feat(helm): Add --node-selectors and --output flags to helm init

This feature enables users to specify more control over where Tiller pod
lands by allowing "node-selectors" to be specified. Alternatively, the
"--output" flag will skip install and dump Tiller's raw Deployment manifest to stdout so user may alter it as they see fit (probably with a JSON manipulation tool like jq).

Closes #2299

cmd/helm/init.go

@@ -17,6 +17,8 @@ limitations under the License.
 package main
 
 import (
+	"bytes"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -26,6 +28,7 @@ import (
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/client-go/kubernetes"
 
+	"k8s.io/apimachinery/pkg/util/yaml"
 	"k8s.io/helm/cmd/helm/installer"
 	"k8s.io/helm/pkg/getter"
 	"k8s.io/helm/pkg/helm/helmpath"
@@ -120,6 +123,10 @@ func newInitCmd(out io.Writer) *cobra.Command {
 	f.StringVar(&i.serviceAccount, "service-account", "", "name of service account")
 	f.IntVar(&i.maxHistory, "history-max", 0, "limit the maximum number of revisions saved per release. Use 0 for no limit.")
 
+	f.StringVar(&i.opts.NodeSelectors, "node-selectors", "", "labels to specify the node on which Tiller is installed (app=tiller,helm=rocks)")
+	f.VarP(&i.opts.Output, "output", "o", "skip installation and output Tiller's manifest in specified format (json or yaml)")
+	f.StringArrayVar(&i.opts.Values, "override", []string{}, "override values for the Tiller Deployment manifest (can specify multiple or separate values with commas: key1=val1,key2=val2)")
+
 	return cmd
 }
 
@@ -160,31 +167,66 @@ func (i *initCmd) run() error {
 	i.opts.ServiceAccount = i.serviceAccount
 	i.opts.MaxHistory = i.maxHistory
 
-	if settings.Debug {
-		writeYAMLManifest := func(apiVersion, kind, body string, first, last bool) error {
-			w := i.out
-			if !first {
-				// YAML starting document boundary marker
-				if _, err := fmt.Fprintln(w, "---"); err != nil {
-					return err
-				}
+	writeYAMLManifest := func(apiVersion, kind, body string, first, last bool) error {
+		w := i.out
+		if !first {
+			// YAML starting document boundary marker
+			if _, err := fmt.Fprintln(w, "---"); err != nil {
+				return err
 			}
-			if _, err := fmt.Fprintln(w, "apiVersion:", apiVersion); err != nil {
+		}
+		if _, err := fmt.Fprintln(w, "apiVersion:", apiVersion); err != nil {
+			return err
+		}
+		if _, err := fmt.Fprintln(w, "kind:", kind); err != nil {
+			return err
+		}
+		if _, err := fmt.Fprint(w, body); err != nil {
+			return err
+		}
+		if !last {
+			return nil
+		}
+		// YAML ending document boundary marker
+		_, err := fmt.Fprintln(w, "...")
+		return err
+	}
+	if len(i.opts.Output) > 0 {
+		var body string
+		var err error
+		const tm = `{"apiVersion":"extensions/v1beta1","kind":"Deployment",`
+		if body, err = installer.DeploymentManifest(&i.opts); err != nil {
+			return err
+		}
+		switch i.opts.Output.String() {
+		case "json":
+			var out bytes.Buffer
+			jsonb, err := yaml.ToJSON([]byte(body))
+			if err != nil {
 				return err
 			}
-			if _, err := fmt.Fprintln(w, "kind:", kind); err != nil {
+			buf := bytes.NewBuffer(make([]byte, 0, len(tm)+len(jsonb)-1))
+			buf.WriteString(tm)
+			// Drop the opening object delimiter ('{').
+			buf.Write(jsonb[1:])
+			if err := json.Indent(&out, buf.Bytes(), "", "    "); err != nil {
 				return err
 			}
-			if _, err := fmt.Fprint(w, body); err != nil {
+			if _, err = i.out.Write(out.Bytes()); err != nil {
 				return err
 			}
-			if !last {
-				return nil
+
+			return nil
+		case "yaml":
+			if err := writeYAMLManifest("extensions/v1beta1", "Deployment", body, true, false); err != nil {
+				return err
 			}
-			// YAML ending document boundary marker
-			_, err := fmt.Fprintln(w, "...")
-			return err
+			return nil
+		default:
+			return fmt.Errorf("unknown output format: %q", i.opts.Output)
 		}
+	}
+	if settings.Debug {
 
