Merge remote-tracking branch 'origin/pr/138'

Author: samuelkarp

runtime/config.go

@@ -17,6 +17,8 @@ import (
 	"encoding/json"
 	"io/ioutil"
 	"os"
+
+	"github.com/pkg/errors"
 )
 
 const (
@@ -53,12 +55,12 @@ func LoadConfig(path string) (*Config, error) {
 
 	data, err := ioutil.ReadFile(path)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrapf(err, "failed to read config from %q", path)
 	}
 
 	var cfg Config
 	if err := json.Unmarshal(data, &cfg); err != nil {
-		return nil, err
+		return nil, errors.Wrapf(err, "failed to unmarshal config from %q", path)
 	}
 
 	return &cfg, nil

runtime/service.go

@@ -665,10 +665,10 @@ func (s *service) startVM(ctx context.Context,
 	// Note: We've chosen to override here instead of merging in order to
 	// provide a cleaner, simpler interface to reason about for clients.
 	// Any config provided by clients for create task opts will always override
-	// the default cofig generated by the runtime.
+	// the default config generated by the runtime.
 	cfg, driveBuilder, err = overrideVMConfigFromTaskOpts(cfg, vmConfig, driveBuilder)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "failed to build VM options")
 	}
 	cfg.Drives = driveBuilder.Build()
 	cmd := firecracker.VMCommandBuilder{}.
@@ -683,20 +683,20 @@ func (s *service) startVM(ctx context.Context,
 	defer vmmCancel()
 	s.machine, err = firecracker.NewMachine(vmmCtx, cfg, machineOpts...)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "failed to create firecracker config")
 	}
 	s.machineCID = cid
 
 	log.G(ctx).Info("starting instance")
 	if err := s.machine.Start(vmmCtx); err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "failed to start firecracker VM")
 	}
 
 	log.G(ctx).Info("calling agent")
 	conn, err := dialVsock(ctx, cid, defaultVsockPort)
 	if err != nil {
 		s.stopVM()
-		return nil, err
+		return nil, errors.Wrap(err, "failed to dial vsock")
 	}
 
 	log.G(ctx).Info("creating clients")