fixed pdbMinAvailableGreaterThanHPAMinReplicas and added validation for pdbMinAvailableEqualToHPAMinReplicas.

.gitignore

@@ -17,6 +17,8 @@ polaris
 *.test
 
 # Output of the go coverage tool
+coverage.txt
+
 /*.out
 
 Tiltfile

docs/checks/reliability.md

@@ -22,6 +22,7 @@ key | default | description
 `hpaMaxAvailability` | `warning` | Fails when `maxAvailable` lesser or equal than `minAvailable` (if defined) for a HorizontalPodAutoscaler
 `hpaMinAvailability` | `warning` | Fails when `minAvailable` (if defined) lesser or equal to one for a HorizontalPodAutoscaler
 `pdbMinAvailableGreaterThanHPAMinReplicas` | `warning` |  Fails when PDB `minAvailable` is greater than HPA `minReplicas`
+`pdbMinAvailableEqualToHPAMinReplicas` | `warning` |  Fails when PDB `minAvailable` is equal to HPA `minReplicas`
 
 ## Background
 

pkg/config/checks.go

@@ -70,6 +70,7 @@ var (
 		"hpaMaxAvailability",
 		"hpaMinAvailability",
 		"pdbMinAvailableGreaterThanHPAMinReplicas",
+		"pdbMinAvailableEqualToHPAMinReplicas",
 	}
 
 	// BuiltInChecks contains the checks that come pre-installed w/ Polaris

pkg/config/checks/pdbMinAvailableEqualToHPAMinReplicas.yaml

@@ -0,0 +1,7 @@
+successMessage: PDB and HPA are correctly configured
+failureMessage: PDB minAvailable is equal to HPA minReplicas
+category: Reliability
+target: Controller
+controllers:
+  include:
+    - Deployment

pkg/config/default.yaml

@@ -13,6 +13,7 @@ checks:
   hpaMaxAvailability: warning
   hpaMinAvailability: warning
   pdbMinAvailableGreaterThanHPAMinReplicas: warning
+  pdbMinAvailableEqualToHPAMinReplicas: warning
 
   # efficiency
   cpuRequestsMissing: warning

pkg/config/examples/config-full.yaml

@@ -13,6 +13,7 @@ checks:
   hpaMaxAvailability: warning
   hpaMinAvailability: warning
   pdbMinAvailableGreaterThanHPAMinReplicas: warning
+  pdbMinAvailableEqualToHPAMinReplicas: warning
 
   # efficiency
   cpuRequestsMissing: warning

pkg/validator/pdb_hpa_validator.go

@@ -17,6 +17,7 @@ import (
 
 func init() {
 	registerCustomChecks("pdbMinAvailableGreaterThanHPAMinReplicas", pdbMinAvailableGreaterThanHPAMinReplicas)
+	registerCustomChecks("pdbMinAvailableEqualToHPAMinReplicas", pdbMinAvailableEqualToHPAMinReplicas)
 }
 
 func pdbMinAvailableGreaterThanHPAMinReplicas(test schemaTestCase) (bool, []jsonschema.ValError, error) {
@@ -69,12 +70,76 @@ func pdbMinAvailableGreaterThanHPAMinReplicas(test schemaTestCase) (bool, []json
 			}
 		}
 
-		if attachedHPA.Spec.MinReplicas != nil && pdbMinAvailable >= int(*attachedHPA.Spec.MinReplicas) {
+		if attachedHPA.Spec.MinReplicas != nil && pdbMinAvailable > int(*attachedHPA.Spec.MinReplicas) {
 			return false, []jsonschema.ValError{
 				{
 					PropertyPath: "spec.minAvailable",
 					InvalidValue: pdbMinAvailable,
-					Message:      fmt.Sprintf("The minAvailable value in the PodDisruptionBudget(%s) is %d, which is greater or equal than the minReplicas value in the HorizontalPodAutoscaler(%s) (%d)", attachedPDB.Name, pdbMinAvailable, attachedHPA.Name, *attachedHPA.Spec.MinReplicas),
+					Message:      fmt.Sprintf("The minAvailable value in the PodDisruptionBudget(%s) is %d, which is greater than the minReplicas value in the HorizontalPodAutoscaler(%s) (%d)", attachedPDB.Name, pdbMinAvailable, attachedHPA.Name, *attachedHPA.Spec.MinReplicas),
+				},
+			}, nil
+		}
+	}
+
+	return true, nil, nil
+}
+
+func pdbMinAvailableEqualToHPAMinReplicas(test schemaTestCase) (bool, []jsonschema.ValError, error) {
+	if test.ResourceProvider == nil {
+		return true, nil, nil
+	}
+
+	deployment := &appsv1.Deployment{}
+	err := runtime.DefaultUnstructuredConverter.FromUnstructured(test.Resource.Resource.Object, deployment)
+	if err != nil {
+		logrus.Warnf("error converting unstructured to Deployment: %v", err)
+		return true, nil, nil
+	}
+
+	attachedPDB, err := hasPDBAttached(*deployment, test.ResourceProvider.Resources["policy/PodDisruptionBudget"])
+	if err != nil {
+		logrus.Warnf("error getting PodDisruptionBudget: %v", err)
+		return true, nil, nil
+	}
+
+	attachedHPA, err := hasHPAAttached(*deployment, test.ResourceProvider.Resources["autoscaling/HorizontalPodAutoscaler"])
+	if err != nil {
+		logrus.Warnf("error getting HorizontalPodAutoscaler: %v", err)
+		return true, nil, nil
+	}
+
+	if attachedPDB != nil && attachedHPA != nil {
+		logrus.Debugf("both PDB and HPA are attached to deployment %s", deployment.Name)
+
+		if attachedPDB.Spec.MinAvailable == nil {
+			return true, nil, nil
+		}
+
+		pdbMinAvailable, isPercent, err := getIntOrPercentValueSafely(attachedPDB.Spec.MinAvailable)
+		if err != nil {
+			logrus.Warnf("error getting getIntOrPercentValueSafely: %v", err)
+			return true, nil, nil
+		}
+
+		if isPercent {
+			// if the value is a percentage, we need to calculate the actual value
+			if attachedHPA.Spec.MinReplicas == nil {
+				return true, nil, nil
+			}
+
+			pdbMinAvailable, err = intstr.GetScaledValueFromIntOrPercent(attachedPDB.Spec.MinAvailable, int(*attachedHPA.Spec.MinReplicas), true)
+			if err != nil {
+				logrus.Warnf("error getting minAvailable value from PodDisruptionBudget: %v", err)
+				return true, nil, nil
+			}
+		}
+
+		if attachedHPA.Spec.MinReplicas != nil && pdbMinAvailable == int(*attachedHPA.Spec.MinReplicas) {
+			return false, []jsonschema.ValError{
+				{
+					PropertyPath: "spec.minAvailable",
+					InvalidValue: pdbMinAvailable,
+					Message:      fmt.Sprintf("The minAvailable value in the PodDisruptionBudget(%s) is %d, which is equal to the minReplicas value in the HorizontalPodAutoscaler(%s) (%d)", attachedPDB.Name, pdbMinAvailable, attachedHPA.Name, *attachedHPA.Spec.MinReplicas),
 				},
 			}, nil
 		}

