Make sure plugins only mount the workspace base in a predefinde locat…

…ion (#3933)

docs/docs/20-usage/20-workflow-syntax.md

@@ -518,7 +518,9 @@ For more details check the [services docs](./60-services.md).
 
 ## `workspace`
 
-The workspace defines the shared volume and working directory shared by all workflow steps. The default workspace matches the pattern `/woodpecker/src/github.com/octocat/hello-world`, based on your repository URL.
+The workspace defines the shared volume and working directory shared by all workflow steps.
+The default workspace base is `/woodpecker` and the path is extended with the repository URL (`src/{url-without-schema}`).
+So an example would be `/woodpecker/src/github.com/octocat/hello-world`.
 
 The workspace can be customized using the workspace block in the YAML file:
 
@@ -535,6 +537,10 @@ The workspace can be customized using the workspace block in the YAML file:
        - go test
 ```
 
+:::note
+Plugins will always have the workspace base at `/woodpecker`
+:::
+
 The base attribute defines a shared base volume available to all steps. This ensures your source code, dependencies and compiled binaries are persisted and shared between steps.
 
 ```diff

docs/docs/20-usage/51-plugins/51-overview.md

@@ -29,6 +29,11 @@ steps:
 ## Plugin Isolation
 
 Plugins are just pipeline steps. They share the build workspace, mounted as a volume, and therefore have access to your source tree.
+While normal steps are all about arbitrary code execution, plugins should only allow the functions intended by the plugin author.
+
+So there are a few limitations, like the workspace base is always mounted at `/woodpecker`, but the working directory is dynamically adjusted acordingly. So as user of a plugin you should not have to care about this.
+
+Also instead of using environment variables the plugin should only care about one prefixed with `PLUGIN_` witch are the internaml representation of the **settings** ([read more](./20-creating-plugins.md)).
 
 ## Finding Plugins
 

pipeline/frontend/yaml/compiler/compiler.go

@@ -16,6 +16,7 @@ package compiler
 
 import (
 	"fmt"
+	"path"
 
 	backend_types "go.woodpecker-ci.org/woodpecker/v2/pipeline/backend/types"
 	"go.woodpecker-ci.org/woodpecker/v2/pipeline/frontend/metadata"
@@ -98,8 +99,8 @@ type Compiler struct {
 	networks          []string
 	env               map[string]string
 	cloneEnv          map[string]string
-	base              string
-	path              string
+	workspaceBase     string
+	workspacePath     string
 	metadata          metadata.Metadata
 	registries        []Registry
 	secrets           map[string]Secret
@@ -156,10 +157,10 @@ func (c *Compiler) Compile(conf *yaml_types.Workflow) (*backend_types.Config, er
 	// overrides the default workspace paths when specified
 	// in the YAML file.
 	if len(conf.Workspace.Base) != 0 {
-		c.base = conf.Workspace.Base
+		c.workspaceBase = path.Clean(conf.Workspace.Base)
 	}
 	if len(conf.Workspace.Path) != 0 {
-		c.path = conf.Workspace.Path
+		c.workspacePath = path.Clean(conf.Workspace.Path)
 	}
 
 	cloneImage := constant.DefaultCloneImage

pipeline/frontend/yaml/compiler/compiler_test.go

@@ -61,13 +61,14 @@ func TestSecretAvailable(t *testing.T) {
 }
 
 func TestCompilerCompile(t *testing.T) {
+	repoURL := "https://github.com/octocat/hello-world"
 	compiler := New(
 		WithMetadata(metadata.Metadata{
 			Repo: metadata.Repo{
 				Owner:    "octacat",
 				Name:     "hello-world",
 				Private:  true,
-				ForgeURL: "https://github.com/octocat/hello-world",
+				ForgeURL: repoURL,
 				CloneURL: "https://github.com/octocat/hello-world.git",
 			},
 		}),
@@ -76,6 +77,8 @@ func TestCompilerCompile(t *testing.T) {
 			"COLORED": "true",
 		}),
 		WithPrefix("test"),
+		// we use "/test" as custom workspace base to ensure the enforcement of the pluginWorkspaceBase is applied
+		WithWorkspaceFromURL("/test", repoURL),
 	)
 
