add quotation marks for Makefile substitution

Makefile

@@ -28,44 +28,44 @@ db: $(DB_TARGETS)
 
 db_postgres:
 	@echo -e $(BOLD)Setting up Postgres database...$(END_BOLD)
-	docker run --rm -d --name $(POSTGRES_CONTAINER) -p 5432:5432 \
-		-e POSTGRES_DB=$(POSTGRES_DB) \
-		-e POSTGRES_USER=$(POSTGRES_USER) \
-		-e POSTGRES_PASSWORD=$(POSTGRES_PASSWORD) \
+	docker run --rm -d --name "$(POSTGRES_CONTAINER)" -p 5432:5432 \
+		-e POSTGRES_DB="$(POSTGRES_DB)" \
+		-e POSTGRES_USER="$(POSTGRES_USER)" \
+		-e POSTGRES_PASSWORD="$(POSTGRES_PASSWORD)" \
 		postgres:latest
 	$(MAKE) diesel_postgres
 
 db_mysql:
 	@echo -e $(BOLD)Setting up MySQL database...$(END_BOLD)
-	docker run --rm -d --name $(MYSQL_CONTAINER) -p 3306:3306 \
-		-e MYSQL_DATABASE=$(MYSQL_DB) \
-		-e MYSQL_ROOT_PASSWORD=$(MYSQL_PASSWORD) \
+	docker run --rm -d --name "$(MYSQL_CONTAINER)" -p 3306:3306 \
+		-e MYSQL_DATABASE="$(MYSQL_DB)" \
+		-e MYSQL_ROOT_PASSWORD="$(MYSQL_PASSWORD)" \
 		-e TZ=UTC \
 		mysql:latest
 	$(MAKE) diesel_mysql
 
 db_sqlite:
 	@echo -e $(BOLD)Setting up SQLite database...$(END_BOLD)
-	sqlite3 $(SQLITE_FILE) "VACUUM;"
+	sqlite3 "$(SQLITE_FILE)" "VACUUM;"
 	$(MAKE) diesel_sqlite
 
 wait_for_postgres:
 	@echo -e $(BOLD)Waiting for Postgres server to be up and running...$(END_BOLD)
-	while ! docker exec $(POSTGRES_CONTAINER) psql -U $(POSTGRES_USER) --command='' 2> /dev/null; \
+	while ! docker exec "$(POSTGRES_CONTAINER)" psql -U "$(POSTGRES_USER)" --command='' 2> /dev/null; \
 	do \
 		sleep 1; \
 	done
 
 wait_for_mysql:
 	@echo -e $(BOLD)Waiting for MySQL server to be up and running...$(END_BOLD)
-	while ! docker exec $(MYSQL_CONTAINER) mysql --user=$(MYSQL_USER) --password=$(MYSQL_PASSWORD) --execute='' 2> /dev/null; \
+	while ! docker exec "$(MYSQL_CONTAINER)" mysql --user="$(MYSQL_USER)" --password="$(MYSQL_PASSWORD)" --execute='' 2> /dev/null; \
 	do \
 		sleep 1; \
 	done
 
 wait_for_sqlite:
 	@echo -e $(BOLD)Waiting for SQLite DB file to be created...$(END_BOLD)
-	while [ ! -f $(SQLITE_FILE) ]; \
+	while [ ! -f "$(SQLITE_FILE)" ]; \
 	do \
 		sleep 1; \
 	done
@@ -75,37 +75,37 @@ diesel: $(DIESEL_TARGETS)
 diesel_postgres: wait_for_postgres
 	@echo -e $(BOLD)Running Diesel migrations on Postgres database...$(END_BOLD)
 	diesel migration run \
-		--database-url $(POSTGRES_URL) \
-		--migration-dir $(POSTGRES_MIGRATIONS) \
-		--config-file $(POSTGRES_CONFIG)
+		--database-url "$(POSTGRES_URL)" \
+		--migration-dir "$(POSTGRES_MIGRATIONS)" \
+		--config-file "$(POSTGRES_CONFIG)"
 
 diesel_mysql: wait_for_mysql
 	@echo -e $(BOLD)Running Diesel migrations on MySQL database...$(END_BOLD)
 	diesel migration run \
-		--database-url $(MYSQL_URL) \
-		--migration-dir $(MYSQL_MIGRATIONS) \
-		--config-file $(MYSQL_CONFIG)
+		--database-url "$(MYSQL_URL)" \
+		--migration-dir "$(MYSQL_MIGRATIONS)" \
+		--config-file "$(MYSQL_CONFIG)"
 
 diesel_sqlite: wait_for_sqlite
 	@echo -e $(BOLD)Running Diesel migrations on SQLite database...$(END_BOLD)
 	diesel migration run \
-		--database-url sqlite://$(SQLITE_FILE) \
-		--migration-dir $(SQLITE_MIGRATIONS) \
-		--config-file $(SQLITE_CONFIG)
+		--database-url sqlite://"$(SQLITE_FILE)" \
+		--migration-dir "$(SQLITE_MIGRATIONS)" \
+		--config-file "$(SQLITE_CONFIG)"
 
 clean: $(CLEAN_TARGETS)
 
 clean_postgres: wait_for_postgres
 	@echo -e $(BOLD)Cleaning Postgres database...$(END_BOLD)
-	docker exec $(POSTGRES_CONTAINER) dropdb -U $(POSTGRES_USER) $(POSTGRES_DB)
-	docker exec $(POSTGRES_CONTAINER) psql -U $(POSTGRES_USER) --command="CREATE DATABASE $(POSTGRES_DB);"
+	docker exec "$(POSTGRES_CONTAINER)" dropdb -U "$(POSTGRES_USER)" "$(POSTGRES_DB)"
+	docker exec "$(POSTGRES_CONTAINER)" psql -U "$(POSTGRES_USER)" --command="CREATE DATABASE $(POSTGRES_DB);"
 	$(MAKE) diesel_postgres
 
 clean_mysql: wait_for_mysql
 	@echo -e $(BOLD)Cleaning MySQL database...$(END_BOLD)
-	docker exec $(MYSQL_CONTAINER) mysql \
-		--user=$(MYSQL_USER) \
-		--password=$(MYSQL_PASSWORD) \
+	docker exec "$(MYSQL_CONTAINER)" mysql \
+		--user="$(MYSQL_USER)" \
+		--password="$(MYSQL_PASSWORD)" \
 		--execute="DROP DATABASE $(MYSQL_DB); CREATE DATABASE $(MYSQL_DB);"
 	$(MAKE) diesel_mysql
 
@@ -117,15 +117,15 @@ stop: $(STOP_TARGETS)
 
 stop_postgres:
 	@echo -e $(BOLD)Stopping Postgres database...$(END_BOLD)
-	docker kill $(POSTGRES_CONTAINER)
+	docker kill "$(POSTGRES_CONTAINER)"
 
 stop_mysql:
 	@echo -e $(BOLD)Stopping MySQL database...$(END_BOLD)
-	docker kill $(MYSQL_CONTAINER)
+	docker kill "$(MYSQL_CONTAINER)"
 
 stop_sqlite:
 	@echo -e $(BOLD)Stopping SQLite database...$(END_BOLD)
-	rm $(SQLITE_FILE)
+	rm "$(SQLITE_FILE)"
 
 clippy:
 	cargo clippy --verbose --all-targets --all-features -- -D warnings