Add support for 'platforms' in both task and command (#980)

docs/docs/api_reference.md

@@ -139,6 +139,7 @@ includes:
 | `prefix` | `string` | | Defines a string to prefix the output of tasks running in parallel. Only used when the output mode is `prefixed`. |
 | `ignore_error` | `bool` | `false` | Continue execution if errors happen while executing commands. |
 | `run` | `string` | The one declared globally in the Taskfile or `always` | Specifies whether the task should run again or not if called more than once. Available options: `always`, `once` and `when_changed`. |
+| `platforms` | `[]string` | All platforms | Specifies which platforms the task should be run on. |
 
 :::info
 
@@ -189,6 +190,7 @@ tasks:
 | `vars` | [`map[string]Variable`](#variable) | | Optional additional variables to be passed to the referenced task. Only relevant when setting `task` instead of `cmd`. |
 | `ignore_error` | `bool` | `false` | Continue execution if errors happen while executing the command. |
 | `defer` | `string` | | Alternative to `cmd`, but schedules the command to be executed at the end of this task instead of immediately. This cannot be used together with `cmd`. |
+| `platforms` | `[]string` | All platforms | Specifies which platforms the command should be run on. |
 
 :::info
 

docs/docs/usage.md

@@ -439,6 +439,73 @@ tasks:
       - echo {{.TEXT}}
 ```
 
+## Platform specific tasks and commands
+
+If you want to restrict the running of tasks to explicit platforms, this can be achieved
+using the `platforms` key. Tasks can be restricted to a specific OS, architecture or a
+combination of both.
+
+The `build-windows` task below will run only on Windows, and on any architecture:
+
+```yaml
+version: '3'
+
+tasks:
+  build-windows:
+    platforms: [windows]
+    cmds:
+      - echo 'Running command on windows'
+```
+
+This can be restricted to a specific architecture as follows:
+
+```yaml
+version: '3'
+
+tasks:
+  build-windows-amd64:
+    platforms: [windows/amd64]
+    cmds:
+      - echo 'Running command on windows (amd64)'
+```
+
+It is also possible to restrict the task to specific architectures:
+
+```yaml
+version: '3'
+
+tasks:
+  build-amd64:
+    platforms: [amd64]
+    cmds:
+      - echo 'Running command on amd64'
+```
+
+Multiple platforms can be specified as follows:
+
+```yaml
+version: '3'
+
+tasks:
+  build-windows:
+    platforms: [windows/amd64, darwin]
+    cmds:
+      - echo 'Running command on windows (amd64) and darwin'
+```
+
+Individual commands can also be restricted to specific platforms:
+
+```yaml
+version: '3'
+
+tasks:
+  build-windows:
+    cmds:
+      - cmd: echo 'Running command on windows (amd64) and darwin'
+        platforms: [windows/amd64, darwin]
+      - cmd: echo 'Running on all platforms'
+```
+
 ## Calling another task
 
 When a task has many dependencies, they are executed concurrently. This will

docs/static/schema.json

@@ -155,6 +155,13 @@
           "run": {
             "description": "Specifies whether the task should run again or not if called more than once. Available options: `always`, `once` and `when_changed`.",
             "$ref": "#/definitions/3/run"
+          },
+          "platforms": {
+            "description": "Specifies which platforms the task should be run on.",
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
           }
         }
       },
@@ -233,6 +240,13 @@
           "defer": {
             "description": "",
             "type": "boolean"
+          },
+          "platforms": {
+            "description": "Specifies which platforms the command should be run on.",
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
           }
         },
         "additionalProperties": false,

task.go

@@ -135,6 +135,13 @@ func (e *Executor) RunTask(ctx context.Context, call taskfile.Call) error {
 	defer release()
 
