ensure addon image is overwritten during upgrade

docs/clusterdefinition.md

@@ -180,7 +180,21 @@ Above you see custom configuration for both tiller and kubernetes-dashboard. Bot
 
 See https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/ for more on Kubernetes resource limits.
 
-Additionally above, we specified a custom docker image for tiller, let's say we want to build a cluster and test an alpha version of tiller in it.
+Additionally above, we specified a custom docker image for tiller, let's say we want to build a cluster and test an alpha version of tiller in it. **Important note!** customizing the image is not sticky across upgrade/scale, to ensure that acs-engine always delivers a version-curated, known-working addon when moving a cluster to a new version. Considering all that, providing a custom image reference for an addon configuration should be considered for testing/development, but not for a production cluster. If you'd like to entirely customize one of the addons available, including across scale/upgrade operations, you may include in an addon's spec a gzip+base64-encoded (in that order) string of a Kubernetes yaml manifest. E.g.,
+
+```
+"kubernetesConfig": {
+    "addons": [
+        {
+            "name": "kube-proxy-daemonset",
+            "enabled": true,
+            "data": "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"
+        }
+    ]
+}
+```
+
+The reason for the unsightly gzip+base64 encoded input type is to optimize delivery payload, and to squash a human-maintainable yaml file representation into something that can be tightly pasted into a JSON string value without the arguably more unsightly carriage returns / whitespace that would be delivered with a literal copy/paste of a Kubernetes manifest.
 
 Finally, the `addons.enabled` boolean property was omitted above; that's by design. If you specify a `containers` configuration, acs-engine assumes you're enabling the addon. The very first example above demonstrates a simple "enable this addon with default configuration" declaration.
 

pkg/api/addons.go

@@ -7,7 +7,7 @@ import (
 	"github.com/Azure/acs-engine/pkg/helpers"
 )
 
-func (cs *ContainerService) setAddonsConfig() {
+func (cs *ContainerService) setAddonsConfig(isUpdate bool) {
 	o := cs.Properties.OrchestratorProfile
 	cloudSpecConfig := cs.GetCloudSpecConfig()
 	k8sComponents := K8sComponentsByVersionMap[o.OrchestratorVersion]
@@ -252,7 +252,7 @@ func (cs *ContainerService) setAddonsConfig() {
 	}
 
 	for _, addon := range defaultAddons {
-		synthesizeAddonsConfig(o.KubernetesConfig.Addons, addon, false)
+		synthesizeAddonsConfig(o.KubernetesConfig.Addons, addon, false, isUpdate)
 	}
 }
 
@@ -266,7 +266,7 @@ func getAddonsIndexByName(addons []KubernetesAddon, name string) int {
 }
 
 // assignDefaultAddonVals will assign default values to addon from defaults, for each property in addon that has a zero value
-func assignDefaultAddonVals(addon, defaults KubernetesAddon) KubernetesAddon {
+func assignDefaultAddonVals(addon, defaults KubernetesAddon, isUpdate bool) KubernetesAddon {
 	if addon.Enabled == nil {
 		addon.Enabled = defaults.Enabled
 	}
@@ -275,7 +275,7 @@ func assignDefaultAddonVals(addon, defaults KubernetesAddon) KubernetesAddon {
 		if c < 0 {
 			addon.Containers = append(addon.Containers, defaults.Containers[i])
 		} else {
-			if addon.Containers[c].Image == "" {
+			if addon.Containers[c].Image == "" || isUpdate {
 				addon.Containers[c].Image = defaults.Containers[i].Image
 			}
 			if addon.Containers[c].CPURequests == "" {
@@ -303,11 +303,11 @@ func assignDefaultAddonVals(addon, defaults KubernetesAddon) KubernetesAddon {
 	return addon
 }
 
-func synthesizeAddonsConfig(addons []KubernetesAddon, addon KubernetesAddon, enableIfNil bool) {
+func synthesizeAddonsConfig(addons []KubernetesAddon, addon KubernetesAddon, enableIfNil bool, isUpdate bool) {
 	i := getAddonsIndexByName(addons, addon.Name)
 	if i >= 0 {
 		if addons[i].IsEnabled(enableIfNil) {
-			addons[i] = assignDefaultAddonVals(addons[i], addon)
+			addons[i] = assignDefaultAddonVals(addons[i], addon, isUpdate)
 		}
 	}
 }

pkg/api/defaults.go

@@ -226,7 +226,7 @@ func (cs *ContainerService) setOrchestratorDefaults(isUpdate bool) {
 		}
 
