Rest Template Exchange not working inside docker container but working outside

I have the following java code:

  ResponseEntity<FAQResolver.FAQResponse[]> responseEntity = restTemplate.exchange(SUGGESTION_URL, HttpMethod.POST,
                    requestEntity, FAQResolver.FAQResponse[].class);

Now if I try to run the java application inside docker through docker-compose, I get

org.springframework.web.client.ResourceAccessException: I/O error on POST request for "http://localhost:8888/search": Connection refused (Connection refused); nested exception is java.net.ConnectException: Connection refused (Connection refused)
searchbot_1      |
searchbot_1      | org.springframework.web.client.ResourceAccessException: I/O error on POST request for "http://localhost:8888/search": Connection refused (Connection refused); nested exception is java.net.ConnectException: Connection refused (Connection refused)
searchbot_1      |      at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:744)
searchbot_1      |      at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:670)
searchbot_1      |      at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:579)
searchbot_1      |      at com.globant.fluentlab.searchbot.search.api.SearchController.suggest(SearchController.java:106)
searchbot_1      |      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
searchbot_1      |      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
searchbot_1      |      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
searchbot_1      |      at java.lang.reflect.Method.invoke(Method.java:498)
searchbot_1      |      at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)
searchbot_1      |      at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
searchbot_1      |      at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
searchbot_1      |      at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:892)
searchbot_1      |      at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797)
searchbot_1      |      at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
searchbot_1      |      at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1039)
searchbot_1      |      at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
searchbot_1      |      at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
searchbot_1      |      at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897)
searchbot_1      |      at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
searchbot_1      |      at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
searchbot_1      |      at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
searchbot_1      |      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
searchbot_1      |      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
searchbot_1      |      at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
searchbot_1      |      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
searchbot_1      |      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
searchbot_1      |      at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:90)
searchbot_1      |      at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
searchbot_1      |      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

However if I stop the java application running in docker an use Intellij's debu g mode I get:

To be quite honest I don't know why. I was wondering if docker-compose is restricting communication between containers or something. Any help will be much appreciated.

Solution

Well, my boss just came back from holidays and answered this. Basically when you have several services running using docker-compose they can't find each other using localhost. Instead you must use the name of the service you want to connect to. This means SUGGESTION_URL = http://faqserver:8888/search. That did the trick for me. Hope this helps anyone if they get stuck like me.