scale{Up,Down}Adjustment to add/remove constant number of replicas on scaling (#315)

* `scale{Up,Down}Adjustment` to add/remove constant number of replicas on scaling

Ref #305

* Bump chart version

charts/actions-runner-controller/Chart.yaml

@@ -15,7 +15,7 @@ type: application
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: 0.4.0
+version: 0.5.0
 
 home: https://github.com/summerwind/actions-runner-controller
 

charts/actions-runner-controller/crds/actions.summerwind.dev_horizontalrunnerautoscalers.yaml

@@ -78,6 +78,11 @@ spec:
                     items:
                       type: string
                     type: array
+                  scaleDownAdjustment:
+                    description: ScaleDownAdjustment is the number of runners removed
+                      on scale-down. You can only specify either ScaleDownFactor or
+                      ScaleDownAdjustment.
+                    type: integer
                   scaleDownFactor:
                     description: ScaleDownFactor is the multiplicative factor applied
                       to the current number of runners used to determine how many
@@ -87,6 +92,10 @@ spec:
                     description: ScaleDownThreshold is the percentage of busy runners
                       less than which will trigger the hpa to scale the runners down.
                     type: string
+                  scaleUpAdjustment:
+                    description: ScaleUpAdjustment is the number of runners added
+                      on scale-up. You can only specify either ScaleUpFactor or ScaleUpAdjustment.
+                    type: integer
                   scaleUpFactor:
                     description: ScaleUpFactor is the multiplicative factor applied
                       to the current number of runners used to determine how many