Allow passing environent variables to StreamProcessors

Add support for an 'env' field to the StreamProcessor configuration
and append the environment variables found there to the os.Environ()
array.
The env field takes environment variables in the form of key=value.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>

diff/stream.go

@@ -168,7 +168,7 @@ func (c *compressedProcessor) Close() error {
 	return c.rc.Close()
 }
 
-func BinaryHandler(id, returnsMediaType string, mediaTypes []string, path string, args []string) Handler {
+func BinaryHandler(id, returnsMediaType string, mediaTypes []string, path string, args, env []string) Handler {
 	set := make(map[string]struct{}, len(mediaTypes))
 	for _, m := range mediaTypes {
 		set[m] = struct{}{}
@@ -177,7 +177,7 @@ func BinaryHandler(id, returnsMediaType string, mediaTypes []string, path string
 		if _, ok := set[mediaType]; ok {
 			return func(ctx context.Context, stream StreamProcessor, payloads map[string]*types.Any) (StreamProcessor, error) {
 				payload := payloads[id]
-				return NewBinaryProcessor(ctx, mediaType, returnsMediaType, stream, path, args, payload)
+				return NewBinaryProcessor(ctx, mediaType, returnsMediaType, stream, path, args, env, payload)
 			}, true
 		}
 		return nil, false

diff/stream_unix.go

@@ -33,9 +33,10 @@ import (
 )
 
 // NewBinaryProcessor returns a binary processor for use with processing content streams
-func NewBinaryProcessor(ctx context.Context, imt, rmt string, stream StreamProcessor, name string, args []string, payload *types.Any) (StreamProcessor, error) {
+func NewBinaryProcessor(ctx context.Context, imt, rmt string, stream StreamProcessor, name string, args, env []string, payload *types.Any) (StreamProcessor, error) {
 	cmd := exec.CommandContext(ctx, name, args...)
 	cmd.Env = os.Environ()
+	cmd.Env = append(cmd.Env, env...)
 
 	var payloadC io.Closer
 	if payload != nil {

diff/stream_windows.go

@@ -39,9 +39,10 @@ import (
 const processorPipe = "STREAM_PROCESSOR_PIPE"
 
 // NewBinaryProcessor returns a binary processor for use with processing content streams
-func NewBinaryProcessor(ctx context.Context, imt, rmt string, stream StreamProcessor, name string, args []string, payload *types.Any) (StreamProcessor, error) {
+func NewBinaryProcessor(ctx context.Context, imt, rmt string, stream StreamProcessor, name string, args, env []string, payload *types.Any) (StreamProcessor, error) {
 	cmd := exec.CommandContext(ctx, name, args...)
 	cmd.Env = os.Environ()
+	cmd.Env = append(cmd.Env, env...)
 
 	if payload != nil {
 		data, err := proto.Marshal(payload)

services/server/config/config.go

@@ -80,6 +80,8 @@ type StreamProcessor struct {
 	Path string `toml:"path"`
 	// Args to the binary
 	Args []string `toml:"args"`
+	// Environment variables for the binary
+	Env []string `toml:"env"`
 }
 
 // GetVersion returns the config file's version

services/server/server.go

@@ -91,7 +91,7 @@ func New(ctx context.Context, config *srvconfig.Config) (*Server, error) {
 		return nil, err
 	}
 	for id, p := range config.StreamProcessors {
-		diff.RegisterProcessor(diff.BinaryHandler(id, p.Returns, p.Accepts, p.Path, p.Args))
+		diff.RegisterProcessor(diff.BinaryHandler(id, p.Returns, p.Accepts, p.Path, p.Args, p.Env))
 	}
 
 	serverOpts := []grpc.ServerOption{