Mastodon on AWS

Want to host your own Mastodon instance on AWS? Here you go.

The architecture consists of the following building blocks.

• Application Load Balancer (ALB)
• ECS and Fargate
• RDS Aurora Serverless v1
• ElastiCache (Redis)
• S3
• SES
• CloudWatch
• IAM
• KMS
• Route 53
• CloudFront

Check out our blog post Mastodon on AWS: Host your own instance for more details.

Prerequisites

First, you need an AWS account.

Second, a top-level or sub domain where you are able to configure a NS record to delegate to the Route 53 nameservers is required. For example, you could register a domain with Rout 53 or use an existing domain and add an NS record to the hosted zone.

Third, we recommend to install Docker Desktop on your local machine to generate the required secrets.

Installation

Deploy the infrastructure

Click here to deploy Mastodon on AWS to your AWS account.

To generate the required secrets and keys use the following commands.

# Start Docker container locally
$ docker run -it ghcr.io/mastodon/mastodon:latest sh

# Generate SECRET_KEY_BASE
$ bundle exec rails secret
758a3b431265776b9ab55910890162bb84aec0617724ca611475c3a774965f2d0aca183091d3c1a84ff3640cf7cc438c559034a2735253ee895b7a2308ac450c

# Generate OTP_SECRET
$ bundle exec rails secret
c528b5cbb0236e4b0c2fe38a6d7ed1edc5fa12608c67a45690e225f005bad8bfbabfa99f7b83cb9c0981ba8fcc5fd76c68918d9bc854bd158c2c23fd6df89abc

# Generate VAPID_PRIVATE_KEY and VAPID_PUBLIC_KEY
$ bundle exec rake mastodon:webpush:generate_vapid_key
VAPID_PRIVATE_KEY=am3vlPBGQGv7Rl3xOKXSv7lRYyWfZITItb88FXX9IOs=
VAPID_PUBLIC_KEY=BMGkIr1PaK4v7Kut7q7eoHtWxu9gEBQ5BeV28xOIR9c9VIvDWvOViTn1SV5G2LIEFGWo0f1dQka-UynR58WMn2Y=

# Generate ACTIVE_RECORD_ENCRYPTION_DETERMINISTIC_KEY, ACTIVE_RECORD_ENCRYPTION_KEY_DERIVATION_SALT, and ACTIVE_RECORD_ENCRYPTION_PRIMARY_KEY
$ bundle exec rake db:encryption:init
ACTIVE_RECORD_ENCRYPTION_DETERMINISTIC_KEY=V2FgMcCXJDCBythgGzWvhIDqiA8TUr2k
ACTIVE_RECORD_ENCRYPTION_KEY_DERIVATION_SALT=otljXH8L0xL1sPwyfOTHGCk5r6uohkCM
ACTIVE_RECORD_ENCRYPTION_PRIMARY_KEY=JnC6I2X2iTVfiu2KNRThvc3fSJnJhCOH

Configure the domain name

By creating the CloudFormation stack, you also created a Route 53 hosted zone for the DomainName you specified as a parameter.

1. Open Route 53 via the AWS Management Console.
2. Select Hosted zones from the sub navigation.
3. Search and open the hosted zone with the domain name of your Mastodon instance (DomainName parameter).
4. Search for the NS record and copy the name servers (e.g., ns-52.awsdns-06.com., ns-659.awsdns-18.net., ns-1698.awsdns-20.co.uk., and ns-1034.awsdns-01.org.).

In case, you are using a top-level domain like cloudonaut.io as the DomainName for your Mastodon instance, you need to modify the name servers for your domain. See Adding or changing name servers and glue records for a domain in case you are using Route 53 to register domains.

In case, you are using a sub-domain like social.cloudonaut.io as the DomainName for your Mastodon instance, you need add an NS record to the parent zone. In our example, we added the NS record social.cloudonaut pointing to ns-52.awsdns-06.com., ns-659.awsdns-18.net., ns-1698.awsdns-20.co.uk., and ns-1034.awsdns-01.org. to the hosted zone managing cloudonaut.io.

Enable the admin user / Accessing tootctl

Use the following instructions to access the Mastodon CLI:

1. Open Elastic Container Service (ECS) via the AWS Management Console.
2. Select the ECS cluster with the name prefixed with the name of your CloudFormation stack (e.g., mastodon-on-aws-*).
3. Note down the full name of the cluster (e.g., mastodon-on-aws-Cluster-1NHBMI9NL62QP-Cluster-pkxgiUVXxLC7).
4. Select the Tasks tab.
5. Search for a task with status Running and a task definition containing *-WebService-* in its name.
6. Note down the task ID (e.g., a752b99a4cf843ce8a957c374fc98abf).
7. Install the AWS CLI.

