Setting up MockServer

Main goals:

• Simple and declarative testing environment setup.
• Runs everywhere

Strategy

• Set up a replicable local server.

Docker - Containerized applications (actually write once, runs anywhere)

• Provide an expectations json where all the requests are mapped out.

MockServer - Creates a local server with complex request/response expectations through a json resource or a REST API.

Making it happen

• Install Docker.

• Install Docker Compose.

• Make sure your docker daemon is up and running.

• Create a folder for your MockServer setup.

  $ mkdir /path/to/mockserver_container/ && cd /path/to/mockserver_container

• Create the docker-compose.yml .

  • This is where you'll setup your container for MockServer.

  $ touch ./docker-compose.yml && vim ./docker-compose.yml

Paste this code snippet:

version: "2.4"
services:
  mockServer:
      image: mockserver/mockserver:latest
      ports:
        - 1080:1080
      environment:
        MOCKSERVER_WATCH_INITIALIZATION_JSON: "true"
        MOCKSERVER_PROPERTY_FILE: /config/mockserver.properties
        MOCKSERVER_INITIALIZATION_JSON_PATH: /config/initializerJson.json
      volumes:
        - type: bind
          source: .
          target: /config

This is saying:

• Create a service named mockserver using the docker image from mockserver/mockserver:latest.

• Assign the host port 1080 to the container port 1080.

• Set the enviroment variables to the provided paths.

• Create a volume binding from the current directory (this file's dir) to /config inside the container.

  • Setup the Expectation Initializer JSON.

• Create the initializerJson

  $ touch ./initializerJson.json && vim ./initializerJson.json

• Paste this code snippet:

  [
    {
      "httpRequest" : {
        "method" : "GET",
        "path" : "/api/v1/weather",
        "queryStringParameters" : {
          "code" : ["10969"]
      }
    },
      "httpResponse" : {
        "body" : "{\"wheather\": 20.5}",
        "statusCode": 200
      }
    }
  ]

Full documentation reference can be found here

Running your container

Now that we've got the plumbing out of the way, it's time to run it.

• Inside the folder you created the .yml type:

  $ docker-compose up

Your terminal should print something like this:

  Creating mockserver_mockServer_1 ... done
  Attaching to mockserver_mockServer_1
  mockServer_1  | 
  mockServer_1  | java  -Dfile.encoding=UTF-8 -jar /opt/mockserver/mockserver-netty-jar-with-dependencies.jar  -server
  mockServer_1  | 
  mockServer_1  | 2020-04-11 15:52:30  org.mockserver.log.MockServerEventLog  INFO  creating expectation:
  mockServer_1  | 
  mockServer_1  |   {
  mockServer_1  |     "id" : "3f3962d2-9c03-4dce-95cd-2522962ceccb",
  mockServer_1  |     "priority" : 0,
  mockServer_1  |     "httpRequest" : {
  mockServer_1  |       "method" : "GET",
  mockServer_1  |       "path" : "/api/v1/weather",
  mockServer_1  |       "queryStringParameters" : {
  mockServer_1  |         "code" : [ "10969" ]
  mockServer_1  |       }
  mockServer_1  |     },
  mockServer_1  |     "times" : {
  mockServer_1  |       "unlimited" : true
  mockServer_1  |     },
  mockServer_1  |     "timeToLive" : {
  mockServer_1  |       "unlimited" : true
  mockServer_1  |     },
  mockServer_1  |     "httpResponse" : {
  mockServer_1  |       "statusCode" : 200,
  mockServer_1  |       "body" : "{\"wheather\": 20.5}"
  mockServer_1  |     }
  mockServer_1  |   }
  mockServer_1  |  
  mockServer_1  | 2020-04-11 15:52:30  org.mockserver.cli.Main  INFO  logger level is INFO, change using:
  mockServer_1  |  - 'ConfigurationProperties.logLevel(String level)' in Java code,
  mockServer_1  |  - '-logLevel' command line argument,
  mockServer_1  |  - 'mockserver.logLevel' JVM system property or,
  mockServer_1  |  - 'mockserver.logLevel' property value in 'mockserver.properties' 
  mockServer_1  | 2020-04-11 15:52:30  org.mockserver.log.MockServerEventLog  INFO  started on port: 1080 

Sending requests

Open a new terminal window and enter:

To see info about your available containers enter again:

$ docker ps -a

You can now see some info about your running container.

$ curl localhost:1080/api/v1/weather\?code\=10969           

You should see the response:

{"wheather": 20.5}

And thats it!

You've got yourself a local server where you can mock simple and complex requests and responses.

Useful links:

REST API Swagger docs