Shell out package

shell/assertions_test.go

@@ -0,0 +1,45 @@
+/*
+Copyright 2020 The Knative 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
+
+    https://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 shell_test
+
+import (
+	"strings"
+	"testing"
+)
+
+type assertions struct {
+	t *testing.T
+}
+
+func (a assertions) NoError(err error) {
+	if err != nil {
+		a.t.Error(err)
+	}
+}
+
+func (a assertions) Contains(haystack, needle string) {
+	if !strings.Contains(haystack, needle) {
+		a.t.Errorf("wanted to \ncontain: %#v\n     in: %#v",
+			needle, haystack)
+	}
+}
+
+func (a assertions) Equal(want, got string) {
+	if got != want {
+		a.t.Errorf("want: %#v\n got:%#v", want, got)
+	}
+}

shell/executor.go

@@ -0,0 +1,189 @@
+/*
+Copyright 2020 The Knative 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
+
+    https://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 shell
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+)
+
+const (
+	defaultLabelOut = "[OUT]"
+	defaultLabelErr = "[ERR]"
+	executeMode     = 0700
+)
+
+// ErrNoProjectLocation is returned if user didnt provided the project location.
+var ErrNoProjectLocation = errors.New("project location isn't provided")
+
+// NewExecutor creates a new executor from given config.
+func NewExecutor(config ExecutorConfig) Executor {
+	configureDefaultValues(&config)
+	return &streamingExecutor{
+		ExecutorConfig: config,
+	}
+}
+
+// RunScript executes a shell script with args.
+func (s *streamingExecutor) RunScript(script Script, args ...string) error {
+	err := validate(s.ExecutorConfig)
+	if err != nil {
+		return err
+	}
+	cnt := script.scriptContent(s.ProjectLocation, args)
+	return withTempScript(cnt, func(bin string) error {
+		return stream(bin, s.ExecutorConfig, script.Label)
+	})
+}
+
+// RunFunction executes a shell function with args.
+func (s *streamingExecutor) RunFunction(fn Function, args ...string) error {
+	err := validate(s.ExecutorConfig)
+	if err != nil {
+		return err
+	}
+	cnt := fn.scriptContent(s.ProjectLocation, args)
+	return withTempScript(cnt, func(bin string) error {
+		return stream(bin, s.ExecutorConfig, fn.Label)
+	})
+}
+
+type streamingExecutor struct {
+	ExecutorConfig
+}
+
+func validate(config ExecutorConfig) error {
+	if config.ProjectLocation == nil {
+		return ErrNoProjectLocation
+	}
+	return nil
+}
+
+func configureDefaultValues(config *ExecutorConfig) {
+	if config.Out == nil {
+		config.Out = os.Stdout
+	}
+	if config.Err == nil {
+		config.Err = os.Stderr
+	}
+	if config.LabelOut == "" {
+		config.LabelOut = defaultLabelOut
+	}
+	if config.LabelErr == "" {
+		config.LabelErr = defaultLabelErr
+	}
+	if config.Environ == nil {
+		config.Environ = os.Environ()
+	}
+	if !config.SkipDate && config.DateFormat == "" {
+		config.DateFormat = time.StampMilli
+	}
+	if config.PrefixFunc == nil {
+		config.PrefixFunc = defaultPrefixFunc
+	}
+}
+
+func stream(bin string, cfg ExecutorConfig, label string) error {
+	c := exec.Command(bin)
+	c.Env = cfg.Environ
+	c.Stdout = NewPrefixer(cfg.Out, prefixFunc(StreamTypeOut, label, cfg))
+	c.Stderr = NewPrefixer(cfg.Err, prefixFunc(StreamTypeErr, label, cfg))
+	return c.Run()
+}
+
+func prefixFunc(st StreamType, label string, cfg ExecutorConfig) func() string {
+	return func() string {
+		return cfg.PrefixFunc(st, label, cfg)
+	}
+}
+
+func defaultPrefixFunc(st StreamType, label string, cfg ExecutorConfig) string {
+	sep := " "
+	var buf []string
+	if !cfg.SkipDate {
+		dt := time.Now().Format(cfg.DateFormat)
+		buf = append(buf, dt)
+	}
+	buf = append(buf, label)
+	switch st {
+	case StreamTypeOut:
+		buf = append(buf, cfg.LabelOut)
+	case StreamTypeErr:
+		buf = append(buf, cfg.LabelErr)
+	}
+	return strings.Join(buf, sep) + sep
+}
+
+func withTempScript(contents string, fn func(bin string) error) error {
+	tmpfile, err := ioutil.TempFile("", "shellout-*.sh")
+	if err != nil {
+		return err
+	}
+	_, err = tmpfile.WriteString(contents)
+	if err != nil {
+		return err
+	}
+	err = tmpfile.Chmod(executeMode)
+	if err != nil {
+		return err
+	}
+	err = tmpfile.Close()
+	if err != nil {
+		return err
+	}
+	defer func() {
+		// clean up
+		_ = os.Remove(tmpfile.Name())
+	}()
+
+	return fn(tmpfile.Name())
+}
+
+func (fn *Function) scriptContent(location ProjectLocation, args []string) string {
+	return fmt.Sprintf(`#!/usr/bin/env bash
+
+set -Eeuo pipefail
+
+cd "%s"
+source %s
+
+%s %s
+`, location.RootPath(), fn.ScriptPath, fn.FunctionName, quoteArgs(args))
+}
+
+func (sc *Script) scriptContent(location ProjectLocation, args []string) string {
+	return fmt.Sprintf(`#!/usr/bin/env bash
+
+set -Eeuo pipefail
+
+cd "%s"
+%s %s
+`, location.RootPath(), sc.ScriptPath, quoteArgs(args))
+}
+
+func quoteArgs(args []string) string {
+	quoted := make([]string, len(args))
+	for i, arg := range args {
+		quoted[i] = "\"" + strings.ReplaceAll(arg, "\"", "\\\"") + "\""
+	}
+	return strings.Join(quoted, " ")
+}

