Fixes: #4222
# Data Filtering
This PR will implement filtering for the following endpoints:
## Supported HTTP Endpoints
- `/agent/checks`
- `/agent/services`
- `/catalog/nodes`
- `/catalog/service/:service`
- `/catalog/connect/:service`
- `/catalog/node/:node`
- `/health/node/:node`
- `/health/checks/:service`
- `/health/service/:service`
- `/health/connect/:service`
- `/health/state/:state`
- `/internal/ui/nodes`
- `/internal/ui/services`
More can be added going forward and any endpoint which is used to list some data is a good candidate.
## Usage
When using the HTTP API a `filter` query parameter can be used to pass a filter expression to Consul. Filter Expressions take the general form of:
```
<selector> == <value>
<selector> != <value>
<value> in <selector>
<value> not in <selector>
<selector> contains <value>
<selector> not contains <value>
<selector> is empty
<selector> is not empty
not <other expression>
<expression 1> and <expression 2>
<expression 1> or <expression 2>
```
Normal boolean logic and precedence is supported. All of the actual filtering and evaluation logic is coming from the [go-bexpr](https://github.com/hashicorp/go-bexpr) library
## Other changes
Adding the `Internal.ServiceDump` RPC endpoint. This will allow the UI to filter services better.
- register endpoints with supported methods
- support OPTIONS requests, indicating supported methods
- extract method validation (error 405) from individual endpoints
- on 405 where multiple methods are allowed, create a single Allow
header with comma-separated values, not multiple Allow headers.
* agent: consolidate http method not allowed checks
This patch uses the error handling of the http handlers to handle HTTP
method not allowed errors across all available endpoints. It also adds a
test for testing whether the endpoints respond with the correct status
code.
* agent: do not panic on metrics tests
* agent: drop other tests for MethodNotAllowed
* agent: align /agent/join with reality
/agent/join uses PUT instead of GET as documented.
* agent: align /agent/check/{fail,warn,pass} with reality
/agent/check/{fail,warn,pass} uses PUT instead of GET as documented.
* fix some tests
* Drop more tests for method not allowed
* Align TestAgent_RegisterService_InvalidAddress with reality
* Changes API client join to use PUT instead of GET.
* Fixes agent endpoint verbs and removes obsolete tests.
* Updates the change log.
* Removes unnecessary set for model component which will be null.
* Returns a 404 for a missing node, not a 200 with an empty response.
* Updates built-in web assets.