test/checks/pdbMinAvailableEqualToHPAMinReplicas/success-gt-percent.yaml

@@ -0,0 +1,44 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: zookeeper
+spec:
+  replicas: 10
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: zookeeper
+        foo: bar
+    spec:
+      containers:
+        - name: zookeeper
+          image: zookeeper
+---
+apiVersion: policy/v1
+kind: PodDisruptionBudget
+metadata:
+  name: zookeeper-pdb
+spec:
+  minAvailable: 150% # 1.5 * 10 = 15
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: zookeeper
+---
+apiVersion: autoscaling/v2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: zookeeper-hpa
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: zookeeper
+  minReplicas: 10
+  maxReplicas: 15
+  metrics:
+    - type: Resource
+      resource:
+        name: cpu
+        target:
+          type: Utilization
+          averageUtilization: 50

test/checks/pdbMinAvailableEqualToHPAMinReplicas/success-gt-scalar.yaml

@@ -0,0 +1,43 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: zookeeper
+spec:
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: zookeeper
+        foo: bar
+    spec:
+      containers:
+        - name: zookeeper
+          image: zookeeper
+---
+apiVersion: policy/v1
+kind: PodDisruptionBudget
+metadata:
+  name: zookeeper-pdb
+spec:
+  minAvailable: 10
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: zookeeper
+---
+apiVersion: autoscaling/v2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: zookeeper-hpa
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: zookeeper
+  minReplicas: 5
+  maxReplicas: 7
+  metrics:
+    - type: Resource
+      resource:
+        name: cpu
+        target:
+          type: Utilization
+          averageUtilization: 50

test/checks/pdbMinAvailableEqualToHPAMinReplicas/success-lt-percent.yaml

@@ -0,0 +1,44 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: zookeeper
+spec:
+  replicas: 10
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: zookeeper
+        foo: bar
+    spec:
+      containers:
+        - name: zookeeper
+          image: zookeeper
+---
+apiVersion: policy/v1
+kind: PodDisruptionBudget
+metadata:
+  name: zookeeper-pdb
+spec:
+  minAvailable: 50% # 0.5 * 10 = 5
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: zookeeper
+---
+apiVersion: autoscaling/v2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: zookeeper-hpa
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: zookeeper
+  minReplicas: 10
+  maxReplicas: 15
+  metrics:
+    - type: Resource
+      resource:
+        name: cpu
+        target:
+          type: Utilization
+          averageUtilization: 50

test/checks/pdbMinAvailableEqualToHPAMinReplicas/success-maxUnavailable.yaml

@@ -0,0 +1,43 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: zookeeper
+spec:
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: zookeeper
+        foo: bar
+    spec:
+      containers:
+        - name: zookeeper
+          image: zookeeper
+---
+apiVersion: policy/v1
+kind: PodDisruptionBudget
+metadata:
+  name: zookeeper-pdb
+spec:
+  maxUnavailable: 5
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: zookeeper
+---
+apiVersion: autoscaling/v2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: zookeeper-hpa
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: zookeeper
+  minReplicas: 5
+  maxReplicas: 7
+  metrics:
+    - type: Resource
+      resource:
+        name: cpu
+        target:
+          type: Utilization
+          averageUtilization: 50

test/checks/pdbMinAvailableEqualToHPAMinReplicas/success.hpa-no-match.yaml

@@ -0,0 +1,43 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: zookeeper
+spec:
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: zookeeper
+        foo: bar
+    spec:
+      containers:
+        - name: zookeeper
+          image: zookeeper
+---
+apiVersion: policy/v1
+kind: PodDisruptionBudget
+metadata:
+  name: zookeeper-pdb
+spec:
+  minAvailable: 5
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: zookeeper
+---
+apiVersion: autoscaling/v2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: zookeeper-hpa
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: no-match
+  minReplicas: 5
+  maxReplicas: 7
+  metrics:
+    - type: Resource
+      resource:
+        name: cpu
+        target:
+          type: Utilization
+          averageUtilization: 50