 		var body string
 		var err error

cmd/helm/init_test.go

@@ -35,6 +35,8 @@ import (
 	"k8s.io/client-go/pkg/apis/extensions/v1beta1"
 	testcore "k8s.io/client-go/testing"
 
+	"encoding/json"
+
 	"k8s.io/helm/cmd/helm/installer"
 	"k8s.io/helm/pkg/helm/helmpath"
 )
@@ -303,3 +305,53 @@ func TestInitCmd_tlsOptions(t *testing.T) {
 		}
 	}
 }
+
+// TestInitCmd_output tests that init -o formats are unmarshal-able
+func TestInitCmd_output(t *testing.T) {
+	// This is purely defensive in this case.
+	home, err := ioutil.TempDir("", "helm_home")
+	if err != nil {
+		t.Fatal(err)
+	}
+	dbg := settings.Debug
+	settings.Debug = true
+	defer func() {
+		os.Remove(home)
+		settings.Debug = dbg
+	}()
+	fc := fake.NewSimpleClientset()
+	tests := []struct {
+		expectF    func([]byte, interface{}) error
+		expectName string
+	}{
+		{
+			json.Unmarshal,
+			"json",
+		},
+		{
+			yaml.Unmarshal,
+			"yaml",
+		},
+	}
+	for _, s := range tests {
+		var buf bytes.Buffer
+		cmd := &initCmd{
+			out:        &buf,
+			home:       helmpath.Home(home),
+			kubeClient: fc,
+			opts:       installer.Options{Output: installer.OutputFormat(s.expectName)},
+			namespace:  v1.NamespaceDefault,
+		}
+		if err := cmd.run(); err != nil {
+			t.Fatal(err)
+		}
+		if got := len(fc.Actions()); got != 0 {
+			t.Errorf("expected no server calls, got %d", got)
+		}
+		d := &v1beta1.Deployment{}
+		if err = s.expectF(buf.Bytes(), &d); err != nil {
+			t.Errorf("error unmarshalling init %s output %s %s", s.expectName, err, buf.String())
+		}
+	}
+
+}

cmd/helm/installer/install.go

@@ -19,6 +19,7 @@ package installer // import "k8s.io/helm/cmd/helm/installer"
 import (
 	"fmt"
 	"io/ioutil"
+	"strings"
 
 	"github.com/ghodss/yaml"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
@@ -29,6 +30,7 @@ import (
 	extensionsclient "k8s.io/client-go/kubernetes/typed/extensions/v1beta1"
 	"k8s.io/client-go/pkg/api/v1"
 	"k8s.io/client-go/pkg/apis/extensions/v1beta1"
+	"k8s.io/helm/pkg/chartutil"
 )
 
 // Install uses Kubernetes client to install Tiller.
@@ -74,13 +76,17 @@ func Upgrade(client kubernetes.Interface, opts *Options) error {
 
 // createDeployment creates the Tiller Deployment resource.
 func createDeployment(client extensionsclient.DeploymentsGetter, opts *Options) error {
-	obj := deployment(opts)
-	_, err := client.Deployments(obj.Namespace).Create(obj)
+	obj, err := deployment(opts)
+	if err != nil {
+		return err
+	}
+	_, err = client.Deployments(obj.Namespace).Create(obj)
 	return err
+
 }
 
