mdb: add GCE type, refactor PubSub configuration a bit

mdb/mdb.go

@@ -1,3 +1,54 @@
 // Package mdb contains a number of database wrappers for databases I commonly
 // use
 package mdb
+
+import (
+	"context"
+
+	"github.com/mediocregopher/mediocre-go-lib/mcfg"
+	"github.com/mediocregopher/mediocre-go-lib/mlog"
+	"google.golang.org/api/option"
+)
+
+// DefaultGCEProject can be set before any of the Cfg* functions are called for
+// GCE services, and will be used as the default value for the "project"
+// configuration parameter for each service.
+var DefaultGCEProject string
+
+// GCE wraps configuration parameters commonly used for interacting with GCE
+// services.
+type GCE struct {
+	Project  string
+	CredFile string
+}
+
+// CfgGCE configures and returns a GCE instance which will be usable once Run is
+// called on the passed in Cfg instance.
+func CfgGCE(cfg *mcfg.Cfg) *GCE {
+	proj := cfg.ParamString("project", DefaultGCEProject, "name of GCE project")
+	credFile := cfg.ParamString("cred-file", "", "path to GCE credientials json file, if any")
+	var gce GCE
+	cfg.Start.Then(func(ctx context.Context) error {
+		gce.Project = *proj
+		gce.CredFile = *credFile
+		return nil
+	})
+	return &gce
+}
+
+// ClientOptions generates and returns the ClientOption instances which can be
+// passed into most GCE client drivers.
+func (gce *GCE) ClientOptions() []option.ClientOption {
+	var opts []option.ClientOption
+	if gce.CredFile != "" {
+		opts = append(opts, option.WithCredentialsFile(gce.CredFile))
+	}
+	return opts
+}
+
+// KV implements the mlog.KVer interface
+func (gce *GCE) KV() mlog.KV {
+	return mlog.KV{
+		"project": gce.Project,
+	}
+}

mdb/ps.go

@@ -11,7 +11,6 @@ import (
 	"github.com/mediocregopher/mediocre-go-lib/mcfg"
 	"github.com/mediocregopher/mediocre-go-lib/mlog"
 	oldctx "golang.org/x/net/context"
-	"google.golang.org/api/option"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )
@@ -30,68 +29,34 @@ type Message = pubsub.Message
 // PubSub holds onto the info needed to communicate with PubSub and wraps a
 // *pubsub.Client
 type PubSub struct {
-	proj, credFile string
 	*pubsub.Client
 
+	gce *GCE
 	log *mlog.Logger
 }
 
-// NewPubSub initializes and returns PubSub instance for the given projectID and
-// using the credentials file (if given)
-func NewPubSub(ctx context.Context, projectID, credFile string) (*PubSub, error) {
-	ps := &PubSub{
-		proj:     projectID,
-		credFile: credFile,
-	}
-	ps.log = mlog.DefaultLogger.WithKV(ps.KV())
-	var err error
-	ps.Client, err = pubsub.NewClient(ctx, ps.proj, ps.clientOpts()...)
-	return ps, mlog.ErrWithKV(err, ps)
-}
-
 // CfgPubSub configures and returns a PubSub instance which will be usable once
 // Run is called on the passed in Cfg instance
-//
-// defaultProject is optional and can be given to indcate the default gce
-// project id for the configuration parameter which is created.
-func CfgPubSub(cfg *mcfg.Cfg, defaultProject string) *PubSub {
+func CfgPubSub(cfg *mcfg.Cfg) *PubSub {
 	cfg = cfg.Child("pubsub")
-	proj := cfg.ParamString("project", defaultProject, "name of the project in gce")
-	credFile := cfg.ParamString("cred-file", "", "path to pubsub credientials json file, if any")
-
 	var ps PubSub
+	ps.gce = CfgGCE(cfg)
 	cfg.Start.Then(func(ctx context.Context) error {
-		ps.proj = *proj
-		ps.credFile = *credFile
-		log := m.Log(cfg, ps.KV())
-		log.Info("connecting to pubsub")
-		psInner, err := NewPubSub(ctx, *proj, *credFile)
+		ps.log = m.Log(cfg, ps.KV())
+		ps.log.Info("connecting to pubsub")
+		var err error
+		ps.Client, err = pubsub.NewClient(ctx, ps.gce.Project, ps.gce.ClientOptions()...)
 		if err != nil {
 			return mlog.ErrWithKV(err, &ps)
 		}
-		ps = *psInner
-		ps.log = log
 		return nil
 	})
 	return &ps
 }
 
-func (ps *PubSub) clientOpts() []option.ClientOption {
-	var opts []option.ClientOption
-	//opts := []option.ClientOption{
-	//	option.WithGRPCConnectionPool(ps.NumConns),
-	//}
-	if ps.credFile != "" {
-		opts = append(opts, option.WithCredentialsFile(ps.credFile))
-	}
-	return opts
-}
-
 // KV implements the mlog.KVer interface
 func (ps *PubSub) KV() mlog.KV {
-	return mlog.KV{
-		"psProj": ps.proj,
-	}
+	return ps.gce.KV()
 }
 
 // Topic provides methods around a particular topic in PubSub
@@ -130,9 +95,7 @@ func (ps *PubSub) Topic(ctx context.Context, name string, create bool) (*Topic,
 
 // KV implements the mlog.KVer interface
 func (t *Topic) KV() mlog.KV {
-	kv := t.ps.KV()
-	kv["topicName"] = t.name
-	return kv
+	return t.ps.KV().Set("topicName", t.name)
 }
 
 // Publish publishes a message with the given data as its body to the Topic
@@ -186,9 +149,7 @@ func (t *Topic) Subscription(ctx context.Context, name string, create bool) (*Su
 
 // KV implements the mlog.KVer interface
 func (s *Subscription) KV() mlog.KV {
-	kv := s.topic.KV()
-	kv["subName"] = s.name
-	return kv
+	return s.topic.KV().Set("subName", s.name)
 }
 
 // ConsumerFunc is a function which messages being consumed will be passed. The

mdb/ps_test.go

@@ -14,8 +14,9 @@ import (
 var testPS *PubSub
 
 func init() {
+	DefaultGCEProject = "test"
 	cfg := mcfg.New()
-	testPS = CfgPubSub(cfg, "test")
+	testPS = CfgPubSub(cfg)
 	cfg.StartTestRun()
 }