b34d46b4ffc6a Launch Stack
ap-south-1 PV Launch Stack
HVM ami-0a0c241c8a489c8cf Launch Stack
ap-southeast-1 PV ami-0009f81e71f13ed5a Launch Stack
HVM ami-098ad77c448f2ff2e Launch Stack
ap-southeast-2 PV ami-05d9a2df990a07bc2 Launch Stack
HVM ami-0d802205c77868a9c Launch Stack
ca-central-1 PV Launch Stack
HVM ami-0cc194c9c85e70acd Launch Stack
eu-central-1 PV ami-09d69f8a46031299f Launch Stack
HVM ami-03c61fd02eaec5719 Launch Stack
eu-west-1 PV ami-0d5cd6084ca2ed9df Launch Stack
HVM ami-0a44701765130db4c Launch Stack
eu-west-2 PV Launch Stack
HVM ami-02226f7c0afa43251 Launch Stack
eu-west-3 PV Launch Stack
HVM ami-0d276361dada4f9cd Launch Stack
sa-east-1 PV ami-0b4d8b87a582407d6 Launch Stack
HVM ami-02694f3e9780726c4 Launch Stack
us-east-1 PV ami-0792237d650de6d05 Launch Stack
HVM ami-0a9b5b92e3200a9df Launch Stack
us-east-2 PV Launch Stack
HVM ami-01310bbbbe7ec9489 Launch Stack
us-west-1 PV ami-09791b2443da50c0c Launch Stack
HVM ami-0fa526c4987ba805a Launch Stack
us-west-2 PV ami-09d8474c08c8c7efd Launch Stack
HVM ami-06573256c8340db79 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 Linux 2219.99.1.

EC2 Region AMI Type AMI ID CloudFormation
ap-northeast-1 PV ami-0219730ca3987400c Launch Stack
HVM ami-0a2352b5fed9a0a44 Launch Stack
ap-northeast-2 PV Launch Stack
HVM ami-0f98e312e82b58afd Launch Stack
ap-south-1 PV Launch Stack
HVM ami-045caa4247368079c Launch Stack
ap-southeast-1 PV ami-0e84728f29518fc38 Launch Stack
HVM ami-071d4f72302a1ac50 Launch Stack
ap-southeast-2 PV ami-0acb540a48e270e32 Launch Stack
HVM ami-0e9e700e0afe5e0c0 Launch Stack
ca-central-1 PV Launch Stack
HVM ami-0f47498ceaa5e2589 Launch Stack
eu-central-1 PV ami-0d3a27b89de184cc7 Launch Stack
HVM ami-0d7c680ecbe1dbca1 Launch Stack
eu-west-1 PV ami-0c5e7630aa80aae11 Launch Stack
HVM ami-03d251ddc5bfdb894 Launch Stack
eu-west-2 PV Launch Stack
HVM ami-0cf997c1692c82999 Launch Stack
eu-west-3 PV Launch Stack
HVM ami-0cd71e28c23523834 Launch Stack
sa-east-1 PV ami-0f84c136dfab07fd7 Launch Stack
HVM ami-055a34db81df140fe Launch Stack
us-east-1 PV ami-043307eb20d776e14 Launch Stack
HVM ami-0be12f29f4ffd0fc9 Launch Stack
us-east-2 PV Launch Stack
HVM ami-0364abcc277d4685a Launch Stack
us-west-1 PV ami-026dd7e3dcd076886 Launch Stack
HVM ami-08e03fb152057f320 Launch Stack
us-west-2 PV ami-0b541db5a628b39b1 Launch Stack
HVM ami-08ae4b1532d37c554 Launch Stack

The Stable channel should be used by production clusters. Versions of Flatcar Linux are battle-tested within the Beta and Alpha channels before being promoted. The current version is Flatcar Linux 2191.4.0.

View as json feed
EC2 Region AMI Type AMI ID CloudFormation
ap-northeast-1 PV ami-0e33d3c7dce75f73c Launch Stack
HVM ami-0f047c5c3ac5f1759 Launch Stack
ap-northeast-2 PV Launch Stack
HVM ami-09d6ddd1ff89aaec7 Launch Stack
ap-south-1 PV Launch Stack
HVM ami-0fd882055965ae18c Launch Stack
ap-southeast-1 PV ami-0c2ef0f85b8338551 Launch Stack
HVM ami-0062961a6807a33cd Launch Stack
ap-southeast-2 PV ami-08fe953b419c19819 Launch Stack
HVM ami-09eec72bd43e0899c Launch Stack
ca-central-1 PV Launch Stack
HVM ami-0fc1eadcd5022c642 Launch Stack
eu-central-1 PV ami-07294368ca0106810 Launch Stack
HVM ami-093214988f05d6470 Launch Stack
eu-west-1 PV ami-02ce214809a98f30b Launch Stack
HVM ami-02fe6a37bb19aebbf Launch Stack
eu-west-2 PV Launch Stack
HVM ami-092f0c88a138d83b7 Launch Stack
eu-west-3 PV Launch Stack
HVM ami-0c673b528303ac122 Launch Stack
sa-east-1 PV ami-02871b7dbd66713ba Launch Stack
HVM ami-07164a6cca615c772 Launch Stack
us-east-1 PV ami-07061814367d71bbe Launch Stack
HVM ami-0c0aa2040c8480d75 Launch Stack
us-east-2 PV Launch Stack
HVM ami-0a100d34c58888f57 Launch Stack
us-west-1 PV ami-0f2370ae6cbb8ecdf Launch Stack
HVM ami-03edd970cd106e566 Launch Stack
us-west-2 PV ami-00097ec6788d9092f Launch Stack
HVM ami-0f1138a7b08b312ed Launch Stack

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

Container Linux Configs

Flatcar 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 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 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 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-0792237d650de6d05 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 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 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-0792237d650de6d05.
  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-06bff0e5027d11427.
  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-07061814367d71bbe.
  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 Linux

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