 // deployment gets the deployment object that installs Tiller.
-func deployment(opts *Options) *v1beta1.Deployment {
+func deployment(opts *Options) (*v1beta1.Deployment, error) {
 	return generateDeployment(opts)
 }
 
@@ -99,7 +105,10 @@ func service(namespace string) *v1.Service {
 // DeploymentManifest gets the manifest (as a string) that describes the Tiller Deployment
 // resource.
 func DeploymentManifest(opts *Options) (string, error) {
-	obj := deployment(opts)
+	obj, err := deployment(opts)
+	if err != nil {
+		return "", err
+	}
 	buf, err := yaml.Marshal(obj)
 	return string(buf), err
 }
@@ -117,8 +126,28 @@ func generateLabels(labels map[string]string) map[string]string {
 	return labels
 }
 
-func generateDeployment(opts *Options) *v1beta1.Deployment {
+// parseNodeSelectors parses a comma delimited list of key=values pairs into a map.
+func parseNodeSelectorsInto(labels string, m map[string]string) error {
+	kv := strings.Split(labels, ",")
+	for _, v := range kv {
+		el := strings.Split(v, "=")
+		if len(el) == 2 {
+			m[el[0]] = el[1]
+		} else {
+			return fmt.Errorf("invalid nodeSelector label: %q", kv)
+		}
+	}
+	return nil
+}
+func generateDeployment(opts *Options) (*v1beta1.Deployment, error) {
 	labels := generateLabels(map[string]string{"name": "tiller"})
+	nodeSelectors := map[string]string{}
+	if len(opts.NodeSelectors) > 0 {
+		err := parseNodeSelectorsInto(opts.NodeSelectors, nodeSelectors)
+		if err != nil {
+			return nil, err
+		}
+	}
 	d := &v1beta1.Deployment{
 		ObjectMeta: metav1.ObjectMeta{
 			Namespace: opts.Namespace,
@@ -166,10 +195,8 @@ func generateDeployment(opts *Options) *v1beta1.Deployment {
 							},
 						},
 					},
-					HostNetwork: opts.EnableHostNetwork,
-					NodeSelector: map[string]string{
-						"beta.kubernetes.io/os": "linux",
-					},
+					HostNetwork:  opts.EnableHostNetwork,
+					NodeSelector: nodeSelectors,
 				},
 			},
 		},
@@ -205,7 +232,40 @@ func generateDeployment(opts *Options) *v1beta1.Deployment {
 			},
 		})
 	}
-	return d
+	// if --override values were specified, ultimately convert values and deployment to maps,
+	// merge them and convert back to Deployment
+	if len(opts.Values) > 0 {
+		// base deployment struct
+		var dd v1beta1.Deployment
+		// get YAML from original deployment
+		dy, err := yaml.Marshal(d)
+		if err != nil {
+			return nil, fmt.Errorf("Error marshalling base Tiller Deployment: %s", err)
+		}
+		// convert deployment YAML to values
+		dv, err := chartutil.ReadValues(dy)
+		if err != nil {
+			return nil, fmt.Errorf("Error converting Deployment manifest: %s ", err)
+		}
+		dm := dv.AsMap()
+		// merge --set values into our map
+		sm, err := opts.valuesMap(dm)
+		if err != nil {
+			return nil, fmt.Errorf("Error merging --set values into Deployment manifest")
+		}
+		finalY, err := yaml.Marshal(sm)
+		if err != nil {
+			return nil, fmt.Errorf("Error marshalling merged map to YAML: %s ", err)
+		}
+		// convert merged values back into deployment
+		err = yaml.Unmarshal(finalY, &dd)
+		if err != nil {
+			return nil, fmt.Errorf("Error unmarshalling Values to Deployment manifest: %s ", err)
+		}
+		d = &dd
+	}
+
+	return d, nil
 }
 
 func generateService(namespace string) *v1.Service {

cmd/helm/installer/install_test.go

@@ -30,6 +30,7 @@ import (
 	"k8s.io/client-go/pkg/apis/extensions/v1beta1"
 	testcore "k8s.io/client-go/testing"
 
