Mastodon Docker Setup

Setting up

Clone Mastodon's repository.

# Clone mastodon to ~/live directory
git clone https://github.com/tootsuite/mastodon.git live
# Change directory to ~/live
cd ~/live
# Checkout to the latest stable branch
git checkout $(git tag -l | grep -v 'rc[0-9]*$' | sort -V | tail -n 1)

Review the settings in docker-compose.yml. Note that it is not default to store the postgresql database and redis databases in a persistent storage location. If you plan on running your instance in production, you must uncomment the volumes directive in docker-compose.yml.

Getting the Mastodon image

Using a prebuilt image

If you're not making any local code changes or customizations on your instance, you can use a prebuilt Docker image to avoid the time and resource consumption of a build. Images are available from Docker Hub: https://hub.docker.com/r/tootsuite/mastodon/

To use the prebuilt images:

Open docker-compose.yml in your favorite text editor.
1. Comment out the build: . lines for all images (web, streaming, sidekiq).
2. Edit the image: tootsuite/mastodon lines for all images to include the release you want. The default is latest which is the most recent stable version, however it recommended to explicitly pin a version: If you wanted to use v2.2.0 for example, you would edit the lines to say: image: tootsuite/mastodon:v2.2.0
3. Save the file and exit the text editor.
Run cp .env.production.sample .env.production to bootstrap the configuration. Edit the correct values now.
Run docker-compose build. It will now pull the correct image from Docker Hub.
Set correct file-owner with sudo chown -R 991:991 public/system

Building your own image

You must build your own image if you've made any code modifications. To build your own image:

Open docker-compose.yml in your favorite text editor.
1. Uncomment the build: . lines for all images (web, streaming, sidekiq) if needed.
2. Save the file and exit the text editor.
Run cp .env.production.sample .env.production to bootstrap the configuration. Edit the correct values now.
Run docker-compose build.
Set correct file-owner with chown -R 991:991 public

Building the app

Now the image can be used to generate a configuration with:

docker-compose run --rm web bundle exec rake mastodon:setup

This is an interactive wizard that will guide you through the basic and necessary options and generate new app secrets. At some point it will output your configuration, copy and paste that configuration into the .env.production file.

The wizard will setup the database schema and precompile assets. After it's done, you can launch Mastodon with:

docker-compose up -d

nginx Configuration

You need to configure nginx to serve your Mastodon instance.

Reminder: Replace all occurrences of example.com with your own instance's domain or sub-domain.

cd to /etc/nginx/sites-available and open a new file:

nano /etc/nginx/sites-available/example.com.conf

Copy and paste the following and make edits as necessary:

map $http_upgrade $connection_upgrade {
  default upgrade;
  ''      close;
}

server {
  listen 80;
  listen [::]:80;
  server_name example.com;
  root /home/mastodon/live/public;
  # Useful for Let's Encrypt
  location /.well-known/acme-challenge/ { allow all; }
  location / { return 301 https://$host$request_uri; }
}

server {
  listen 443 ssl http2;
  listen [::]:443 ssl http2;
  server_name example.com;

  ssl_protocols TLSv1.2;
  ssl_ciphers HIGH:!MEDIUM:!LOW:!aNULL:!NULL:!SHA;
  ssl_prefer_server_ciphers on;
  ssl_session_cache shared:SSL:10m;

  ssl_certificate     /etc/letsencrypt/live/example.com/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;

  keepalive_timeout    70;
  sendfile             on;
  client_max_body_size 80m;

  root /home/mastodon/live/public;

  gzip on;
  gzip_disable "msie6";
  gzip_vary on;
  gzip_proxied any;
  gzip_comp_level 6;
  gzip_buffers 16 8k;
  gzip_http_version 1.1;
  gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

  add_header Strict-Transport-Security "max-age=31536000";

  location / {
    try_files $uri @proxy;
  }

  location ~ ^/(emoji|packs|system/accounts/avatars|system/media_attachments/files) {
    add_header Cache-Control "public, max-age=31536000, immutable";
    try_files $uri @proxy;
  }
  
  location /sw.js {
    add_header Cache-Control "public, max-age=0";
    try_files $uri @proxy;
  }

  location @proxy {
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto https;
    proxy_set_header Proxy "";
    proxy_pass_header Server;

    proxy_pass http://127.0.0.1:3000;
    proxy_buffering off;
    proxy_redirect off;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;

    tcp_nodelay on;
  }

  location /api/v1/streaming {
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto https;
    proxy_set_header Proxy "";

    proxy_pass http://127.0.0.1:4000;
    proxy_buffering off;
    proxy_redirect off;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;

    tcp_nodelay on;
  }

  error_page 500 501 502 503 504 /500.html;
}

Activate the nginx configuration added:

cd /etc/nginx/sites-enabled
ln -s ../sites-available/example.com.conf

This configuration makes the assumption you are using Let's Encrypt as your TLS certificate provider.

If you are going to be using Let's Encrypt as your TLS certificate provider, see the next sub-section. If not edit the ssl_certificate and ssl_certificate_key values accordingly.

Let's Encrypt

This section is only relevant if you are using Let's Encrypt as your TLS certificate provider.

Generation Of The Certificate

We need to generate Let's Encrypt certificates.

Make sure to replace any occurrence of 'example.com' with your Mastodon instance's domain.

Make sure that nginx is stopped at this point:

systemctl stop nginx

We will be creating the certificate twice, once with TLS SNI validation in standalone mode and the second time we will be using the webroot method. This is required due to the way nginx and the Let's Encrypt tool works.

certbot certonly --standalone -d example.com

After that successfully completes, we will use the webroot method. This requires nginx to be running:

systemctl start nginx
# The certbot tool will ask if you want to keep the existing certificate or renew it. Choose to renew it.
certbot certonly --webroot -d example.com -w /home/mastodon/live/public/

Automated Renewal Of Let's Encrypt Certificate

Let's Encrypt certificates have a validity period of 90 days.

You need to renew your certificate before the expiration date. Not doing so will make users of your instance unable to access the instance and users of other instances unable to federate with yours.

We can create a cron job that runs daily to do this:

nano /etc/cron.daily/letsencrypt-renew

Copy and paste this script into that file:

#!/usr/bin/env bash
certbot renew
systemctl reload nginx

Save and exit the file.

Make the script executable and restart the cron daemon so that the script runs daily:

chmod +x /etc/cron.daily/letsencrypt-renew
systemctl restart cron

That is it. Your server will renew your Let's Encrypt certificate.

akuechl/mastodon-docker-setup.md