Add missing unit test.

api/stacks/deployments/deployment_compose_config.go

@@ -2,13 +2,14 @@ package deployments
 
 import (
 	"fmt"
-	"log"
 
-	"github.com/pkg/errors"
 	portainer "github.com/portainer/portainer/api"
 	"github.com/portainer/portainer/api/dataservices"
 	"github.com/portainer/portainer/api/http/security"
 	"github.com/portainer/portainer/api/stacks/stackutils"
+
+	"github.com/pkg/errors"
+	"github.com/rs/zerolog/log"
 )
 
 type ComposeStackDeploymentConfig struct {
@@ -55,15 +56,22 @@ func (config *ComposeStackDeploymentConfig) GetUsername() string {
 	if config.user != nil {
 		return config.user.Username
 	}
+
 	return ""
 }
 
 func (config *ComposeStackDeploymentConfig) Deploy() error {
 	if config.FileService == nil || config.StackDeployer == nil {
-		log.Println("[deployment, compose] file service or stack deployer is not initialised")
+		log.Error().Msg("file service or stack deployer is not initialised")
+
 		return errors.New("file service or stack deployer cannot be nil")
 	}
 
+	err := stackutils.ValidateStackFiles(config.stack, stackutils.IsValidBuildContext, config.FileService)
+	if err != nil {
+		return err
+	}
+
 	isAdminOrEndpointAdmin, err := stackutils.UserIsAdminOrEndpointAdmin(config.user, config.endpoint.ID)
 	if err != nil {
 		return errors.Wrap(err, "failed to validate user admin privileges")
@@ -79,11 +87,14 @@ func (config *ComposeStackDeploymentConfig) Deploy() error {
 		!securitySettings.AllowContainerCapabilitiesForRegularUsers) &&
 		!isAdminOrEndpointAdmin {
 
-		err = stackutils.ValidateStackFiles(config.stack, securitySettings, config.FileService)
+		validStackFn := stackutils.IsValidStackFileAdapter(securitySettings)
+
+		err = stackutils.ValidateStackFiles(config.stack, validStackFn, config.FileService)
 		if err != nil {
 			return err
 		}
 	}
+
 	if stackutils.IsRelativePathStack(config.stack) {
 		return config.StackDeployer.DeployRemoteComposeStack(config.stack, config.endpoint, config.registries, config.forcePullImage, config.ForceCreate)
 	}

api/stacks/deployments/deployment_swarm_config.go

@@ -2,13 +2,14 @@ package deployments
 
 import (
 	"fmt"
-	"log"
 
-	"github.com/pkg/errors"
 	portainer "github.com/portainer/portainer/api"
 	"github.com/portainer/portainer/api/dataservices"
 	"github.com/portainer/portainer/api/http/security"
 	"github.com/portainer/portainer/api/stacks/stackutils"
+
+	"github.com/pkg/errors"
+	"github.com/rs/zerolog/log"
 )
 
 type SwarmStackDeploymentConfig struct {
@@ -60,10 +61,16 @@ func (config *SwarmStackDeploymentConfig) GetUsername() string {
 
 func (config *SwarmStackDeploymentConfig) Deploy() error {
 	if config.FileService == nil || config.StackDeployer == nil {
-		log.Println("[deployment, swarm] file service or stack deployer is not initialised")
+		log.Error().Msg("file service or stack deployer is not initialised")
+
 		return errors.New("file service or stack deployer cannot be nil")
 	}
 
+	err := stackutils.ValidateStackFiles(config.stack, stackutils.IsValidBuildContext, config.FileService)
+	if err != nil {
+		return err
+	}
+
 	isAdminOrEndpointAdmin, err := stackutils.UserIsAdminOrEndpointAdmin(config.user, config.endpoint.ID)
 	if err != nil {
 		return errors.Wrap(err, "failed to validate user admin privileges")
@@ -72,7 +79,9 @@ func (config *SwarmStackDeploymentConfig) Deploy() error {
 	settings := &config.endpoint.SecuritySettings
 
 	if !settings.AllowBindMountsForRegularUsers && !isAdminOrEndpointAdmin {
-		err = stackutils.ValidateStackFiles(config.stack, settings, config.FileService)
+		validStackFn := stackutils.IsValidStackFileAdapter(settings)
+
+		err = stackutils.ValidateStackFiles(config.stack, validStackFn, config.FileService)
 		if err != nil {
 			return err
 		}

api/stacks/stackutils/validation.go

@@ -1,16 +1,19 @@
 package stackutils
 
 import (
+	"strings"
+
+	portainer "github.com/portainer/portainer/api"
+
 	"github.com/docker/cli/cli/compose/loader"
 	"github.com/docker/cli/cli/compose/types"
 	"github.com/pkg/errors"
-	portainer "github.com/portainer/portainer/api"
 )
 
-func IsValidStackFile(stackFileContent []byte, securitySettings *portainer.EndpointSecuritySettings) error {
+func loadComposeConfig(stackFileContent []byte) (*types.Config, error) {
 	composeConfigYAML, err := loader.ParseYAML(stackFileContent)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	composeConfigFile := types.ConfigFile{
@@ -22,14 +25,19 @@ func IsValidStackFile(stackFileContent []byte, securitySettings *portainer.Endpo
 		Environment: map[string]string{},
 	}
 