+	"k8s.io/helm/pkg/chartutil"
 	"k8s.io/helm/pkg/version"
 )
 
@@ -330,7 +331,7 @@ func TestInstall_canary(t *testing.T) {
 func TestUpgrade(t *testing.T) {
 	image := "gcr.io/kubernetes-helm/tiller:v2.0.0"
 	serviceAccount := "newServiceAccount"
-	existingDeployment := deployment(&Options{
+	existingDeployment, _ := deployment(&Options{
 		Namespace:      v1.NamespaceDefault,
 		ImageSpec:      "imageToReplace",
 		ServiceAccount: "serviceAccountToReplace",
@@ -371,7 +372,7 @@ func TestUpgrade(t *testing.T) {
 func TestUpgrade_serviceNotFound(t *testing.T) {
 	image := "gcr.io/kubernetes-helm/tiller:v2.0.0"
 
-	existingDeployment := deployment(&Options{
+	existingDeployment, _ := deployment(&Options{
 		Namespace: v1.NamespaceDefault,
 		ImageSpec: "imageToReplace",
 		UseCanary: false,
@@ -419,3 +420,107 @@ func tlsTestFile(t *testing.T, path string) string {
 	}
 	return path
 }
+func TestDeploymentManifest_WithNodeSelectors(t *testing.T) {
+	tests := []struct {
+		opts   Options
+		name   string
+		expect map[string]interface{}
+	}{
+		{
+			Options{Namespace: v1.NamespaceDefault, NodeSelectors: "app=tiller"},
+			"nodeSelector app=tiller",
+			map[string]interface{}{"app": "tiller"},
+		},
+		{
+			Options{Namespace: v1.NamespaceDefault, NodeSelectors: "app=tiller,helm=rocks"},
+			"nodeSelector app=tiller, helm=rocks",
+			map[string]interface{}{"app": "tiller", "helm": "rocks"},
+		},
+		// note: nodeSelector key and value are strings
+		{
+			Options{Namespace: v1.NamespaceDefault, NodeSelectors: "app=tiller,minCoolness=1"},
+			"nodeSelector app=tiller, helm=rocks",
+			map[string]interface{}{"app": "tiller", "minCoolness": "1"},
+		},
+	}
+	for _, tt := range tests {
+		o, err := DeploymentManifest(&tt.opts)
+		if err != nil {
+			t.Fatalf("%s: error %q", tt.name, err)
+		}
+
+		var d v1beta1.Deployment
+		if err := yaml.Unmarshal([]byte(o), &d); err != nil {
+			t.Fatalf("%s: error %q", tt.name, err)
+		}
+		// Verify that environment variables in Deployment reflect the use of TLS being enabled.
+		got := d.Spec.Template.Spec.NodeSelector
+		for k, v := range tt.expect {
+			if got[k] != v {
+				t.Errorf("%s: expected nodeSelector value %q, got %q", tt.name, tt.expect, got)
+			}
+		}
+	}
+}
+func TestDeploymentManifest_WithSetValues(t *testing.T) {
+	tests := []struct {
+		opts       Options
+		name       string
+		expectPath string
+		expect     interface{}
+	}{
+		{
+			Options{Namespace: v1.NamespaceDefault, Values: []string{"spec.template.spec.nodeselector.app=tiller"}},
+			"setValues spec.template.spec.nodeSelector.app=tiller",
+			"spec.template.spec.nodeSelector.app",
+			"tiller",
+		},
+		{
+			Options{Namespace: v1.NamespaceDefault, Values: []string{"spec.replicas=2"}},
+			"setValues spec.replicas=2",
+			"spec.replicas",
+			2,
+		},
+		{
+			Options{Namespace: v1.NamespaceDefault, Values: []string{"spec.template.spec.activedeadlineseconds=120"}},
+			"setValues spec.template.spec.activedeadlineseconds=120",
+			"spec.template.spec.activeDeadlineSeconds",
+			120,
+		},
+	}
+	for _, tt := range tests {
+		o, err := DeploymentManifest(&tt.opts)
+		if err != nil {
+			t.Fatalf("%s: error %q", tt.name, err)
+		}
+		values, err := chartutil.ReadValues([]byte(o))
+		if err != nil {
+			t.Errorf("Error converting Deployment manifest to Values: %s", err)
+		}
+		// path value
+		pv, err := values.PathValue(tt.expectPath)
+		if err != nil {
+			t.Errorf("Error retrieving path value from Deployment Values: %s", err)
+		}
+
+		// convert our expected value to match the result type for comparison
+		ev := tt.expect
+		switch pvt := pv.(type) {
+		case float64:
+			floatType := reflect.TypeOf(float64(0))
+			v := reflect.ValueOf(ev)
+			v = reflect.Indirect(v)
+			if !v.Type().ConvertibleTo(floatType) {
+				t.Fatalf("Error converting expected value %v to float64", v.Type())
+			}
+			fv := v.Convert(floatType)
+			if fv.Float() != pvt {
+				t.Errorf("%s: expected value %q, got %q", tt.name, tt.expect, pv)
+			}
+		default:
+			if pv != tt.expect {
+				t.Errorf("%s: expected value %q, got %q", tt.name, tt.expect, pv)
+			}
+		}
+	}
+}