Use the following command to connect with the container running the Ruby on Rails (Web) application. Replace <CLUSTER_NAME> with the name of your ECS cluster and <TASK_ID> with the ID of a running ECS task.

aws ecs execute-command --cluster <CLUSTER_NAME> --container app --command /bin/bash --interactive --task <TASK_ID>

After the session got established you are ready to use the tootctl.

After signing up, you will need to use the command line to give your newly created account admin privileges. Replace <USERNAME> with your user name (e.g., andreas).

RAILS_ENV=production bin/tootctl accounts modify <USERNAME> --role Owner

Activating SES

In case you haven't used SES in your AWS account before, you most likely need to request production access for SES. This is required so that your Mastodon instance is able to send emails (e.g., registration, forgot password, and many more). See Moving out of the Amazon SES sandbox to learn more.

Costs for running Mastodon on AWS

Estimating costs for AWS is not trivial. My estimation assumes a small Mastodon instance for 1-50 users. The architecture's monthly charges are about $65 per month. The following table lists the details (us-east-1).

Service	Configuration	Monthly Costs (USD)
ECS + Fargate	3 Spot Tasks	$12.08
RDS for Postgres	t4g.micro	$12.10
ElastiCache for Redis	t4g.micro	$11.52
ALB	Load Balancer Hours	$16.20
S3	25 GB + requests	$0.58
Route 53	Hosted Zone	$0.50
Total		$52.97

Please note that the cost estimation is not complete and costs differ per region. For example, the estimation does not include network traffic, CloudWatch, SES, and domain. Monitor your costs!

Update

Here is how you update your infrastructure.

1. Open CloudFormation via the AWS Management Console.
2. Select the CloudFormation stack which is named mastodon-on-aws in case you created the stack with our defaults.
3. Press the Edit button.
4. Choose the option Replace current template with https://s3.eu-central-1.amazonaws.com/mastodon-on-aws-cloudformation/latest/quickstart.yml.
5. Go through the rest of the wizard and keep the defaults.

v0.24.0

Upgrading to Mastodon 4.3 requires to set three new CloudFormation parameters:

ActiveRecordEncryptionDeterministicKey
ActiveRecordEncryptionKeyDerivationSalt
ActiveRecordEncryptionPrimaryKey

Create the values for those parameters as described above (see Installation instructions).

Development

IaC based on cfn-modules.

$ npm install
$ aws cloudformation package --template-file mastodon.yaml --s3-bucket <S3_BUCKET> --output-template-file packaged.yml
$ aws cloudformation deploy --template-file packaged.yml --stack-name mastodon-on-aws --capabilities CAPABILITY_IAM --parameter-overrides "DomainName=<DOMAIN_NAME>" "SecretKeyBase=<SECRET_KEY_BASE>" "OtpSecret=<OTP_SECRET>" "VapidPrivateKey=<VAPID_PRIVATE_KEY>" "VapidPublicKey=<VAPID_PUBLIC_KEY>"

Push Mastodon container image to ECR Public.

MASTODON_VERSION="v4.3.2"
docker pull --platform linux/amd64 ghcr.io/mastodon/mastodon:${MASTODON_VERSION}
docker image tag ghcr.io/mastodon/mastodon:${MASTODON_VERSION} public.ecr.aws/h6i3a8b9/mastodon:${MASTODON_VERSION}
aws ecr-public get-login-password --region us-east-1 | docker login --username AWS --password-stdin public.ecr.aws/h6i3a8b9
docker push public.ecr.aws/h6i3a8b9/mastodon:${MASTODON_VERSION}
docker pull --platform linux/amd64 ghcr.io/mastodon/mastodon-streaming:${MASTODON_VERSION}
docker image tag ghcr.io/mastodon/mastodon-streaming:${MASTODON_VERSION} public.ecr.aws/h6i3a8b9/mastodon-streaming:${MASTODON_VERSION}
aws ecr-public get-login-password --region us-east-1 | docker login --username AWS --password-stdin public.ecr.aws/h6i3a8b9
docker push public.ecr.aws/h6i3a8b9/mastodon-streaming:${MASTODON_VERSION}