feat: port git :report subcommand to golang

The bash :report implementation for the git plugin is replaced with a compiled golang binary. Property, computed and global keys are collected in parallel, while the sha and last-updated-at keys still shell out to git and stat the deploy branch ref so their values are unchanged. The non-report git helpers such as fn-git-cmd and the computed deploy-branch and keep-git-dir getters remain in place for the build pipeline.

plugins/git/report.go

@@ -0,0 +1,154 @@
+package git
+
+import (
+	"os"
+	"path/filepath"
+	"strconv"
+
+	"github.com/dokku/dokku/plugins/common"
+)
+
+// ReportSingleApp is an internal function that displays the git report for one or more apps
+func ReportSingleApp(appName string, format string, infoFlag string) error {
+	if appName != "--global" {
+		if err := common.VerifyAppName(appName); err != nil {
+			return err
+		}
+	}
+
+	var flags map[string]common.ReportFunc
+	if appName == "--global" {
+		flags = map[string]common.ReportFunc{
+			"--git-computed-archive-max-files": reportComputedArchiveMaxFiles,
+			"--git-computed-archive-max-size":  reportComputedArchiveMaxSize,
+			"--git-computed-deploy-branch":     reportComputedDeployBranch,
+			"--git-computed-keep-git-dir":      reportComputedKeepGitDir,
+			"--git-global-archive-max-files":   reportGlobalArchiveMaxFiles,
+			"--git-global-archive-max-size":    reportGlobalArchiveMaxSize,
+			"--git-global-deploy-branch":       reportGlobalDeployBranch,
+			"--git-global-keep-git-dir":        reportGlobalKeepGitDir,
+		}
+	} else {
+		flags = map[string]common.ReportFunc{
+			"--git-computed-archive-max-files": reportComputedArchiveMaxFiles,
+			"--git-computed-archive-max-size":  reportComputedArchiveMaxSize,
+			"--git-computed-deploy-branch":     reportComputedDeployBranch,
+			"--git-computed-keep-git-dir":      reportComputedKeepGitDir,
+			"--git-deploy-branch":              reportDeployBranch,
+			"--git-global-archive-max-files":   reportGlobalArchiveMaxFiles,
+			"--git-global-archive-max-size":    reportGlobalArchiveMaxSize,
+			"--git-global-deploy-branch":       reportGlobalDeployBranch,
+			"--git-global-keep-git-dir":        reportGlobalKeepGitDir,
+			"--git-keep-git-dir":               reportKeepGitDir,
+			"--git-last-updated-at":            reportLastUpdatedAt,
+			"--git-rev-env-var":                reportRevEnvVar,
+			"--git-sha":                        reportSha,
+			"--git-source-image":               reportSourceImage,
+		}
+	}
+
+	flagKeys := []string{}
+	for flagKey := range flags {
+		flagKeys = append(flagKeys, flagKey)
+	}
+
+	infoFlags := common.CollectReport(appName, infoFlag, flags)
+	return common.ReportSingleApp(common.ReportSingleAppInput{
+		ReportType:              "git",
+		AppName:                 appName,
+		InfoFlag:                infoFlag,
+		InfoFlags:               infoFlags,
+		InfoFlagKeys:            flagKeys,
+		Format:                  format,
+		TrimPrefix:              true,
+		UppercaseFirstCharacter: true,
+		EmitLegacyPrefix:        false,
+	})
+}
+
+func reportGlobalArchiveMaxFiles(appName string) string {
+	return common.PropertyGet("git", "--global", "archive-max-files")
+}
+
+func reportComputedArchiveMaxFiles(appName string) string {
+	return common.PropertyGetDefault("git", "--global", "archive-max-files", "10000")
+}
+
+func reportGlobalArchiveMaxSize(appName string) string {
+	return common.PropertyGet("git", "--global", "archive-max-size")
+}
+
+func reportComputedArchiveMaxSize(appName string) string {
+	return common.PropertyGetDefault("git", "--global", "archive-max-size", "1073741824")
+}
+
+func reportDeployBranch(appName string) string {
+	return common.PropertyGet("git", appName, "deploy-branch")
+}
+
+func reportGlobalDeployBranch(appName string) string {
+	return common.PropertyGet("git", "--global", "deploy-branch")
+}
+
+func reportComputedDeployBranch(appName string) string {
+	if value := common.PropertyGet("git", appName, "deploy-branch"); value != "" {
+		return value
+	}
+	if value := common.PropertyGet("git", "--global", "deploy-branch"); value != "" {
+		return value
+	}
+
+	return "master"
+}
+
+func reportKeepGitDir(appName string) string {
+	return common.PropertyGet("git", appName, "keep-git-dir")
+}
+
+func reportGlobalKeepGitDir(appName string) string {
+	return common.PropertyGet("git", "--global", "keep-git-dir")
+}
+
+func reportComputedKeepGitDir(appName string) string {
+	if value := common.PropertyGet("git", appName, "keep-git-dir"); value != "" {
+		return value
+	}
+	if value := common.PropertyGet("git", "--global", "keep-git-dir"); value != "" {
+		return value
+	}
+
+	return "false"
+}
+
+func reportRevEnvVar(appName string) string {
+	return common.PropertyGetDefault("git", appName, "rev-env-var", "GIT_REV")
+}
+
+func reportSourceImage(appName string) string {
+	return common.PropertyGet("git", appName, "source-image")
+}
+
+func reportSha(appName string) string {
+	appRoot := filepath.Join(common.MustGetEnv("DOKKU_ROOT"), appName)
+	result, err := common.CallExecCommand(common.ExecCommandInput{
+		Command:          "git",
+		Args:             []string{"rev-parse", "HEAD"},
+		WorkingDirectory: appRoot,
+	})
+	if err != nil {
+		return ""
+	}
+
+	return result.StdoutContents()
+}
+
+func reportLastUpdatedAt(appName string) string {
+	branch := reportComputedDeployBranch(appName)
+	headFile := filepath.Join(common.MustGetEnv("DOKKU_ROOT"), appName, "refs", "heads", branch)
+	info, err := os.Stat(headFile)
+	if err != nil {
+		return ""
+	}
+
+	return strconv.FormatInt(info.ModTime().Unix(), 10)
+}