Refactor `install`'s `render` output to be helm compatible (#2098)

# Problem
In order to refactor `install` to allow for a more flexible configuration, we
should start with the format of the YAML that it renders. Using the Helm
YAML format will make it easier add flexible configuration options in the
future. Currently, the rendered template that `install` produces does not
follow this format.

# Solution
Use the internals that Helm itself uses to render an inject template that
follows the same formatting rules. Helm's `template` cmd provides a good
outline of what is needed to make Linkerd's `install` cmd work as if it was
a Chart.

# Validation
There are no new tests, but there may not be anything to test at this stage.
This is a WIP PR towards the ultimate goal of `install` allowing a more
flexible configuration.

However, `install` now uses all the Helm `template` internals and therefore
satisfies the needed properties for Helm Charts.

Signed-off-by: Kevin Leimkuhler <kevin@kleimkuhler.com>

Gopkg.lock

@@ -21,6 +21,30 @@
   pruneopts = ""
   revision = "1ff28809256a84bb6966640ff3d0371af82ccba4"
 
+[[projects]]
+  digest = "1:e4b30804a381d7603b8a344009987c1ba351c26043501b23b8c7ce21f0b67474"
+  name = "github.com/BurntSushi/toml"
+  packages = ["."]
+  pruneopts = ""
+  revision = "3012a1dbe2e4bd1391d42b32f0577cb7bbc7f005"
+  version = "v0.3.1"
+
+[[projects]]
+  digest = "1:b856d8248663c39265a764561c1a1a149783f6cc815feb54a1f3a591b91f6eca"
+  name = "github.com/Masterminds/semver"
+  packages = ["."]
+  pruneopts = ""
+  revision = "c7af12943936e8c39859482e61f0574c2fd7fc75"
+  version = "v1.4.2"
+
+[[projects]]
+  digest = "1:846dde8a0ba9d0599cb4ecf300eeb8b2ae54e8905d081afc67ffe828fe7802d5"
+  name = "github.com/Masterminds/sprig"
+  packages = ["."]
+  pruneopts = ""
+  revision = "544a9b1d90f323f6509491b389714fbbd126bee3"
+  version = "v2.17.1"
+
 [[projects]]
   digest = "1:8e47871087b94913898333f37af26732faaab30cdb41571136cf7aec9921dae7"
   name = "github.com/PuerkitoBio/purell"
@@ -37,6 +61,14 @@
   pruneopts = ""
   revision = "de5bf2ad457846296e2031421a34e2568e304e35"
 
+[[projects]]
+  digest = "1:debe400440582cfe5580591afd0f7fdef5b17a25945f06bd3087bc67b4b8fd03"
+  name = "github.com/aokoli/goutils"
+  packages = ["."]
+  pruneopts = ""
+  revision = "41ac8693c5c10a92ea1ff5ac3a7f95646f6123b0"
+  version = "v1.1.0"
+
 [[projects]]
   branch = "master"
   digest = "1:0c5485088ce274fac2e931c1b979f2619345097b39d91af3239977114adf0320"
@@ -52,6 +84,14 @@
   pruneopts = ""
   revision = "195c31b675a7d5ac6859ea5371d6f3bc775f003d"
 
+[[projects]]
+  digest = "1:a9854984bc40330dde2125537b7f46d0a8d7860b3750de2e7cd0a6f904506212"
+  name = "github.com/cyphar/filepath-securejoin"
+  packages = ["."]
+  pruneopts = ""
+  revision = "a261ee33d7a517f054effbf451841abaafe3e0fd"
+  version = "v0.2.2"
+
 [[projects]]
   digest = "1:56c130d885a4aacae1dd9c7b71cfe39912c7ebc1ff7d2b46083c8812996dc43b"
   name = "github.com/davecgh/go-spew"
@@ -126,6 +166,23 @@
   revision = "5899d5c5e619fda5fa86e14795a835f473ca284c"
   version = "v0.17.2"
 
