Run database migrations in pre-install,pre-upgrade hook

[andydennehy]

Description

Link to issue.

This solves issue #98 by adding a pre-upgrade hook which runs pnpm -F backend migrate-production, without being constrained by startupProbe or livenessProbe.

Also, this job runs on pre-install when using an external database. To make sure all necessary environment variables are available to the migration Job, the chart creates ephemeral pre-install ConfigMap and Secret objects that are mounted into the migration container.

[almeidabbm]

Hey hey!! Thank you for you contribution 🚀
This looks mostly good although I do have a couple suggestions

Also, in the PR description you mention changing the entrypoint to node dist/index.js, this change isn't here but I do think it should be kept out so that pods still run migrations if they just get their new version via a kubectl command (not upgraded via helm)

[andydennehy]

Hey hey!! Thank you for you contribution 🚀 This looks mostly good although I do have a couple suggestions

Also, in the PR description you mention changing the entrypoint to node dist/index.js, this change isn't here but I do think it should be kept out so that pods still run migrations if they just get their new version via a kubectl command (not upgraded via helm)

Yes, that was my initial idea but we can leave it like this. It shouldn't matter as long as the migration runs before the backend pods starts...

[almeidabbm]

Can we add a migrationJob.enabled value and conditionally render all the templates:

• configmap
• secrets
• serviceAccount
• migration job

This way someone could opt out of running this job and render the resources

Also, we should bump the version in charts/lightdash/Chart.yaml and charts/lightdash/README.md like - here's a PR with the example https://github.com/lightdash/helm-charts/pull/120/changes

[almeidabbm]

LGTM 🚀

Rendering test results:

  Results:

  ┌─────────────────────────────────┬─────────────────────────────────────────────────────┐
  │            Scenario             │                       Outcome                       │
  ├─────────────────────────────────┼─────────────────────────────────────────────────────┤
  │ Default values                  │ All 4 migration resources render correctly          │
  ├─────────────────────────────────┼─────────────────────────────────────────────────────┤
  │ migrationJob.enabled: false     │ Nothing renders — clean                             │
  ├─────────────────────────────────┼─────────────────────────────────────────────────────┤
  │ migrationJob: {} (empty object) │ Renders fine — Helm deep-merges with chart defaults │
  ├─────────────────────────────────┼─────────────────────────────────────────────────────┤
  │ migrationJob: null              │ Nil pointer error on migrationServiceAccount.yaml:1 - same pattern as scheduler │
  └─────────────────────────────────┴─────────────────────────────────────────────────────┘