bitnami-containers/bitnami/mastodon

Bitnami Secure Image for Mastodon

What is Mastodon?

Mastodon is self-hosted social network server based on ActivityPub. Written in Ruby, features real-time updates, multimedia attachments and no vendor lock-in.

Overview of Mastodon Trademarks: This software listing is packaged by Bitnami. The respective trademarks mentioned in the offering are owned by the respective companies, and use of them does not imply any affiliation or endorsement.

TL;DR

docker run -it --name mastodon bitnami/mastodon

⚠️ Important Notice: Upcoming changes to the Bitnami Catalog

Beginning August 28th, 2025, Bitnami will evolve its public catalog to offer a curated set of hardened, security-focused images under the new Bitnami Secure Images initiative. As part of this transition:

• Granting community users access for the first time to security-optimized versions of popular container images.
• Bitnami will begin deprecating support for non-hardened, Debian-based software images in its free tier and will gradually remove non-latest tags from the public catalog. As a result, community users will have access to a reduced number of hardened images. These images are published only under the “latest” tag and are intended for development purposes
• Starting August 28th, over two weeks, all existing container images, including older or versioned tags (e.g., 2.50.0, 10.6), will be migrated from the public catalog (docker.io/bitnami) to the “Bitnami Legacy” repository (docker.io/bitnamilegacy), where they will no longer receive updates.
• For production workloads and long-term support, users are encouraged to adopt Bitnami Secure Images, which include hardened containers, smaller attack surfaces, CVE transparency (via VEX/KEV), SBOMs, and enterprise support.

These changes aim to improve the security posture of all Bitnami users by promoting best practices for software supply chain integrity and up-to-date deployments. For more details, visit the Bitnami Secure Images announcement.

Why use Bitnami Secure Images?

• Bitnami Secure Images and Helm charts are built to make open source more secure and enterprise ready.
• Triage security vulnerabilities faster, with transparency into CVE risks using industry standard Vulnerability Exploitability Exchange (VEX), KEV, and EPSS scores.
• Our hardened images use a minimal OS (Photon Linux), which reduces the attack surface while maintaining extensibility through the use of an industry standard package format.
• Stay more secure and compliant with continuously built images updated within hours of upstream patches.
• Bitnami containers, virtual machines and cloud images use the same components and configuration approach - making it easy to switch between formats based on your project needs.
• Hardened images come with attestation signatures (Notation), SBOMs, virus scan reports and other metadata produced in an SLSA-3 compliant software factory.

Only a subset of BSI applications are available for free. Looking to access the entire catalog of applications as well as enterprise support? Try the commercial edition of Bitnami Secure Images today.

Supported tags and respective Dockerfile links

Learn more about the Bitnami tagging policy and the difference between rolling tags and immutable tags in our documentation page.

You can see the equivalence between the different tags by taking a look at the tags-info.yaml file present in the branch folder, i.e bitnami/ASSET/BRANCH/DISTRO/tags-info.yaml.

Subscribe to project updates by watching the bitnami/containers GitHub repo.

Get this image

The recommended way to get the Bitnami Mastodon Docker Image is to pull the prebuilt image from the Docker Hub Registry.

docker pull bitnami/mastodon:latest

To use a specific version, you can pull a versioned tag. You can view the list of available versions in the Docker Hub Registry.

docker pull bitnami/mastodon:[TAG]

If you wish, you can also build the image yourself by cloning the repository, changing to the directory containing the Dockerfile and executing the docker build command. Remember to replace the APP, VERSION and OPERATING-SYSTEM path placeholders in the example command below with the correct values.

git clone https://github.com/bitnami/containers.git
cd bitnami/APP/VERSION/OPERATING-SYSTEM
docker build -t bitnami/APP:latest .

Maintenance

Upgrade this image

Bitnami provides up-to-date versions of Mastodon, including security patches, soon after they are made upstream. We recommend that you follow these steps to upgrade your container.

Step 1: Get the updated image

docker pull bitnami/mastodon:latest

or if you're using Docker Compose, update the value of the image property to bitnami/mastodon:latest.

