In this guide you will learn how to use RIF to send a POST request with a JSON body. Then, you will learn how to use templates to add a variable to the JSON payload.

Create the RIF file

First we will create a .rif file that describes a POST request to http://httpbin.org/post. This endpoint will echo back the body of the request we are going to send. Save the following file as post-json-body.rif:

rif_version: 0
url: "http://httpbin.org/post"
method: "POST"

Then run RIF on the file:

$ rif post-json-body.rif

You should see something like the following output:

{
  "args": {}, 
  "data": "", 
  "files": {}, 
  "form": {}, 
  "headers": {
    "Accept-Encoding": "gzip", 
    "Connection": "close", 
    "Content-Length": "0", 
    "Host": "httpbin.org", 
    "User-Agent": "RIF/0.3.1"
  }, 
  "json": null, 
  "origin": "<YOUR IP ADDRESS>", 
  "url": "http://httpbin.org/post"
}

Add a JSON body

The next step is to add a JSON body to the request. You can do this using the multiline yaml syntax:

rif_version: 0
url: "http://httpbin.org/post"
method: "POST"
headers:
  content-type: "application/json"
body: |
  {
    "message": "Hello World!"
  }

This adds a JSON body along with the application/json content type header to the request. If you run rif on this file you will see that the JSON body has been added to the echoed response:

{
  "args": {}, 
  "data": "{\n  \"message\": \"Hello World!\"\n}\n", 
  "files": {}, 
  "form": {}, 
  "headers": {
    "Accept-Encoding": "gzip", 
    "Connection": "close", 
    "Content-Length": "32", 
    "Content-Type": "application/json", 
    "Host": "httpbin.org", 
    "User-Agent": "RIF/0.3.1"
  }, 
  "json": {
    "message": "Hello World!"
  }, 
  "origin": "<YOUR IP ADDRESS>", 
  "url": "http://httpbin.org/post"
}

Add a variable

The final step is to add a template variable to your JSON body so that you can substitute this value when calling RIF:

rif_version: 0
url: "http://httpbin.org/post"
method: "POST"
headers:
  content-type: "application/json"
body: |
  {
    "message": "$(body)"
  }
variables:
  body:
    type: "string"

You can now pass in a message as a command line argument when calling RIF:

$ rif post-json-body.rif body="RIF Rocks!"

And you should see the result returned in the request response:

{
  "args": {}, 
  "data": "{\n  \"message\": \"RIF Rocks!\"\n}\n", 
  "files": {}, 
  "form": {}, 
  "headers": {
    "Accept-Encoding": "gzip", 
    "Connection": "close", 
    "Content-Length": "30", 
    "Content-Type": "application/json", 
    "Host": "httpbin.org", 
    "User-Agent": "RIF/0.3.1"
  }, 
  "json": {
    "message": "RIF Rocks!"
  }, 
  "origin": "<YOUR IP ADDRESS>", 
  "url": "http://httpbin.org/post"
}