Initial port-forward implementation for services (#231)

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

src/main/router.ts

@@ -7,6 +7,7 @@ import { resourceApplierApi } from "./resource-applier-api"
 import { kubeconfigRoute } from "./routes/kubeconfig"
 import { metricsRoute } from "./routes/metrics"
 import { watchRoute } from "./routes/watch"
+import { portForwardRoute } from "./routes/port-forward"
 import { readFile } from "fs"
 
 // eslint-disable-next-line @typescript-eslint/no-var-requires
@@ -118,6 +119,9 @@ export class Router {
     // Metrics API
     this.router.add({ method: 'post', path: '/api/metrics' }, metricsRoute.routeMetrics.bind(metricsRoute))
 
+    // Port-forward API
+    this.router.add({ method: 'post', path: '/api/services/{namespace}/{service}/port-forward/{port}' }, portForwardRoute.routeServicePortForward.bind(portForwardRoute))
+
     // Helm API
     this.router.add({ method: 'get', path: '/api-helm/v2/charts' }, helmApi.listCharts.bind(helmApi))
     this.router.add({ method: 'get', path: '/api-helm/v2/charts/{repo}/{chart}' }, helmApi.getChart.bind(helmApi))

src/main/routes/port-forward.ts

@@ -0,0 +1,107 @@
+import { LensApiRequest } from "../router"
+import { LensApi } from "../lens-api"
+import { spawn, ChildProcessWithoutNullStreams } from "child_process"
+import { bundledKubectl } from "../kubectl"
+import { getFreePort } from "../port"
+import { shell } from "electron"
+import * as tcpPortUsed from "tcp-port-used"
+import logger from "../logger"
+
+class PortForward {
+  public static portForwards: PortForward[] = []
+
+  static getPortforward(forward: {clusterId: string; kind: string; name: string; namespace: string; port: string}) {
+    return PortForward.portForwards.find((pf) => {
+      return (
+        pf.clusterId == forward.clusterId &&
+        pf.kind == "service" &&
+        pf.name == forward.name &&
+        pf.namespace == forward.namespace &&
+        pf.port == forward.port
+      )
+    })
+  }
+
+  public clusterId: string
+  public process: ChildProcessWithoutNullStreams
+  public kubeConfig: string
+  public kind: string
+  public namespace: string
+  public name: string
+  public port: string
+  public localPort: number
+
+  constructor(obj: any) {
+    Object.assign(this, obj)
+  }
+
+  public async start() {
+    this.localPort = await getFreePort(8000, 9999)
+    const kubectlBin = await bundledKubectl.kubectlPath()
+    const args = [
+      "--kubeconfig", this.kubeConfig,
+      "port-forward",
+      "-n", this.namespace,
+      `service/${this.name}`,
+      `${this.localPort}:${this.port}`
+    ]
+
+    this.process = spawn(kubectlBin, args, {
+      env: process.env
+    })
+    PortForward.portForwards.push(this)
+    this.process.on("exit", () => {
+      const index = PortForward.portForwards.indexOf(this)
+      if (index > -1) {
+        PortForward.portForwards.splice(index, 1)
+      }
+    })
+    try {
+      await tcpPortUsed.waitUntilUsed(this.localPort, 500, 3000)
+      return true
+    } catch (error) {
+      this.process.kill()
+      return false
+    }
+  }
+
+  public open() {
+    shell.openExternal(`http://localhost:${this.localPort}`)
+  }
+}
+
+class PortForwardRoute extends LensApi {
+
+  public async routeServicePortForward(request: LensApiRequest) {
+    const { params, response, cluster} = request
+
+    let portForward = PortForward.getPortforward({
+      clusterId: cluster.id, kind: "service", name: params.service,
+      namespace: params.namespace, port: params.port
+    })
+    if (!portForward) {
+      logger.info(`Creating a new port-forward ${params.namespace}/${params.service}:${params.port}`)
+      portForward = new PortForward({
+        clusterId: cluster.id,
+        kind: "service",
+        namespace: params.namespace,
+        name: params.service,
+        port: params.port,
+        kubeConfig: cluster.kubeconfigPath()
+      })
+      const started = await portForward.start()
+      if (!started) {
+        this.respondJson(response, {
+          message: "Failed to open port-forward"
+        }, 400)
+        return
+      }
+    }
+
+    portForward.open()
+
+    this.respondJson(response, {})
+  }
+}
+
+export const portForwardRoute = new PortForwardRoute()