chore: migrate exec behavior for maru (#80)

## Description

This migrates `exec` here in preparation of `maru` disconnecting itself
from `zarf`.

## Related Issue

Fixes #N/A

---------

Co-authored-by: razzle <[email protected]>
Co-authored-by: Lucas Rodriguez <[email protected]>

.github/workflows/release-exec.yaml

@@ -0,0 +1,60 @@
+name: Release Exec
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - "exec/**"
+
+permissions:
+  contents: read
+
+jobs:
+  bump-version-and-release-notes:
+    runs-on: ubuntu-latest
+    outputs:
+      new-version: ${{ steps.bump-version.outputs.new-version }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@44c2b7a8a4ea60a981eaca3cf939b5f4305c123b # v4.1.5
+        with:
+          fetch-depth: 0
+
+      - name: Bump Version and Generate Release Notes
+        uses: ./.github/actions/bump-and-notes
+        id: bump-version
+        with:
+          module: "exec"
+
+  release:
+    runs-on: ubuntu-latest
+    needs: bump-version-and-release-notes
+    # contents: write via the GH app
+    environment: release
+    steps:
+      - name: Checkout
+        uses: actions/checkout@44c2b7a8a4ea60a981eaca3cf939b5f4305c123b # v4.1.5
+        with:
+          fetch-depth: 0
+
+      - name: Download Release Notes
+        uses: actions/download-artifact@65a9edc5881444af0b9093a5e628f2fe47ea3b2e # v4.1.7
+        with:
+          name: release-notes
+
+      - name: Get pkg app token
+        id: pkg-app-token
+        uses: actions/create-github-app-token@a0de6af83968303c8c955486bf9739a57d23c7f1 # v1.10.0
+        with:
+          app-id: ${{ vars.PKG_WORKFLOW_GITHUB_APP_ID }}
+          private-key: ${{ secrets.PKG_WORKFLOW_GITHUB_APP_SECRET }}
+          owner: defenseunicorns
+          repositories: pkg
+
+      - name: Release
+        env:
+          GH_TOKEN: ${{ steps.pkg-app-token.outputs.token }}
+          NEW_VERSION: ${{ needs.bump-version-and-release-notes.outputs.new-version }}
+        run: |
+          gh release create "$NEW_VERSION" --title "$NEW_VERSION" --notes-file notes.md

exec/exec.go

@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2024-Present Defense Unicorns
+
+// Package exec provides a wrapper around the os/exec package
+package exec
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+
+	"golang.org/x/sync/errgroup"
+)
+
+// Config is a struct for configuring the Cmd function.
+type Config struct {
+	Print          bool
+	Dir            string
+	Env            []string
+	CommandPrinter func(format string, a ...any)
+	Stdout         io.Writer
+	Stderr         io.Writer
+}
+
+// Cmd executes a given command with given config.
+func Cmd(config Config, command string, args ...string) (string, string, error) {
+	return CmdWithContext(context.TODO(), config, command, args...)
+}
+
+// CmdWithContext executes a given command with given config.
+func CmdWithContext(ctx context.Context, config Config, command string, args ...string) (string, string, error) {
+	if command == "" {
+		return "", "", errors.New("command is required")
+	}
+
+	// Set up the command.
+	cmd := exec.CommandContext(ctx, command, args...)
+	cmd.Dir = config.Dir
+	cmd.Env = append(os.Environ(), config.Env...)
+
+	// Capture the command outputs.
+	cmdStdout, _ := cmd.StdoutPipe()
+	cmdStderr, _ := cmd.StderrPipe()
+
+	var (
+		stdoutBuf, stderrBuf bytes.Buffer
+	)
+
+	stdoutWriters := []io.Writer{
+		&stdoutBuf,
+	}
+
+	stdErrWriters := []io.Writer{
+		&stderrBuf,
+	}
+
+	// Add the writers if requested.
+	if config.Stdout != nil {
+		stdoutWriters = append(stdoutWriters, config.Stdout)
+	}
+
+	if config.Stderr != nil {
+		stdErrWriters = append(stdErrWriters, config.Stderr)
+	}
+
+	// Print to stdout if requested.
+	if config.Print {
+		stdoutWriters = append(stdoutWriters, os.Stdout)
+		stdErrWriters = append(stdErrWriters, os.Stderr)
+	}
+
+	// Bind all the writers.
+	stdout := io.MultiWriter(stdoutWriters...)
+	stderr := io.MultiWriter(stdErrWriters...)
+
+	// If a CommandPrinter was provided print the command.
+	if config.CommandPrinter != nil {
+		config.CommandPrinter("%s %s", command, strings.Join(args, " "))
+	}
+
+	// Start the command.
+	if err := cmd.Start(); err != nil {
+		return "", "", err
+	}
+
+	// Add to waitgroup for each goroutine.
+	g := new(errgroup.Group)
+
+	// Run a goroutine to capture the command's stdout live.
+	g.Go(func() error {
+		_, err := io.Copy(stdout, cmdStdout)
+		return err
+	})
+
+	// Run a goroutine to capture the command's stderr live.
+	g.Go(func() error {
+		_, err := io.Copy(stderr, cmdStderr)
+		return err
+	})
+
+	// Wait for the goroutines to finish and abort if there was an error capturing the command's outputs.
+	if err := g.Wait(); err != nil {
+		return "", "", fmt.Errorf("failed to capture the command output: %w", err)
+	}
+
+	// Return the buffered outputs, regardless of whether we printed them.
+	return stdoutBuf.String(), stderrBuf.String(), cmd.Wait()
+}
+
+// LaunchURL opens a URL in the default browser.
+func LaunchURL(url string) error {
+	switch runtime.GOOS {
+	case "linux":
+		return exec.Command("xdg-open", url).Start()
+	case "windows":
+		return exec.Command("rundll32", "url.dll,FileProtocolHandler", url).Start()
+	case "darwin":
+		return exec.Command("open", url).Start()
+	}
+
+	return nil
+}

