Primer on ytt Overlays by John Ryan

Ever been frustrated writing an ytt Overlay? Here's that primer you wish you had. ▬▬▬▬▬▬ T I M E S T A M P S ⏰ ▬▬▬▬▬▬ 0:00 Intro 01:05 - Scene 0: The YAML we're handed 01:58 - Scene 1: Targeting the staging area 02:24 - Why use an overlay? 03:15 - What is an overlay? 04:49 - How to read an overlay error message. 06:44 - Overlay = Matcher + Action 09:12 - Adding new items with missing_ok=True 11:40 - Scene 2: Enable Session Management w/ Redis 12:15 - Targeting a specific document 14:13 - Targeting a specific map item 15:46 - Overlaying on arrays 17:27 - Scene 3: Upgrade Nginx 19:23 - Targeting a specific array item 21:10 - Scene 4: Resolving a pod scheduling issue 23:16 - Deleting/removing YAML in an overlay 25:23 - How ytt annotations attach to YAML nodes 29:30 - Scene 5: Enable debugging 34:23 - Editing a string 37:08 - Multiple edits in a single overlay 39:24 - Making an overlay more resilient to future changes 43:47 - Matching on part of a string 45:16 - Short-circuiting an edit with the when= keyword