volumes/service: NewStore: add more context to error

Adding some more context to errors to debug a failure in TestDaemonEvents

    === RUN   TestDockerDaemonSuite/TestDaemonEvents
    docker_cli_events_unix_test.go:399: [dd34383dd9b63] failed to start daemon with arguments [--data-root /go/src/github.com/docker/docker/bundles/test-integration/TestDockerDaemonSuite/TestDaemonEvents/dd34383dd9b63/root --exec-root /tmp/dxr/dd34383dd9b63 --pidfile /go/src/github.com/docker/docker/bundles/test-integration/TestDockerDaemonSuite/TestDaemonEvents/dd34383dd9b63/docker.pid --userland-proxy=true --containerd-namespace dd34383dd9b63 --containerd-plugins-namespace dd34383dd9b63p --containerd /var/run/docker/containerd/containerd.sock --host unix:///tmp/docker-integration/dd34383dd9b63.sock --debug --storage-driver overlay2 --config-file=test.json] : [dd34383dd9b63] daemon exited during startup: exit status 1
    check_test.go:307: [dd34383dd9b63] daemon is not started
    --- FAIL: TestDockerDaemonSuite/TestDaemonEvents (1.59s)

daemon logs:

    level=info  msg="Starting up"
    level=debug msg="Listener created for HTTP on unix (/tmp/docker-integration/dd34383dd9b63.sock)"
    level=debug msg="Golang's threads limit set to 55530"
    level=info  msg="[core] original dial target is: \"unix:///var/run/docker/containerd/containerd.sock\"" module=grpc
    level=info  msg="[core] parsed dial target is: {Scheme:unix Authority: Endpoint:var/run/docker/containerd/containerd.sock URL:{Scheme:unix Opaque: User: Host: Path:/var/run/docker/containerd/containerd.sock RawPath: ForceQuery:false RawQuery: Fragment: RawFragment:}}" module=grpc
    level=info  msg="[core] Channel authority set to \"localhost\"" module=grpc
    level=info  msg="[core] ccResolverWrapper: sending update to cc: {[{/var/run/docker/containerd/containerd.sock  0xc000010898 <nil> 0 <nil>}] <nil> <nil>}" module=grpc
    level=info  msg="[core] ClientConn switching balancer to \"pick_first\"" module=grpc
    level=info  msg="[core] Channel switches to new LB policy \"pick_first\"" module=grpc
    level=info  msg="[core] Subchannel Connectivity change to CONNECTING" module=grpc
    level=info  msg="[core] Subchannel picks a new address \"/var/run/docker/containerd/containerd.sock\" to connect" module=grpc
    level=debug msg="metrics API listening on /var/run/docker/metrics.sock"
    level=info  msg="[core] Channel Connectivity change to CONNECTING" module=grpc
    level=info  msg="[core] Subchannel Connectivity change to READY" module=grpc
    level=info  msg="[core] Channel Connectivity change to READY" module=grpc
    level=info  msg="[core] original dial target is: \"unix:///var/run/docker/containerd/containerd.sock\"" module=grpc
    level=info  msg="[core] parsed dial target is: {Scheme:unix Authority: Endpoint:var/run/docker/containerd/containerd.sock URL:{Scheme:unix Opaque: User: Host: Path:/var/run/docker/containerd/containerd.sock RawPath: ForceQuery:false RawQuery: Fragment: RawFragment:}}" module=grpc
    level=info  msg="[core] Channel authority set to \"localhost\"" module=grpc
    level=info  msg="[core] ccResolverWrapper: sending update to cc: {[{/var/run/docker/containerd/containerd.sock  0xc00045ece8 <nil> 0 <nil>}] <nil> <nil>}" module=grpc
    level=info  msg="[core] ClientConn switching balancer to \"pick_first\"" module=grpc
    level=info  msg="[core] Channel switches to new LB policy \"pick_first\"" module=grpc
    level=info  msg="[core] Subchannel Connectivity change to CONNECTING" module=grpc
    level=info  msg="[core] Subchannel picks a new address \"/var/run/docker/containerd/containerd.sock\" to connect" module=grpc
    level=info  msg="[core] Channel Connectivity change to CONNECTING" module=grpc
    level=info  msg="[core] Subchannel Connectivity change to READY" module=grpc
    level=info  msg="[core] Channel Connectivity change to READY" module=grpc
    level=debug msg="Using default logging driver json-file"
    level=info  msg="[graphdriver] trying configured driver: overlay2"
    level=debug msg="processing event stream" module=libcontainerd namespace=plugins.moby
    level=debug msg="successfully detected metacopy status" storage-driver=overlay2 usingMetacopy=false
    level=debug msg="backingFs=extfs, projectQuotaSupported=false, usingMetacopy=false, indexOff=\"index=off,\", userxattr=\"\"" storage-driver=overlay2
    level=debug msg="Initialized graph driver overlay2"
    level=debug msg="No quota support for local volumes in /var/lib/docker/volumes: Filesystem does not support, or has not enabled quotas"
    level=info  msg="[core] Channel Connectivity change to SHUTDOWN" module=grpc
    level=info  msg="[core] Subchannel Connectivity change to SHUTDOWN" module=grpc
    level=debug msg="Cleaning up old mountid : start."
    failed to start daemon: error while opening volume store metadata database: timeout

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

volume/service/store.go

@@ -95,9 +95,10 @@ func NewStore(rootPath string, drivers *drivers.Store, opts ...StoreOpt) (*Volum
 		}
 
 		var err error
-		vs.db, err = bolt.Open(filepath.Join(volPath, "metadata.db"), 0600, &bolt.Options{Timeout: 1 * time.Second})
+		dbPath := filepath.Join(volPath, "metadata.db")
+		vs.db, err = bolt.Open(dbPath, 0600, &bolt.Options{Timeout: 1 * time.Second})
 		if err != nil {
-			return nil, errors.Wrap(err, "error while opening volume store metadata database")
+			return nil, errors.Wrapf(err, "error while opening volume store metadata database (%s)", dbPath)
 		}
 
 		// initialize volumes bucket