[Fleet] Remove deprecated APIs, parameters, and response properties from Fleet API

[kpollich]

These are breaking changes for 9.0

The following API operations, request parameters, and response properties are deprecated, and should be removed in 9.0

Endpoints to remove

Endpoint	Deprecated version + PR	Telemetry (last 4 weeks)	Notes	Removal PR
POST /service-tokens	8.0.0 - #121091	1 request from a cluster on 8.5.3	Deprecated in favor of POST /service_tokens (underscore)	#198313
GET /agent-status	8.0.0 - #121091	18868 requests all on 7.x	Deprecated in favor of GET /agent_status (underscore)	#198313
PUT /agents/:agentid/reassign	8.8.0 - #152236	2 requests from 8.13.4 clusters	PUT verb deprecated in favor of POST	#198313
GET/POST/DELETE /epm/packages/:pkgkey	8.0.0 - #121091	N/A - wildcard query errors out in CCS	Deprecated in favor of corresponding /epm/packages/:pkgname/:pkgversion endpoints (slash delimiter for name/version)	#198434
GET/POST/DELETE /enrollment-api-keys/*	8.0.0 - #121091	950997 requests mainly from 8.13.x + 8.14.x clusters	Deprecated in favor of /enrollment_api_keys (underscores)	#198799

Query parameters to remove

Endpoint	Query parameter	Deprecated version + PR	Notes	Removal PR
GET /epm/categories	?experimental	8.6.0 - #143853		#198434
GET /epm/packages/	?experimental	8.7.0 - #150743		#198434
GET /agent_status	?kuery	8.9.0 - #159095		Will not be removed deprecated by error
Usage across many endpoints. All should be removed.	?sort_field	8.9.0 - #159095	Supported by many endpoints today

Request/response properties to remove

Endpoint	Request/Response Property	Deprecated version + PR	Notes	Removal PR
DELETE /epm/packages/:pkgname/:pkgversion	Entire request body	8.11.0 - #166623		#198434
POST /health_check	host in request + response	8.15.0 - #185014	Recent deprecation	#198799
GET /epm/packages/:pkgname/:pkgversion	savedObject + release in response	8.9.0 - #159095		#198434
GET /agent_status	total in response	8.8.0 - #151564		#198313
GET /enrollment_api_keys/	list in response	8.0.0 - #119494
POST /settings	fleet_server_hosts in response	8.6.0 - #145005		#198799
POST /epm/bulk_assets	Entire response body	8.9.0 - #158350
GET /epm/categories	response in response	8.0.0 - #121091		#198434
GET /epm/packages	response in response	8.0.0 - #121091		#198434
GET /epm/packages	saved_object in response	8.9.0 - #159095		#198434
GET /agents	list in response	8.0.0 - #121091		#198313
POST/PUT /packages_policies	policy_id in response	8.15.0 - #184636	Recent deprecation
GET/POST/PUT /settings/outputs	topics in response	8.13.0 - #177229	Recent deprecation	#199226

[elasticmachine]

Pinging @elastic/fleet (Team:Fleet)

[criamico]

Not sure if it should be part of this ticket, but we also have some deprecations in fleet/server/config:

kibana/x-pack/plugins/fleet/server/config.ts

Line 52 in d9c1f97

deprecations: ({ renameFromRoot, unused, unusedFromRoot }) => [

[criamico]

We also have an older ticket where we tracked some of the API deprecations: #121485

I don't see some of them (like the output_id property in package_policies) listed here so we should to take a look at it as well.

[kpollich]

The list should be accurate now based on all deprecated notices in https://github.com/elastic/kibana/blob/main/x-pack/plugins/fleet/common/openapi/bundled.yaml

[kpollich]

This is going to require a new API version for serverless.

[kpollich]

Reopening since the private breaking change committee issue will be closed at some point to indicate the changes are approved.

[nchaulet]

@criamico I have a question regarding removing sortField it seems it's not marked as deprecated in the schema generated open API, and it's used by our UI, do we have a better option for that property? or should we skip that removal?

[nchaulet]

I think we can close this one, all API removal PRs have been merged, except for:

• policy_id has not been removed has that change is really recent and it's still used in some of our tools (terraform plugin, observability-perf) I created follow up issues
• sortField has not been removed has it actively used in our UI and we do not have a better solution