Merge pull request #856 from cloudfoundry/app-log-rate-limiting

Add ops-file to enable app log rate limiting

[finishes #170267485](https://www.pivotaltracker.com/story/show/170267485)

Co-authored-by: Sebastian Vidrio <[email protected]>

Author: davewalter

operations/experimental/README.md

@@ -26,6 +26,7 @@ This is the README for Experimental Ops-files. To learn more about `cf-deploymen
 | [`add-system-metrics-agent-windows2019.yml`](add-system-metrics-agent-windows2019.yml) | Add agent to windows2019 Diego cells for the purpose of egressing system metrics | | **NO** |
 | [`disable-interpolate-service-bindings.yml`](disable-interpolate-service-bindings.yml) | Disables the interpolation of CredHub service credentials by Cloud Controller. | | **NO** |
 | [`disable-uaa-client-redirect-uri-legacy-matching-mode.yml`](disable-uaa-client-redirect-uri-legacy-matching-mode.yml) | Disables legacy (non-exact) matching of redirect URIs in the UAA. | | **NO** |
+| [`enable-app-log-rate-limiting.yml`](enable-app-log-rate-limiting.yml) | Enable rate limiting for number of logs generated by the application.  | Introduces variable `app_log_rate_limit`.  | **NO** |
 | [`enable-bpm-garden.yml`](enable-bpm-garden.yml) | Enables the [BOSH Process Manager](https://github.com/cloudfoundry-incubator/bpm-release) for Garden. | This ops file **cannot** be deployed in conjunction with `enable-oci-phase-1.yml`. | **NO** |
 | [`enable-containerd-for-processes.yml`](enable-containerd-for-processes.yml) | Configure Garden to run processes via containerd. | This ops file **cannot** be deployed in conjunction with `rootless-containers.yml`. | **YES** |
 | [`enable-iptables-logger.yml`](enable-iptables-logger.yml) | Enables iptables logger. | | **YES** |

operations/experimental/enable-app-log-rate-limiting.yml

@@ -0,0 +1,4 @@
+---
+- type: replace
+  path: /instance_groups/name=diego-cell/jobs/name=rep/properties/diego/executor/max_log_lines_per_second?
+  value: ((app_log_rate_limit))

units/tests/experimental_test/operations.yml

@@ -31,6 +31,9 @@ add-system-metrics-agent-windows2019.yml:
 add-system-metrics-agent.yml: {}
 disable-interpolate-service-bindings.yml: {}
 disable-uaa-client-redirect-uri-legacy-matching-mode.yml: {}
+enable-app-log-rate-limiting.yml:
+  vars:
+  - app_log_rate_limit=100
 enable-bpm-garden.yml: {}
 enable-containerd-for-processes.yml: {}
 enable-iptables-logger.yml: {}