Fix Makefile to match temporal-sql-tool's instructions (#3264)

The tools/sql/README.md instructions ask user to pass in SQL
username/password via environment variables. However the scripts in
Makefile to install SQL schemas hard code username/password, effectively
rendering temporal-sql-tool's instructions invalid. This cause
confusion/frustration for end-users trying to set up Temporal the first
time.

This commit will allow env vars override via SQL_USER and SQL_PASSWORD,
and maintain the default values if those env vars are not set.

Makefile

@@ -90,6 +90,10 @@ INTEG_XDC_COVER_PROFILE    := $(COVER_ROOT)/integ_xdc_$(PERSISTENCE_DRIVER)_cove
 INTEG_NDC_COVER_PROFILE    := $(COVER_ROOT)/integ_ndc_$(PERSISTENCE_DRIVER)_coverprofile.out
 SUMMARY_COVER_PROFILE      := $(COVER_ROOT)/summary.out
 
+# DB
+SQL_USER ?= temporal
+SQL_PASSWORD ?= temporal
+
 # Need the following option to have integration tests count towards coverage. godoc below:
 # -coverpkg pkg1,pkg2,pkg3
 #   Apply coverage analysis in each test to the given list of packages.
@@ -353,25 +357,25 @@ install-schema: temporal-cassandra-tool
 
 install-schema-mysql: temporal-sql-tool
 	@printf $(COLOR) "Install MySQL schema..."
-	./temporal-sql-tool -u temporal --pw temporal --db $(TEMPORAL_DB) drop -f
-	./temporal-sql-tool -u temporal --pw temporal --db $(TEMPORAL_DB) create
-	./temporal-sql-tool -u temporal --pw temporal --db $(TEMPORAL_DB) setup-schema -v 0.0
-	./temporal-sql-tool -u temporal --pw temporal --db $(TEMPORAL_DB) update-schema -d ./schema/mysql/v57/temporal/versioned
-	./temporal-sql-tool -u temporal --pw temporal --db $(VISIBILITY_DB) drop  -f
-	./temporal-sql-tool -u temporal --pw temporal --db $(VISIBILITY_DB) create
-	./temporal-sql-tool -u temporal --pw temporal --db $(VISIBILITY_DB) setup-schema -v 0.0
-	./temporal-sql-tool -u temporal --pw temporal --db $(VISIBILITY_DB) update-schema -d ./schema/mysql/v57/visibility/versioned
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) --db $(TEMPORAL_DB) drop -f
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) --db $(TEMPORAL_DB) create
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) --db $(TEMPORAL_DB) setup-schema -v 0.0
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) --db $(TEMPORAL_DB) update-schema -d ./schema/mysql/v57/temporal/versioned
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) --db $(VISIBILITY_DB) drop  -f
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) --db $(VISIBILITY_DB) create
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) --db $(VISIBILITY_DB) setup-schema -v 0.0
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) --db $(VISIBILITY_DB) update-schema -d ./schema/mysql/v57/visibility/versioned
 
 install-schema-postgresql: temporal-sql-tool
 	@printf $(COLOR) "Install Postgres schema..."
-	./temporal-sql-tool -u temporal -pw temporal -p 5432 --pl postgres --db $(TEMPORAL_DB) drop -f
-	./temporal-sql-tool -u temporal -pw temporal -p 5432 --pl postgres --db $(TEMPORAL_DB) create
-	./temporal-sql-tool -u temporal -pw temporal -p 5432 --pl postgres --db $(TEMPORAL_DB) setup -v 0.0
-	./temporal-sql-tool -u temporal -pw temporal -p 5432 --pl postgres --db $(TEMPORAL_DB) update-schema -d ./schema/postgresql/v96/temporal/versioned
-	./temporal-sql-tool -u temporal -pw temporal -p 5432 --pl postgres --db $(VISIBILITY_DB) drop -f
-	./temporal-sql-tool -u temporal -pw temporal -p 5432 --pl postgres --db $(VISIBILITY_DB) create
-	./temporal-sql-tool -u temporal -pw temporal -p 5432 --pl postgres --db $(VISIBILITY_DB) setup-schema -v 0.0
-	./temporal-sql-tool -u temporal -pw temporal -p 5432 --pl postgres --db $(VISIBILITY_DB) update-schema -d ./schema/postgresql/v96/visibility/versioned
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) -p 5432 --pl postgres --db $(TEMPORAL_DB) drop -f
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) -p 5432 --pl postgres --db $(TEMPORAL_DB) create
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) -p 5432 --pl postgres --db $(TEMPORAL_DB) setup -v 0.0
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) -p 5432 --pl postgres --db $(TEMPORAL_DB) update-schema -d ./schema/postgresql/v96/temporal/versioned
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) -p 5432 --pl postgres --db $(VISIBILITY_DB) drop -f
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) -p 5432 --pl postgres --db $(VISIBILITY_DB) create
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) -p 5432 --pl postgres --db $(VISIBILITY_DB) setup-schema -v 0.0
+	./temporal-sql-tool -u $(SQL_USER) --pw $(SQL_PASSWORD) -p 5432 --pl postgres --db $(VISIBILITY_DB) update-schema -d ./schema/postgresql/v96/visibility/versioned
 
 install-schema-es:
 	@printf $(COLOR) "Install Elasticsearch schema..."