From 33598cc5d3ddd8f577f3b1e3ea9debf07f439b93 Mon Sep 17 00:00:00 2001
From: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>
Date: Wed, 14 Jun 2017 08:50:58 -0700
Subject: [PATCH] linux: Wrap error with contextual message

Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>
---
 linux/shim/exec.go            | 15 ++++++++-------
 linux/shim/init.go            | 17 +++++++++--------
 services/execution/service.go |  3 ++-
 3 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/linux/shim/exec.go b/linux/shim/exec.go
index 39e2b3aeb..d54593da0 100644
--- a/linux/shim/exec.go
+++ b/linux/shim/exec.go
@@ -20,6 +20,7 @@ import (
 	"github.com/containerd/fifo"
 	runc "github.com/containerd/go-runc"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
 )
 
 type execProcess struct {
@@ -59,13 +60,13 @@ func newExecProcess(context context.Context, path string, r *shimapi.ExecRequest
 	)
 	if r.Terminal {
 		if socket, err = runc.NewConsoleSocket(filepath.Join(path, "pty.sock")); err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "failed to create runc console socket")
 		}
 		defer os.Remove(socket.Path())
 	} else {
 		// TODO: get uid/gid
 		if io, err = runc.NewPipeIO(0, 0); err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "failed to create runc io pipes")
 		}
 		e.io = io
 	}
@@ -90,7 +91,7 @@ func newExecProcess(context context.Context, path string, r *shimapi.ExecRequest
 	if r.Stdin != "" {
 		sc, err := fifo.OpenFifo(context, r.Stdin, syscall.O_WRONLY|syscall.O_NONBLOCK, 0)
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrapf(err, "failed to open stdin fifo %s", r.Stdin)
 		}
 		e.closers = append(e.closers, sc)
 		e.stdin = sc
@@ -99,21 +100,21 @@ func newExecProcess(context context.Context, path string, r *shimapi.ExecRequest
 	if socket != nil {
 		console, err := socket.ReceiveMaster()
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "failed to retrieve console master")
 		}
 		e.console = console
 		if err := copyConsole(context, console, r.Stdin, r.Stdout, r.Stderr, &e.WaitGroup, &copyWaitGroup); err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "failed to start console copy")
 		}
 	} else {
 		if err := copyPipes(context, io, r.Stdin, r.Stdout, r.Stderr, &e.WaitGroup, &copyWaitGroup); err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "failed to start io pipe copy")
 		}
 	}
 	copyWaitGroup.Wait()
 	pid, err := runc.ReadPidFile(opts.PidFile)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "failed to retrieve runc exec pid")
 	}
 	e.pid = pid
 	return e, nil
diff --git a/linux/shim/init.go b/linux/shim/init.go
index 6748e687b..16c8f510d 100644
--- a/linux/shim/init.go
+++ b/linux/shim/init.go
@@ -21,6 +21,7 @@ import (
 	"github.com/containerd/containerd/mount"
 	"github.com/containerd/fifo"
 	runc "github.com/containerd/go-runc"
+	"github.com/pkg/errors"
 )
 
 type initProcess struct {
@@ -57,7 +58,7 @@ func newInitProcess(context context.Context, path, namespace string, r *shimapi.
 			Options: rm.Options,
 		}
 		if err := m.Mount(filepath.Join(path, "rootfs")); err != nil {
-			return nil, err
+			return nil, errors.Wrapf(err, "failed to mount rootfs component %v", m)
 		}
 	}
 	runtime := &runc.Runc{
@@ -83,13 +84,13 @@ func newInitProcess(context context.Context, path, namespace string, r *shimapi.
 	)
 	if r.Terminal {
 		if socket, err = runc.NewConsoleSocket(filepath.Join(path, "pty.sock")); err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "failed to create runc console socket")
 		}
 		defer os.Remove(socket.Path())
 	} else {
 		// TODO: get uid/gid
 		if io, err = runc.NewPipeIO(0, 0); err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "failed to create runc io pipes")
 		}
 		p.io = io
 	}
@@ -126,7 +127,7 @@ func newInitProcess(context context.Context, path, namespace string, r *shimapi.
 	if r.Stdin != "" {
 		sc, err := fifo.OpenFifo(context, r.Stdin, syscall.O_WRONLY|syscall.O_NONBLOCK, 0)
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrapf(err, "failed to open stdin fifo %s", r.Stdin)
 		}
 		p.stdin = sc
 		p.closers = append(p.closers, sc)
@@ -135,22 +136,22 @@ func newInitProcess(context context.Context, path, namespace string, r *shimapi.
 	if socket != nil {
 		console, err := socket.ReceiveMaster()
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "failed to retrieve console master")
 		}
 		p.console = console
 		if err := copyConsole(context, console, r.Stdin, r.Stdout, r.Stderr, &p.WaitGroup, &copyWaitGroup); err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "failed to start console copy")
 		}
 	} else {
 		if err := copyPipes(context, io, r.Stdin, r.Stdout, r.Stderr, &p.WaitGroup, &copyWaitGroup); err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "failed to start io pipe copy")
 		}
 	}
 
 	copyWaitGroup.Wait()
 	pid, err := runc.ReadPidFile(pidFile)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "failed to retrieve runc container pid")
 	}
 	p.pid = pid
 	return p, nil
diff --git a/services/execution/service.go b/services/execution/service.go
index b6d944c0b..a688e08f1 100644
--- a/services/execution/service.go
+++ b/services/execution/service.go
@@ -23,6 +23,7 @@ import (
 	protobuf "github.com/gogo/protobuf/types"
 	google_protobuf "github.com/golang/protobuf/ptypes/empty"
 	specs "github.com/opencontainers/image-spec/specs-go"
+	"github.com/pkg/errors"
 	"golang.org/x/net/context"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
@@ -129,7 +130,7 @@ func (s *Service) Create(ctx context.Context, r *api.CreateRequest) (*api.Create
 	}
 	c, err := runtime.Create(ctx, r.ContainerID, opts)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "runtime create failed")
 	}
 	state, err := c.State(ctx)
 	if err != nil {