cmd/helm/installer/options.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 
 	"k8s.io/client-go/pkg/api/v1"
+	"k8s.io/helm/pkg/strvals"
 	"k8s.io/helm/pkg/version"
 )
 
@@ -76,6 +77,15 @@ type Options struct {
 	//
 	// Less than or equal to zero means no limit.
 	MaxHistory int
+
+	// NodeSelectors determine which nodes Tiller can land on.
+	NodeSelectors string
+
+	// Output dumps the Tiller manifest in the specified format (e.g. JSON) but skips Helm/Tiller installation.
+	Output OutputFormat
+
+	// Set merges additional values into the Tiller Deployment manifest.
+	Values []string
 }
 
 func (opts *Options) selectImage() string {
@@ -97,3 +107,42 @@ func (opts *Options) pullPolicy() v1.PullPolicy {
 }
 
 func (opts *Options) tls() bool { return opts.EnableTLS || opts.VerifyTLS }
+
+// valuesMap returns user set values in map format
+func (opts *Options) valuesMap(m map[string]interface{}) (map[string]interface{}, error) {
+	for _, skv := range opts.Values {
+		if err := strvals.ParseInto(skv, m); err != nil {
+			return nil, err
+		}
+	}
+	return m, nil
+}
+
+// OutputFormat defines valid values for init output (json, yaml)
+type OutputFormat string
+
+// String returns the string value of the OutputFormat
+func (f *OutputFormat) String() string {
+	return string(*f)
+}
+
+// Type returns the string value of the OutputFormat
+func (f *OutputFormat) Type() string {
+	return "OutputFormat"
+}
+
+const (
+	fmtJSON OutputFormat = "json"
+	fmtYAML OutputFormat = "yaml"
+)
+
+// Set validates and sets the value of the OutputFormat
+func (f *OutputFormat) Set(s string) error {
+	for _, of := range []OutputFormat{fmtJSON, fmtYAML} {
+		if s == string(of) {
+			*f = of
+			return nil
+		}
+	}
+	return fmt.Errorf("unknown output format %q", s)
+}

docs/helm/helm_init.md

@@ -39,6 +39,9 @@ helm init
       --history-max int          limit the maximum number of revisions saved per release. Use 0 for no limit.
       --local-repo-url string    URL for local repository (default "http://127.0.0.1:8879/charts")
       --net-host                 install Tiller with net=host
+      --node-selectors string    labels to specify the node on which Tiller is installed (app=tiller,helm=rocks)
+  -o, --output OutputFormat      skip installation and output Tiller's manifest in specified format (json or yaml)
+      --override stringArray     override values for the Tiller Deployment manifest (can specify multiple or separate values with commas: key1=val1,key2=val2)
       --service-account string   name of service account
       --skip-refresh             do not refresh (download) the local repository cache
       --stable-repo-url string   URL for stable repository (default "https://kubernetes-charts.storage.googleapis.com")
@@ -64,4 +67,4 @@ helm init
 ### SEE ALSO
 * [helm](helm.md)	 - The Helm package manager for Kubernetes.
 
