mdatastore: implement basic initialization code

env.test

@@ -1,5 +1,13 @@
+export CLOUDSDK_CORE_PROJECT="test"
+
 if [ "$(ps aux | grep '[p]ubsub-emulator')" = "" ]; then
     echo "starting pubsub emulator"
     yes | gcloud beta emulators pubsub start >/dev/null 2>&1 &
 fi
 $(gcloud beta emulators pubsub env-init)
+
+if [ "$(ps aux | grep '[c]loud-datastore-emulator')" = "" ]; then
+    echo "starting datastore emulator"
+    yes | gcloud beta emulators datastore start >/dev/null 2>&1 &
+fi
+$(gcloud beta emulators datastore env-init)

mdb/mdatastore/datastore.go

@@ -0,0 +1,43 @@
+// Package mdatastore implements connecting to Google's Datastore service and
+// simplifying a number of interactions with it.
+package mdatastore
+
+import (
+	"context"
+
+	"cloud.google.com/go/datastore"
+	"github.com/mediocregopher/mediocre-go-lib/m"
+	"github.com/mediocregopher/mediocre-go-lib/mcfg"
+	"github.com/mediocregopher/mediocre-go-lib/mdb"
+	"github.com/mediocregopher/mediocre-go-lib/mlog"
+)
+
+// Datastore is a wrapper around a datastore client providing more
+// functionality.
+type Datastore struct {
+	*datastore.Client
+
+	gce *mdb.GCE
+	log *mlog.Logger
+}
+
+// Cfg configures and returns a Datastore instance which will be usable once
+// StartRun is called on the passed in Cfg instance.
+func Cfg(cfg *mcfg.Cfg) *Datastore {
+	cfg = cfg.Child("datastore")
+	var ds Datastore
+	ds.gce = mdb.CfgGCE(cfg)
+	ds.log = m.Log(cfg, &ds)
+	cfg.Start.Then(func(ctx context.Context) error {
+		ds.log.Info("connecting to datastore")
+		var err error
+		ds.Client, err = datastore.NewClient(ctx, ds.gce.Project, ds.gce.ClientOptions()...)
+		return mlog.ErrWithKV(err, &ds)
+	})
+	return &ds
+}
+
+// KV implements the mlog.KVer interface.
+func (ds *Datastore) KV() mlog.KV {
+	return ds.gce.KV()
+}

mdb/mdatastore/datastore_test.go

@@ -0,0 +1,50 @@
+package mdatastore
+
+import (
+	"context"
+	. "testing"
+	"time"
+
+	"cloud.google.com/go/datastore"
+	"github.com/mediocregopher/mediocre-go-lib/mcfg"
+	"github.com/mediocregopher/mediocre-go-lib/mdb"
+	"github.com/mediocregopher/mediocre-go-lib/mrand"
+	"github.com/mediocregopher/mediocre-go-lib/mtest/massert"
+)
+
+var testDS *Datastore
+
+func init() {
+	mdb.DefaultGCEProject = "test"
+	cfg := mcfg.New()
+	testDS = Cfg(cfg)
+	cfg.StartTestRun()
+}
+
+// Requires datastore emulator to be running
+func TestBasic(t *T) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	name := mrand.Hex(8)
+	key := datastore.NameKey("testKind", name, nil)
+	key.Namespace = "TestBasic_" + mrand.Hex(8)
+	type valType struct {
+		A, B int
+	}
+	val := valType{
+		A: mrand.Int(),
+		B: mrand.Int(),
+	}
+
+	if _, err := testDS.Put(ctx, key, &val); err != nil {
+		t.Fatal(err)
+	}
+
+	var val2 valType
+	if err := testDS.Get(ctx, key, &val2); err != nil {
+		t.Fatal(err)
+	}
+
+	massert.Fatal(t, massert.Equal(val, val2))
+}

mdb/mpubsub/pubsub.go

@@ -37,8 +37,8 @@ type PubSub struct {
 	log *mlog.Logger
 }
 
-// Cfg configures and returns a PubSub instance which will be usable once Run is
-// called on the passed in Cfg instance
+// Cfg configures and returns a PubSub instance which will be usable once
+// StartRun is called on the passed in Cfg instance.
 func Cfg(cfg *mcfg.Cfg) *PubSub {
 	cfg = cfg.Child("pubsub")
 	var ps PubSub