Refactor prepare package for external use

cmd/maesh/maesh.go

@@ -68,9 +68,11 @@ func maeshCommand(iConfig *cmd.MaeshConfiguration) error {
 		return fmt.Errorf("error building clients: %v", err)
 	}
 
-	prepare := preparepkg.NewPrepare(log, clients)
-	if err = prepare.CheckCluster(); err != nil {
-		return fmt.Errorf("error during cluster check: %v", err)
+	prep := preparepkg.NewPrepare(log, clients)
+
+	_, err = prep.CheckDNSProvider()
+	if err != nil {
+		return fmt.Errorf("no valid DNS provider found: %v", err)
 	}
 
 	minHTTPPort := int32(5000)

cmd/prepare/prepare.go

@@ -45,16 +45,24 @@ func prepareCommand(pConfig *cmd.PrepareConfig) error {
 
 	p := prepare.NewPrepare(log, clients)
 
-	if err = p.CheckCluster(); err != nil {
+	provider, err := p.CheckDNSProvider()
+	if err != nil {
 		return fmt.Errorf("error during cluster check: %v", err)
 	}
 
 	if err = p.StartInformers(pConfig.SMI); err != nil {
 		return fmt.Errorf("error during informer check: %v, this can be caused by pre-existing objects in your cluster that do not conform to the spec", err)
 	}
 
-	if err = p.PatchDNS(pConfig.Namespace, pConfig.ClusterDomain); err != nil {
-		return fmt.Errorf("error initializing cluster: %v", err)
+	switch provider {
+	case prepare.CoreDNS:
+		if err := p.ConfigureCoreDNS(pConfig.ClusterDomain, pConfig.Namespace); err != nil {
+			return fmt.Errorf("unable to configure CoreDNS: %v", err)
+		}
+	case prepare.KubeDNS:
+		if err := p.ConfigureKubeDNS(); err != nil {
+			return fmt.Errorf("unable to configure KubeDNS: %v", err)
+		}
 	}
 
 	return nil

pkg/prepare/fixtures/checkdnsprovider_kubedns.yaml

@@ -0,0 +1,11 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: kube-dns
+  namespace: kube-system
+spec:
+  template:
+    spec:
+      containers:
+        - name: titi
+          image: titi/toto:latest

pkg/prepare/fixtures/checkdnsprovider_no_provider.yaml

@@ -0,0 +1,11 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: notaprovider
+  namespace: kube-system
+spec:
+  template:
+    spec:
+      containers:
+        - name: titi
+          image: titi/toto:latest

pkg/prepare/fixtures/checkdnsprovider_supported_version.yaml

@@ -0,0 +1,13 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: coredns
+  namespace: kube-system
+spec:
+  template:
+    spec:
+      containers:
+        - name: coredns
+          image: image-registry.canonical.com:5000/cdk/coredns/coredns-amd64:1.6.9
+        - name: titi
+          image: titi/toto:latest

pkg/prepare/fixtures/checkdnsprovider_unsupported_version.yaml

@@ -0,0 +1,13 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: coredns
+  namespace: kube-system
+spec:
+  template:
+    spec:
+      containers:
+        - name: coredns
+          image: coredns-amd64:0.4.2
+        - name: titi
+          image: titi/toto:latest

pkg/prepare/fixtures/configurecoredns_already_patched.yaml

@@ -0,0 +1,64 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: coredns
+  namespace: kube-system
+spec:
+  template:
+    spec:
+      volumes:
+        - configMap:
+            name: "other-cfgmap"
+        - configMap:
+            name: "coredns-cfgmap"
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: other-cfgmap
+  namespace: kube-system
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: coredns-cfgmap
+  namespace: kube-system
+  labels:
+    maesh-patched: "true"
+data:
+  Corefile: |
+    .:53 {
+            errors
+            health {
+                lameduck 5s
+            }
+            ready
+            kubernetes {{ pillar['dns_domain'] }} in-addr.arpa ip6.arpa {
+                pods insecure
+                fallthrough in-addr.arpa ip6.arpa
+                ttl 30
+            }
+            prometheus :9153
+            forward . /etc/resolv.conf
+            cache 30
+            loop
+            reload
+            loadbalance
+        }
+    maesh:53 {
+        errors
+        rewrite continue {
+            name regex ([a-zA-Z0-9-_]*)\.([a-zv0-9-_]*)\.maesh toto-{1}-6d61657368-{2}.toto.svc.titi
+            answer name toto-([a-zA-Z0-9-_]*)-6d61657368-([a-zA-Z0-9-_]*)\.toto\.svc\.titi {1}.{2}.maesh
+        }
+        kubernetes titi in-addr.arpa ip6.arpa {
+            pods insecure
+            upstream
+        	fallthrough in-addr.arpa ip6.arpa
+        }
+        forward . /etc/resolv.conf
+        cache 30
+        loop
+        reload
+        loadbalance
+    }

pkg/prepare/fixtures/configurecoredns_missing_configmap.yaml

@@ -0,0 +1,5 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: coredns
+  namespace: kube-system

pkg/prepare/fixtures/configurecoredns_not_patched.yaml

@@ -0,0 +1,45 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: coredns
+  namespace: kube-system
+spec:
+  template:
+    spec:
+      volumes:
+        - configMap:
+            name: "other-cfgmap"
+        - configMap:
+            name: "coredns-cfgmap"
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: other-cfgmap
+  namespace: kube-system
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: coredns-cfgmap
+  namespace: kube-system
+data:
+  Corefile: |
+    .:53 {
+        errors
+        health {
+            lameduck 5s
+        }
+        ready
+        kubernetes {{ pillar['dns_domain'] }} in-addr.arpa ip6.arpa {
+            pods insecure
+            fallthrough in-addr.arpa ip6.arpa
+            ttl 30
+        }
+        prometheus :9153
+        forward . /etc/resolv.conf
+        cache 30
+        loop
+        reload
+        loadbalance
+    }

pkg/prepare/fixtures/configurekubedns_already_patched.yaml

@@ -0,0 +1,27 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: kube-dns
+  namespace: kube-system
+spec:
+  template:
+    spec:
+      volumes:
+        - configMap:
+            name: "kubedns-cfgmap"
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: kubedns-cfgmap
+  namespace: kube-system
+  labels:
+    maesh-patched: "true"
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: coredns
+  namespace: maesh
+spec:
+  clusterIP: "1.2.3.4"

pkg/prepare/fixtures/configurekubedns_not_patched.yaml

@@ -0,0 +1,25 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: kube-dns
+  namespace: kube-system
+spec:
+  template:
+    spec:
+      volumes:
+        - configMap:
+            name: "kubedns-cfgmap"
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: kubedns-cfgmap
+  namespace: kube-system
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: coredns
+  namespace: maesh
+spec:
+  clusterIP: "1.2.3.4"