Charm Testing

There are many types of software tests available, most of which are applicable for Charmed PostgreSQL.

This reference addresses the following types:

• Smoke test
• Unit tests
• Integration tests
• System test
• Performance test

Smoke test

This type of test ensures that basic functionality works over a short amount of time.

Steps

1. Set up a juju v.3.x environment
2. Deploy database with test application
3. Start “continuous write” test

juju add-model smoke-test

juju deploy postgresql --channel 14/edge
juju add-unit postgresql -n 2 # (optional)

juju deploy postgresql-test-app
juju integrate postgresql-test-app:first-database postgresql

# Start "continuous write" test:
juju run postgresql-test-app/leader start-continuous-writes
juju run postgresql/leader get-password

export user=operator
export pass=$(juju run postgresql/leader get-password username=${user} | yq '.. | select(. | has("password")).password')
export relname=first-database
export ip=$(juju show-unit postgresql/0 --endpoint database | yq '.. | select(. | has("public-address")).public-address')
export db=$(juju show-unit postgresql/0 --endpoint database | yq '.. | select(. | has("database")).database')
export relid=$(juju show-unit postgresql/0 --endpoint database | yq '.. | select(. | has("relation-id")).relation-id')
export query="select count(*) from continuous_writes"

watch -n1 -x juju run postgresql-test-app/leader run-sql dbname=${db} query="${query}" relation-id=${relid} relation-name=${relname}

# OR

watch -n1 -x juju ssh postgresql/leader "psql postgresql://${user}:${pass}@${ip}:5432/${db} -c \"${query}\""

# Watch that the counter is growing!

Expected results

• postgresql-test-app continuously inserts records into the database received through the integration (the table continuous_writes).
• The counters (amount of records in table) are growing on all cluster members

Tips

To stop the “continuous write” test, run

juju run postgresql-test-app/leader stop-continuous-writes

To truncate the “continuous write” table (i.e. delete all records from database), run

juju run postgresql-test-app/leader clear-continuous-writes

Unit tests

Check the “Contributing” guide and follow tox run -e unit examples there.

Integration tests

Check the “Contributing” guide and follow tox run -e integration examples there.

System test

Check/deploy the charm postgresql-k8s-bundle (charmhub | git).

It deploys and tests all the necessary parts at once.

Performance test

Refer to the sysbench documentation.