Initial API draft for serial builds

Author: mfojtik

pkg/build/api/types.go

@@ -86,6 +86,10 @@ type BuildStatus struct {
 	// Cancelled describes if a cancel event was triggered for the build.
 	Cancelled bool
 
+	// Skipped indicates that this build was marked as skipped. The build will be
+	// cancelled, but this field is used to set the appropriate reason.
+	Skipped bool
+
 	// Reason is a brief CamelCase string that describes any failure and is meant for machine parsing and tidy display in the CLI.
 	Reason StatusReason
 
@@ -177,6 +181,9 @@ const (
 	// StatusReasonExceededRetryTimeout is an error condition when the build has
 	// not completed and retrying the build times out.
 	StatusReasonExceededRetryTimeout = "ExceededRetryTimeout"
+
+	// StatusReasonSkipped indicates that the build was skipped.
+	StatusReasonSkipped = "Skipped"
 )
 
 // BuildSource is the input used for the build.
@@ -559,10 +566,30 @@ type BuildConfigSpec struct {
 	// are defined, a new build can only occur as a result of an explicit client build creation.
 	Triggers []BuildTriggerPolicy
 
+	// SchedulePolicy describes how the new build created from this build
+	// configuration will be scheduled for execution.
+	// This is optional, if not specified we default to "parallel".
+	SchedulePolicy *BuildSchedulePolicy
+
 	// BuildSpec is the desired build specification
 	BuildSpec
 }
 
+// BuildSchedulePolicy defines the behaviour of how the new builds are executed
+// from the existing build configuration.
+type BuildSchedulePolicy string
+
+const (
+	// BuildSchedulePolicyParallel schedules new builds immediately after they are
+	// created. Builds will be executed in parallel. This is the default policy.
+	BuildSchedulePolicyParallel BuildSchedulePolicy = "parallel"
+
+	// BuildSchedulePolicySerial schedules new builds to execute in a sequence as
+	// they are created. Every build gets queued up and will execute when the
+	// previous build completes.
+	BuildSchedulePolicySerial BuildSchedulePolicy = "serial"
+)
+
 // BuildConfigStatus contains current state of the build config object.
 type BuildConfigStatus struct {
 	// LastVersion is used to inform about number of last triggered build.