 	defaultNetworks := []*backend_types.Network{{
@@ -92,7 +95,8 @@ func TestCompilerCompile(t *testing.T) {
 			Image:      constant.DefaultCloneImage,
 			OnSuccess:  true,
 			Failure:    "fail",
-			Volumes:    []string{defaultVolumes[0].Name + ":"},
+			Volumes:    []string{defaultVolumes[0].Name + ":/woodpecker"},
+			WorkingDir: "/woodpecker/src/github.com/octocat/hello-world",
 			Networks:   []backend_types.Conn{{Name: "test_default", Aliases: []string{"clone"}}},
 			ExtraHosts: []backend_types.HostAlias{},
 		}},
@@ -137,7 +141,8 @@ func TestCompilerCompile(t *testing.T) {
 						Image:      "dummy_img",
 						OnSuccess:  true,
 						Failure:    "fail",
-						Volumes:    []string{defaultVolumes[0].Name + ":"},
+						Volumes:    []string{defaultVolumes[0].Name + ":/woodpecker"},
+						WorkingDir: "/woodpecker/src/github.com/octocat/hello-world",
 						Networks:   []backend_types.Conn{{Name: "test_default", Aliases: []string{"dummy"}}},
 						ExtraHosts: []backend_types.HostAlias{},
 					}},
@@ -172,7 +177,8 @@ func TestCompilerCompile(t *testing.T) {
 						Commands:   []string{"env"},
 						OnSuccess:  true,
 						Failure:    "fail",
-						Volumes:    []string{defaultVolumes[0].Name + ":"},
+						Volumes:    []string{defaultVolumes[0].Name + ":/test"},
+						WorkingDir: "/test/src/github.com/octocat/hello-world",
 						Networks:   []backend_types.Conn{{Name: "test_default", Aliases: []string{"echo env"}}},
 						ExtraHosts: []backend_types.HostAlias{},
 					}},
@@ -184,7 +190,8 @@ func TestCompilerCompile(t *testing.T) {
 						Commands:   []string{"echo 1"},
 						OnSuccess:  true,
 						Failure:    "fail",
-						Volumes:    []string{defaultVolumes[0].Name + ":"},
+						Volumes:    []string{defaultVolumes[0].Name + ":/test"},
+						WorkingDir: "/test/src/github.com/octocat/hello-world",
 						Networks:   []backend_types.Conn{{Name: "test_default", Aliases: []string{"parallel echo 1"}}},
 						ExtraHosts: []backend_types.HostAlias{},
 					}, {
@@ -194,7 +201,8 @@ func TestCompilerCompile(t *testing.T) {
 						Commands:   []string{"echo 2"},
 						OnSuccess:  true,
 						Failure:    "fail",
-						Volumes:    []string{defaultVolumes[0].Name + ":"},
+						Volumes:    []string{defaultVolumes[0].Name + ":/test"},
+						WorkingDir: "/test/src/github.com/octocat/hello-world",
 						Networks:   []backend_types.Conn{{Name: "test_default", Aliases: []string{"parallel echo 2"}}},
 						ExtraHosts: []backend_types.HostAlias{},
 					}},
@@ -228,7 +236,8 @@ func TestCompilerCompile(t *testing.T) {
 						Commands:   []string{"env"},
 						OnSuccess:  true,
 						Failure:    "fail",
-						Volumes:    []string{defaultVolumes[0].Name + ":"},
+						Volumes:    []string{defaultVolumes[0].Name + ":/test"},
+						WorkingDir: "/test/src/github.com/octocat/hello-world",
 						Networks:   []backend_types.Conn{{Name: "test_default", Aliases: []string{"echo env"}}},
 						ExtraHosts: []backend_types.HostAlias{},
 					}, {
@@ -238,7 +247,8 @@ func TestCompilerCompile(t *testing.T) {
 						Commands:   []string{"echo 2"},
 						OnSuccess:  true,
 						Failure:    "fail",
-						Volumes:    []string{defaultVolumes[0].Name + ":"},
+						Volumes:    []string{defaultVolumes[0].Name + ":/test"},
+						WorkingDir: "/test/src/github.com/octocat/hello-world",
 						Networks:   []backend_types.Conn{{Name: "test_default", Aliases: []string{"echo 2"}}},
 						ExtraHosts: []backend_types.HostAlias{},
 					}},
@@ -250,7 +260,8 @@ func TestCompilerCompile(t *testing.T) {
 						Commands:   []string{"echo 1"},
 						OnSuccess:  true,
 						Failure:    "fail",
-						Volumes:    []string{defaultVolumes[0].Name + ":"},
+						Volumes:    []string{defaultVolumes[0].Name + ":/test"},
+						WorkingDir: "/test/src/github.com/octocat/hello-world",
 						Networks:   []backend_types.Conn{{Name: "test_default", Aliases: []string{"echo 1"}}},
 						ExtraHosts: []backend_types.HostAlias{},
 					}},

pipeline/frontend/yaml/compiler/convert.go

@@ -30,19 +30,32 @@ import (
 	"go.woodpecker-ci.org/woodpecker/v2/pipeline/frontend/yaml/utils"
 )
 
