Merge pull request #33 from aidenkeating/INTLY-1330-backup-docs

INTLY-1330 Add docs for adding CronJobs

README.md

@@ -8,3 +8,4 @@ This repository contains:
 
 * [Backup linux container source code](./image)
 * [Openshift templates](./templates/openshift)
+* [Documentation](./docs)

docs/README.md

@@ -0,0 +1,3 @@
+# Integreatly Backup Documentation
+
+- [Adding new CronJobs](./adding-backup-cronjobs.md)

docs/adding-backup-cronjobs.md

@@ -0,0 +1,47 @@
+# Adding backup CronJobs to Integreatly
+
+Documentation for adding a new backup CronJob to an Integreatly instance.
+
+## Adding a new type of backup
+
+Currently, we have a [backup image](https://github.com/integr8ly/backup-container-image)
+that can perform generic backups for a number of components such as `MySQL`,
+`Redis` and `Postgres`. If there is a new component type that needs to be
+backed-up, it should be added to this image by adding a new script into
+[`image/tools/lib/component/`](https://github.com/integr8ly/backup-container-image/tree/master/image/tools/lib/component).
+
+The name of the script is important, as it will be referenced in the
+[CronJob spec](https://github.com/integr8ly/backup-container-image/blob/master/templates/openshift/backup-cronjob-template.yaml#L35)
+to define what type of backup should be performed in the Job.
+
+For a detailed description of how the default backup CronJob template is used,
+[see the documentation](https://github.com/integr8ly/backup-container-image/tree/master/templates/openshift).
+
+## Adding a new backup CronJob
+
+Adding a new backup CronJob can be done either in the Integreatly installation
+Ansible scripts or in the Operators for a service.
+
+### Installer
+
+When adding a CronJob through the installer, a `backup.yml` task file should be
+added to the component. This `backup.yml` file should follow the same pattern
+as other existing components e.g. [3scale](https://github.com/integr8ly/installation/blob/master/roles/3scale/tasks/backup.yml)
+with any shared logic being kept in the [Backup Role](https://github.com/integr8ly/installation/tree/master/roles/backup).
+
+### Operator
+
+When adding a CronJob through an operator, it can follow the pattern from the
+[Keycloak Operator](https://github.com/integr8ly/keycloak-operator/blob/cf1bcad27ca0a36a4e3ecb8f70f801d19a416839/pkg/keycloak/phaseHandler.go#L219).
+
+### Monitoring
+
+In order for the CronJob and the Jobs that it creates to be monitored correctly
+a number of steps must be done:
+- The CronJob and the Job it creates must have a label `monitoring-key: middleware`.
+This allows us to filter out any CronJobs that aren't related to Integreatly.
+- The Job that the CronJob creates must also have a label `cronjob-name: <cronjob>`,
+where `<cronjob>` is the `name` of the parent CronJob. This allows us to link
+Jobs to their CronJobs.
+- The CronJob must be added to the `backup_expected_cronjobs` var in the `backup`
+role of the installer, regardless of where the CronJob is created.