fix(k8s): patch bugs in kubernetes client

One was malformed Error objects, which made error outputs less than
useful. The other was that all patch methods were broken due to
the wrong header being sent.

src/plugins/kubernetes/api.ts

@@ -10,7 +10,12 @@ import { KubeConfig, Core_v1Api, Extensions_v1beta1Api, RbacAuthorization_v1Api
 import { join } from "path"
 import { readFileSync } from "fs"
 import { safeLoad } from "js-yaml"
-import { zip } from "lodash"
+import {
+  zip,
+  isFunction,
+  omitBy,
+} from "lodash"
+import { GardenBaseError } from "../../exceptions"
 
 let kubeConfigStr: string
 let kubeConfig: any
@@ -48,23 +53,74 @@ function getConfig(context: string): KubeConfig {
 export function coreApi(context: string) {
   const config = getConfig(context)
   const k8sApi = new Core_v1Api(config.getCurrentCluster().server)
-  k8sApi.setDefaultAuthentication(config)
-
-  return k8sApi
+  return proxyApi(k8sApi, config)
 }
 
 export function extensionsApi(context: string) {
   const config = getConfig(context)
   const k8sApi = new Extensions_v1beta1Api(config.getCurrentCluster().server)
-  k8sApi.setDefaultAuthentication(config)
-
-  return k8sApi
+  return proxyApi(k8sApi, config)
 }
 
 export function rbacApi(context: string) {
   const config = getConfig(context)
   const k8sApi = new RbacAuthorization_v1Api(config.getCurrentCluster().server)
-  k8sApi.setDefaultAuthentication(config)
+  return proxyApi(k8sApi, config)
+}
+
+export class KubernetesError extends GardenBaseError {
+  type = "kubernetes"
+
+  code?: number
+  response?: any
+}
 
-  return k8sApi
+/**
+ * Wrapping the API objects to deal with bugs.
+ */
+function proxyApi<T extends Core_v1Api | Extensions_v1beta1Api | RbacAuthorization_v1Api>(
+  api: T, config: KubeConfig,
+): T {
+  api.setDefaultAuthentication(config)
+
+  const wrapError = err => {
+    if (!err.message) {
+      const wrapped = new KubernetesError(`Got error from Kubernetes API - ${err.body.message}`, {
+        body: err.body,
+        request: omitBy(err.response.request, (v, k) => isFunction(v) || k[0] === "_"),
+      })
+      wrapped.code = err.response.statusCode
+      wrapped.response = err.response
+      throw wrapped
+    } else {
+      throw err
+    }
+  }
+
+  return new Proxy(api, {
+    get: (target: T, name: string, receiver) => {
+      if (name in Object.getPrototypeOf(target)) { // assume methods live on the prototype
+        return function(...args) {
+          const defaultHeaders = target["defaultHeaders"]
+
+          if (name.startsWith("patch")) {
+            // patch the patch bug... (https://github.com/kubernetes-client/javascript/issues/19)
+            target["defaultHeaders"] = { ...defaultHeaders, "content-type": "application/strategic-merge-patch+json" }
+          }
+
+          const output = target[name](...args)
+          target["defaultHeaders"] = defaultHeaders
+
+          if (typeof output.then === "function") {
+            // the API errors are not properly formed Error objects
+            return output.catch(wrapError)
+          } else {
+            return output
+          }
+        }
+      } else { // assume instance vars live on the target
+        return Reflect.get(target, name, receiver)
+      }
+    },
+  })
 }