+[[projects]]
+  digest = "1:9ab1b1c637d7c8f49e39d8538a650d7eb2137b076790cff69d160823b505964c"
+  name = "github.com/gobwas/glob"
+  packages = [
+    ".",
+    "compiler",
+    "match",
+    "syntax",
+    "syntax/ast",
+    "syntax/lexer",
+    "util/runes",
+    "util/strings",
+  ]
+  pruneopts = ""
+  revision = "5ccd90ef52e1e632236f7326478d4faa74f99438"
+  version = "v0.2.3"
+
 [[projects]]
   digest = "1:0a3f6a0c68ab8f3d455f8892295503b179e571b7fefe47cc6c556405d1f83411"
   name = "github.com/gogo/protobuf"
@@ -183,6 +240,14 @@
   pruneopts = ""
   revision = "24818f796faf91cd76ec7bddd72458fbced7a6c1"
 
+[[projects]]
+  digest = "1:a25a2c5ae694b01713fb6cd03c3b1ac1ccc1902b9f0a922680a88ec254f968e1"
+  name = "github.com/google/uuid"
+  packages = ["."]
+  pruneopts = ""
+  revision = "9b3b1e0f5f99ae461456d768e7d301a7acdaa2d8"
+  version = "v1.1.0"
+
 [[projects]]
   digest = "1:2a131706ff80636629ab6373f2944569b8252ecc018cda8040931b05d32e3c16"
   name = "github.com/googleapis/gnostic"
@@ -249,6 +314,14 @@
   pruneopts = ""
   revision = "0fb14efe8c47ae851c0034ed7a448854d3d34cf3"
 
+[[projects]]
+  digest = "1:35979179658d20a73693589e67bdc3baf4dc0ef9f524b1dfd3cc55fb5f6ae384"
+  name = "github.com/huandu/xstrings"
+  packages = ["."]
+  pruneopts = ""
+  revision = "f02667b379e2fb5916c3cda2cf31e0eb885d79f8"
+  version = "v1.2.0"
+
 [[projects]]
   digest = "1:23bc0b496ba341c6e3ba24d6358ff4a40a704d9eb5f9a3bd8e8fbd57ad869013"
   name = "github.com/imdario/mergo"
@@ -489,7 +562,11 @@
   branch = "master"
   digest = "1:733bbd39aeb07cba7586933ac301c66f5504f687b393529125affaf9a096d2a8"
   name = "golang.org/x/crypto"
-  packages = ["ssh/terminal"]
+  packages = [
+    "pbkdf2",
+    "scrypt",
+    "ssh/terminal",
+  ]
   pruneopts = ""
   revision = "d9133f5469342136e669e85192a26056b587f503"
 
@@ -977,6 +1054,24 @@
   pruneopts = ""
   revision = "4242d8e6c5dba56827bb7bcf14ad11cda38f3991"
 
+[[projects]]
+  digest = "1:a96ffeefef3ae5a7eb243ce0ac10a0d9b844336e8a360cc1404b2e7903166d55"
+  name = "k8s.io/helm"
+  packages = [
+    "pkg/chartutil",
+    "pkg/engine",
+    "pkg/ignore",
+    "pkg/proto/hapi/chart",
+    "pkg/proto/hapi/version",
+    "pkg/renderutil",
+    "pkg/sympath",
+    "pkg/timeconv",
+    "pkg/version",
+  ]
+  pruneopts = ""
+  revision = "7d2b0c73d734f6586ed222a567c5d103fed435be"
+  version = "v2.12.2"
+
 [[projects]]
   branch = "master"
   digest = "1:526095379da1098c3f191a0008cc59c9bf9927492e63da7689e5de424219c162"
@@ -1074,6 +1169,10 @@
     "k8s.io/code-generator/cmd/defaulter-gen",
     "k8s.io/code-generator/cmd/informer-gen",
     "k8s.io/code-generator/cmd/lister-gen",
+    "k8s.io/helm/pkg/chartutil",
+    "k8s.io/helm/pkg/proto/hapi/chart",
+    "k8s.io/helm/pkg/renderutil",
+    "k8s.io/helm/pkg/timeconv",
   ]
   solver-name = "gps-cdcl"
   solver-version = 1

