Run Taskfiles from sub/child directories (#920)

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+- It's now possible to run Taskfiles from subdirectories! A new `USER_WORKING_DIR` special
+  variable was added to add even more flexibility for monorepos
+  ([#289](https://github.com/go-task/task/issues/289), [#920](https://github.com/go-task/task/pull/920)).
 - Add task-level `dotenv` support
   ([#389](https://github.com/go-task/task/issues/389), [#904](https://github.com/go-task/task/pull/904)).
 - It's now possible to use global level variables on `includes`

docs/docs/api_reference.md

@@ -55,6 +55,7 @@ There are some special variables that is available on the templating system:
 | `TASK` | The name of the current task. |
 | `ROOT_DIR` | The absolute path of the root Taskfile. |
 | `TASKFILE_DIR` | The absolute path of the included Taskfile. |
+| `USER_WORKING_DIR` | The absolute path of the directory `task` was called from. |
 | `CHECKSUM` | The checksum of the files listed in `sources`. Only available within the `status` prop and if method is set to `checksum`. |
 | `TIMESTAMP` | The date object of the greatest timestamp of the files listes in `sources`. Only available within the `status` prop and if method is set to `timestamp`. |
 

docs/docs/usage.md

@@ -52,6 +52,35 @@ committed version (`.dist`) while still allowing individual users to override
 the Taskfile by adding an additional `Taskfile.yml` (which would be on
 `.gitignore`).
 
+### Running a Taskfile from a subdirectory
+
+If a Taskfile cannot be found in the current working directory, it will walk up
+the file tree until it finds one (similar to how `git` works). When running Task
+from a subdirectory like this, it will behave as if you ran it from the
+directory containing the Taskfile.
+
+You can use this functionality along with the special `{{.USER_WORKING_DIR}}`
+variable to create some very useful reusable tasks. For example, if you have a
+monorepo with directories for each microservice, you can `cd` into a
+microservice directory and run a task command to bring it up without having to
+create multiple tasks or Taskfiles with identical content. For example:
+
+```yaml
+version: '3'
+
+tasks:
+  up:
+    dir: '{{.USER_WORKING_DIR}}'
+    preconditions:
+      - test -f docker-compose.yml
+    cmds:
+      - docker-compose up -d
+```
+
+In this example, we can run `cd <service>` and `task up` and as long as the
+`<service>` directory contains a `docker-compose.yml`, the Docker composition will be
+brought up.
+
 ## Environment variables
 
 ### Task

internal/compiler/v3/compiler_v3.go

@@ -18,7 +18,8 @@ import (
 var _ compiler.Compiler = &CompilerV3{}
 
 type CompilerV3 struct {
-	Dir string
+	Dir            string
+	UserWorkingDir string
 
 	TaskfileEnv  *taskfile.Vars
 	TaskfileVars *taskfile.Vars
@@ -179,9 +180,10 @@ func (c *CompilerV3) getSpecialVars(t *taskfile.Task) (map[string]string, error)
 	}
 
 	return map[string]string{
-		"TASK":         t.Task,
-		"ROOT_DIR":     c.Dir,
-		"TASKFILE_DIR": taskfileDir,
+		"TASK":             t.Task,
+		"ROOT_DIR":         c.Dir,
+		"TASKFILE_DIR":     taskfileDir,
+		"USER_WORKING_DIR": c.UserWorkingDir,
 	}, nil
 }
 

internal/sysinfo/uid.go

@@ -0,0 +1,22 @@
+//go:build !windows
+
+package sysinfo
+
+import (
+	"os"
+	"syscall"
+)
+
+func Owner(path string) (int, error) {
+	info, err := os.Stat(path)
+	if err != nil {
+		return 0, err
+	}
+	var uid int
+	if stat, ok := info.Sys().(*syscall.Stat_t); ok {
+		uid = int(stat.Uid)
+	} else {
+		uid = os.Getuid()
+	}
+	return uid, nil
+}