exec/exec_test.go

@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2024-Present Defense Unicorns
+
+package exec
+
+import (
+	"bytes"
+	"errors"
+	"testing"
+)
+
+func TestCmd(t *testing.T) {
+	type test struct {
+		config     Config
+		command    string
+		args       []string
+		wantStdOut string
+		wantStdErr string
+		wantErr    error
+	}
+
+	var stdOutBuff bytes.Buffer
+	var stdErrBuff bytes.Buffer
+
+	tests := []test{
+		{wantErr: errors.New("command is required")},
+		{config: Config{}, command: "echo", args: []string{"hello kitteh"}, wantStdOut: "hello kitteh\n"},
+		{config: Config{Env: []string{"ARCH=amd64"}}, command: "printenv", args: []string{"ARCH"}, wantStdOut: "amd64\n"},
+		{config: Config{Dir: "/"}, command: "pwd", wantStdOut: "/\n"},
+		{config: Config{Stdout: &stdOutBuff}, command: "sh", args: []string{"-c", "echo \"hello kitteh out\""}, wantStdOut: "hello kitteh out\n"},
+		{config: Config{Stderr: &stdErrBuff}, command: "sh", args: []string{"-c", "echo \"hello kitteh err\" >&2"}, wantStdErr: "hello kitteh err\n"},
+	}
+
+	// Run tests without registering command mutations
+	for _, tc := range tests {
+		gotStdOut, gotStdErr, gotErr := Cmd(tc.config, tc.command, tc.args...)
+		if gotStdOut != tc.wantStdOut {
+			t.Fatalf("wanted std out: %s, got std out: %s", tc.wantStdOut, gotStdOut)
+		}
+		if gotStdErr != tc.wantStdErr {
+			t.Fatalf("wanted std err: %s, got std err: %s", tc.wantStdErr, gotStdErr)
+		}
+		if gotErr != nil && tc.wantErr != nil {
+			if gotErr.Error() != tc.wantErr.Error() {
+				t.Fatalf("wanted err: %s, got err: %s", tc.wantErr, gotErr)
+			}
+		} else if gotErr != nil {
+			t.Fatalf("got unexpected err: %s", gotErr)
+		}
+	}
+
+	stdOutBufferString := stdOutBuff.String()
+	if stdOutBufferString != "hello kitteh out\n" {
+		t.Fatalf("wanted std out buffer: hello kitteh out\n got std out buffer: %s", stdOutBufferString)
+	}
+
+	stdErrBufferString := stdErrBuff.String()
+	if stdErrBufferString != "hello kitteh err\n" {
+		t.Fatalf("wanted std err buffer: hello kitteh err\n got std err buffer: %s", stdErrBufferString)
+	}
+}

