Add export command with GitHubActions support

internal/cmdexport/cmdexport.go

@@ -0,0 +1,101 @@
+// Copyright 2020 Google LLC
+//
+// 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 cmdexport contains the export command.
+package cmdexport
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/GoogleContainerTools/kpt/internal/cmdexport/orchestrators"
+	"github.com/GoogleContainerTools/kpt/internal/cmdexport/types"
+	"github.com/GoogleContainerTools/kpt/internal/docs/generated/fndocs"
+	"github.com/spf13/cobra"
+)
+
+// The `kpt fn export` command.
+func ExportCommand() *cobra.Command {
+	return GetExportRunner().Command
+}
+
+// Create a ExportRunner instance and wire it to the corresponding Command.
+func GetExportRunner() *ExportRunner {
+	r := &ExportRunner{PipelineConfig: &types.PipelineConfig{}}
+	c := &cobra.Command{
+		Use:     "export orchestrator DIR/",
+		Short:   fndocs.ExportShort,
+		Long:    fndocs.ExportLong,
+		Example: fndocs.ExportExamples,
+		// Validate and parse args.
+		Args: func(cmd *cobra.Command, args []string) error {
+			if len(args) != 2 {
+				return fmt.Errorf("accepts %d args, received %d", 2, len(args))
+			}
+
+			r.Orchestrator, r.Dir = args[0], args[1]
+
+			switch r.Orchestrator {
+			case "github-actions":
+				{
+					r.Pipeline = new(orchestrators.GitHubActions)
+				}
+			default:
+				return fmt.Errorf("unsupported orchestrator %v", r.Orchestrator)
+			}
+
+			return nil
+		},
+		RunE: r.runE,
+	}
+
+	c.Flags().StringSliceVar(
+		&r.FnPaths, "fn-path", []string{},
+		"read functions from these directories instead of the configuration directory.")
+	c.Flags().StringVar(
+		&r.OutputFilePath, "output", "",
+		"specify the filename of the generated pipeline. If omitted, the default output is stdout")
+
+	r.Command = c
+
+	return r
+}
+
+// The ExportRunner wraps the user's input and runs the command.
+type ExportRunner struct {
+	Orchestrator   string
+	OutputFilePath string
+	Command        *cobra.Command
+	*types.PipelineConfig
+	Pipeline orchestrators.Pipeline
+}
+
+// Generate the pipeline and write it into a file or stdout.
+func (r *ExportRunner) runE(c *cobra.Command, args []string) error {
+	pipeline := r.Pipeline.Init(r.PipelineConfig).Generate()
+
+	if r.OutputFilePath != "" {
+		fo, err := os.Create(r.OutputFilePath)
+
+		if err != nil {
+			return err
+		}
+
+		c.SetOut(fo)
+	}
+
+	_, err := c.OutOrStdout().Write(pipeline)
+
+	return err
+}

internal/cmdexport/cmdexport_test.go

@@ -0,0 +1,142 @@
+// Copyright 2020 Google LLC
+//
+// 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 cmdexport
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"gotest.tools/assert"
+)
+
+var tempDir, _ = ioutil.TempDir("", "kpt-fn-export-test")
+
+type TestCase struct {
+	description string
+	params      []string
+	expected    string
+	err         string
+}
+
+var testCases = []TestCase{
+	{
+		description: "fails on an unsupported orchestrator",
+		params:      []string{"random-orchestrator", "."},
+		err:         "unsupported orchestrator random-orchestrator",
+	},
+	{
+		description: "exports a GitHub Actions pipeline",
+		params:      []string{"github-actions", "."},
+		expected: `
+name: kpt
+on:
+    push:
+        branches:
+          - master
+jobs:
+    Kpt:
+        runs-on: ubuntu-latest
+        steps:
+          - name: Run all kpt functions
+            uses: docker://gongpu/kpt:latest
+            with:
+                args: fn run .
+`,
+	},
+	{
+		description: "exports a GitHub Actions pipeline with --output",
+		params: []string{
+			"github-actions",
+			".",
+			"--output",
+			filepath.Join(tempDir, "main.yaml"),
+		},
+		expected: `
+name: kpt
+on:
+    push:
+        branches:
+          - master
+jobs:
+    Kpt:
+        runs-on: ubuntu-latest
+        steps:
+          - name: Run all kpt functions
+            uses: docker://gongpu/kpt:latest
+            with:
+                args: fn run .
+`,
+	},
+	{
+		description: "exports a GitHub Actions pipeline with --fn-path",
+		params:      []string{"github-actions", ".", "--fn-path", "functions/"},
+		expected: `
+name: kpt
+on:
+    push:
+        branches:
+          - master
+jobs:
+    Kpt:
+        runs-on: ubuntu-latest
+        steps:
+          - name: Run all kpt functions
+            uses: docker://gongpu/kpt:latest
+            with:
+                args: fn run . --fn-path functions/
+`,
+	},
+}
+
+func TestCmdExport(t *testing.T) {
+	for i := range testCases {
+		testCase := testCases[i]
+
+		t.Run(testCase.description, func(t *testing.T) {
+			r := GetExportRunner()
+			r.Command.SetArgs(testCase.params)
+
+			b := &bytes.Buffer{}
+			// out will be overridden during execution if OutputFilePath is present.
+			r.Command.SetOut(b)
+
+			err := r.Command.Execute()
+
+			if testCase.err != "" {
+				assert.Error(t, err, testCase.err)
+			} else {
+				assert.NilError(t, err)
+
+				expected := strings.TrimLeft(testCase.expected, "\n")
+				var actual string
+				if r.OutputFilePath == "" {
+					actual = b.String()
+				} else {
+					content, _ := ioutil.ReadFile(r.OutputFilePath)
+
+					actual = string(content)
+				}
+
+				assert.Equal(t, expected, actual)
+			}
+		})
+	}
+
+	_ = os.RemoveAll(tempDir)
+}