internal/sysinfo/uid_win.go

@@ -0,0 +1,9 @@
+//go:build windows
+
+package sysinfo
+
+// NOTE: This always returns -1 since there is currently no easy way to get
+// file owner information on Windows.
+func Owner(path string) (int, error) {
+	return -1, nil
+}

setup.go

@@ -80,7 +80,7 @@ func (e *Executor) setCurrentDir() error {
 
 func (e *Executor) readTaskfile() error {
 	var err error
-	e.Taskfile, err = read.Taskfile(&read.ReaderNode{
+	e.Taskfile, e.Dir, err = read.Taskfile(&read.ReaderNode{
 		Dir:        e.Dir,
 		Entrypoint: e.Entrypoint,
 		Parent:     nil,
@@ -179,11 +179,16 @@ func (e *Executor) setupCompiler(v float64) error {
 			Logger:       e.Logger,
 		}
 	} else {
+		userWorkingDir, err := os.Getwd()
+		if err != nil {
+			return err
+		}
 		e.Compiler = &compilerv3.CompilerV3{
-			Dir:          e.Dir,
-			TaskfileEnv:  e.Taskfile.Env,
-			TaskfileVars: e.Taskfile.Vars,
-			Logger:       e.Logger,
+			Dir:            e.Dir,
+			UserWorkingDir: userWorkingDir,
+			TaskfileEnv:    e.Taskfile.Env,
+			TaskfileVars:   e.Taskfile.Vars,
+			Logger:         e.Logger,
 		}
 	}
 

task_test.go

@@ -1703,3 +1703,52 @@ Hello, World!
 	err = os.RemoveAll(filepathext.SmartJoin(dir, "src"))
 	assert.NoError(t, err)
 }
+
+func TestTaskfileWalk(t *testing.T) {
+	tests := []struct {
+		name     string
+		dir      string
+		expected string
+	}{
+		{
+			name:     "walk from root directory",
+			dir:      "testdata/taskfile_walk",
+			expected: "foo\n",
+		}, {
+			name:     "walk from sub directory",
+			dir:      "testdata/taskfile_walk/foo",
+			expected: "foo\n",
+		}, {
+			name:     "walk from sub sub directory",
+			dir:      "testdata/taskfile_walk/foo/bar",
+			expected: "foo\n",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			var buff bytes.Buffer
+			e := task.Executor{
+				Dir:    test.dir,
+				Stdout: &buff,
+				Stderr: &buff,
+			}
+			assert.NoError(t, e.Setup())
+			assert.NoError(t, e.Run(context.Background(), taskfile.Call{Task: "default"}))
+			assert.Equal(t, test.expected, buff.String())
+		})
+	}
+}
+
+func TestUserWorkingDirectory(t *testing.T) {
+	var buff bytes.Buffer
+	e := task.Executor{
+		Dir:    "testdata/user_working_dir",
+		Stdout: &buff,
+		Stderr: &buff,
+	}
+	wd, err := os.Getwd()
+	assert.NoError(t, err)
+	assert.NoError(t, e.Setup())
+	assert.NoError(t, e.Run(context.Background(), taskfile.Call{Task: "default"}))
+	assert.Equal(t, fmt.Sprintf("%s\n", wd), buff.String())
+}

taskfile/read/taskfile.go

@@ -10,6 +10,7 @@ import (
 	"gopkg.in/yaml.v3"
 
 	"github.com/go-task/task/v3/internal/filepathext"
+	"github.com/go-task/task/v3/internal/sysinfo"
 	"github.com/go-task/task/v3/internal/templater"
 	"github.com/go-task/task/v3/taskfile"
 )
@@ -36,29 +37,30 @@ type ReaderNode struct {
 // Taskfile reads a Taskfile for a given directory
 // Uses current dir when dir is left empty. Uses Taskfile.yml
 // or Taskfile.yaml when entrypoint is left empty
-func Taskfile(readerNode *ReaderNode) (*taskfile.Taskfile, error) {
+func Taskfile(readerNode *ReaderNode) (*taskfile.Taskfile, string, error) {
 	if readerNode.Dir == "" {
 		d, err := os.Getwd()
 		if err != nil {
-			return nil, err
+			return nil, "", err
 		}
 		readerNode.Dir = d
 	}
 
