Auto-detect prometheus installation (#343)

Signed-off-by: Jari Kolehmainen <jari.kolehmainen@gmail.com>

src/main/cluster.ts

@@ -95,7 +95,6 @@ export class Cluster implements ClusterInfo {
     this.contextName = kc.currentContext
     this.url = this.contextHandler.url
     this.apiUrl = kc.getCurrentCluster().server
-    await this.contextHandler.init()
   }
 
   public stopServer() {

src/main/context-handler.ts

@@ -1,4 +1,4 @@
-import { KubeConfig } from "@kubernetes/client-node"
+import { KubeConfig, CoreV1Api } from "@kubernetes/client-node"
 import { readFileSync } from "fs"
 import * as http from "http"
 import { ServerOptions } from "http-proxy"
@@ -7,6 +7,9 @@ import logger from "./logger"
 import { getFreePort } from "./port"
 import { KubeAuthProxy } from "./kube-auth-proxy"
 import { Cluster, ClusterPreferences } from "./cluster"
+import { prometheusProviders } from "../common/prometheus-providers"
+import { PrometheusService, PrometheusProvider } from "./prometheus/provider-registry"
+import { PrometheusLens } from "./prometheus/lens"
 
 export class ContextHandler {
   public contextName: string
@@ -28,6 +31,7 @@ export class ContextHandler {
   protected defaultNamespace: string
   protected proxyPort: number
   protected kubernetesApi: string
+  protected prometheusProvider: string
   protected prometheusPath: string
   protected clusterName: string
 
@@ -56,7 +60,6 @@ export class ContextHandler {
     this.defaultNamespace = kc.getContextObject(kc.currentContext).namespace
     this.url = `http://${this.id}.localhost:${cluster.port}/`
     this.kubernetesApi = `http://127.0.0.1:${cluster.port}/${this.id}`
-    this.setClusterPreferences(cluster.preferences)
     this.kc.clusters = [
       {
         name: kc.getCurrentCluster().name,
@@ -64,14 +67,17 @@ export class ContextHandler {
         skipTLSVerify: true
       }
     ]
+    this.setClusterPreferences(cluster.preferences)
   }
 
   public setClusterPreferences(clusterPreferences?: ClusterPreferences) {
+    this.prometheusProvider = clusterPreferences.prometheusProvider?.type
+
     if (clusterPreferences && clusterPreferences.prometheus) {
       const prom = clusterPreferences.prometheus
       this.prometheusPath = `${prom.namespace}/services/${prom.service}:${prom.port}`
     } else {
-      this.prometheusPath = "lens-metrics/services/prometheus:80"
+      this.prometheusPath = null
     }
     if(clusterPreferences && clusterPreferences.clusterName) {
       this.clusterName = clusterPreferences.clusterName;
@@ -80,28 +86,48 @@ export class ContextHandler {
     }
   }
 
-  public getPrometheusPath() {
-    return this.prometheusPath
+  protected async resolvePrometheusPath(): Promise<string> {
+    const service = await this.getPrometheusService()
+    return `${service.namespace}/services/${service.service}:${service.port}`
   }
 
-  public async init() {
-    const currentCluster = this.kc.getCurrentCluster()
-    if (currentCluster.caFile) {
-      this.certData = readFileSync(currentCluster.caFile).toString()
-    } else if (currentCluster.caData) {
-      this.certData = Buffer.from(currentCluster.caData, "base64").toString("ascii")
+  public async getPrometheusProvider() {
+    if (!this.prometheusProvider) {
+      const service = await this.getPrometheusService()
+      logger.info(`using ${service.id} as prometheus provider`)
+      this.prometheusProvider = service.id
     }
-    const user = this.kc.getCurrentUser()
-    if (user.authProvider && user.authProvider.name === "oidc") {
-      const authConfig = user.authProvider.config
-      if (authConfig["idp-certificate-authority"]) {
-        this.authCertData = readFileSync(authConfig["idp-certificate-authority"]).toString()
-      } else if (authConfig["idp-certificate-authority-data"]) {
-        this.authCertData = Buffer.from(authConfig["idp-certificate-authority-data"], "base64").toString("ascii")
+    return prometheusProviders.find(p => p.id === this.prometheusProvider)
+  }
+
+  public async getPrometheusService(): Promise<PrometheusService> {
+    const providers = this.prometheusProvider ? prometheusProviders.filter((p, _) => p.id == this.prometheusProvider) : prometheusProviders
+    const prometheusPromises: Promise<PrometheusService>[] = providers.map(async (provider: PrometheusProvider): Promise<PrometheusService> => {
+      const apiClient = this.kc.makeApiClient(CoreV1Api)
+      return await provider.getPrometheusService(apiClient)
+    })
+    const resolvedPrometheusServices = await Promise.all(prometheusPromises)
+    const service = resolvedPrometheusServices.filter(n => n)[0]
+    if (service) {
+      return service
+    } else {
+      return {
+        id: "lens",
+        namespace: "lens-metrics",
+        service: "prometheus",
+        port: 80
       }
     }
   }
 
