Add elasticsearch_capture_body_urls option (#670)

* Add elasticsearch_capture_body_urls option

* Update tracing-instrumentation-db.md

* leading '/' anchor in patterns; add sql and eql search endpoints

Co-authored-by: Felix Barnsteiner <[email protected]>

* Fix url fields

Co-authored-by: Trent Mick <[email protected]>

* The body MUST be decoded

Co-authored-by: Trent Mick <[email protected]>

specs/agents/tracing-instrumentation-db.md

@@ -117,11 +117,15 @@ The following fields are relevant for database and datastore spans. Where possib
 |`action`| `request` |
 | __**context.db._**__  |<hr/>|<hr/>|
 |`_.instance`| e.g. `my-cluster` | [Cluster name](#cluster-name), if available.
-|`_.statement`| e.g. <pre lang="json">{"query": {"match": {"user.id": "kimchy"}}}</pre> | For Elasticsearch search-type queries, the request body may be recorded. Alternatively, if a query is specified in HTTP query parameters, that may be used instead. If the body is gzip-encoded, the body should be decoded first.|
+|`_.statement`| e.g. <pre lang="json">{"query": {"match": {"user.id": "kimchy"}}}</pre> | For Elasticsearch search-type queries, the request body SHOULD be recorded according to the `elasticsearch_capture_body_urls` option (see below). If the body is gzip-encoded, the body MUST be decoded first.|
 |`_.type`|`elasticsearch`|
 |`_.user`| :heavy_minus_sign: |
 |`_.link`| :heavy_minus_sign: |
 |`_.rows_affected`| :heavy_minus_sign: |
+| __**context.http._**__ |<hr/>|<hr/>|
+|`_.status_code`|`200`|
+|`_.method`|`GET`|
+|`_.url`|`https://localhost:9200/index/_search?q=user.id:kimchy`|
 | __**context.destination._**__ |<hr/>|<hr/>|
 |`_.address`|e.g. `localhost`|
 |`_.port`|e.g. `5432`|
@@ -146,6 +150,18 @@ The Elasticsearch cluster name is not always available in ES clients, as a resul
 - Instrument `_node/http` calls and cache the result in the agent with `host:port` as key.
 - execute a request to Elasticsearch and cache the result in the agent with `host:port` as key.
 
+#### `elasticsearch_capture_body_urls` configuration
+
+The URL patterns for which the agent is capturing the request body for Elasticsearch clients.
+
+Agents MAY offer this configuration option.
+If they don't, they MUST use a hard-coded list of URLs that correspond with the default value of this option.
+
+|                |            |
+|----------------|------------|
+| Type           | `List<`[`WildcardMatcher`](../../tests/agents/json-specs/wildcard_matcher_tests.json)`>` |
+| Default        | `*/_search, */_search/template, */_msearch, */_msearch/template, */_async_search, */_count, */_sql, */_eql/search`|
+| Central config | `false`     
 
 ### MongoDB