ITSquad/Mastodon/Maintenance

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This page aims to describe procedures to maintain the Pirate Party's Mastodon instance.

How to upgrade?

A script called update.sh located in /home/mastodon will reproduce the steps below. Note: this script stops at step 11 and does not go further.

Before running this script or the following commands, please check the instruction for the current release. Sometimes, aditionnal actions are needed (other than migrate database and compile assets)

  1. git fetch -t # update the git branch, including new tags
  2. git stash # prevent changes made to the files to be overwritten (mainly, the docker-compose.yml file)
  3. git checkout vX.X.X # jump to the version where we want to update
  4. git stash pop # restore your changes
  5. docker-compose pull # pull from the docker-hub https://hub.docker.com/r/tootsuite/mastodon/
  6. docker-compose exec db pg_dump -U postgres -Fc postgres > ../dump_$(date +%d-%m-%Y"_"%H_%M_%S).sql # backup the database
  7. tail ../your_dump_file.sql # check if the backup worked, with your_dump_file.sql being the dumpfile you have created in the previous step.
  8. docker-compose down # shut down the containers.
    # You'll maybe get "ERROR: An HTTP request took too long to complete" and other errors. Don't mind this and just wait 'till it's done.
  9. docker-compose run --rm web rails db:migrate # upgrade the database
  10. docker-compose run --rm web rails assets:precompile # complie the assets
  11. docker-compose up -d # start the mastodon instance (create new volumes)
  12. docker-compose logs -ft web # (optional) if you want to monitor the progress. Once this is done you ctrl+c
  13. docker system prune # remove all unused volumes, images, etc.

What to do when something went wrong?

Don't panic. You can restore the database backup as follows:

  1. docker-compose stop
  2. docker-compose start db
  3. docker-compose exec db dropdb postgres -U postgres # remove the db !!!!!!!
  4. docker-compose exec db createdb postgres -U postgres # create a fresh and new db
  5. cat ../your_dump_file.sql | docker exec -i mastodon_db_1 psql -U postgres # restore the database, with "your_dump_file" being a database backup
  6. docker-compose down
  7. docker-compose up -d

You can also go to a previous version of Mastodon with:

  1. git checkout vX.X.X
  2. sed -r 's/(image:.+mastodon)(:.+)?$/\1:vX.X.X/g' docker-compose.yml # don't forget to change this back to "latest" when things get fixed
  3. docker-compose pull

How to backup?

Backups of the database are not enough. We need to backup images, user feeds, etc.

We can simply copy the whole Mastodon's directory. For instance:

tar cvf /home/mastodon/backup/mastodon.tar /home/mastodon/mastodon/

Then, we backup the database:

docker-compose exec db pg_dump -U postgres -Fc postgres | bzip2 --best > /home/mastodon/backup/db/dump_$(date +%d-%m-%Y"_"%H_%M_%S).bz2

It can be interesting to execute the following command before doing a backup:

docker-compose run --rm web bin/tootctl media remove --days=14

This will remove local cache of media older than NUM_DAYS (=7 by default, but here we set at 14 days). Note that this command is executed every day on our instance.


Currently, HgO is doing a daily backup (db + media), and keep them up to 7 days. Data are stored on his laptop. We need a backup solution…

Every night, a backup of the db is also made on the server (but is overwritten by the next nightly backup).

We still need to implement a more reliable solution