Gopkg.toml

@@ -32,6 +32,10 @@ required = [
   name = "k8s.io/apimachinery"
   version = "kubernetes-1.11.1"
 
+[[constraint]]
+  name = "k8s.io/helm"
+  version = "v2.12.2"
+
 [[constraint]]
   name = "github.com/briandowns/spinner"
   revision = "195c31b675a7d5ac6859ea5371d6f3bc775f003d"

cli/Dockerfile-bin

@@ -1,5 +1,5 @@
 ## compile binaries
-FROM gcr.io/linkerd-io/go-deps:02bd701f as golang
+FROM gcr.io/linkerd-io/go-deps:8864229a as golang
 WORKDIR /go/src/github.com/linkerd/linkerd2
 COPY cli cli
 COPY controller/k8s controller/k8s

cli/cmd/install.go

@@ -6,14 +6,19 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"path"
 	"strings"
-	"text/template"
 
+	"github.com/ghodss/yaml"
 	"github.com/linkerd/linkerd2/cli/install"
 	"github.com/linkerd/linkerd2/pkg/k8s"
 	uuid "github.com/satori/go.uuid"
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
+	"k8s.io/helm/pkg/chartutil"
+	"k8s.io/helm/pkg/proto/hapi/chart"
+	"k8s.io/helm/pkg/renderutil"
+	"k8s.io/helm/pkg/timeconv"
 )
 
 type installConfig struct {
@@ -80,6 +85,10 @@ const (
 	prometheusProxyOutboundCapacity = 10000
 	defaultControllerReplicas       = 1
 	defaultHAControllerReplicas     = 3
+
+	baseTemplateName          = "templates/base.yaml"
+	tlsTemplateName           = "templates/tls.yaml"
+	proxyInjectorTemplateName = "templates/proxy_injector.yaml"
 )
 
 func newInstallOptions() *installOptions {
@@ -208,33 +217,60 @@ func validateAndBuildConfig(options *installOptions) (*installConfig, error) {
 }
 
 func render(config installConfig, w io.Writer, options *installOptions) error {
-	template, err := template.New("linkerd").Parse(install.Template)
+	// Render raw values and create chart config
+	rawValues, err := yaml.Marshal(config)
 	if err != nil {
 		return err
 	}
-	buf := &bytes.Buffer{}
-	err = template.Execute(buf, config)
+
+	chrtConfig := &chart.Config{Raw: string(rawValues), Values: map[string]*chart.Value{}}
+
+	// Load chart files
+	files := []*chartutil.BufferedFile{
+		{Name: chartutil.ChartfileName, Data: install.Chart},
+		{Name: baseTemplateName, Data: install.BaseTemplate},
+		{Name: tlsTemplateName, Data: install.TLSTemplate},
+		{Name: proxyInjectorTemplateName, Data: install.ProxyInjectorTemplate},
+	}
+
+	// Create chart and render templates
+	chrt, err := chartutil.LoadFiles(files)
 	if err != nil {
 		return err
 	}
 
+	renderOpts := renderutil.Options{
+		ReleaseOptions: chartutil.ReleaseOptions{
+			Name:      "linkerd",
+			IsInstall: true,
+			IsUpgrade: false,
+			Time:      timeconv.Now(),
+			Namespace: controlPlaneNamespace,
+		},
+		KubeVersion: "",
+	}
+
+	renderedTemplates, err := renderutil.Render(chrt, chrtConfig, renderOpts)
+	if err != nil {
+		return err
+	}
+
+	// Merge templates and inject
+	var buf bytes.Buffer
+	bt := path.Join(renderOpts.ReleaseOptions.Name, baseTemplateName)
+	if _, err := buf.WriteString(renderedTemplates[bt]); err != nil {
+		return err
+	}
+
 	if config.EnableTLS {
-		tlsTemplate, err := template.New("linkerd").Parse(install.TLSTemplate)
-		if err != nil {
-			return err
-		}
-		err = tlsTemplate.Execute(buf, config)
-		if err != nil {
+		tt := path.Join(renderOpts.ReleaseOptions.Name, tlsTemplateName)
+		if _, err := buf.WriteString(renderedTemplates[tt]); err != nil {
 			return err
 		}
 