exec/go.mod

@@ -0,0 +1,16 @@
+module github.com/defenseunicorns/pkg/exec
+
+go 1.21.8
+
+replace github.com/defenseunicorns/pkg/helpers => ../helpers
+
+require (
+	github.com/defenseunicorns/pkg/helpers v1.1.1
+	golang.org/x/sync v0.6.0
+)
+
+require (
+	github.com/otiai10/copy v1.14.0 // indirect
+	golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 // indirect
+	oras.land/oras-go/v2 v2.5.0 // indirect
+)

exec/go.sum

@@ -0,0 +1,18 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/otiai10/copy v1.14.0 h1:dCI/t1iTdYGtkvCuBG2BgR6KZa83PTclw4U5n2wAllU=
+github.com/otiai10/copy v1.14.0/go.mod h1:ECfuL02W+/FkTWZWgQqXPWZgW9oeKCSQ5qVfSc4qc4w=
+github.com/otiai10/mint v1.5.1 h1:XaPLeE+9vGbuyEHem1JNk3bYc7KKqyI/na0/mLd/Kks=
+github.com/otiai10/mint v1.5.1/go.mod h1:MJm72SBthJjz8qhefc4z1PYEieWmy8Bku7CjcAqyUSM=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
+golang.org/x/sync v0.6.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 h1:0A+M6Uqn+Eje4kHMK80dtF3JCXC4ykBgQG4Fe06QRhQ=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+oras.land/oras-go/v2 v2.5.0 h1:o8Me9kLY74Vp5uw07QXPiitjsw7qNXi8Twd+19Zf02c=
+oras.land/oras-go/v2 v2.5.0/go.mod h1:z4eisnLP530vwIOUOJeBIj0aGI0L1C3d53atvCBqZHg=

exec/shell.go

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2024-Present Defense Unicorns
+
+package exec
+
+import "runtime"
+
+// ShellPreference represents the desired shell to use for a given command
+type ShellPreference struct {
+	Windows string `json:"windows,omitempty" jsonschema:"description=(default 'powershell') Indicates a preference for the shell to use on Windows systems (note that choosing 'cmd' will turn off migrations like touch -> New-Item),example=powershell,example=cmd,example=pwsh,example=sh,example=bash,example=gsh"`
+	Linux   string `json:"linux,omitempty" jsonschema:"description=(default 'sh') Indicates a preference for the shell to use on Linux systems,example=sh,example=bash,example=fish,example=zsh,example=pwsh"`
+	Darwin  string `json:"darwin,omitempty" jsonschema:"description=(default 'sh') Indicates a preference for the shell to use on macOS systems,example=sh,example=bash,example=fish,example=zsh,example=pwsh"`
+}
+
+// IsPowerShell returns whether a shell name is PowerShell
+func IsPowerShell(shellName string) bool {
+	return shellName == "powershell" || shellName == "pwsh"
+}
+
+// GetOSShell returns the shell and shellArgs based on the current OS
+func GetOSShell(shellPref ShellPreference) (string, []string) {
+	return getOSShellForOS(shellPref, runtime.GOOS)
+}
+
+func getOSShellForOS(shellPref ShellPreference, operatingSystem string) (string, []string) {
+	var shell string
+	var shellArgs []string
+	powershellShellArgs := []string{"-Command", "$ErrorActionPreference = 'Stop';"}
+	shShellArgs := []string{"-e", "-c"}
+
+	switch operatingSystem {
+	case "windows":
+		shell = "powershell"
+		if shellPref.Windows != "" {
+			shell = shellPref.Windows
+		}
+
+		shellArgs = powershellShellArgs
+		if shell == "cmd" {
+			// Change shellArgs to /c if cmd is chosen
+			shellArgs = []string{"/c"}
+		} else if !IsPowerShell(shell) {
+			// Change shellArgs to -c if a real shell is chosen
+			shellArgs = shShellArgs
+		}
+	case "darwin":
+		shell = "sh"
+		if shellPref.Darwin != "" {
+			shell = shellPref.Darwin
+		}
+
+		shellArgs = shShellArgs
+		if IsPowerShell(shell) {
+			// Change shellArgs to -Command if pwsh is chosen
+			shellArgs = powershellShellArgs
+		}
+	case "linux":
+		shell = "sh"
+		if shellPref.Linux != "" {
+			shell = shellPref.Linux
+		}
+
+		shellArgs = shShellArgs
+		if IsPowerShell(shell) {
+			// Change shellArgs to -Command if pwsh is chosen
+			shellArgs = powershellShellArgs
+		}
+	default:
+		shell = "sh"
+		shellArgs = shShellArgs
+	}
+
+	return shell, shellArgs
+}