PUT vs POST when adding documents in elastic search - elasticsearch

Question

I am new to Elasticsearch and trying to add documents in elastic index. I have got confused between PUT and POST here as both are producing same results in below scenario:
curl -H "Content-Type: application/json" -XPUT "localhost:9200/products/mobiles/1?pretty" -d"
{
"name": "iPhone 7",
"camera": "12MP",
"storage": "256GB",
"display": "4.7inch",
"battery": "1,960mAh",
"reviews": ["Incredibly happy after having used it for one week", "Best iPhone so far", "Very expensive, stick to Android"]
}
"
vs
curl -H "Content-Type: application/json" -XPOST "localhost:9200/products/mobiles/1?pretty" -d"
{
"name": "iPhone 7",
"camera": "12MP",
"storage": "256GB",
"display": "4.7inch",
"battery": "1,960mAh",
"reviews": ["Incredibly happy after having used it for one week", "Best iPhone so far", "Very expensive, stick to Android"]
}
"

Answer 1

POST :used to achieve auto-generation of ids.
PUT :used when you want to specify an id.
see this

Answer 2

They both are among safe methods of HTTP.
usually we use POST to create a resource and PUT to modify that. besides if you're free to set-up the server side, you can use both of them because they both have similar properties like: they both have body, they are safe, data is not shown in URL, and ....
though it is better to consider standard rules that I said one of them before:
usually we use POST to create a resource and PUT to modify that. this way your code is more readable, changeable ...
for going deeper you can consider these tips according to put-versus-post:
Deciding between POST and PUT is easy: use PUT if and only if the endpoint will follow these 2 rules:
The endpoint must be idempotent: so safe to redo the request over and over again;
The URI must be the address to the resource being updated.
When we use PUT, we’re saying that we want the resource that we’re sending in our request to be stored at the given URI. We’re literally “putting” the resource at this address.

Answer 3

The only different between POST and PUT is that you cannot use PUT to create documents with auto ID generation.
The following query will create a document and auto generate an ID:
POST /products/_doc
{
"name": "Shoes",
"price": 100,
"in_stock": 64
}
Trying the same with PUT results to an "Incorrect HTTP method".
PUT /products/_doc
{
"name": "Shoes",
"price": 100,
"in_stock": 64
}
Unless I didn't experiment hard enough, this is the only difference between POST and PUT when creating documents.
Other than this, POST and PUT will get you to achieve the same things.