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 2296.0.0.

View as json feed
EC2 Region AMI Type AMI ID CloudFormation
ap-northeast-1 PV ami-0a735909b2696434a Launch Stack
HVM ami-0f48d694a2142c176 Launch Stack
ap-northeast-2 PV Launch Stack
HVM ami-01e0c3e3fb2fd1d4d Launch Stack
ap-south-1 PV Launch Stack
HVM ami-0a0017de61db3f89e Launch Stack
ap-southeast-1 PV ami-0119573dcc17a598c Launch Stack
HVM ami-0a330fceec5ab0389 Launch Stack
ap-southeast-2 PV ami-0b0d15b53020e06ad Launch Stack
HVM ami-087c3810df156287f Launch Stack
ca-central-1 PV Launch Stack
HVM ami-016b31cf3175e38d1 Launch Stack
eu-central-1 PV ami-029a3a499f584afb6 Launch Stack
HVM ami-01a8c5d3018049c10 Launch Stack
eu-west-1 PV ami-06796d2e4cdca7006 Launch Stack
HVM ami-0907b6b599020535d Launch Stack
eu-west-2 PV Launch Stack
HVM ami-0339f0d21fb3ca853 Launch Stack
eu-west-3 PV Launch Stack
HVM ami-03ce5e4bbbebfe691 Launch Stack
sa-east-1 PV ami-05e7844b4a434c9d5 Launch Stack
HVM ami-022e1383e090b36d1 Launch Stack
us-east-1 PV ami-086089c2c1e8dfd67 Launch Stack
HVM ami-02099fab6b69c02fa Launch Stack
us-east-2 PV Launch Stack
HVM ami-05d6f09829787c5b3 Launch Stack
us-west-1 PV ami-08906cae2d434ff27 Launch Stack
HVM ami-02681f97feb2c9283 Launch Stack
us-west-2 PV ami-0e4903780386be9ca Launch Stack
HVM ami-0063a892bc84ad872 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 2275.99.0.

EC2 Region AMI Type AMI ID CloudFormation
ap-northeast-1 PV ami-05450742526428af1 Launch Stack
HVM ami-0d81fde2245c172c0 Launch Stack
ap-northeast-2 PV Launch Stack
HVM ami-04e182664c18b1c68 Launch Stack
ap-south-1 PV Launch Stack
HVM ami-013ac26b2b9411784 Launch Stack
ap-southeast-1 PV ami-0edf6c0065e3674ff Launch Stack
HVM ami-09eb0a7dbb2488df6 Launch Stack
ap-southeast-2 PV ami-0a0e41507c770a80a Launch Stack
HVM ami-05ee499aad735b568 Launch Stack
ca-central-1 PV Launch Stack
HVM ami-000647feff25a113f Launch Stack
eu-central-1 PV ami-05612a7e234adc899 Launch Stack
HVM ami-0e941237ca9c6020c Launch Stack
eu-west-1 PV ami-02a5e882ccd5c806d Launch Stack
HVM ami-05615f19bc9a28688 Launch Stack
eu-west-2 PV Launch Stack
HVM ami-00c0bff06a7b72e20 Launch Stack
eu-west-3 PV Launch Stack
HVM ami-0bf110313bc69684b Launch Stack
sa-east-1 PV ami-0155cccaf3c3ade3f Launch Stack
HVM ami-0850a9490f590f712 Launch Stack
us-east-1 PV ami-00c9999e21eb3ebf0 Launch Stack
HVM ami-08cc35f20e6626c11 Launch Stack
us-east-2 PV Launch Stack
HVM ami-00ddae2670518a467 Launch Stack
us-west-1 PV ami-0d12b585c2f032284 Launch Stack
HVM ami-073015937ab5efaf4 Launch Stack
us-west-2 PV ami-04dc964d6cc8e66cc Launch Stack
HVM ami-0d802baaf0ebc0cb3 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 2247.5.0.

View as json feed
EC2 Region AMI Type AMI ID CloudFormation
ap-northeast-1 PV ami-0e5952427b3689c00 Launch Stack
HVM ami-0df58a66c0b2fdc66 Launch Stack
ap-northeast-2 PV Launch Stack
HVM ami-0ccb6ca76e1bd6092 Launch Stack
ap-south-1 PV Launch Stack
HVM ami-0c0e023691b55dc61 Launch Stack
ap-southeast-1 PV ami-08b8bb2d63adb096d Launch Stack
HVM ami-061cbfd985a9d8f8e Launch Stack
ap-southeast-2 PV ami-0e05b801b4375160b Launch Stack
HVM ami-083ffda3957a602fe Launch Stack
ca-central-1 PV Launch Stack
HVM ami-0c4c1c1e7cd65b2d2 Launch Stack
eu-central-1 PV ami-0402718f903433533 Launch Stack
HVM ami-0d4f8de8cdb783338 Launch Stack
eu-west-1 PV ami-004609d16c9c8346c Launch Stack
HVM ami-0feee01c888f0da46 Launch Stack
eu-west-2 PV Launch Stack
HVM ami-01051a6731786b642 Launch Stack
eu-west-3 PV Launch Stack
HVM ami-06c0b8dfeb7becf70 Launch Stack
sa-east-1 PV ami-03f07661bf265b740 Launch Stack
HVM ami-0bb50e7274175f3c2 Launch Stack
us-east-1 PV ami-0fbddb4ba1055fb11 Launch Stack
HVM ami-07ecdd174665b9180 Launch Stack
us-east-2 PV Launch Stack
HVM ami-0a23274d2f7966f54 Launch Stack
us-west-1 PV ami-07532592484701f5f Launch Stack
HVM ami-015e4ecc50b60a5f5 Launch Stack
us-west-2 PV ami-056c301420bf97e9d Launch Stack
HVM ami-0cff3b30a036b4013 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-086089c2c1e8dfd67 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-086089c2c1e8dfd67.
  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-0974a6e21f8a50ddd.
  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-0fbddb4ba1055fb11.
  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.