+  public async getPrometheusPath(): Promise<string> {
+    if (this.prometheusPath) return this.prometheusPath
+
+    this.prometheusPath = await this.resolvePrometheusPath()
+
+    return this.prometheusPath
+  }
+
   public async getApiTarget(isWatchRequest = false) {
     if (this.apiTarget && !isWatchRequest) {
       return this.apiTarget

src/main/prometheus/helm.ts

@@ -1,10 +1,29 @@
 import { PrometheusLens } from "./lens"
+import { CoreV1Api } from "@kubernetes/client-node"
+import { PrometheusService } from "./provider-registry";
+import logger from "../logger"
 
 export class PrometheusHelm extends PrometheusLens {
-  constructor() {
-    super()
-    this.id = "helm"
-    this.name = "Helm"
-    this.rateAccuracy = "5m"
+  id = "helm"
+  name = "Helm"
+  rateAccuracy = "5m"
+
+  public async getPrometheusService(client: CoreV1Api): Promise<PrometheusService> {
+    const labelSelector = "app=prometheus,component=server,heritage=Helm"
+    try {
+      const serviceList = await client.listServiceForAllNamespaces(false, "", null, labelSelector)
+      const service = serviceList.body.items[0]
+      if (!service) return
+
+      return {
+        id: this.id,
+        namespace: service.metadata.namespace,
+        service: service.metadata.name,
+        port: service.spec.ports[0].port
+      }
+    } catch(error) {
+      logger.warn(`PrometheusHelm: failed to list services: ${error.toString()}`)
+      return
+    }
   }
 }

src/main/prometheus/lens.ts

@@ -1,11 +1,28 @@
-import { PrometheusProvider, PrometheusQueryOpts, PrometheusClusterQuery, PrometheusNodeQuery, PrometheusPodQuery, PrometheusPvcQuery, PrometheusIngressQuery } from "./provider-registry";
+import { PrometheusProvider, PrometheusQueryOpts, PrometheusQuery, PrometheusService } from "./provider-registry";
+import { CoreV1Api } from "@kubernetes/client-node";
+import logger from "../logger"
 
 export class PrometheusLens implements PrometheusProvider {
   id = "lens"
   name = "Lens"
   rateAccuracy = "1m"
 
-  public getQueries(opts: PrometheusQueryOpts): PrometheusNodeQuery | PrometheusClusterQuery | PrometheusPodQuery | PrometheusPvcQuery | PrometheusIngressQuery {
+  public async getPrometheusService(client: CoreV1Api): Promise<PrometheusService> {
+    try {
+      const resp = await client.readNamespacedService("prometheus", "lens-metrics")
+      const service = resp.body
+      return {
+        id: this.id,
+        namespace: service.metadata.namespace,
+        service: service.metadata.name,
+        port: service.spec.ports[0].port
+      }
+    } catch(error) {
+      logger.warn(`PrometheusLens: failed to list services: ${error.toString()}`)
+    }
+  }
+
+  public getQueries(opts: PrometheusQueryOpts): PrometheusQuery {
     switch(opts.category) {
     case 'cluster':
       return {

src/main/prometheus/operator.ts

@@ -1,11 +1,36 @@
-import { PrometheusProvider, PrometheusQueryOpts, PrometheusClusterQuery, PrometheusNodeQuery, PrometheusPodQuery, PrometheusPvcQuery, PrometheusIngressQuery } from "./provider-registry";
+import { PrometheusProvider, PrometheusQueryOpts, PrometheusQuery, PrometheusService } from "./provider-registry";
+import { CoreV1Api, V1Service } from "@kubernetes/client-node";
+import logger from "../logger";
 
 export class PrometheusOperator implements PrometheusProvider {
   rateAccuracy = "1m"
   id = "operator"
   name = "Prometheus Operator"
 
-  public getQueries(opts: PrometheusQueryOpts): PrometheusNodeQuery | PrometheusClusterQuery | PrometheusPodQuery | PrometheusPvcQuery | PrometheusIngressQuery {
+  public async getPrometheusService(client: CoreV1Api): Promise<PrometheusService> {
+    try {
+      let service: V1Service
+      for (const labelSelector of ["operated-prometheus=true", "self-monitor=true"]) {
+        if (!service) {
+          const serviceList = await client.listServiceForAllNamespaces(null, null, null, labelSelector)
+          service = serviceList.body.items[0]
+        }
+      }
+      if (!service) return
+
+      return {
+        id: this.id,
+        namespace: service.metadata.namespace,
+        service: service.metadata.name,
+        port: service.spec.ports[0].port
+      }
+    } catch(error) {
+      logger.warn(`PrometheusOperator: failed to list services: ${error.toString()}`)
+      return
+    }
+  }
+
+  public getQueries(opts: PrometheusQueryOpts): PrometheusQuery {
     switch(opts.category) {
     case 'cluster':
       return {

src/main/prometheus/provider-registry.ts

@@ -1,3 +1,5 @@
+import { CoreV1Api } from "@kubernetes/client-node"
+
 export type PrometheusClusterQuery = {
   memoryUsage: string;
   memoryRequests: string;
@@ -48,8 +50,20 @@ export type PrometheusQueryOpts = {
   [key: string]: string | any;
 };
 
