Problem

Currently we store our notification templates in the database.

• https://github.com/coder/coder/blob/43b1a034b10799a369e2b3010c26386d39ec7cf4/coderd/database/migrations/000295_test_notification.up.sql
• https://github.com/coder/coder/blob/43b1a034b10799a369e2b3010c26386d39ec7cf4/coderd/database/migrations/000295_test_notification.down.sql

If we want to make small changes to our notifications we have to make migrations like the following:

• https://github.com/coder/coder/blob/43b1a034b10799a369e2b3010c26386d39ec7cf4/coderd/database/migrations/000311_improve_dormant_workspace_notification.up.sql
• https://github.com/coder/coder/blob/43b1a034b10799a369e2b3010c26386d39ec7cf4/coderd/database/migrations/000311_improve_dormant_workspace_notification.down.sql

Whilst this isn't difficult to do, it does feel a bit janky.

Proposed solution

We move to file-based notification templates. These could be embedded in the Go binary with the embed package.

An example

Given the following notification template:

INSERT INTO notification_templates
	(id, name, title_template, body_template, "group", actions)
VALUES (
	'a9d027b4-ac49-4fb1-9f6d-45af15f64e7a',
	'Workspace Out Of Memory',
	E'Your workspace "{{.Labels.workspace}}" is low on memory',
	E'Hi {{.UserName}},\n\n'||
		E'Your workspace **{{.Labels.workspace}}** has reached the memory usage threshold set at **{{.Labels.threshold}}**.',
	'Workspace Events',
	'[
		{
			"label": "View workspace",
			"url": "{{base_url}}/@{{.UserUsername}}/{{.Labels.workspace}}"
		}
	]'::jsonb
);

We could store this in a TOML file with the design:

id    = "a9d027b4-ac49-4fb1-9f6d-45af15f64e7a"
name  = "Workspace Out Of Memory"
group = "Workspace Events"

title_template = 'Your workspace "{{.Labels.workspace}}" is low on memory'
body_template = '''
Hi {{.UserName}},

Your workspace **{{.Labels.workspace}}** has reached the memory usage threshold set at **{{.Labels.threshold}}*.
'''

[[actions]]
label = "View workspace"
url   = '{{base_url}}/@{{.UserUsername}}/{{.Labels.workspace}}'

Any future changes to this notification wouldn't require creating a new migration where you need to ensure the down migration goes back to the correct state.

Custom Notifications

The original database oriented design was indented to allow making it easy for supporting the use-case of custom notifications. This solution could support that by having a table in the database that stores custom notifications templates.