Don't fail to parse YAML on template errors

cmd/pint/tests/0081_rulefmt.txt

@@ -3,9 +3,9 @@ pint.error --no-color lint rules
 cmp stderr stderr.txt
 
 -- stderr.txt --
-level=error msg="Failed to unmarshal file content" error="0:0: group \"foo\", rule 1, \"foo\": field 'expr' must be set in rule" lines=1-4 path=rules/strict.yml
-rules/strict.yml:1: field 'expr' must be set in rule (yaml/parse)
-groups:
+level=info msg="File parsed" path=rules/strict.yml rules=1
+rules/strict.yml:4: missing expr key (yaml/parse)
+  - record: foo
 
 level=info msg="Problems found" Fatal=1
 level=fatal msg="Fatal error" error="problems found"

cmd/pint/tests/0086_rulefmt_ignored_errors.txt

@@ -0,0 +1,44 @@
+pint.error --no-color lint rules
+! stdout .
+cmp stderr stderr.txt
+
+-- stderr.txt --
+level=info msg="File parsed" path=rules/strict.yml rules=5
+rules/strict.yml:4: incomplete rule, no alert or record key (yaml/parse)
+  - expr: MissingAlertOrRecord
+
+rules/strict.yml:7: syntax error: no expression found in input (promql/syntax)
+    expr: 
+
+rules/strict.yml:10: syntax error: unknown function with name "sumz" (promql/syntax)
+    expr: sumz(0)
+
+rules/strict.yml:15: template parse error: function "bogus" not defined (alerts/template)
+      dashboard: '{{ bogus }}'
+
+rules/strict.yml:20: template parse error: function "bogus" not defined (alerts/template)
+      dashboard: '{{ bogus }}'
+
+level=info msg="Problems found" Fatal=5
+level=fatal msg="Fatal error" error="problems found"
+-- rules/strict.yml --
+groups:
+- name: foo
+  rules:
+  - expr: MissingAlertOrRecord
+
+  - alert: MissingExpr
+    expr: 
+
+  - record: BadPromQL
+    expr: sumz(0)
+
+  - alert: IgnoreTemplateErrors
+    expr: up == 0
+    annotations:
+      dashboard: '{{ bogus }}'
+
+  - alert: IgnoreTemplateErrors
+    expr: up == 0
+    labels:
+      dashboard: '{{ bogus }}'

docs/changelog.md

@@ -2,6 +2,11 @@
 
 ## v0.26.0
 
+### Fixed
+
+- Strict parsing mode shouldn't fail on template errors, those will be later
+  reported by `alerts/template` check.
+
 ### Added
 
 - [promql/range_query](checks/promql/range_query.md) check.

internal/discovery/discovery.go

@@ -21,8 +21,10 @@ const (
 
 var ignoredErrors = []string{
 	"one of 'record' or 'alert' must be set",
+	"field 'expr' must be set in rule",
 	"could not parse expression: ",
 	"cannot unmarshal !!seq into rulefmt.ruleGroups",
+	": template: __",
 }
 
 func isStrictIgnored(err error) bool {