santteegt / docker-consul-demo

Hands-on tutorial on how to use Consul for Service Discovery

Service Discovery using Consul

The aim of this repository is to present an hands-on tutorial on how to setup Consul as a service discovery framework. One of main advantages of Consul are its available REST API to register and query services, so it is not necessary to import extra libraries and/or dependencies to manage the communication between services.

Installation instructions

1. Requirements

• Docker 3.2+

2. Run the following commands:

$ git clone <REPO_GIT_URL>
$ cd docker-consul-demo
$ docker-compose up  

How to check everything is working ?

• The sample microservice implements AS A MUST the health method to allow Consul to check the service status.
• Access the leader node WebUI http://localhost:8501/ui/ and check services status. You can also have access using one of the replicas Web UI as well. In this example: consul_replica node access to the WebUI is through port 8502
• Get available services through API: http://127.0.0.1:8501/v1/agent/services
• To test the communication between microservices using Consul by accesing the following link http://127.0.0.1:8180/call/service/1

Create and execute service queries

• To create a sample query template, run the following command:

$ curl --request POST --data @consul.query.sample.json http://127.0.0.1:8501/v1/query >> query_id.json

In this tutorial, the query registration is made through the Microservice Sample 2

• To Executing the prepared service query created above, copy the ID field from query_id.json file and run the following command:

$ curl --request GET http://127.0.0.1:8501/v1/query/<query-template-id>/execute

An example of query response can be seen in query_execution.sample.json file.

• To query current available queries:

$ curl --request GET http://127.0.0.1:8501/v1/query