Merge pull request #16486 from lenguyenthanh/expose-kamon-prometheus-…

…manually

Expose kamon's prometheus metrics manually

app/controllers/Main.scala

@@ -112,6 +112,11 @@ final class Main(
         env.security.lilaCookie.withSession(remember = true): s =>
           s + ("theme" -> "ic") + ("pieceSet" -> "icpieces")
 
+  def prometheusMetrics(key: String) = Action:
+    if key == env.web.config.prometheusKey
+    then kamon.prometheus.PrometheusReporter.latestScrapeData().fold(NotFound("No metrics found"))(Ok(_))
+    else NotFound("Invalid prometheus key")
+
   def legacyQaQuestion(id: Int, _slug: String) = Open:
     MovedPermanently:
       StaticContent.legacyQaQuestion(id)

conf/base.conf

@@ -437,6 +437,7 @@ kamon {
     }
   }
   prometheus {
+    lilaKey = ""
     buckets {
       default-buckets = [10, 100, 1000, 10000, 100000]
       time-buckets = [0.01, 0.05, 0.1, 0.5, 1, 5, 10]

conf/routes

@@ -874,6 +874,7 @@ POST  /dev/cli                         controllers.Dev.cliPost
 GET   /dev/settings                    controllers.Dev.settings
 POST  /dev/settings/:id                controllers.Dev.settingsPost(id)
 
+GET   /prometheus-metrics/:key         controllers.Main.prometheusMetrics(key: String)
 POST  /dev/socket-test                 controllers.Dev.socketTestResult
 
 # Push

modules/web/src/main/WebConfig.scala

@@ -10,6 +10,7 @@ final class WebConfig(
     val apiToken: Secret,
     val influxEventEndpoint: String,
     val influxEventEnv: String,
+    val prometheusKey: String,
     val pagerDuty: WebConfig.PagerDuty
 )
 
@@ -32,6 +33,7 @@ object WebConfig:
       c.get[Secret]("api.token"),
       c.get[String]("api.influx_event.endpoint"),
       c.get[String]("api.influx_event.env"),
+      c.get[String]("kamon.prometheus.lilaKey"),
       new PagerDuty(
         c.get[String]("pagerDuty.serviceId"),
         c.get[Secret]("pagerDuty.apiKey")