-	composeConfig, err := loader.Load(composeConfigDetails, func(options *loader.Options) {
+	return loader.Load(composeConfigDetails, func(options *loader.Options) {
 		options.SkipValidation = true
 		options.SkipInterpolation = true
 	})
-	if err != nil {
-		return err
-	}
+}
 
+func IsValidStackFileAdapter(securitySettings *portainer.EndpointSecuritySettings) func(*types.Config) error {
+	return func(composeConfig *types.Config) error {
+		return IsValidStackFile(composeConfig, securitySettings)
+	}
+}
+
+func IsValidStackFile(composeConfig *types.Config, securitySettings *portainer.EndpointSecuritySettings) error {
 	for key := range composeConfig.Services {
 		service := composeConfig.Services[key]
 		if !securitySettings.AllowBindMountsForRegularUsers {
@@ -64,17 +72,42 @@ func IsValidStackFile(stackFileContent []byte, securitySettings *portainer.Endpo
 	return nil
 }
 
-func ValidateStackFiles(stack *portainer.Stack, securitySettings *portainer.EndpointSecuritySettings, fileService portainer.FileService) error {
+func ValidateStackFiles(stack *portainer.Stack, isValidFn func(content *types.Config) error, fileService portainer.FileService) error {
 	for _, file := range GetStackFilePaths(stack, false) {
 		stackContent, err := fileService.GetFileContent(stack.ProjectPath, file)
 		if err != nil {
 			return errors.Wrap(err, "failed to get stack file content")
 		}
 
-		err = IsValidStackFile(stackContent, securitySettings)
+		composeConfig, err := loadComposeConfig(stackContent)
+		if err != nil {
+			return err
+		}
+
+		err = isValidFn(composeConfig)
 		if err != nil {
 			return errors.Wrap(err, "stack config file is invalid")
 		}
 	}
+
+	return nil
+}
+
+func IsValidBuildContext(composeConfig *types.Config) error {
+	for key := range composeConfig.Services {
+		service := composeConfig.Services[key]
+
+		if strings.HasPrefix(service.Build.Context, "/") || strings.Contains(service.Build.Context, "..") {
+			return errors.New("invalid build context")
+		}
+
+		driveLetter, _, ok := strings.Cut(service.Build.Context, ":")
+		driveLetter = strings.ToUpper(driveLetter)
+
+		if ok && len(driveLetter) == 1 && driveLetter >= "A" && driveLetter <= "Z" {
+			return errors.New("invalid build context")
+		}
+	}
+
 	return nil
 }

api/stacks/stackutils/validation_test.go

@@ -0,0 +1,66 @@
+package stackutils
+
+import (
+	"testing"
+)
+
+func composeFileWithBuild(p string) []byte {
+	return []byte(`
+services:
+  service1:
+    build: ` + p)
+}
+
+func composeFileWithBuildContext(p string) []byte {
+	return []byte(`
+services:
+  service1:
+    build:
+      context: ` + p)
+}
+
+func TestIsValidBuildContext(t *testing.T) {
+	var validPaths = []string{
+		".",
+		"./portainer",
+		`portainer\agent`,
+		"portainer",
+		" portainer",
+		"https://github.com/portainer/portainer",
+		"git@github.com/portainer/portainer.git",
+	}
+
+	var invalidPaths = []string{
+		"/etc/shadow",
+		`C:\Windows`,
+		"C:/Windows",
+		"./../../../../../etc/shadow",
+		" ..",
+	}
+
+	testFn := func(p string, mustFail bool) {
+		for _, fn := range []func(string) []byte{composeFileWithBuild, composeFileWithBuildContext} {
+			composeConfig, err := loadComposeConfig(fn(p))
+			if err != nil {
+				t.Fatalf("failed to load compose config: %v", err)
+			}
+
+			err = IsValidBuildContext(composeConfig)
+			if mustFail && err == nil {
+				t.Errorf("expected '%s' to be an invalid build context", p)
+			}
+
+			if !mustFail && err != nil {
+				t.Errorf("expected '%s' to be a valid build context", p)
+			}
+		}
+	}
+
+	for _, p := range validPaths {
+		testFn(p, false)
+	}
+
+	for _, p := range invalidPaths {
+		testFn(p, true)
+	}
+}

pkg/libstack/compose/internal/composeplugin/composeplugin.go

@@ -126,10 +126,7 @@ func (wrapper *PluginWrapper) command(command composeCommand, options libstack.O
 		command.WithHost(options.Host)
 	}
 
-	var stderr bytes.Buffer
-
-	args := []string{}
-	args = append(args, command.ToArgs()...)
+	args := append([]string{}, command.ToArgs()...)
 
 	cmd := exec.Command(program, args...)
 	cmd.Dir = options.WorkingDir
@@ -150,7 +147,8 @@ func (wrapper *PluginWrapper) command(command composeCommand, options libstack.O
 		Interface("env", cmd.Env).
 		Msg("run command")
 
-	cmd.Stderr = &stderr
+	stderr := &bytes.Buffer{}
+	cmd.Stderr = stderr
 
 	output, err := cmd.Output()
 	if err != nil {