Step 2: Remove the currently running container

docker rm -v mastodon

or using Docker Compose:

docker-compose rm -v mastodon

Step 3: Run the new image

Re-create your container from the new image.

docker run --name mastodon bitnami/mastodon:latest

or using Docker Compose:

docker-compose up mastodon

Configuration

Environment variables

Customizable environment variables

Name	Description	Default Value
MASTODON_MODE	Mastodon service to run (can be web, streaming or sidekiq).	web
ALLOW_EMPTY_PASSWORD	Allow an empty password.	no
MASTODON_CREATE_ADMIN	Create admin for Mastodon.	true
MASTODON_ADMIN_USERNAME	Mastodon admin username.	user
MASTODON_ADMIN_PASSWORD	Mastodon admin password.	bitnami1
MASTODON_ADMIN_EMAIL	Mastodon admin email.	user@bitnami.org
MASTODON_ALLOW_ALL_DOMAINS	Allow accessing Mastodon with any domain.	true
MASTODON_SECRET_KEY_BASE	Mastodon secret key base.	bitnami123
MASTODON_OTP_SECRET	Mastodon OTP secret.	bitnami123
MASTODON_HTTPS_ENABLED	Enable HTTPS in Mastodon.	false
MASTODON_ASSETS_PRECOMPILE	Run rake assets:precompile on startup.	true
MASTODON_WEB_DOMAIN	Mastodon web domain (for generating links).	127.0.0.1
MASTODON_WEB_HOST	Mastodon web host (for the streaming and sidekiq services to access).	mastodon
MASTODON_WEB_PORT_NUMBER	Mastodon web port.	3000
MASTODON_STREAMING_PORT_NUMBER	Mastodon streaming port.	4000
MASTODON_AUTHORIZED_FETCH	Use secure mode.	false
MASTODON_LIMITED_FEDERATION_MODE	Use an allow-list for federating with other servers.	false
MASTODON_STREAMING_API_BASE_URL	Mastodon public api base url.	ws://localhost:${MASTODON_STREAMING_PORT_NUMBER}
MASTODON_SMTP_LOGIN	SMTP server authentication username.	5432
MASTODON_SMTP_PASSWORD	SMTP server authentication password.	bitnami_mastodon
RAILS_SERVE_STATIC_FILES	Have puma server the static files in the public/ folder	true
MASTODON_BIND_ADDRESS	Address to listen for interfaces	0.0.0.0
MASTODON_DATA_TO_PERSIST	Data to persist from installations.	$MASTODON_ASSETS_DIR $MASTODON_SYSTEM_DIR
MASTODON_USE_LIBVIPS	Use libvips for image processing instead of ImageMagick.	true
MASTODON_MIGRATE_DATABASE	Run rake db:migrate job.	true
MASTODON_DATABASE_HOST	Database server host.	postgresql
MASTODON_DATABASE_PORT_NUMBER	Database server port.	5432
MASTODON_DATABASE_NAME	Database name.	bitnami_mastodon
MASTODON_DATABASE_USERNAME	Database user name.	bn_mastodon
MASTODON_DATABASE_PASSWORD	Database user password.	nil
MASTODON_DATABASE_POOL	Number of DB pool processes.	5
MASTODON_REDIS_HOST	Redis server host.	redis
MASTODON_REDIS_PORT_NUMBER	Redis server port.	6379
MASTODON_REDIS_PASSWORD	Redis user password.	nil
MASTODON_ELASTICSEARCH_ENABLED	Enable Elasticsearch.	true
MASTODON_MIGRATE_ELASTICSEARCH	Run rake chewy:upgrade on startup.	true
MASTODON_ELASTICSEARCH_HOST	Elasticsearch server host.	elasticsearch
MASTODON_ELASTICSEARCH_PORT_NUMBER	Elasticsearch server port.	9200
MASTODON_ELASTICSEARCH_USER	Elasticsearch user.	elastic
MASTODON_ELASTICSEARCH_PASSWORD	Elasticsearch user password.	nil
MASTODON_S3_ENABLED	Enable S3	false
MASTODON_S3_BUCKET	S3 Bucket for storing data	bitnami_mastodon
MASTODON_S3_HOSTNAME	S3 endpoint	minio
MASTODON_S3_PROTOCOL	S3 protocol (can be https or http)	http
MASTODON_S3_PORT_NUMBER	S3 port	9000
MASTODON_S3_ALIAS_HOST	S3 route for uploaded files (for generating links in Mastodon)	localhost:${MASTODON_S3_PORT_NUMBER}
MASTODON_AWS_SECRET_ACCESS_KEY	AWS secret access key	nil
MASTODON_AWS_ACCESS_KEY_ID	AWS access key id	nil
MASTODON_S3_REGION	S3 region	us-east-1
MASTODON_S3_ENDPOINT	S3 endpoint	${MASTODON_S3_PROTOCOL}://${MASTODON_S3_HOSTNAME}:${MASTODON_S3_PORT_NUMBER}
MASTODON_STARTUP_ATTEMPTS	Startup check attempts.	40

