Run coordinator together with router (pg-sharding#287)

Dispatch coordinator goroutines with router binary start. Proxy all modifying requests to Coordinator via grpc.

Run admin console in proxy way for several type of queries:

    All modify requests to router console should be proxied to coordinator via particular gRPC-call. It is very dangerous to allow user to modify router metadata, like key-ranges or sharding rules, etc. This only should by done by coordinator or via coord. API.

    All show requests, like SHOW CLIENTS etc should be processed locally. In future, we can support installation-wide
    show requests processing using additional syntax, like SHOW CLIENTS is processed by router but SHOW GLOBAL CLIENTS to be proccesed by coordinator (coord. can process such queries already).

test/feature/docker-compose.yaml

@@ -85,18 +85,18 @@ services:
       - "router"
       - "router2"
       - "qdb01"
-  
+
   coordinator2:
     build:
       dockerfile: ./docker/coordinator/Dockerfile
       context: ../../
     ports:
-      - "7004:7002"
-      - "7005:7003"
+      - "7032:7002"
+      - "7033:7003"
     environment:
-      - COORDINATOR_CONFIG=${COORDINATOR_CONFIG}
-    hostname: regress_coordinator
-    container_name: regress_coordinator2
+      - COORDINATOR_CONFIG=/spqr/test/feature/conf/coordinator2.yaml
+    hostname: regress_coordinator_2
+    container_name: regress_coordinator_2
     depends_on:
       - "router"
       - "router2"

test/feature/spqr_test.go

@@ -255,17 +255,7 @@ func (tctx *testContext) connectorWithCredentials(username string, password stri
 func (tctx *testContext) getPostgresqlConnection(host string) (*sqlx.DB, error) {
 	db, ok := tctx.dbs[host]
 	if !ok {
-		addr, err := tctx.composer.GetAddr(host, coordinatorPort)
-		if err != nil {
-			return nil, fmt.Errorf("postgresql %s is not in cluster", host)
-		}
-
-		db, err := tctx.connectCoordinatorWithCredentials(shardUser, shardPassword, addr, postgresqlInitialConnectTimeout)
-		if err != nil {
-			return nil, fmt.Errorf("postgresql %s is not in cluster", host)
-		}
-		tctx.dbs[host] = db
-		return db, nil
+		return nil, fmt.Errorf("postgresql %s is not in cluster", host)
 	}
 	if strings.HasSuffix(host, "admin") || strings.HasPrefix(host, "coordinator") {
 		return db, nil
@@ -390,17 +380,6 @@ func (tctx *testContext) stepClusterIsUpAndRunning(createHaNodes bool) error {
 		return fmt.Errorf("failed to setup compose cluster: %s", err)
 	}
 
-	err = tctx.stepHostIsStopped("coordinator2")
-	if err != nil {
-		return err
-	}
-	defer func() {
-		err := tctx.stepHostIsStarted("coordinator2")
-		if err != nil {
-			spqrlog.Zero.Error().Err(err).Msg("failed to start second coordinator")
-		}
-	}()
-
 	// check databases
 	for _, service := range tctx.composer.Services() {
 		if strings.HasPrefix(service, spqrShardName) {
@@ -445,9 +424,6 @@ func (tctx *testContext) stepClusterIsUpAndRunning(createHaNodes bool) error {
 
 	// check coordinator
 	for _, service := range tctx.composer.Services() {
-		if strings.HasPrefix(service, spqrCoordinatorName+"2") {
-			continue
-		}
 		if strings.HasPrefix(service, spqrCoordinatorName) {
 			addr, err := tctx.composer.GetAddr(service, spqrCoordinatorPort)
 			if err != nil {