CODEWITHSUNDEEP
javarestdockerspring-bootmicroservices
Mehraj Malik
Mehraj Malik

Reputation: 15844

How to call one microservice from another microservice using docker images

I have two SpringBoot microservices M1(port 2002) and M2(port 2004)

M1 and M2 are communicating successfully if I run them using eclipse (run as Java Project or SpringBoot Project).

However, I want to communicate them using Docker container.

So I build images for both Microservices (M1 and M2) using the command:

docker build -f Dockerfile -t image_name .

And run the images using:

docker run -p 2004:2004 image_name

Note: I am exposing same port from docker as defined above

But the M1 and M2 are not able to communicate. I am using RestTemplate 

RestTemplate restTemplate = new RestTemplate();
ResponseEntity<Boolean> isUp = restTemplate.getForEntity("http://localhost:2002/apis/test",Boolean.class);

I am getting below exception : 

I/O error on GET request for \"http://localhost:2002/apis/test\": Connection refused (Connection refused); nested exception is java.net.ConnectException: Connection refused (Connection refused)

However, If I call the other microservice using my machine's IP, It's communicating successfully 

ResponseEntity<Boolean> isUp = restTemplate.getForEntity("http://XX.XX.XX.XXX:2002/apis/test",Boolean.class);

Can someone please tell if I am doing it write(using IP address) or there is another good approach to call one microservice from another using Docker?

Upvotes: 5

Views: 10205

Answers (2)

piy26
piy26

Reputation: 1592

Alternately, you can also link the two containers together by --link. Assuming you want container1 as client to container2, you can use below:

sudo docker run --link container2 --name=container1 -d image_name

Upvotes: 3

chris
chris

Reputation: 4351

Trying to communicate with the other container won't work with localhost.

You should create a custom bridged network, which will allow you to refer to the containers by name. And there is no need to publish the ports if you are only talking internally.

# create network
docker network create -d bridge mynet
# container 1
docker container run --network mynet --name container1 -d image_name
# container 2
docker container run --network mynet --name container2 -d some_other_image_name

The IP in code snippet can then be replaced with the name of the other container

RestTemplate restTemplate = new RestTemplate();
ResponseEntity<Boolean> isUp = restTemplate.getForEntity("http://container2:2002/apis/test",Boolean.class)

Upvotes: 6

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