Charm Testing reference

Hint: Use Juju 3. Otherwise replace juju run ... with juju run-action --wait ... for Juju 2.9.

There are a lot of test types available and most of them are well applicable for Charmed MySQL. Here is a list prepared by Canonical:

Smoke test
Unit tests
Integration tests
System test
Performance test

Smoke test

Complexity: trivial
Speed: fast
Goal: ensure basic functionality works over short amount of time.

Setup an Juju 3.x environment, deploy DB with test application and start “continuous write” test:

juju add-model smoke-test

juju deploy mysql --channel 8.0/edge --config profile=testing
juju add-unit mysql -n 2 # (optional)

juju deploy mysql-test-app --channel latest/edge
juju relate mysql-test-app mysql:database

# Make sure random data inserted into DB by test application:
juju run mysql-test-app/leader get-inserted-data

# Start "continuous write" test:
juju run mysql-test-app/leader start-continuous-writes
export password=$(juju run mysql/leader get-password username=root | yq '.. | select(. | has("password")).password')
watch -n1 -x juju ssh mysql/leader "mysql -h 127.0.0.1 -uroot -p${password} -e \"select count(*) from continuous_writes_database.data\""

# Watch the counter is growing!

Expected results:

mysql-test-app continuously inserts records in database continuous_writes_database table data.
the counters (amount of records in table) are growing on all cluster members

Hints:

# Stop "continuous write" test
juju run mysql-test-app/leader stop-continuous-writes

# Truncate "continuous write" table (delete all records from DB)
juju run mysql-test-app/leader clear-continuous-writes