shell/executor_test.go

@@ -0,0 +1,160 @@
+/*
+Copyright 2020 The Knative 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
+
+    https://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 shell_test
+
+import (
+	"bytes"
+	"testing"
+
+	"knative.dev/hack/shell"
+)
+
+func TestNewExecutor(t *testing.T) {
+	assert := assertions{t: t}
+	tests := []testcase{
+		helloWorldTestCase(t),
+		abortTestCase(t),
+		failExampleCase(t),
+		missingProjectLocationCase(),
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var outB, errB bytes.Buffer
+			tt.config.Out = &outB
+			tt.config.Err = &errB
+			executor := shell.NewExecutor(tt.config)
+			err := tt.op(executor)
+			if err != nil && !tt.wants.failed {
+				t.Errorf("%s: \n got: %#v\nfailed: %#v", tt.name, err, tt.failed)
+			}
+
+			for _, wantOut := range tt.wants.outs {
+				assert.Contains(outB.String(), wantOut)
+			}
+			for _, wantErr := range tt.wants.errs {
+				assert.Contains(errB.String(), wantErr)
+			}
+		})
+	}
+}
+
+func TestExecutorDefaults(t *testing.T) {
+	assert := assertions{t: t}
+	loc, err := shell.NewProjectLocation("..")
+	assert.NoError(err)
+	exec := shell.NewExecutor(shell.ExecutorConfig{
+		ProjectLocation: loc,
+	})
+	err = exec.RunFunction(fn("true"))
+	assert.NoError(err)
+}
+
+func helloWorldTestCase(t *testing.T) testcase {
+	return testcase{
+		"echo Hello, World!",
+		config(t, func(cfg *shell.ExecutorConfig) {
+			cfg.SkipDate = true
+		}),
+		func(exec shell.Executor) error {
+			return exec.RunFunction(fn("echo"), "Hello, World!")
+		},
+		wants{
+			outs: []string{
+				"echo [OUT] Hello, World!",
+			},
+		},
+	}
+}
+
+func abortTestCase(t *testing.T) testcase {
+	return testcase{
+		"abort function",
+		config(t, func(cfg *shell.ExecutorConfig) {}),
+		func(exec shell.Executor) error {
+			return exec.RunFunction(fn("abort"), "reason")
+		},
+		wants{
+			failed: true,
+		},
+	}
+}
+
+func failExampleCase(t *testing.T) testcase {
+	return testcase{
+		"fail-example.sh",
+		config(t, func(cfg *shell.ExecutorConfig) {}),
+		func(exec shell.Executor) error {
+			return exec.RunScript(shell.Script{
+				Label:      "fail-example.sh",
+				ScriptPath: "shell/fail-example.sh",
+			}, "expected err")
+		},
+		wants{
+			failed: true,
+			errs: []string{
+				"expected err",
+			},
+		},
+	}
+}
+
+func missingProjectLocationCase() testcase {
+	return testcase{
+		"missing project location",
+		shell.ExecutorConfig{},
+		func(exec shell.Executor) error {
+			return exec.RunFunction(fn("id"))
+		},
+		wants{
+			failed: true,
+		},
+	}
+}
+
+type wants struct {
+	failed bool
+	outs   []string
+	errs   []string
+}
+
+type testcase struct {
+	name   string
+	config shell.ExecutorConfig
+	op     func(exec shell.Executor) error
+	wants
+}
+
+func config(t *testing.T, customize func(cfg *shell.ExecutorConfig)) shell.ExecutorConfig {
+	assert := assertions{t: t}
+	loc, err := shell.NewProjectLocation("..")
+	assert.NoError(err)
+	cfg := shell.ExecutorConfig{
+		ProjectLocation: loc,
+	}
+	customize(&cfg)
+	return cfg
+}
+
+func fn(name string) shell.Function {
+	return shell.Function{
+		Script: shell.Script{
+			Label:      name,
+			ScriptPath: "library.sh",
+		},
+		FunctionName: name,
+	}
+}