 		// Configure addons
-		cs.setAddonsConfig()
+		cs.setAddonsConfig(isUpdate)
 		// Configure kubelet
 		cs.setKubeletConfig()
 		// Configure controller-manager

pkg/api/defaults_test.go

@@ -237,6 +237,7 @@ func TestAssignDefaultAddonImages(t *testing.T) {
 
 func TestAssignDefaultAddonVals(t *testing.T) {
 	addonName := "testaddon"
+	customImage := "myimage"
 	customCPURequests := "60m"
 	customMemoryRequests := "160Mi"
 	customCPULimits := "40m"
@@ -248,6 +249,7 @@ func TestAssignDefaultAddonVals(t *testing.T) {
 		Containers: []KubernetesContainerSpec{
 			{
 				Name:           addonName,
+				Image:          customImage,
 				CPURequests:    customCPURequests,
 				MemoryRequests: customMemoryRequests,
 				CPULimits:      customCPULimits,
@@ -256,10 +258,14 @@ func TestAssignDefaultAddonVals(t *testing.T) {
 		},
 	}
 	addonWithDefaults := getMockAddon(addonName)
-	modifiedAddon := assignDefaultAddonVals(customAddon, addonWithDefaults)
+	isUpdate := false
+	modifiedAddon := assignDefaultAddonVals(customAddon, addonWithDefaults, isUpdate)
 	if modifiedAddon.Containers[0].Name != customAddon.Containers[0].Name {
 		t.Fatalf("assignDefaultAddonVals() should not have modified Containers 'Name' value %s to %s,", customAddon.Containers[0].Name, modifiedAddon.Containers[0].Name)
 	}
+	if modifiedAddon.Containers[0].Image != customAddon.Containers[0].Image {
+		t.Fatalf("assignDefaultAddonVals() should not have modified Containers 'Image' value %s to %s,", customAddon.Containers[0].Image, modifiedAddon.Containers[0].Image)
+	}
 	if modifiedAddon.Containers[0].CPURequests != customAddon.Containers[0].CPURequests {
 		t.Fatalf("assignDefaultAddonVals() should not have modified Containers 'CPURequests' value %s to %s,", customAddon.Containers[0].CPURequests, modifiedAddon.Containers[0].CPURequests)
 	}
@@ -283,7 +289,11 @@ func TestAssignDefaultAddonVals(t *testing.T) {
 			},
 		},
 	}
-	modifiedAddon = assignDefaultAddonVals(customAddon, addonWithDefaults)
+	isUpdate = false
+	modifiedAddon = assignDefaultAddonVals(customAddon, addonWithDefaults, isUpdate)
+	if modifiedAddon.Containers[0].Image != addonWithDefaults.Containers[0].Image {
+		t.Fatalf("assignDefaultAddonVals() should have assigned a default 'Image' value of %s, instead assigned %s,", addonWithDefaults.Containers[0].Image, modifiedAddon.Containers[0].Image)
+	}
 	if modifiedAddon.Containers[0].CPURequests != addonWithDefaults.Containers[0].CPURequests {
 		t.Fatalf("assignDefaultAddonVals() should have assigned a default 'CPURequests' value of %s, instead assigned %s,", addonWithDefaults.Containers[0].CPURequests, modifiedAddon.Containers[0].CPURequests)
 	}
@@ -309,7 +319,11 @@ func TestAssignDefaultAddonVals(t *testing.T) {
 			},
 		},
 	}
-	modifiedAddon = assignDefaultAddonVals(customAddon, addonWithDefaults)
+	isUpdate = false
+	modifiedAddon = assignDefaultAddonVals(customAddon, addonWithDefaults, isUpdate)
+	if modifiedAddon.Containers[0].Image != addonWithDefaults.Containers[0].Image {
+		t.Fatalf("assignDefaultAddonVals() should have assigned a default 'Image' value of %s, instead assigned %s,", addonWithDefaults.Containers[0].Image, modifiedAddon.Containers[0].Image)
+	}
 	if modifiedAddon.Containers[0].Name != customAddon.Containers[0].Name {
 		t.Fatalf("assignDefaultAddonVals() should not have modified Containers 'Name' value %s to %s,", customAddon.Containers[0].Name, modifiedAddon.Containers[0].Name)
 	}
@@ -323,11 +337,29 @@ func TestAssignDefaultAddonVals(t *testing.T) {
 		t.Fatalf("assignDefaultAddonVals() should not have modified Containers 'MemoryLimits' value %s to %s,", customAddon.Containers[0].MemoryLimits, modifiedAddon.Containers[0].MemoryLimits)
 	}
 
+	// Verify that an addon with a custom image value will be overridden during upgrade/scale
+	customAddon = KubernetesAddon{
+		Name:    addonName,
+		Enabled: helpers.PointerToBool(true),
+		Containers: []KubernetesContainerSpec{
+			{
+				Name:  addonName,
+				Image: customImage,
+			},
+		},
+	}
+	isUpdate = true
+	modifiedAddon = assignDefaultAddonVals(customAddon, addonWithDefaults, isUpdate)
+	if modifiedAddon.Containers[0].Image != addonWithDefaults.Containers[0].Image {
+		t.Fatalf("assignDefaultAddonVals() should have assigned a default 'Image' value of %s, instead assigned %s,", addonWithDefaults.Containers[0].Image, modifiedAddon.Containers[0].Image)
+	}
+
 	addonWithDefaults.Config = map[string]string{
 		"os":    "Linux",
 		"taint": "node.kubernetes.io/memory-pressure",
 	}
-	modifiedAddon = assignDefaultAddonVals(customAddon, addonWithDefaults)
+	isUpdate = false
+	modifiedAddon = assignDefaultAddonVals(customAddon, addonWithDefaults, isUpdate)
 
 	if modifiedAddon.Config["os"] != "Linux" {
 		t.Error("assignDefaultAddonVals() should have added the default config property")