review fixes 3

.changelog/17858.txt

@@ -1,3 +1,3 @@
 ```release-note:feature
-jobspec: Add 'crons' fileld for multiple `cron` entity's 
+jobspec: Add 'crons' fileld for multiple `cron` expressions
 ```

api/jobs.go

@@ -855,27 +855,22 @@ func (p *PeriodicConfig) Canonicalize() {
 // returned. The `time.Location` of the returned value matches that of the
 // passed time.
 func (p *PeriodicConfig) Next(fromTime time.Time) (time.Time, error) {
-	// Once spec parsing
+	// Single spec parsing
 	if p != nil && *p.SpecType == PeriodicSpecCron {
 		if p.Spec != nil && *p.Spec != "" {
 			return cronParseNext(fromTime, *p.Spec)
 		}
 	}
 
 	// multiple specs parsing
-	times := make([]time.Time, len(p.Specs))
 	var nextTime time.Time
-	var err error
-	for i, spec := range p.Specs {
-		times[i], err = cronParseNext(fromTime, spec)
+	for _, spec := range p.Specs {
+		t, err := cronParseNext(fromTime, spec)
 		if err != nil {
 			return time.Time{}, fmt.Errorf("failed parsing cron expression %s: %v", spec, err)
 		}
-	}
-	nextTime = times[0]
-	for _, next := range times {
-		if next.Before(nextTime) {
-			nextTime = next
+		if nextTime.IsZero() || t.Before(nextTime) {
+			nextTime = t
 		}
 	}
 	return nextTime, nil

nomad/structs/structs.go

@@ -4797,6 +4797,12 @@ func (j *Job) Warnings() error {
 		mErr.Errors = append(mErr.Errors, err)
 	}
 
+	// cron -> crons
+	if j.Periodic.Spec != "" {
+		err := fmt.Errorf("cron is deprecated and may be removed in a future release. Use crons instead")
+		mErr.Errors = append(mErr.Errors, err)
+	}
+
 	return mErr.ErrorOrNil()
 }
 
@@ -5685,25 +5691,20 @@ func CronParseNext(fromTime time.Time, spec string) (t time.Time, err error) {
 func (p *PeriodicConfig) Next(fromTime time.Time) (time.Time, error) {
 	switch p.SpecType {
 	case PeriodicSpecCron:
-		// Once spec parsing
+		// Single spec parsing
 		if p.Spec != "" {
 			return CronParseNext(fromTime, p.Spec)
 		}
 
 		// multiple specs parsing
-		times := make([]time.Time, len(p.Specs))
 		var nextTime time.Time
-		var err error
-		for i, spec := range p.Specs {
-			times[i], err = CronParseNext(fromTime, spec)
+		for _, spec := range p.Specs {
+			t, err := CronParseNext(fromTime, spec)
 			if err != nil {
-				return times[i], err
+				return time.Time{}, fmt.Errorf("failed parsing cron expression %s: %v", spec, err)
 			}
-		}
-		nextTime = times[0]
-		for _, next := range times {
-			if next.Before(nextTime) {
-				nextTime = next
+			if nextTime.IsZero() || t.Before(nextTime) {
+				nextTime = t
 			}
 		}
 		return nextTime, nil

website/content/api-docs/json-jobs.mdx

@@ -337,7 +337,8 @@ The `Job` object supports the following keys:
     documentation of supported cron specs and the predefined expressions.
 
   - `Specs` - A cron expressions configuring the interval the job is launched
-    at. Like `Spec`, but support multiple entity.
+    at. Like `Spec`, but support multiple expressions. The job will
+    run at the next time that matches any of the expressions.
 
   - <a id="prohibit_overlap">`ProhibitOverlap`</a> - `ProhibitOverlap` can be set
     to true to enforce that the periodic job doesn't spawn a new instance of the

website/content/docs/job-specification/periodic.mdx

@@ -39,7 +39,8 @@ consistent evaluation when Nomad spans multiple time zones.
   option also includes predefined expressions such as `@daily` or `@weekly`.
 
 - `crons` - A cron expressions configuring the interval the job is launched
-  at. Like `cron`, but support multiple entity.
+  at. Like `cron`, but support expressions. The job will run at the next
+  time that matches any of the expressions.
 
 - `prohibit_overlap` `(bool: false)` - Specifies if this job should wait until
   previous instances of this job have completed. This only applies to this job;