toolman.org/net/peercred/grpcpeer

grpcpeer

import "toolman.org/net/peercred/grpcpeer"

• Install
• Overview
• Index

Install

    go get toolman.org/net/peercred/grpcpeer

Overview

Package grpcpeer adds gRPC support to toolman.org/net/peercred with a ServerOption that helps gRPC recognize peercred Listeners and a helper function for extracting foreign process credentials from a service method's Context.

The following example illustrates how to use a peercred.Listener with a gRPC server over a Unix domain socket:

    // As with a simple unix-domain socket server, we'll first create
    // a new peercred.Listener listening on socketName
    lsnr, err := peercred.Listen(ctx, socketName)
    if err != nil {
        return err
    }

    // We'll need to tell gRPC how to deal with the process credentials
    // acquired by the peercred Listener. This is easily accomplished by
    // passing this package's TransportCredentials ServerOption as we
    // create the gRPC Server.
    svr := grpc.NewServer(grpcpeer.TransportCredentials())

    // Next, we'll install your service implementation into the gRPC
    // Server we just created...
    urpb.RegisterYourService(svr, svcImpl)

    // ...and start the gRPC Server using the peercred.Listener created
    // above.
    svr.Serve(lsnr)

Finally, when you need to access the client's process creds from one of
your service's methods, pass the method's Context to this package's
FromContext function.

    func (s *svcImpl) SomeMethod(ctx context.Context, req *SomeRequest, opts ...grpc.CallOption) (*SomeResponse, error) {
        creds, err := grpcpeer.FromContext(ctx)
        // (Unless there's an error) creds now holds a *unix.Ucred
        // containing the PID, UID and GID of the calling client process.
    }

Index

• Variables
• func FromContext(ctx context.Context) (*unix.Ucred, error)
• func TransportCredentials() grpc.ServerOption

Package files

creds.go

Variables

var ErrNoCredentials = errors.New("context contains no credentials")

ErrNoCredentials is returned by FromContext if the provided Context contains no peer process credentials.

var ErrNoPeer = errors.New("context has no grpc peer")

ErrNoPeer is returned by FromContext if the provided Context contains no gRPC peer.

func TransportCredentials

func TransportCredentials() grpc.ServerOption

TransportCredentials returns a grpc.ServerOption that exposes the peer process credentials (i.e. PID, UID, GID) extracted by a peercred Listener. The peer credentials are available by passing a server method's Context to this package's FromContext function.

func FromContext

func FromContext(ctx context.Context) (*unix.Ucred, error)

FromContext extracts peer process credentials, if any, from the given Context. This is only possible if the gRPC server was creating with the ServerOption provided by this package's TransportCredentials function.

If the provided Context has no gRPC peer, ErrNoPeer is returned. If the Context's peer is of the wrong type (i.e. contains no peer process credentials), ErrNoCredentials will be returned.