Dev Tools should support PATCH method

[peternied]

Reproduction:

• Find some documentation about a scenario in OpenSearch APIs that use a PATCH command, like
• Get excited to try it out in your own cluster
• Open Dashboards, login as an admin user
• Navigate to Dev Tools
• Paste the following into the console window

PATCH _plugins/_security/api/roles/my_role
[
  {
    "op": "replace", "path": "/index_permissions/0/fls", "value": ["myfield1", "myfield2"]
  },
  {
    "op": "remove", "path": "/index_permissions/0/dls"
  }
]

• Select that text and hit the 'send request' button

Expected:

The request should succeed

Actual:

An error message appears in the response window:

{"statusCode":400,"error":"Bad Request","message":"[request query.method]: Method must be one of, case insensitive ['HEAD', 'GET', 'POST', 'PUT', 'DELETE']. Received 'PATCH'."}

Be sad you can't use this great tool to vet the scenario called out in the documentation

[peternied]

FYI @cwillum

[BSFishy]

It seems that the request method simply isn't in the list here:

OpenSearch-Dashboards/src/plugins/console/server/routes/api/console/proxy/validation_config.ts

Lines 37 to 43 in 06abe83

	validate: (method) => {
	return ['HEAD', 'GET', 'POST', 'PUT', 'DELETE'].some(
	(verb) => verb.toLowerCase() === method.toLowerCase()
	)
	? undefined
	: `Method must be one of, case insensitive ['HEAD', 'GET', 'POST', 'PUT', 'DELETE']. Received '${method}'.`;
	},

Something else of note is that it looks like the website doesn't recognize PATCH methods either, which would most likely be an issue with code somewhere else.

Just by changing that, though, the error is just propagated through to Open Search, which ends up here:

https://github.com/opensearch-project/OpenSearch/blob/2bfe8b31af354e5d00e4ac67d544ce664f083934/server/src/main/java/org/opensearch/rest/RestController.java#L490-L506