improve error messages

[ssube]

The raw error messages from Ajv and diffs from deep-diff are not the most readable, but are wonderfully detailed:

{"name":"salty-dog","hostname":"cerberus","pid":23892,"level":20,"item":{"metadata":{"name":"example"},"spec":{"template":{"spec":{"containers":[{"name":"test"}]}}}},"msg":"checking item","time":"2019-07-01T14:09:15.175Z","v":0}
{"name":"kubernetes-labels","hostname":"cerberus","pid":23892,"level":40,"errors":[{"keyword":"required","dataPath":".metadata","schemaPath":"#/properties/metadata/required","params":{"missingProperty":"labels"},"message":"should have required property 'labels
'"}],"item":{"metadata":{"name":"example"},"spec":{"template":{"spec":{"containers":[{"name":"test"}]}}}},"rule":{"desc":"all resources should have labels","level":"info","name":"kubernetes-labels","select":"$","tags":["kubernetes","labels"],"check":{"type":"o
bject","required":["metadata"],"properties":{"metadata":{"type":"object","required":["labels"],"properties":{"labels":{"type":"object","additionalProperties":false,"patternProperties":{"^[-.a-z0-9]{1,63}$":{"type":"string"}}}}}}}},"msg":"rule failed on item","
time":"2019-07-01T14:09:15.175Z","v":0}                       
{"name":"salty-dog","hostname":"cerberus","pid":23892,"level":40,"count":1,"rule":{"desc":"all resources should have labels","level":"info","name":"kubernetes-labels","select":"$","tags":["kubernetes","labels"],"check":{"type":"object","required":["metadata"],
"properties":{"metadata":{"type":"object","required":["labels"],"properties":{"labels":{"type":"object","additionalProperties":false,"patternProperties":{"^[-.a-z0-9]{1,63}$":{"type":"string"}}}}}}}},"msg":"rule failed","time":"2019-07-01T14:09:15.175Z","v":0}
{"name":"salty-dog","hostname":"cerberus","pid":23892,"level":50,"count":2,"errors":[{"keyword":"required","dataPath":"","schemaPath":"#/required","params":{"missingProperty":"resources"},"message":"should have required property 'resources'"},{"keyword":"requi
red","dataPath":".metadata","schemaPath":"#/properties/metadata/required","params":{"missingProperty":"labels"},"message":"should have required property 'labels'"}],"msg":"some rules failed","time":"2019-07-01T14:09:15.175Z","v":0}

Parts:

• errors
  • improve error messages #71
  • include item index in error messages #116
  • WIP: add index to errors #117

[ssube]

Messages are much improved, but still not quite there:

[
  "some rules failed",
  ".resources.limits should have required property 'memory' at $.spec.template.spec.containers[*] for kubernetes-resources",
  ".metadata should have required property 'labels' at $ for kubernetes-labels"
]

These explain the rule that was running and the selector used, but not which item was selected (the index). For a deployment with many containers, there's no way to tell which container failed without digging through the logs.

[ssube]

Adding the visited item index means moving the ...check.errors.map((err) => friendlyError(ctx, err, this)) call at https://github.com/ssube/salty-dog/blob/fix/xx-build-template/src/rule/SchemaRule.ts#L60 up into visitRules, which should itself be formalized into a generic visiting method and a specific rule inner.