Define same instanceId for ALL primaries in the same HA in dual-primary.

All the primary Gerrit nodes in HA must use the same instanceId, the reason is because "logically" they are a single site.

Change-Id: I6206e5df3c4c248b0e9346e835b63d3671af6b4d
diff --git a/dual-primary/Makefile b/dual-primary/Makefile
index 392cb61..af51604 100644
--- a/dual-primary/Makefile
+++ b/dual-primary/Makefile
@@ -102,8 +102,8 @@
 					set-high-availability-optional-params \
 					set-optional-refs-db-params \
 					set-optional-x-ray
-ifdef GERRIT_PRIMARY1_INSTANCE_ID
-		$(eval PRIMARY1_SERVICE_OPTIONAL_PARAMS := $(PRIMARY1_SERVICE_OPTIONAL_PARAMS) ParameterKey=InstanceId,ParameterValue=$(GERRIT_PRIMARY1_INSTANCE_ID))
+ifdef GERRIT_PRIMARY_INSTANCE_ID
+		$(eval PRIMARY1_SERVICE_OPTIONAL_PARAMS := $(PRIMARY1_SERVICE_OPTIONAL_PARAMS) ParameterKey=InstanceId,ParameterValue=$(GERRIT_PRIMARY_INSTANCE_ID))
 endif
 ifdef LOAD_BALANCER_SCHEME
 		$(eval PRIMARY1_SERVICE_OPTIONAL_PARAMS := $(PRIMARY1_SERVICE_OPTIONAL_PARAMS) ParameterKey=LoadBalancerScheme,ParameterValue=$(LOAD_BALANCER_SCHEME))
@@ -164,8 +164,8 @@
 					set-high-availability-optional-params \
 					set-optional-refs-db-params \
 					set-optional-x-ray
-ifdef GERRIT_PRIMARY2_INSTANCE_ID
-		$(eval PRIMARY2_SERVICE_OPTIONAL_PARAMS := $(PRIMARY2_SERVICE_OPTIONAL_PARAMS) ParameterKey=InstanceId,ParameterValue=$(GERRIT_PRIMARY2_INSTANCE_ID))
+ifdef GERRIT_PRIMARY_INSTANCE_ID
+		$(eval PRIMARY2_SERVICE_OPTIONAL_PARAMS := $(PRIMARY2_SERVICE_OPTIONAL_PARAMS) ParameterKey=InstanceId,ParameterValue=$(GERRIT_PRIMARY_INSTANCE_ID))
 endif
 ifdef LOAD_BALANCER_SCHEME
 		$(eval PRIMARY2_SERVICE_OPTIONAL_PARAMS := $(PRIMARY2_SERVICE_OPTIONAL_PARAMS) ParameterKey=LoadBalancerScheme,ParameterValue=$(LOAD_BALANCER_SCHEME))
@@ -300,11 +300,9 @@
 
 dashboard:
 ifeq ($(METRICS_CLOUDWATCH_ENABLED),true)
-ifdef GERRIT_PRIMARY1_INSTANCE_ID
-		$(eval DASHBOARD_OPTIONAL_PARAMS := $(DASHBOARD_OPTIONAL_PARAMS) ParameterKey=Primary1InstanceId,ParameterValue=$(GERRIT_PRIMARY1_INSTANCE_ID))
-endif
-ifdef GERRIT_PRIMARY2_INSTANCE_ID
-		$(eval DASHBOARD_OPTIONAL_PARAMS := $(DASHBOARD_OPTIONAL_PARAMS) ParameterKey=Primary2InstanceId,ParameterValue=$(GERRIT_PRIMARY2_INSTANCE_ID))
+ifdef GERRIT_PRIMARY_INSTANCE_ID
+        $(eval DASHBOARD_OPTIONAL_PARAMS := $(DASHBOARD_OPTIONAL_PARAMS) ParameterKey=Primary1InstanceId,ParameterValue=$(GERRIT_PRIMARY_INSTANCE_ID))
+        $(eval DASHBOARD_OPTIONAL_PARAMS := $(DASHBOARD_OPTIONAL_PARAMS) ParameterKey=Primary2InstanceId,ParameterValue=$(GERRIT_PRIMARY_INSTANCE_ID))
 endif
 ifdef GERRIT_REPLICA_INSTANCE_ID
 		$(eval DASHBOARD_OPTIONAL_PARAMS := $(DASHBOARD_OPTIONAL_PARAMS) ParameterKey=ReplicaInstanceId,ParameterValue=$(GERRIT_REPLICA_INSTANCE_ID))
diff --git a/dual-primary/README.md b/dual-primary/README.md
index 3bbb5cc..513da00 100644
--- a/dual-primary/README.md
+++ b/dual-primary/README.md
@@ -176,12 +176,10 @@
 * `PRIMARY_FILESYSTEM_PROVISIONED_THROUGHPUT_IN_MIBPS`: Optional. Only used when `PRIMARY_FILESYSTEM_THROUGHPUT_MODE` is set to `provisioned`.
 default: `256`.
 
+* `GERRIT_PRIMARY_INSTANCE_ID`: Optional. Identifier for the ALL Gerrit primaries instance.
+  "gerrit-dual-primary-PRIMARY" by default.
 * `GERRIT_REPLICA_INSTANCE_ID`: Optional. Identifier for the Gerrit replica instance.
 "gerrit-dual-primary-REPLICA" by default.
-* `GERRIT_PRIMARY1_INSTANCE_ID`: Optional. Identifier for the Gerrit primary1 instance.
-"gerrit-dual-primary-PRIMARY1" by default.
-* `GERRIT_PRIMARY2_INSTANCE_ID`: Optional. Identifier for the Gerrit primary2 instance.
-"gerrit-dual-primary-PRIMARY2" by default.
 
 * `PRIMARY_MAX_COUNT`: Optional. Maximum number of EC2 instances in the primary autoscaling group.
 "2" by default. Minimum: "2".
diff --git a/dual-primary/setup.env.template b/dual-primary/setup.env.template
index 032a252..0073f17 100644
--- a/dual-primary/setup.env.template
+++ b/dual-primary/setup.env.template
@@ -39,8 +39,7 @@
 FILESYSTEM_THROUGHPUT_MODE=bursting
 
 GERRIT_REPLICA_INSTANCE_ID=gerrit-dual-primary-REPLICA
-GERRIT_PRIMARY1_INSTANCE_ID=gerrit-dual-primary-PRIMARY1
-GERRIT_PRIMARY2_INSTANCE_ID=gerrit-dual-primary-PRIMARY2
+GERRIT_PRIMARY_INSTANCE_ID=gerrit-dual-primary-PRIMARY
 
 LDAP_SERVER:=ldap://yourldap.yourcompany.com
 LDAP_USERNAME:=cn=admin,dc=example,dc=org