feat(cmd): add Cobra framework (#90)

* feat(cmd): add Cobra framework

This commit introduces the Cobra CLI framework, and reorganizes /cmd to adhere to Cobra-recommended standards. Moves primary functionality to the generate subcommand, and introduces the version subcommand, which will print the version/commit/date as injected by goreleaser at build time.

* refactor(release): remove non-default main config

Now that we have a root main.go per Cobra standards, we no longer require a non-default path to our main.go to be specified as the build entrypoint.

Author: maggieneterval

.goreleaser.yml

@@ -1,2 +1,3 @@
 builds:
-- main: ./cmd/kleat/main.go
+- ldflags:
+    - -s -w -X cmd.version={{.Version}} -X cmd.commit={{.Commit}} -X cmd.date={{.Date}}

cmd/kleat/main.go cmd/generate.gocmd/kleat/main.go renamed to cmd/generate.go

@@ -14,26 +14,30 @@
  * limitations under the License.
  */
 
-package main
+package cmd
 
 import (
-	"fmt"
-	"os"
-
 	"github.com/spinnaker/kleat/internal/fileio"
+
+	"github.com/spf13/cobra"
 )
 
-func main() {
-	if len(os.Args) != 3 {
-		_, _ = fmt.Fprint(os.Stderr, "arguments must be <halPath> <dir>\n")
-		os.Exit(1)
-	}
+var generateCmd = &cobra.Command{
+	Use:   "generate",
+	Short: "Generate Spinnaker microservice config files",
+	Long: `Given a path to your top-level Spinnaker config (halconfig) and an
+output directory, writes each generated Spinnaker microservice config file to
+the output directory.
 
-	hal := os.Args[1]
-	dir := os.Args[2]
-	if err := writeServiceConfigs(hal, dir); err != nil {
-		panic(err)
-	}
+Example usage:
+
+kleat /path/to/halconfig /path/to/output`,
+	Args: cobra.ExactArgs(2),
+	RunE: func(cmd *cobra.Command, args []string) error {
+		hal := args[0]
+		dir := args[1]
+		return writeServiceConfigs(hal, dir)
+	},
 }
 
 func writeServiceConfigs(halPath string, dir string) error {
@@ -44,3 +48,7 @@ func writeServiceConfigs(halPath string, dir string) error {
 
 	return fileio.WriteConfigs(h, dir)
 }
+
+func init() {
+	rootCmd.AddCommand(generateCmd)
+}

cmd/root.go

@@ -0,0 +1,43 @@
+/*
+ * Copyright The Spinnaker 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 cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+var rootCmd = &cobra.Command{
+	Use:   "kleat",
+	Short: "Kleat is a tool for managing Spinnaker configuration files.",
+	Long: `Kleat is a tool for generating configuration files for each Spinnaker
+microservice from one top-level Spinnaker configuration file. It is intended
+for use with the Spinnaker Kustomization base
+(https://github.com/spinnaker/kustomization-base)
+as an alternative to the Halyard-managed configuration and deployment
+experience. Please check out the README at https://github.com/spinnaker/kleat
+for more details.`,
+}
+
+func Execute() {
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}

cmd/version.go

@@ -0,0 +1,42 @@
+/*
+ * Copyright The Spinnaker 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 cmd
+
+import (
+	"github.com/spf13/cobra"
+)
+
+// Dynamically inserted at build time by goreleaser. See `ldflags` in
+// .goreleaser.yml.
+var (
+	version = "unknown"
+	commit  = "unknown"
+	date    = "unknown"
+)
+
+var versionCmd = &cobra.Command{
+	Use:   "version",
+	Short: "Print kleat version",
+	Long:  "Print the version, commit, and release date of your kleat",
+	Run: func(cmd *cobra.Command, args []string) {
+		cmd.Printf("Kleat has version %s built from %s on %s\n", version, commit, date)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(versionCmd)
+}

go.mod

@@ -3,9 +3,20 @@ module github.com/spinnaker/kleat
 go 1.14
 
 require (
+	github.com/fsnotify/fsnotify v1.4.9 // indirect
 	github.com/golang/protobuf v1.4.1
 	github.com/google/go-cmp v0.4.0
 	github.com/kylelemons/godebug v1.1.0
+	github.com/mitchellh/mapstructure v1.3.2 // indirect
+	github.com/pelletier/go-toml v1.8.0 // indirect
+	github.com/spf13/afero v1.2.2 // indirect
+	github.com/spf13/cast v1.3.1 // indirect
+	github.com/spf13/cobra v1.0.0
+	github.com/spf13/jwalterweatherman v1.1.0 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/spf13/viper v1.7.0 // indirect
+	golang.org/x/sys v0.0.0-20200610111108-226ff32320da // indirect
 	google.golang.org/protobuf v1.22.0
+	gopkg.in/ini.v1 v1.57.0 // indirect
 	sigs.k8s.io/yaml v1.2.0
 )