+export type PrometheusQuery = PrometheusNodeQuery | PrometheusClusterQuery | PrometheusPodQuery | PrometheusPvcQuery | PrometheusIngressQuery
+
+export type PrometheusService = {
+  id: string;
+  namespace: string;
+  service: string;
+  port: number;
+}
+
 export interface PrometheusProvider {
-  getQueries(opts: PrometheusQueryOpts): PrometheusNodeQuery | PrometheusClusterQuery | PrometheusPodQuery | PrometheusPvcQuery | PrometheusIngressQuery;
+  id: string;
+  name: string;
+  getQueries(opts: PrometheusQueryOpts): PrometheusQuery;
+  getPrometheusService(client: CoreV1Api): Promise<PrometheusService>;
 }
 
 export type PrometheusProviderList = {

src/main/proxy.ts

@@ -83,8 +83,6 @@ export class LensProxy {
             }, (250 * retryCount))
           }
         }
-
-        //return
       }
       res.writeHead(500, {
         'Content-Type': 'text/plain'

src/main/routes/metrics.ts

@@ -13,7 +13,6 @@ class MetricsRoute extends LensApi {
     const { response, cluster} = request
     const query: MetricsQuery = request.payload;
     const serverUrl = `http://127.0.0.1:${cluster.port}/api-kube`
-    const metricsUrl = `${serverUrl}/api/v1/namespaces/${cluster.contextHandler.getPrometheusPath()}/proxy/api/v1/query_range`
     const headers = {
       "Host": `${cluster.id}.localhost:${cluster.port}`,
       "Content-type": "application/json",
@@ -23,10 +22,12 @@ class MetricsRoute extends LensApi {
       queryParams[key] = value
     })
 
-    const prometheusInstallationSource = cluster.preferences.prometheusProvider?.type || "lens"
+    let metricsUrl: string
     let prometheusProvider: PrometheusProvider
     try {
-      prometheusProvider = PrometheusProviderRegistry.getProvider(prometheusInstallationSource)
+      const prometheusPath = await cluster.contextHandler.getPrometheusPath()
+      metricsUrl = `${serverUrl}/api/v1/namespaces/${prometheusPath}/proxy/api/v1/query_range`
+      prometheusProvider = await cluster.contextHandler.getPrometheusProvider()
     } catch {
       this.respondJson(response, {})
       return

src/renderer/components/ClusterSettings/Preferences/index.vue

@@ -20,17 +20,7 @@
       <div class="cluster-settings-section">
         <b>Prometheus</b>
         <p>Use pre-installed Prometheus service for metrics. Please refer to the <a href="https://github.com/lensapp/lens/blob/master/troubleshooting/custom-prometheus.md">guide</a> for possible configuration changes.</p>
-        <b-form-group
-          label="Prometheus service address."
-          description="A path to an existing Prometheus installation (<namespace>/<service>:<port>)."
-        >
-          <b-form-input
-            v-model="prometheusPath"
-            placeholder="lens-metrics/prometheus:80"
-            id="input-prometheuspath"
-            @blur="onPrometheusSave"
-          />
-        </b-form-group>
+
         <b-form-group
           label="Prometheus installation method."
           description="What query format is used to fetch metrics from Prometheus"
@@ -41,6 +31,18 @@
             @change="onPrometheusProviderSave"
           />
         </b-form-group>
+        <b-form-group
+          label="Prometheus service address."
+          description="An address to an existing Prometheus installation (<namespace>/<service>:<port>). Lens tries to auto-detect address if left empty."
+          v-if="canEditPrometheusPath"
+        >
+          <b-form-input
+            v-model="prometheusPath"
+            placeholder="<namespace>/<service>:<port>"
+            id="input-prometheuspath"
+            @blur="onPrometheusSave"
+          />
+        </b-form-group>
       </div>
     </div>
     <div class="col-12">
@@ -84,13 +86,25 @@ export default {
       },
       prometheusPath: "",
       prometheusProvider: "",
-      prometheusProviders: [],
+    }
+  },
+  computed: {
+    prometheusProviders: function() {
+      const providers = prometheusProviders.map((provider) => {
+        return { text: provider.name, value: provider.id }
+      })
+      providers.unshift({text: "Auto detect", value: ""})
+
+      return providers;
+    },
+    canEditPrometheusPath: function() {
+      if (this.prometheusProvider === "") return false
+      if (this.prometheusProvider === "lens") return false
+
+      return true
     }
   },
   mounted: async function() {
-    this.prometheusProviders = prometheusProviders.map((provider) => {
-      return { text: provider.name, value: provider.id }
-    })
     this.updateValues()
   },
   methods: {
@@ -104,7 +118,7 @@ export default {
       if (this.cluster.preferences.prometheusProvider) {
         this.prometheusProvider = this.cluster.preferences.prometheusProvider.type
       } else {
-        this.prometheusProvider = "lens"
+        this.prometheusProvider = ""
       }
     },
     parsePrometheusPath: function(path) {