+const (
+	// The pluginWorkspaceBase should not be changed, only if you are sure what you do.
+	pluginWorkspaceBase = "/woodpecker"
+	// DefaultWorkspaceBase is set if not altered by the user.
+	DefaultWorkspaceBase = pluginWorkspaceBase
+)
+
 func (c *Compiler) createProcess(container *yaml_types.Container, stepType backend_types.StepType) (*backend_types.Step, error) {
 	var (
 		uuid = ulid.Make()
 
 		detached   bool
 		workingDir string
 
-		workspace   = fmt.Sprintf("%s_default:%s", c.prefix, c.base)
 		privileged  = container.Privileged
 		networkMode = container.NetworkMode
 		// network    = container.Network
 	)
 
+	workspaceBase := c.workspaceBase
+	if container.IsPlugin() {
+		// plugins have a predefined workspace base to not tamper with entrypoint executables
+		workspaceBase = pluginWorkspaceBase
+	}
+	workspaceVolume := fmt.Sprintf("%s_default:%s", c.prefix, workspaceBase)
+
 	networks := []backend_types.Conn{
 		{
 			Name:    fmt.Sprintf("%s_default", c.prefix),
@@ -67,7 +80,7 @@ func (c *Compiler) createProcess(container *yaml_types.Container, stepType backe
 
 	var volumes []string
 	if !c.local {
-		volumes = append(volumes, workspace)
+		volumes = append(volumes, workspaceVolume)
 	}
 	volumes = append(volumes, c.volumes...)
 	for _, volume := range container.Volumes.Volumes {
@@ -78,7 +91,7 @@ func (c *Compiler) createProcess(container *yaml_types.Container, stepType backe
 	environment := map[string]string{}
 	maps.Copy(environment, c.env)
 
-	environment["CI_WORKSPACE"] = path.Join(c.base, c.path)
+	environment["CI_WORKSPACE"] = path.Join(workspaceBase, c.workspacePath)
 
 	if stepType == backend_types.StepTypeService || container.Detached {
 		detached = true
@@ -222,7 +235,11 @@ func (c *Compiler) stepWorkingDir(container *yaml_types.Container) string {
 	if path.IsAbs(container.Directory) {
 		return container.Directory
 	}
-	return path.Join(c.base, c.path, container.Directory)
+	base := c.workspaceBase
+	if container.IsPlugin() {
+		base = pluginWorkspaceBase
+	}
+	return path.Join(base, c.workspacePath, container.Directory)
 }
 
 func convertPort(portDef string) (backend_types.Port, error) {

pipeline/frontend/yaml/compiler/option.go

@@ -97,8 +97,8 @@ func WithNetrc(username, password, machine string) Option {
 // plugin steps in the pipeline.
 func WithWorkspace(base, path string) Option {
 	return func(compiler *Compiler) {
-		compiler.base = base
-		compiler.path = path
+		compiler.workspaceBase = base
+		compiler.workspacePath = path
 	}
 }
 

pipeline/frontend/yaml/compiler/option_test.go

@@ -29,8 +29,8 @@ func TestWithWorkspace(t *testing.T) {
 			"src/github.com/octocat/hello-world",
 		),
 	)
-	assert.Equal(t, "/pipeline", compiler.base)
-	assert.Equal(t, "src/github.com/octocat/hello-world", compiler.path)
+	assert.Equal(t, "/pipeline", compiler.workspaceBase)
+	assert.Equal(t, "src/github.com/octocat/hello-world", compiler.workspacePath)
 }
 
 func TestWithEscalated(t *testing.T) {

server/pipeline/stepbuilder/stepBuilder.go

@@ -291,7 +291,7 @@ func (b *StepBuilder) toInternalRepresentation(parsed *yaml_types.Workflow, envi
 			),
 		),
 		compiler.WithProxy(b.ProxyOpts),
-		compiler.WithWorkspaceFromURL("/woodpecker", b.Repo.ForgeURL),
+		compiler.WithWorkspaceFromURL(compiler.DefaultWorkspaceBase, b.Repo.ForgeURL),
 		compiler.WithMetadata(metadata),
 		compiler.WithTrusted(b.Repo.IsTrusted),
 		compiler.WithNetrcOnlyTrusted(b.Repo.NetrcOnlyTrusted),