migrtest

migrtest

migrtest is a tool for testing migrations on real data. This tools allows to run migrations on databases in a safe way since they're run in a copy of the target database. This tool is useful while developing new migrations, or to Powergate operations which might want to test a new release which has migrations on real data to see if something bad would happen in the real update.

Usage

Run migrtest -h to know about the available flags.

Target a remote go-datastore and run locally

migrtool --origin-remote "$MONGO_URI;$MONGO_DBNAME"

This command will:

• Create a folder run_<TIMESTAMP> which will have the run assets.
• Make a copy of the remote go-datastore to run_<TIMESTAMP>/badger-migrated.
• Run all detected/needed migrations in the copied datastore.
• Print to stdout Powergate output while doing the migrations.
• run_<TIMESTAMP>/badger-migrated will be the migrated go-datastore that might be useful for inspection.

Target a remote go-datastore and run remotely

migrtool --origin-remote "$MONGO_URI;$MONGO_DBNAME" --run-remote

This command will:

• Create a folder run_<TIMESTAMP> which will have the run assets.
• Make a copy of the remote go-datastore to the same MongoDB cluster, in a fixed tmp_powergate_migrtest database, with a collection name run_<TIMESTAMP>.
• Run all detected/needed migrations in the copied datastore.
• Print to stdout Powergate output while doing the migrations.
• The remote collection is kept that might be useful for inspection.

This setup is useful to double-check that running using go-ds-mongo client works correctly. This may be slower since it's targeting a remote datastore, but as close as simulating the real migration as possible.

Recall that you should delete the remote databases if not needed anymore. They're all under the same database tmp_pow_migrtest, so you can simply delete that database for cleaning all runs.

Target a remote go-datastore and skip the migration

This setup might be useful to just have a local copy of the remote go-datastore.

migrtool --origin-remote "$MONGO_URI;$MONGO_DBNAME" --skip-migrations

This command will:

• Create a folder run_<TIMESTAMP> which will have the run assets.
• Make a copy of the remote go-datastore to the same MongoDB cluster, in a fixed tmp_powergate_migrtest database, with a collection name run_<TIMESTAMP>.