Add ability to add helm chart repositories (#203)

**What this PR does / why we need it**:

**Which issue(s) this PR fixes**:

Fixes #166

**Does this PR introduce a user-facing change?**:
<!--
If no, just write "NONE" in the release-note block below.
-->
```release-note
NONE
```

This PR was merged by Kapetanios.

pkg/app/piped/chartrepo/BUILD.bazel

@@ -0,0 +1,12 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["chartrepo.go"],
+    importpath = "github.com/pipe-cd/pipe/pkg/app/piped/chartrepo",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//pkg/config:go_default_library",
+        "@org_uber_go_zap//:go_default_library",
+    ],
+)

pkg/app/piped/chartrepo/chartrepo.go

@@ -0,0 +1,54 @@
+// Copyright 2020 The PipeCD Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package chartrepo manages a list of configured helm repositories.
+package chartrepo
+
+import (
+	"context"
+	"fmt"
+	"os/exec"
+
+	"go.uber.org/zap"
+
+	"github.com/pipe-cd/pipe/pkg/config"
+)
+
+type registry interface {
+	Helm(ctx context.Context, version string) (string, bool, error)
+}
+
+// Add installs all specified Helm Chart repositories.
+// https://helm.sh/docs/topics/chart_repository/
+// helm repo add fantastic-charts https://fantastic-charts.storage.googleapis.com
+// helm repo add fantastic-charts https://fantastic-charts.storage.googleapis.com --username my-username --password my-password
+func Add(ctx context.Context, repos []config.HelmChartRepository, reg registry, logger *zap.Logger) error {
+	helm, _, err := reg.Helm(ctx, "")
+	if err != nil {
+		return fmt.Errorf("failed to find helm to add repos (%v)", err)
+	}
+	for _, repo := range repos {
+		args := []string{"repo", "add", repo.Address}
+		if repo.Username != "" || repo.Password != "" {
+			args = append(args, "--username", repo.Username, "--password", repo.Password)
+		}
+		cmd := exec.CommandContext(ctx, helm, args...)
+		out, err := cmd.CombinedOutput()
+		if err != nil {
+			return fmt.Errorf("failed to add chart repository %s: %s (%w)", repo.Name, string(out), err)
+		}
+		logger.Info(fmt.Sprintf("successfully added chart repository %s", repo.Name))
+	}
+	return nil
+}

pkg/app/piped/cmd/piped/BUILD.bazel

@@ -12,6 +12,7 @@ go_library(
         "//pkg/app/piped/apistore/applicationstore:go_default_library",
         "//pkg/app/piped/apistore/commandstore:go_default_library",
         "//pkg/app/piped/apistore/deploymentstore:go_default_library",
+        "//pkg/app/piped/chartrepo:go_default_library",
         "//pkg/app/piped/controller:go_default_library",
         "//pkg/app/piped/driftdetector:go_default_library",
         "//pkg/app/piped/executor/registry:go_default_library",

pkg/app/piped/cmd/piped/piped.go

@@ -33,6 +33,7 @@ import (
 	"github.com/pipe-cd/pipe/pkg/app/piped/apistore/applicationstore"
 	"github.com/pipe-cd/pipe/pkg/app/piped/apistore/commandstore"
 	"github.com/pipe-cd/pipe/pkg/app/piped/apistore/deploymentstore"
+	"github.com/pipe-cd/pipe/pkg/app/piped/chartrepo"
 	"github.com/pipe-cd/pipe/pkg/app/piped/controller"
 	"github.com/pipe-cd/pipe/pkg/app/piped/driftdetector"
 	"github.com/pipe-cd/pipe/pkg/app/piped/livestatereporter"
@@ -122,6 +123,14 @@ func (p *piped) run(ctx context.Context, t cli.Telemetry) error {
 		return err
 	}
 
+	// Add configured Helm chart repositories.
+	if len(cfg.ChartRepositories) > 0 {
+		if err := chartrepo.Add(ctx, cfg.ChartRepositories, toolregistry.DefaultRegistry(), t.Logger); err != nil {
+			t.Logger.Error("failed to add configured chart repositories", zap.Error(err))
+			return err
+		}
+	}
+
 	// Make gRPC client and connect to the API.
 	apiClient, err := p.createAPIClient(ctx, cfg.ProjectID, cfg.PipedID, cfg.PipedKeyFile, t.Logger)
 	if err != nil {

pkg/config/piped.go

@@ -40,7 +40,9 @@ type PipedSpec struct {
 	// Git configuration needed for git commands.
 	Git PipedGit `json:"git"`
 	// List of git repositories this piped will handle.
-	Repositories      []PipedRepository       `json:"repositories"`
+	Repositories []PipedRepository `json:"repositories"`
+	// List of helm chart repositories that should be added while starting up.
+	ChartRepositories []HelmChartRepository   `json:"chartRepositories"`
 	CloudProviders    []PipedCloudProvider    `json:"cloudProviders"`
 	AnalysisProviders []PipedAnalysisProvider `json:"analysisProviders"`
 }
@@ -149,6 +151,13 @@ type PipedRepository struct {
 	Branch string `json:"branch"`
 }
 
+type HelmChartRepository struct {
+	Name     string `json:"name"`
+	Address  string `json:"address"`
+	Username string `json:"username"`
+	Password string `json:"password"`
+}
+
 type PipedCloudProvider struct {
 	Name string
 	Type model.CloudProviderType

pkg/config/piped_test.go

@@ -58,6 +58,18 @@ func TestPipedConfig(t *testing.T) {
 						Branch: "master",
 					},
 				},
+				ChartRepositories: []HelmChartRepository{
+					{
+						Name:    "fantastic-charts",
+						Address: "https://fantastic-charts.storage.googleapis.com",
+					},
+					{
+						Name:     "private-charts",
+						Address:  "https://private-charts.com",
+						Username: "basic-username",
+						Password: "basic-password",
+					},
+				},
 				CloudProviders: []PipedCloudProvider{
 					{
 						Name: "kubernetes-default",

pkg/config/testdata/piped/piped-config.yaml

@@ -19,6 +19,14 @@ spec:
       remote: git@github.com:org/repo2.git
       branch: master
 
+  chartRepositories:
+    - name: fantastic-charts
+      address: https://fantastic-charts.storage.googleapis.com
+    - name: private-charts
+      address: https://private-charts.com
+      username: basic-username
+      password: basic-password
+
   cloudProviders:
     - name: kubernetes-default
       type: KUBERNETES