 	return e.startExecution(ctx, t, func(ctx context.Context) error {
+
+		// Check platform
+		if !ShouldRunOnCurrentPlatform(t.Platforms) {
+			e.Logger.VerboseOutf(logger.Yellow, `task: "%s" not for current platform - ignored`, call.Task)
+			return nil
+		}
+
 		e.Logger.VerboseErrf(logger.Magenta, `task: "%s" started`, call.Task)
 		if err := e.runDeps(ctx, t); err != nil {
 			return err
@@ -252,6 +259,11 @@ func (e *Executor) runCommand(ctx context.Context, t *taskfile.Task, call taskfi
 		}
 		return nil
 	case cmd.Cmd != "":
+		// Check platform
+		if !ShouldRunOnCurrentPlatform(cmd.Platforms) {
+			e.Logger.VerboseOutf(logger.Yellow, `task: [%s] %s not for current platform - ignored`, t.Name(), cmd.Cmd)
+			return nil
+		}
 		if e.Verbose || (!cmd.Silent && !t.Silent && !e.Taskfile.Silent && !e.Silent) {
 			e.Logger.Errf(logger.Green, "task: [%s] %s", t.Name(), cmd.Cmd)
 		}
@@ -455,3 +467,15 @@ func FilterOutInternal() FilterFunc {
 		return task.Internal
 	})
 }
+
+func ShouldRunOnCurrentPlatform(platforms []*taskfile.Platform) bool {
+	if len(platforms) == 0 {
+		return true
+	}
+	for _, platform := range platforms {
+		if platform.MatchesCurrentPlatform() {
+			return true
+		}
+	}
+	return false
+}

task_test.go

@@ -1696,3 +1696,14 @@ func TestUserWorkingDirectory(t *testing.T) {
 	assert.NoError(t, e.Run(context.Background(), taskfile.Call{Task: "default"}))
 	assert.Equal(t, fmt.Sprintf("%s\n", wd), buff.String())
 }
+func TestPlatforms(t *testing.T) {
+	var buff bytes.Buffer
+	e := task.Executor{
+		Dir:    "testdata/platforms",
+		Stdout: &buff,
+		Stderr: &buff,
+	}
+	assert.NoError(t, e.Setup())
+	assert.NoError(t, e.Run(context.Background(), taskfile.Call{Task: "build-" + runtime.GOOS}))
+	assert.Equal(t, fmt.Sprintf("task: [build-%s] echo 'Running task on %s'\nRunning task on %s\n", runtime.GOOS, runtime.GOOS, runtime.GOOS), buff.String())
+}

taskfile/cmd.go

@@ -14,6 +14,7 @@ type Cmd struct {
 	Vars        *Vars
 	IgnoreError bool
 	Defer       bool
+	Platforms   []*Platform
 }
 
 // Dep is a task dependency
@@ -40,11 +41,13 @@ func (c *Cmd) UnmarshalYAML(node *yaml.Node) error {
 			Cmd         string
 			Silent      bool
 			IgnoreError bool `yaml:"ignore_error"`
+			Platforms   []*Platform
 		}
 		if err := node.Decode(&cmdStruct); err == nil && cmdStruct.Cmd != "" {
 			c.Cmd = cmdStruct.Cmd
 			c.Silent = cmdStruct.Silent
 			c.IgnoreError = cmdStruct.IgnoreError
+			c.Platforms = cmdStruct.Platforms
 			return nil
 		}
 

taskfile/platforms.go

@@ -0,0 +1,113 @@
+package taskfile
+
+import (
+	"fmt"
+	"runtime"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)
+
+// Platform represents GOOS and GOARCH values
+type Platform struct {
+	OS   string
+	Arch string
+}
+
+// ParsePlatform takes a string representing an OS/Arch combination (or either on their own)
+// and parses it into the Platform struct. It returns an error if the input string is invalid.
+// Valid combinations for input: OS, Arch, OS/Arch
+func (p *Platform) ParsePlatform(input string) error {
+	// tidy up input
+	platformString := strings.ToLower(strings.TrimSpace(input))
+	splitValues := strings.Split(platformString, "/")
+	if len(splitValues) > 2 {
+		return fmt.Errorf("task: Invalid OS/Arch provided: %s", input)
+	}
+	err := p.parseOsOrArch(splitValues[0])
+	if err != nil {
+		return err
+	}
+	if len(splitValues) == 2 {
+		return p.parseArch(splitValues[1])
+	}
+	return nil
+}
+
+// supportedOSes is a list of supported OSes
+var supportedOSes = map[string]struct{}{
+	"windows": {},
+	"darwin":  {},
+	"linux":   {},
+	"freebsd": {},
+}
+
+func isSupportedOS(input string) bool {
+	_, exists := supportedOSes[input]
+	return exists
+}
+
+// supportedArchs is a list of supported architectures
+var supportedArchs = map[string]struct{}{
+	"amd64": {},
+	"arm64": {},
