Lara

Table of Content

• Overview
• Features
  • Handler
  • Callback
  • Dynamic Value
  • Authorization Interceptor
  • Watcher
• Usage

Overview

Lara is a configurable mock server. You just define your specifications as JSON files and let Lara create a server for you.

Features

You can check examples for usage of features.

Handler

Rest Handler

Rest Handler handles your rest request and return response as you defined.

• Regex Match
  Lara supports regex for matching requests with mocks thanks to Gorilla mux library. If the regex matched path variable or request parameters, Lara will match request to defined mock specification and return defined response to matched request.
• Response Delay
  You can also set delay time to simulate real-life scenarios. You only add after field to response or callback objects.

Callback

Rest Callback

• You can define one or multiple callback methods for each request. First, Lara will return response according to the spec then Lara invokes your callback action. As mentioned, you can define a delay time for callbacks as well.

Dynamic Value

Thanks to the dynamic value feature, you can generate unique values for each request. Therefore you can get generic response or send a generic requests to callback services. You only put these scripts to your mock specification.

String Scripts

• Random String
  It will generate ten length random string. You can adjust the length of the string by changing the last parameter.
  ${str::random::10}
• Uuid String
  Generating uuid
  ${str::uuid}
• Random String From Regex
  You can also generate random strings by defining your own regex format. First, you need you to define your regular expression with using config.yml file as below. You are not allowed to define this regular expression to mock specifications because of parsing rules.
  Otherwise, your specification will behave unexpectedly.

regex:
  email: "^[a-z]{5,10}@[a-z]{5,10}\\.(com)$"
  number: "/\d+"

Then you can use this expression with regex keyword. 10 is the length of the string. If you provide the length of the string in your regular expression you don't need to pass string length as parameter. Check the example for more usages.
${str::regex::email::10}

Number Library

• Random Number
  Generating a random number between -10 and 1
  ${number::generate::-10::1}

Date Library

• Date from format
  You can generate date from format
  First you need to define your date format to config file as below. If you are not provided any format the default format will be;
  01-02-2006 -> MM-DD-YYYY

date:
  simpleDateFormat: "2006-01-02"
  myDateFormat : "2006-02-01"

Then you can generate dates with the scripts
${date::now::simpleDateFormat}
${date::random::simpleDateFormat}
The last parameter is the keyword that you added to config file. You can define multiple different date formats to config file with different keywords. You are not allowed to define the format in the mock specification. Check examples for more info.

!!! You need to use go time format time layout. You can check for more info Date format

Value keeper

Lara allowed to you extract values from request and response objects by using value keeper. For instance, this script will retrieve userId value from the request query parameter.
${value::request::queryparams::userId}
You can extract values from

• Request body
• Request path variable
• Request query parameter
• Response body (you may need this for callbacks)
  For more you can check examples.

Authorization Interceptor

If you define callback method and this callback will send request to a server. In some cases, that server is protected with an authorization method. You can define your authorization credential to config yaml file and use it as value of token-generator into callback specification. Before sending request to the callback server, Lara will first fetch token and use this token while sending request to target service.
First, you need to define your authorization service credential as below.
As an example the name of the authorization server is keycloak. You can give any name that you want instead of keycloak.

config.yml

token-generator:
   keycloak:
     type: 
     token-url:  
     client-id: 
     client-secret:
     username: 
     password: 
     scope: 

moc.json

  "callback": [
            {
                "rest" : {
                    "after": "3000ms",
                    "token-generator": "keycloak",
                    "request": {
                        "endpoint" : "https://localhost:8443/users/${value::response::body::uuid}/${value::request::queryparams::test}",
                        "method": "POST",
                        "headers" :  {"content-type": "application/json"},
                        "body" : {"username" : "${value::request::body::username}"}
                        }
                }
            },

Lara supports Password and Client Credentials grant types. Check example config yml for more.

type : Password-Credential -> Password Credentials Grant Type
type :  Client-Credential  -> Client Credentials Grant Type

Watcher

If you want to update server when you update mock file, you can basically pass watcher flag to application. Lara watches your mocks directory and configuration path. If any change happens, Lara will update your server. There two way to initialize lara with watcher
First pass wather flag to application
--watcher
Second add watcher field to config file
watcher: true

Docker

• Passing arguments

docker run -p 8899:8899 -v "$PWD/mocks.json:/mocks.json" -v "$PWD/config.yml:/config.yml"  guvense/lara  --config /config.yml --mocks /mocks.json

License

MIT License, see LICENSE

Inspired by killgrave