-###### Auto generated by spf13/cobra on 10-Aug-2017
+###### Auto generated by spf13/cobra on 10-Oct-2017

docs/install.md

@@ -197,6 +197,127 @@ Tiller can then be re-installed from the client with:
 $ helm init
 ```
 
+## Advanced Usage
+
+`helm init` provides additional flags for modifying Tiller's deployment
+manifest before it is installed.
+
+### Using `--node-selectors`
+
+The `--node-selectors` flag allows us to specify the node labels required
+for scheduling the Tiller pod.
+
+The example below will create the specified label under the nodeSelector
+property.
+
+```
+helm init --node-selectors "beta.kubernetes.io/os"="linux"
+```
+
+The installed deployment manifest will contain our node selector label.
+
+```
+...
+spec:
+  template:
+    spec:
+      nodeSelector:
+        beta.kubernetes.io/os: linux
+...
+```
+
+
+### Using `--override`
+
+`--override` allows you to specify properties of Tiller's
+deployment manifest. Unlike the `--set` command used elsewhere in Helm,
+`helm init --override` manipulates the specified properties of the final
+manifest (there is no "values" file). Therefore you may specify any valid
+value for any valid property in the deployment manifest.
+
+#### Override annotation
+
+In the example below we use `--override` to add the revision property and set
+its value to 1.
+
+```
+helm init --set metadata.annotations."deployment\.kubernetes\.io/revision"="1"
+```
+Output:
+
+```
+apiVersion: extensions/v1beta1
+kind: Deployment
+metadata:
+  annotations:
+    deployment.kubernetes.io/revision: "1"
+...
+```
+
+#### Override affinity
+
+In the example below we set properties for node affinity. Multiple
+`--override` commands may be combined to modify different properties of the
+same list item.
+
+```
+helm init --override "spec.template.spec.affinity.nodeAffinity.preferredDuringSchedulingIgnoredDuringExecution[0].weight"="1" --override "spec.template.spec.affinity.nodeAffinity.preferredDuringSchedulingIgnoredDuringExecution[0].preference.matchExpressions[0].key"="e2e-az-name"
+```
+
+The specified properties are combined into the
+"preferredDuringSchedulingIgnoredDuringExecution" property's first
+list item.
+
+```
+...
+spec:
+  strategy: {}
+  template:
+    ...
+    spec:
+      affinity:
+        nodeAffinity:
+          preferredDuringSchedulingIgnoredDuringExecution:
+          - preference:
+              matchExpressions:
+              - key: e2e-az-name
+                operator: ""
+            weight: 1
+...
+```
+
+### Using `--output`
+
+The `--output` flag allows us skip the installation of Tiller's deployment
+manifest and simply output the deployment manifest to stdout in either
+JSON or YAML format. The output may then be modified with tools like `jq`
+and installed manually with `kubectl`.
+
+In the example below we execute `helm init` with the `--output json` flag.
+
+```
+helm init --output json
+```
+
+The Tiller installation is skipped and the manifest is output to stdout
+in JSON format.
+
+```
+"apiVersion": "extensions/v1beta1",
+"kind": "Deployment",
+"metadata": {
+    "creationTimestamp": null,
+    "labels": {
+        "app": "helm",
+        "name": "tiller"
+    },
+    "name": "tiller-deploy",
+    "namespace": "kube-system"
+},
+...
+```
+
+
 ## Conclusion
 
 In most cases, installation is as simple as getting a pre-built `helm` binary