-	path, err := exists(filepathext.SmartJoin(readerNode.Dir, readerNode.Entrypoint))
+	path, err := existsWalk(filepathext.SmartJoin(readerNode.Dir, readerNode.Entrypoint))
 	if err != nil {
-		return nil, err
+		return nil, "", err
 	}
+	readerNode.Dir = filepath.Dir(path)
 	readerNode.Entrypoint = filepath.Base(path)
 
 	t, err := readTaskfile(path)
 	if err != nil {
-		return nil, err
+		return nil, "", err
 	}
 
 	v, err := t.ParsedVersion()
 	if err != nil {
-		return nil, err
+		return nil, "", err
 	}
 
 	// Annotate any included Taskfile reference with a base directory for resolving relative paths
@@ -113,7 +115,7 @@ func Taskfile(readerNode *ReaderNode) (*taskfile.Taskfile, error) {
 			return err
 		}
 
-		includedTaskfile, err := Taskfile(includeReaderNode)
+		includedTaskfile, _, err := Taskfile(includeReaderNode)
 		if err != nil {
 			if includedTask.Optional {
 				return nil
@@ -163,7 +165,7 @@ func Taskfile(readerNode *ReaderNode) (*taskfile.Taskfile, error) {
 		return nil
 	})
 	if err != nil {
-		return nil, err
+		return nil, "", err
 	}
 
 	if v < 3.0 {
@@ -171,10 +173,10 @@ func Taskfile(readerNode *ReaderNode) (*taskfile.Taskfile, error) {
 		if _, err = os.Stat(path); err == nil {
 			osTaskfile, err := readTaskfile(path)
 			if err != nil {
-				return nil, err
+				return nil, "", err
 			}
 			if err = taskfile.Merge(t, osTaskfile, nil); err != nil {
-				return nil, err
+				return nil, "", err
 			}
 		}
 	}
@@ -187,7 +189,7 @@ func Taskfile(readerNode *ReaderNode) (*taskfile.Taskfile, error) {
 		task.Task = name
 	}
 
-	return t, nil
+	return t, readerNode.Dir, nil
 }
 
 func readTaskfile(file string) (*taskfile.Taskfile, error) {
@@ -221,6 +223,36 @@ func exists(path string) (string, error) {
 	return "", fmt.Errorf(`task: No Taskfile found in "%s". Use "task --init" to create a new one`, path)
 }
 
+func existsWalk(path string) (string, error) {
+	origPath := path
+	owner, err := sysinfo.Owner(path)
+	if err != nil {
+		return "", err
+	}
+	for {
+		fpath, err := exists(path)
+		if err == nil {
+			return fpath, nil
+		}
+
+		// Get the parent path/user id
+		parentPath := filepath.Dir(path)
+		parentOwner, err := sysinfo.Owner(parentPath)
+		if err != nil {
+			return "", err
+		}
+
+		// Error if we reached the root directory and still haven't found a file
+		// OR if the user id of the directory changes
+		if path == parentPath || (parentOwner != owner) {
+			return "", fmt.Errorf(`task: No Taskfile found in "%s" (or any of the parent directories). Use "task --init" to create a new one`, origPath)
+		}
+
+		owner = parentOwner
+		path = parentPath
+	}
+}
+
 func checkCircularIncludes(node *ReaderNode) error {
 	if node == nil {
 		return errors.New("task: failed to check for include cycle: node was nil")

testdata/taskfile_walk/Taskfile.yml

@@ -0,0 +1,7 @@
+version: '3'
+
+tasks:
+  default:
+    cmds:
+      - echo 'foo'
+    silent: true

testdata/user_working_dir/Taskfile.yml

@@ -0,0 +1,7 @@
+version: '3'
+
+tasks:
+  default:
+    cmds:
+      - echo '{{.USER_WORKING_DIR}}'
+    silent: true