How to Update ArangoDb when running it in Docker

Since I already ran into this problem twice, here is a tiny reminder for my future self and potentially others that google something along the lines of the title. If you did docker pull arangodb at some point in the past, then ran a ArangoDB container for a while with something like the command blow and want to update, just follow the error messages!

docker run \
  -e ARANGO_ROOT_PASSWORD=p4ssw0rd -e ARANGO_STORAGE_ENGINE=rocksdb \
  -v /db-storage/data:/var/lib/arangodb3 -v /db-storage/apps:/var/lib/arangodb3-apps \
  -p 8529:8529 --name arangodb-instance -it arangodb

After a fresh pull, the container does not come back with and docker logs arangodb-instance tells you something like this:

2020-06-28T21:33:36Z [1] ERROR [3bc7f] {startup} Database directory version (30401) is lower than current version (30604).
2020-06-28T21:33:36Z [1] ERROR [ebca0] {startup} ----------------------------------------------------------------------
2020-06-28T21:33:36Z [1] ERROR [24e3c] {startup} It seems like you have upgraded the ArangoDB binary.
2020-06-28T21:33:36Z [1] ERROR [8bcec] {startup} If this is what you wanted to do, please restart with the
2020-06-28T21:33:36Z [1] ERROR [b0360] {startup}   --database.auto-upgrade true
2020-06-28T21:33:36Z [1] ERROR [13414] {startup} option to upgrade the data in the database directory.
2020-06-28T21:33:36Z [1] ERROR [7421a] {startup} Normally you can use the control script to upgrade your database'
2020-06-28T21:33:36Z [1] ERROR [fb665] {startup}   /etc/init.d/arangodb stop
2020-06-28T21:33:36Z [1] ERROR [6753e] {startup}   /etc/init.d/arangodb upgrade
2020-06-28T21:33:36Z [1] ERROR [f7b06] {startup}   /etc/init.d/arangodb start
2020-06-28T21:33:36Z [1] ERROR [24bd1] {startup} ----------------------------------------------------------------------'
2020-06-28T21:33:36Z [1] ERROR [1c156] Database '_system' needs upgrade. Please start the server with --database.auto-upgrade
2020-06-28T21:33:36Z [1] FATAL [2eb08] Database '_system' upgrade failed (bad parameter). Please inspect the logs from the upgrade procedure and try starting the server again.

Simply append --database.auto-upgrade true at the very end of docker run to trigger an upgrade of the data store.