 		if config.ProxyAutoInjectEnabled {
-			proxyInjectorTemplate, err := template.New("linkerd").Parse(install.ProxyInjectorTemplate)
-			if err != nil {
-				return err
-			}
-			err = proxyInjectorTemplate.Execute(buf, config)
-			if err != nil {
+			pt := path.Join(renderOpts.ReleaseOptions.Name, proxyInjectorTemplateName)
+			if _, err := buf.WriteString(renderedTemplates[pt]); err != nil {
 				return err
 			}
 		}
@@ -246,7 +282,7 @@ func render(config installConfig, w io.Writer, options *installOptions) error {
 	// Special case for linkerd-proxy running in the Prometheus pod.
 	injectOptions.proxyOutboundCapacity[config.PrometheusImage] = prometheusProxyOutboundCapacity
 
-	return InjectYAML(buf, w, ioutil.Discard, injectOptions)
+	return InjectYAML(&buf, w, ioutil.Discard, injectOptions)
 }
 
 func (options *installOptions) validate() error {

cli/cmd/testdata/install_output.golden

@@ -985,7 +985,6 @@ data:
       options:
         path: /var/lib/grafana/dashboards
         homeDashboardId: linkerd-top-line
-
 ### Service Account CA ###
 ---
 kind: ServiceAccount
@@ -1296,8 +1295,8 @@ metadata:
   name: linkerd-proxy-injector
   namespace: Namespace
 
----
 ### Proxy Injector RBAC ###
+---
 kind: ClusterRole
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
@@ -1322,8 +1321,8 @@ roleRef:
   name: linkerd-Namespace-proxy-injector
   apiGroup: rbac.authorization.k8s.io
 
----
 ### Proxy Injector Service ###
+---
 kind: Service
 apiVersion: v1
 metadata:
@@ -1342,8 +1341,8 @@ spec:
     port: 443
     targetPort: proxy-injector
 
----
 ### Proxy Sidecar Container Spec ###
+---
 kind: ConfigMap
 apiVersion: v1
 metadata:

cli/cmd/testdata/install_single_namespace_output.golden

@@ -895,7 +895,6 @@ data:
       options:
         path: /var/lib/grafana/dashboards
         homeDashboardId: linkerd-top-line
-
 ### Service Account CA ###
 ---
 kind: ServiceAccount

controller/Dockerfile

@@ -1,5 +1,5 @@
 ## compile controller services
-FROM gcr.io/linkerd-io/go-deps:02bd701f as golang
+FROM gcr.io/linkerd-io/go-deps:8864229a as golang
 WORKDIR /go/src/github.com/linkerd/linkerd2
 COPY controller/gen controller/gen
 COPY pkg pkg

proxy-init/Dockerfile

@@ -1,5 +1,5 @@
 ## compile proxy-init utility
-FROM gcr.io/linkerd-io/go-deps:02bd701f as golang
+FROM gcr.io/linkerd-io/go-deps:8864229a as golang
 WORKDIR /go/src/github.com/linkerd/linkerd2
 COPY ./proxy-init ./proxy-init
 RUN CGO_ENABLED=0 GOOS=linux go install -v ./proxy-init/

web/Dockerfile

@@ -26,7 +26,7 @@ COPY web/app .
 RUN $ROOT/bin/web build
 
 ## compile go server
-FROM gcr.io/linkerd-io/go-deps:02bd701f as golang
+FROM gcr.io/linkerd-io/go-deps:8864229a as golang
 WORKDIR /go/src/github.com/linkerd/linkerd2
 RUN mkdir -p web
 COPY web/main.go web