internal/cmdexport/orchestrators/githubactions.go

@@ -0,0 +1,89 @@
+// Copyright 2020 Google LLC
+//
+// 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 orchestrators
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/GoogleContainerTools/kpt/internal/cmdexport/types"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
+)
+
+// Represent a GitHub Actions workflow.
+// @see https://help.github.com/en/actions/reference/workflow-syntax-for-github-actions
+type GitHubActions struct {
+	Name string                          `yaml:",omitempty"`
+	On   map[string]GitHubActionsTrigger `yaml:",omitempty"`
+	Jobs map[string]GitHubActionsJob     `yaml:",omitempty"`
+}
+
+type GitHubActionsTrigger struct {
+	Branches []string `yaml:",omitempty"`
+}
+
+type GitHubActionsJob struct {
+	RunsOn string              `yaml:"runs-on,omitempty"`
+	Steps  []GitHubActionsStep `yaml:",omitempty"`
+}
+
+type GitHubActionsStep struct {
+	Name string               `yaml:",omitempty"`
+	Uses string               `yaml:",omitempty"`
+	With GitHubActionStepArgs `yaml:",omitempty"`
+}
+
+type GitHubActionStepArgs struct {
+	Args string `yaml:",omitempty"`
+}
+
+func (p *GitHubActions) Init(config *types.PipelineConfig) Pipeline {
+	var runFnCommand = fmt.Sprintf("fn run %s", config.Dir)
+
+	if fnPaths := config.FnPaths; len(fnPaths) > 0 {
+		runFnCommand = fmt.Sprintf(
+			"%s --fn-path %s",
+			runFnCommand,
+			strings.Join(fnPaths, " "),
+		)
+	}
+
+	p.Name = "kpt"
+	p.On = map[string]GitHubActionsTrigger{
+		"push": {Branches: []string{"master"}},
+	}
+	p.Jobs = map[string]GitHubActionsJob{
+		"Kpt": {
+			RunsOn: "ubuntu-latest",
+			Steps: []GitHubActionsStep{
+				{
+					Name: "Run all kpt functions",
+					Uses: "docker://" + KptImage,
+					With: GitHubActionStepArgs{
+						Args: runFnCommand,
+					},
+				},
+			},
+		},
+	}
+
+	return p
+}
+
+func (p *GitHubActions) Generate() []byte {
+	data, _ := yaml.Marshal(p)
+
+	return data
+}

internal/cmdexport/orchestrators/pipeline.go

@@ -0,0 +1,26 @@
+// Copyright 2020 Google LLC
+//
+// 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 orchestrators
+
+import "github.com/GoogleContainerTools/kpt/internal/cmdexport/types"
+
+// TODO: update
+const KptImage = "gongpu/kpt:latest"
+
+// Pipeline is an abstraction of different workflow orchestrators.
+type Pipeline interface {
+	Init(config *types.PipelineConfig) Pipeline
+	Generate() []byte
+}

internal/cmdexport/types/PipelineConfig.go

@@ -0,0 +1,21 @@
+// Copyright 2020 Google LLC
+//
+// 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 types
+
+// Configuration of a pipeline.
+type PipelineConfig struct {
+	Dir     string
+	FnPaths []string
+}