不存在或不存取（Docker组合）
我想dockerize我的spring-boot / spring-cloud应用程序。
泊坞窗，compose.yml：
eureka: build: ./eureka-discovery-service ports: - "8761:8761" mongodb: image: mongo:3.0.4 ports: - "32768:32768" postgresql: image: postgresql:9.6-2 ports: - "5432:5432" gateway-service: build: ./gateway-service ports: - "9090:9090" links: - eureka airplane-service: build: ./airplane-service ports: - "2222:2222" links: - eureka - postgresql car-service: build: ./car-service ports: - "2220:2220" links: - eureka - mongodb machine-service: build: ./machine-service ports: - "2224:2224" links: - eureka 在进行docker工作时，我收到下面的错误信息：
Pulling postgresql (postgresql:9.6-2)... ERROR: repository postgresql not found: does not exist or no pull access
如何解决这个问题，为什么我有这个问题？
图像名称应该是postgres:9.6.4