From ef6c2c729742d5efb35e4488c071c052926ec315 Mon Sep 17 00:00:00 2001
From: Mattis Bratland <mattis.bratland@novari.no>
Date: Sun, 20 Oct 2024 05:27:25 +0200
Subject: [PATCH] feat: add liveness and readiness probes to deployment

- Added liveness and readiness probes to monitor the health and readiness of the application
- Added endpoint for /health and /ready
---
 charts/flaiserator/templates/deployment.yaml  | 18 +++++++++
 src/main/kotlin/no/fintlabs/Application.kt    | 13 +++++++
 .../kotlin/no/fintlabs/HttpTests.kt           | 39 +++++++++++++++++++
 3 files changed, 70 insertions(+)

diff --git a/charts/flaiserator/templates/deployment.yaml b/charts/flaiserator/templates/deployment.yaml
index 4ba744d..5d1e053 100644
--- a/charts/flaiserator/templates/deployment.yaml
+++ b/charts/flaiserator/templates/deployment.yaml
@@ -48,6 +48,24 @@ spec:
           env:
               {{- toYaml . | nindent 12 }}
           {{- end }}
+
+          livenessProbe:
+            httpGet:
+              path: /health
+              port: 8080
+            initialDelaySeconds: 10
+            periodSeconds: 10
+            timeoutSeconds: 5
+            failureThreshold: 3
+
+          readinessProbe:
+            httpGet:
+              path: /ready
+              port: 8080
+            initialDelaySeconds: 5
+            periodSeconds: 10
+            timeoutSeconds: 5
+            failureThreshold: 3
       {{- with .Values.volumes }}
       volumes:
         {{- toYaml . | nindent 8 }}
diff --git a/src/main/kotlin/no/fintlabs/Application.kt b/src/main/kotlin/no/fintlabs/Application.kt
index 3139be5..fc71840 100644
--- a/src/main/kotlin/no/fintlabs/Application.kt
+++ b/src/main/kotlin/no/fintlabs/Application.kt
@@ -82,8 +82,21 @@ val baseModule = module {
     }
     single<HttpHandler> {
         val prometheusRegistry: PrometheusMeterRegistry = get()
+        val operator: Operator = get()
         routes(
             "/metrics" bind Method.GET to { Response(Status.OK).body(prometheusRegistry.scrape()) },
+            "/health" bind Method.GET to {
+                when (operator.runtimeInfo.isStarted) {
+                    true -> Response(Status.OK).body("Operator is healthy.")
+                    false -> Response(Status.SERVICE_UNAVAILABLE).body("Operator is not healthy.")
+                }
+            },
+            "/ready" bind Method.GET to {
+                when (operator.runtimeInfo.isStarted) {
+                    true -> Response(Status.OK).body("Operator is ready.")
+                    false -> Response(Status.SERVICE_UNAVAILABLE).body("Operator is not ready.")
+                }
+            }
         )
     }
 }
diff --git a/src/test/integration/kotlin/no/fintlabs/HttpTests.kt b/src/test/integration/kotlin/no/fintlabs/HttpTests.kt
index 66abc7f..01c8270 100644
--- a/src/test/integration/kotlin/no/fintlabs/HttpTests.kt
+++ b/src/test/integration/kotlin/no/fintlabs/HttpTests.kt
@@ -1,6 +1,8 @@
 package no.fintlabs
 
+import no.fintlabs.extensions.KubernetesOperatorContext
 import no.fintlabs.operator.Utils.createKoinTestExtension
+import no.fintlabs.operator.Utils.createKubernetesOperatorExtension
 import org.http4k.core.HttpHandler
 import org.http4k.core.Method
 import org.http4k.core.Request
@@ -22,8 +24,45 @@ class HttpTests : KoinTest {
         assertContains(response.bodyString(), "jvm_memory_used_bytes")
     }
 
+    @Test
+    fun `should return health ok`() {
+        val client: HttpHandler by inject()
+
+        val response = client(Request(Method.GET, "/health"))
+        assertEquals(Status.OK, response.status)
+    }
+
+    @Test
+    fun `should return health fail`(context: KubernetesOperatorContext) {
+        val client: HttpHandler by inject()
+
+        context.operator.stop()
+        val response = client(Request(Method.GET, "/health"))
+        assertEquals(Status.SERVICE_UNAVAILABLE, response.status)
+    }
+
+    @Test
+    fun `should return readiness ok`() {
+        val client: HttpHandler by inject()
+
+        val response = client(Request(Method.GET, "/ready"))
+        assertEquals(Status.OK, response.status)
+    }
+
+    @Test
+    fun `should return readiness fail`(context: KubernetesOperatorContext) {
+        val client: HttpHandler by inject()
+
+        context.operator.stop()
+        val response = client(Request(Method.GET, "/ready"))
+        assertEquals(Status.SERVICE_UNAVAILABLE, response.status)
+    }
+
     companion object {
         @RegisterExtension
         val koinTestExtension = createKoinTestExtension()
+
+        @RegisterExtension
+        val kubernetesOperatorExtension = createKubernetesOperatorExtension()
     }
 }
\ No newline at end of file