Showing posts with label json. Show all posts
Showing posts with label json. Show all posts

Saturday, 23 June 2018

In Node JS, Update A Nested Level JSON Key Value With The New Value.

Most of the time, while working with JSON, we come across a scenario where we would like to update a existing json key with the new value and return the updated json. The key could exist at the nth level, and the value can be in any form (json, string, number..)

Directly updating the root node, is not that difficult.

The scenario become more complex, when we need to update the nth node in the Key value, with the new one.

I have written the basic API (with node js + ramda), where it can update the node at any level and it will return the updated json.

Here is the git repositories for it :

1.  (node js + ramda)

2. (node js + express + ramda)

Let me explain this by example :

Suppose, we have the following json structure :

            "zz":"abc xyz",

Example 1:

Now suppose, if we need to update the value of the key "abc" which is the not the direct value of key "test2".  We will require to iterate till the "json" node and then update the value of the "abc".

The key path is : testing->test2->json->abc , we need to iterate this full path to update the "abc" node.

To update the above node "abc" the API call would be :

Function Prototype : api.updateJson("keypathfromroot", "new value", existing json)

api.updateJson("/testing/test2/json/abc","newvalue", json)

Example 2:

Now, suppose if we need to update the node "test2" with the new json value.

let newValue =
  "key1" : "value1",
  "key2" : "value2"

The API call would be :

api.updateJson("/testing/test2/",newValue, json)

Note, the key path, we have just provided it to the node "test2". The keypath will always be from the root to the child node, which we need to update.

Both the git repository contains the enough documentation, to get started. Here is the link for the file

Hope it helps.

Friday, 26 January 2018

How to create/generate a JSON file dynamically using shell script.

In this post, we will see that, how we can dynamically generate/create a JSON file using shell script.

Some days back, i was having a scenario where i need to generate a JSON file in a docker container using environment variable. And environment variable values are passed through the environment file into the docker container.

Will start with writing a shell/bash script. Lets name it,


cat > /home/app/secrets/account.json << EOF

  "type": $type,
  "project_id": $project_id,


And we can now save this file. Where $type,$project_id,$private_key are the environment variables.

Now, we can run this shell script by executing the following command in the bash.


And this will generate a JSON file in the /home/app/secrets/ folder.

In the shebang, i have used #!/bin/ash as, i was using the alpine docker image.