+	"386":   {},
+}
+
+func isSupportedArch(input string) bool {
+	_, exists := supportedArchs[input]
+	return exists
+}
+
+// MatchesCurrentPlatform returns true if the platform matches the current platform
+func (p *Platform) MatchesCurrentPlatform() bool {
+	return (p.OS == "" || p.OS == runtime.GOOS) &&
+		(p.Arch == "" || p.Arch == runtime.GOARCH)
+}
+
+// UnmarshalYAML implements yaml.Unmarshaler interface.
+func (p *Platform) UnmarshalYAML(node *yaml.Node) error {
+	switch node.Kind {
+
+	case yaml.ScalarNode:
+		var platform string
+		if err := node.Decode(&platform); err != nil {
+			return err
+		}
+		if err := p.ParsePlatform(platform); err != nil {
+			return err
+		}
+		return nil
+	}
+	return fmt.Errorf("yaml: line %d: cannot unmarshal %s into platform", node.Line, node.ShortTag())
+}
+
+// parseOsOrArch will check if the given input is a valid OS or Arch value.
+// If so, it will store it. If not, an error is returned
+func (p *Platform) parseOsOrArch(osOrArch string) error {
+	if osOrArch == "" {
+		return fmt.Errorf("task: Blank OS/Arch value provided")
+	}
+	if isSupportedOS(osOrArch) {
+		p.OS = osOrArch
+		return nil
+	}
+	if isSupportedArch(osOrArch) {
+		p.Arch = osOrArch
+		return nil
+	}
+	return fmt.Errorf("task: Invalid OS/Arch value provided (%s)", osOrArch)
+}
+func (p *Platform) parseArch(arch string) error {
+	if arch == "" {
+		return fmt.Errorf("task: Blank Arch value provided")
+	}
+	if p.Arch != "" {
+		return fmt.Errorf("task: Multiple Arch values provided")
+	}
+	if isSupportedArch(arch) {
+		p.Arch = arch
+		return nil
+	}
+	return fmt.Errorf("task: Invalid Arch value provided (%s)", arch)
+}

taskfile/task.go

@@ -36,6 +36,7 @@ type Task struct {
 	IncludeVars          *Vars
 	IncludedTaskfileVars *Vars
 	IncludedTaskfile     *IncludedTaskfile
+	Platforms            []*Platform
 }
 
 func (t *Task) Name() string {
@@ -90,6 +91,7 @@ func (t *Task) UnmarshalYAML(node *yaml.Node) error {
 			Prefix        string
 			IgnoreError   bool `yaml:"ignore_error"`
 			Run           string
+			Platforms     []*Platform
 		}
 		if err := node.Decode(&task); err != nil {
 			return err
@@ -115,6 +117,7 @@ func (t *Task) UnmarshalYAML(node *yaml.Node) error {
 		t.Prefix = task.Prefix
 		t.IgnoreError = task.IgnoreError
 		t.Run = task.Run
+		t.Platforms = task.Platforms
 		return nil
 	}
 
@@ -150,6 +153,7 @@ func (t *Task) DeepCopy() *Task {
 		IncludeVars:          t.IncludeVars.DeepCopy(),
 		IncludedTaskfileVars: t.IncludedTaskfileVars.DeepCopy(),
 		IncludedTaskfile:     t.IncludedTaskfile.DeepCopy(),
+		Platforms:            deepCopySlice(t.Platforms),
 	}
 	return c
 }

testdata/platforms/Taskfile.yml

@@ -0,0 +1,55 @@
+version: '3'
+
+tasks:
+  build-windows:
+    platforms: [windows]
+    cmds:
+      - echo 'Running task on windows'
+
+  build-darwin:
+    platforms: [darwin]
+    cmds:
+      - echo 'Running task on darwin'
+
+  build-linux:
+    platforms: [linux]
+    cmds:
+      - echo 'Running task on linux'
+
+  build-freebsd:
+    platforms: [freebsd]
+    cmds:
+      - echo 'Running task on freebsd'
+
+  build-blank-os:
+    platforms: []
+    cmds:
+      - echo 'Running command'
+
+  build-multiple:
+    platforms: []
+    cmds:
+      - cmd: echo 'Running command'
+      - cmd: echo 'Running on Windows'
+        platforms: [windows]
+      - cmd: echo 'Running on Darwin'
+        platforms: [darwin]
+
+  build-amd64:
+    platforms: [amd64]
+    cmds:
+      - echo "Running command on amd64"
+
+  build-arm64:
+    platforms: [arm64]
+    cmds:
+      - echo "Running command on arm64"
+
+  build-mixed:
+    cmds:
+      - cmd: echo 'building on windows/arm64'
+        platforms: [windows/arm64]
+      - cmd: echo 'building on linux/amd64'
+        platforms: [linux/amd64]
+      - cmd: echo 'building on darwin'
+        platforms: [darwin]