Merge pull request #8004 from Tashows/buildpacks-detect

Add buildpacks:detect subcommand

contrib/dependencies.json

@@ -86,11 +86,11 @@
     },
     {
       "name": "herokuish",
-      "version": "0.11.3",
+      "version": "0.11.5",
       "urls": {
-        "amd64": "https://github.com/gliderlabs/herokuish/releases/download/v0.11.3/herokuish_0.11.3_linux_x86_64.tgz",
-        "arm64": "https://github.com/gliderlabs/herokuish/releases/download/v0.11.3/herokuish_0.11.3_linux_x86_64.tgz"
+        "amd64": "https://github.com/gliderlabs/herokuish/releases/download/v0.11.5/herokuish_0.11.5_linux_x86_64.tgz",
+        "arm64": "https://github.com/gliderlabs/herokuish/releases/download/v0.11.5/herokuish_0.11.5_linux_x86_64.tgz"
       }
     }
   ]
-}
+}

plugins/buildpacks/Makefile

@@ -1,4 +1,4 @@
-SUBCOMMANDS = subcommands/add subcommands/clear subcommands/list subcommands/remove subcommands/report subcommands/set subcommands/set-property
+SUBCOMMANDS = subcommands/add subcommands/clear subcommands/detect subcommands/list subcommands/remove subcommands/report subcommands/set subcommands/set-property
 TRIGGERS = triggers/buildpack-stack-name triggers/install triggers/post-app-clone-setup triggers/post-app-rename-setup triggers/post-delete triggers/post-extract triggers/report
 BUILD = commands subcommands triggers
 PLUGIN_NAME = buildpacks

plugins/buildpacks/functions.go

@@ -63,3 +63,32 @@ func validBuildpackURL(buildpack string) (string, error) {
 
 	return buildpack, fmt.Errorf("Invalid buildpack specified: %v", buildpack)
 }
+
+func checkoutBareGitRepo(sourceWorkDir string, branch string) (string, error) {
+	tmpdir, err := os.MkdirTemp("", "bare-git-checkout")
+	if err != nil {
+		return "", fmt.Errorf("Unable to create temporary directory: %s", err.Error())
+	}
+
+	args := []string{
+		"--git-dir=" + sourceWorkDir,
+		"--work-tree=" + tmpdir,
+		"checkout", "-f",
+	}
+
+	if branch != "" {
+		args = append(args, branch)
+	}
+
+	result, err := common.CallExecCommand(common.ExecCommandInput{
+		Command: "git",
+		Args:    args,
+	})
+
+	if err != nil {
+		os.RemoveAll(tmpdir)
+		return "", fmt.Errorf("Unable to checkout bare git repository: %s", result.StderrContents())
+	}
+
+	return tmpdir, nil
+}

plugins/buildpacks/src/commands/commands.go

@@ -20,6 +20,7 @@ Additional commands:`
 	helpContent = `
     buildpacks:add [--index 1] <app> <buildpack>, Add new app buildpack while inserting into list of buildpacks if necessary
     buildpacks:clear <app>, Clear all buildpacks set on the app
+    buildpacks:detect <app> [--branch <branch-name>], Detect the buildpack for an app (if not specified, the branch flag defaults to the deploy branch)
     buildpacks:list <app>, List all buildpacks for an app
     buildpacks:remove <app> <buildpack>, Remove a buildpack set on the app
     buildpacks:report [<app>] [<flag>], Displays a buildpack report for one or more apps

plugins/buildpacks/src/subcommands/subcommands.go

@@ -30,6 +30,15 @@ func main() {
 		args.Parse(os.Args[2:])
 		appName := args.Arg(0)
 		err = buildpacks.CommandClear(appName)
+	case "detect":
+		args := flag.NewFlagSet("buildpacks:detect", flag.ExitOnError)
+		branch := args.String("branch", "", "--branch: the branch to detect against (defaults to the deploy branch)")
+		args.Parse(os.Args[2:])
+		appName := args.Arg(0)
+		if *branch == "" {
+            *branch = common.PropertyGet("git", appName, "deploy-branch")
+		}
+		err = buildpacks.CommandDetect(appName, *branch)
 	case "list":
 		args := flag.NewFlagSet("buildpacks:list", flag.ExitOnError)
 		args.Parse(os.Args[2:])

plugins/buildpacks/subcommands.go

@@ -3,6 +3,7 @@ package buildpacks
 import (
 	"errors"
 	"fmt"
+	"os"
 
 	"github.com/dokku/dokku/plugins/common"
 )
@@ -30,6 +31,41 @@ func CommandClear(appName string) error {
 	return common.PropertyDelete("buildpacks", appName, "buildpacks")
 }
 
+// CommandDetect implements buildpacks:detect
+func CommandDetect(appName string, branch string) (err error) {
+	if err := common.VerifyAppName(appName); err != nil {
+		return err
+	}
+
+	workDir := common.AppRoot(appName)
+	checkedOutDir, err := checkoutBareGitRepo(workDir, branch)
+    if err != nil {
+        return err
+    }
+	defer func() {
+		if err := os.RemoveAll(checkedOutDir); err != nil {
+			common.LogWarn(fmt.Sprintf("Failed to remove temporary directory %s: %v", checkedOutDir, err))
+		}
+	}()
+
+	dockerArgs := []string{
+		"run", "--rm",
+		"-v", fmt.Sprintf("%s:/tmp/app", checkedOutDir),
+		"gliderlabs/herokuish", "/bin/herokuish", "buildpack", "detect", "/tmp/app",
+	}
+
+	result, err := common.CallExecCommand(common.ExecCommandInput{
+		Command: common.DockerBin(),
+		Args:    dockerArgs,
+	})
+	if err != nil {
+		return fmt.Errorf("Buildpack detection failed: %s", result.StderrContents())
+	}
+
+	common.LogVerbose(result.StdoutContents())
+	return nil
+}
+
 // CommandList implements buildpacks:list
 func CommandList(appName string) (err error) {
 	if err := common.VerifyAppName(appName); err != nil {