Now open the terminal and go to the Spring Boot employee-producer project folder.
Next we will build an image with the name producer.
docker image build -t employee-producer .
Next we will run the above image as a container named producer. Also we will be publishing the docker port 8080 to centos port 8080.
docker container run --name producer -p 8080:8080 -d employee-producer
So our employee container has started.
We can test this by going to localhost:8080/employee, we will see that our application is deployed successfully.
Employee Consumer -
We have created and started a container named producer where we have deployed the employee-producer service.
So the only change we will be making is while consuming the employee producer service we will be using this container named producer instead of localhost:8080.
So in the ConsumerControllerClient class we will be having the base url as http://producer:8080/employee instead of http://localhost:8080/employee.
package com.javainuse.controllers;
import java.io.IOException;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.client.RestClientException;
import org.springframework.web.client.RestTemplate;
public class ConsumerControllerClient {
public void getEmployee() throws RestClientException, IOException {
String baseUrl = "http://producer:8080/employee";
RestTemplate restTemplate = new RestTemplate();
ResponseEntity<String> response=null;
try{
response=restTemplate.exchange(baseUrl,
HttpMethod.GET, getHeaders(),String.class);
}catch (Exception ex)
{
System.out.println(ex);
}
System.out.println(response.getBody());
}
private static HttpEntity<?> getHeaders() throws IOException {
HttpHeaders headers = new HttpHeaders();
headers.set("Accept", MediaType.APPLICATION_JSON_VALUE);
return new HttpEntity<>(headers);
}
}
The docker file is as follows-
From openjdk:8
copy ./target/employee-consumer-0.0.1-SNAPSHOT.jar employee-consumer-0.0.1-SNAPSHOT.jar
CMD ["java","-jar","employee-consumer-0.0.1-SNAPSHOT.jar"]
Open the terminal and go to the Spring Boot employee consumer project folder.
Next we will build an image with the name consumer.
docker image build -t employee-consumer .
Next we will run the above image as a container named consumer.
docker container run --name consumer -d employee-consumer
Next check the logs using
docker container logs consumer
Here we can see that the container named consumer is not able to communicate with the container named producer.
So we are getting a null pointer exception.
Inter Docker Container Communication Using Docker Networking
We will be using Docker Networking to allow multiple containers to interact with each other.
We will need to create our own network and add both the employee-producer and employee-consumer services to it.
We will stop and remove the existing docker containers named consumer and producer.
Lets first check the available networks
docker network ls
Next we will create our own network will be of type bridge
docker network create consumer-producer
Lets start the employee producer container on the newly created network.
docker container run --network consumer-producer --name producer -p 8080:8080 -d employee-producer
Lets start the employee consumer+ container on the newly created network.
docker container run --network consumer-producer --name consumer -d employee-consumer
Lets check the consumer container logs-
docker container logs consumer
Download Source Code
Download it -
Employee Consumer Docker Networking Module
Download it -
Employee Producer Docker Networking Module