Read-only environment variables

Name	Description	Value
MASTODON_BASE_DIR	Mastodon installation directory.	${BITNAMI_ROOT_DIR}/mastodon
MASTODON_VOLUME_DIR	Mastodon volume directory.	/bitnami/mastodon
MASTODON_ASSETS_DIR	Mastodon public assets directory.	${MASTODON_BASE_DIR}/public/assets
MASTODON_SYSTEM_DIR	Mastodon public system directory.	${MASTODON_BASE_DIR}/public/system
MASTODON_TMP_DIR	Mastodon tmp directory.	${MASTODON_BASE_DIR}/tmp
MASTODON_LOGS_DIR	Mastodon logs directory.	${MASTODON_BASE_DIR}/log
NODE_ENV	Node.js environment mode	production
RAILS_ENV	Rails environment mode	production
MASTODON_DAEMON_USER	Mastodon daemon system user.	mastodon
MASTODON_DAEMON_GROUP	Mastodon daemon system group.	mastodon

When you start the Mastodon image, you can adjust the configuration of the instance by passing one or more environment variables either on the docker-compose file or on the docker run command line. Please note that some variables are only considered when the container is started for the first time. If you want to add a new environment variable:

• For docker-compose add the variable name and value under the application section in the docker-compose.yml file present in this repository:

  mastodon-api:
    ...
    environment:
      - MASTODON_ADMIN_PASSWORD=my_password
    ...
  

• For manual execution add a --env option with each variable and value:

  $ docker run -d --name mastodon-api -p 80:8080 -p 443:8443 \
    --env MASTODON_ADMIN_PASSWORD=my_password \
    --env MASTODON_MODE=backend \
    --network mastodon-tier \
    --volume /path/to/mastodon-persistence:/bitnami \
    bitnami/mastodon:latest
  

This container is fully compatible with the upstream Mastodon environment variables. Check the official Mastodon documentation page for more information.

In addition to the official environment variables, the Bitnami Mastodon image adds the following extra environment variables:

Run mode

Mastodon supports three running modes:

• Web: The Mastodon web frontend. It is the essential functional element of Mastodon.
• Streaming: Necessary for performing real-time interactions inside Mastodon.
• Sidekiq: Performs background operations like sending emails.

The running mode is defined via the MASTODON_MODE environment variable. The possible values are web, streaming and sidekiq.

Connect Mastodon container to an existing database

The Bitnami Mastodon container supports connecting the Mastodon application to an external database. This would be an example of using an external database for Mastodon.

• Modify the docker-compose.yml file present in this repository:

     mastodon:
       ...
       environment:
  -      - DB_HOST=postgresql
  +      - DB_HOST=postgresql_host
         - DB_PORT=5432
         - DB_NAME=mastodon_db
         - DB_USER=mastodon_user
  +      - DB_PASS=mastodon_password
       ...
  

• For manual execution:

  $ docker run -d --name mastodon\
    -p 8080:8080 -p 8443:8443 \
    --network mastodon-network \
    --env DB_HOST=postgresql_host \
    --env DB_PORT=5432 \
    --env DB_NAME=mastodon_db \
    --env DB_USER=mastodon_user \
    --env DB_PASS=mastodon_password \
    --volume mastodon_data:/bitnami/mastodon \
    bitnami/mastodon:latest
  

FIPS configuration in Bitnami Secure Images

The Bitnami Mastodon Docker image from the Bitnami Secure Images catalog includes extra features and settings to configure the container with FIPS capabilities. You can configure the next environment variables:

• OPENSSL_FIPS: whether OpenSSL runs in FIPS mode or not. yes (default), no.

Logging

The Bitnami Mastodon Docker image sends the container logs to stdout. To view the logs:

docker logs mastodon

Or using Docker Compose:

docker-compose logs mastodon

You can configure the containers logging driver using the --log-driver option if you wish to consume the container logs differently. In the default configuration docker uses the json-file driver.

Using docker-compose.yaml

Please be aware this file has not undergone internal testing. Consequently, we advise its use exclusively for development or testing purposes. For production-ready deployments, we highly recommend utilizing its associated Bitnami Helm chart.

If you detect any issue in the docker-compose.yaml file, feel free to report it or contribute with a fix by following our Contributing Guidelines.

Contributing

We'd love for you to contribute to this Docker image. You can request new features by creating an issue or submitting a pull request with your contribution.

Issues

If you encountered a problem running this container, you can file an issue. For us to provide better support, be sure to fill the issue template.

License

Copyright © 2025 Broadcom. The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.