Inject JSON Body

Support
1

Can we inject JSON Body in the request explicitly.

The use case I have is, have to inject inject json body explicitly where in the incoming request no body is present.

2

Try using Transform plugin feature. You can either use a file template mode as shown in our doc or the blob template mode as shown below.

"transform": [
              {
                "template_data": {
                  "input_type": "json",
                  "template_mode": "blob",
                  "enable_session": false,
                  "template_source": "ewogICAgInN0cmluZyI6ICJUaGlzIGlzIGEganNvbiBzdHJpbmchIiwKICAgICJpbnQiOiAxMgp9",
                  "input": "",
                  "output": ""
                },
                "path": "widgets/{id}",
                "method": "POST"
              }
            ]

The value of the template_source is simply a 64 bit encoded value of the template. You can copy the value below and use a base64 decoder to retrieve the json.

3

As I am not getting body in the incoming request and I want TYK to inject some valid JSON DATA ( even valid format (empty json) like {} is also fine).

As per the suggestion I have enabled below settings in the API definition:

“transform”: [
{
“path”: “/”,
“method”: “GET”,
“template_data”: {
“template_mode”: “file”,
“template_source”: “./templates/test.tmpl”,
“input_type”: “json”,
“enable_session”: true,
}
}

I have configured test.tmpl file as below:

{

“transformed_list”:[
{
“name”:“saloni”
}
]

I feel the template file is wrong. I just want to inject some valid json data. Could you Please suggest how I can achieve. Please do note that there is no body present in the coming request. So we want TYK to inject that explicitly.

4

Please help with above query.

5

Could you try using the blob (base 64 encoded) instead. I have tried this and it works.

Seems like the file based template source does not work for an empty body. I have tested this in version 3.0.0. I will check with the internal team regarding this. Can you confirm your version of the gateway so I can test as well.

6

Tested with version 3.2.2 and file based method works. What is your version of the gateway?

7

My gateway version is 3.2. Can you Please suggest how to integrate it using blob.

How do we specify empty template using blob?

8

Integrating with the blob method is very easy. You need to encode the JSON you wish to inject into base 64 and add it as the value for template_source. For example you can decode the sample I shared with you earlier to extract the JSON.

File based method works for your version which is v3.2. It also works in the latest v3.0 release. I noticed v3.0.0 I was using was a year old.

If you still want to use the file based method, then you need to ensure you have the file (transform_test.tmpl) in your templates folder. The templates folder is at the root of your Tyk directory.

# ls
apps   coprocess       install     plugins   templates  tyk.conf
certs  event_handlers  middleware  policies  tyk

# ls templates
error.json  error.xml  transform_test.tmpl

You can follow out github page to recreate the template folder. Hope this helps.