Micro Services example using Spring Boot & Netflix services

Example of using a MicroService application deployed on CloudFoundry.

Overview

There are 2 micro services that each provide a web service interface. They use the Netflix OSS wrapped in the Spring Cloud project. There is also a Netflix Eureka service deployed that provides a service discovery capability. There are three sub-projects:-

• eureka-server - Eureka wrapper. Can be deployed locally or in CloudFoundry. This is required because in Cloud Foundry there is no DNS or discovery capabilities such that microservices have to be registered before they can be called.
• case-server - A basic REST server that utilizes Spring Boot. It incorporates Spring JPA and uses an non-persistent in memory database. The Case object is the only entity persisted.
• response-service - Accepts submitted Responses as a POST. These are enriched with Address information retrieved form the Case service before publishing onto a Redis channel for later consumption.

Services Locally Deployed

When deployed locally via mvn spring-boot:run

• Eureka Service @ http://localhost:8761
• Case service HAL Browser @ http://localhost:8081/api/browser/index.html#
• Case service - Case repo @ http://localhost:8081/api/cases
• Response service - submit responses @ http://localhost:8082/responses

All services have the Spring Acuator (https://docs.spring.io/spring-boot/docs/current/reference/html/production-ready-endpoints.html) enabled. Interesting end points

• http:XXX:YYY/health - general status
• http:XXX:YYY/mappings - all registered endpoints
• http:XXX:YYY/metrics - lots of useful counters

Running some examples

There are a number of example responses for submission in the response-service/examples directory. These can be POSTed via curl.

curl -X POST -d @q123.json http://localhost:8082/responses --header "Content-Type:application/json"

Deploy services on Cloud Foundry

The manifest.yml defines the deployment details. Note the application.yml of the individual apps may also use the profile cloud to override some details. The services must be packaged before via ''mvn package''. Individual services can be deployed as

cf push

There is also a top-level manifest that deploys the whole solution.

Service URLs on CloudFoundry

All services hosted in the Gov. Trial PaaS must be accessed via HTTPS from the internet. This means that the services can not used specific non standard ports but must use port 8080. There is no problem of clashing of ports because each Cloud Foundry service is hosted on a dedicated domain, i.e. different virtual hostnames. The same paths apply as above but each service now has a dedicated fully qualified host name; the host name can be discovered via the ''cf services'' command. Note that the URLs must be unique across the whole of the GDS PaaS so these are suffix with ''-ons''.

Problems

The AddressLookupClinet in the response-service explicitly declares "https" but when running locally outside of CloudFoundry it is "http". Should be way to configure this in the application settings according to a Cloud profile.