configure frontend slider limit and cluster id from backend.

cmd/kubehook/kubehook.go

@@ -32,6 +32,7 @@ import (
 	"github.com/planetlabs/kubehook/auth/jwt"
 	"github.com/planetlabs/kubehook/handlers"
 	"github.com/planetlabs/kubehook/handlers/authenticate"
+	"github.com/planetlabs/kubehook/handlers/client"
 	"github.com/planetlabs/kubehook/handlers/generate"
 	"github.com/planetlabs/kubehook/handlers/kubecfg"
 	_ "github.com/planetlabs/kubehook/statik"
@@ -193,8 +194,10 @@ func main() {
 		t, err := kubecfg.LoadTemplate(*template)
 		kingpin.FatalIfError(err, "cannot load kubeconfig template")
 		r.HandlerFunc("GET", "/kubecfg", kubecfg.Handler(m, t, h))
+		r.HandlerFunc("GET", "/client", client.Handler(*maxlife, t))
 	} else {
 		r.HandlerFunc("GET", "/kubecfg", handlers.NotImplemented())
+		r.HandlerFunc("GET", "/client", client.Handler(*maxlife, nil))
 	}
 
 	log.Info("shutdown", zap.Error(listenAndServe(s, *tlsCert, *tlsKey)))

frontend/package.json

@@ -19,7 +19,7 @@
     "vue-axios": "^2.0.2",
     "vue-highlightjs": "^1.3.3",
     "vue-meta": "^1.4.0",
-    "vue-slider-component": "^2.4.7"
+    "vue-slider-component": "^2.8.4"
   },
   "browserslist": [
     "> 1%",

frontend/src/kubehook.vue

@@ -59,10 +59,7 @@
                 <b-col md="9" order="12" order-md="1">
                   <strong>Token lifetime</strong>
                   <v-slider
-                    formatter="{value} days"
-                    min="1"
-                    max="7"
-                    tooltip-dir="bottom"
+                    v-bind="slider"
                     v-model="lifetime"
                   ></v-slider>
                   <br />
@@ -88,20 +85,48 @@ export default {
   },
   data: function() {
     return {
+      slider: {
+        min: 1,
+        max: 7,
+        tooltipDir: "bottom",
+        formatter: "{value} days"
+      },
       kubecfg: false,
       lifetime: 2,
       clusterID: "radcluster",
       token: null,
       error: null
     };
   },
+  mounted: function() {
+    this.fetchConfig();
+  },
   created: function() {
     this.detectKubeCfg();
   },
   methods: {
     inHours: function(lifetime) {
       return lifetime * 24 + "h";
     },
+    inDays: function(lifetime) {
+      return Math.floor(lifetime / 24);
+    },
+    fetchConfig: function() {
+      var _this = this;
+      this.axios
+        .get("/client")
+        .then(function(response) {
+          _this.slider.max = _this.inDays(response.data.max_lifetime);
+          _this.clusterID = response.data.cluster_id;
+        })
+        .catch(function(e) {
+          if (e.request) {
+            _this.error = "could not connect to API";
+            return;
+          }
+          _this.error = e;
+        });
+    },
     detectKubeCfg: function() {
       var _this = this;
       this.axios

handlers/client/client.go

@@ -0,0 +1,62 @@
+/*
+Copyright 2018 Planet Labs Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+implied. See the License for the specific language governing permissions
+and limitations under the License.
+*/
+
+package client
+
+import (
+	"encoding/json"
+	"net/http"
+	"time"
+
+	"k8s.io/client-go/tools/clientcmd/api"
+)
+
+
+const (
+	defaultClusterId = "radcluster"
+)
+
+type rsp struct {
+	ClusterID   string `json:"cluster_id,omitempty"`
+	MaxLifetime float64 `json:"max_lifetime,omitempty"`
+}
+
+// Handler returns an HTTP handler function that provides the client config.
+func Handler(lifetime time.Duration, template *api.Config) http.HandlerFunc {
+	data := rsp {
+		ClusterID: defaultClusterId,
+		MaxLifetime: lifetime.Hours(),
+	}
+
+	if template != nil {
+		for name, _ := range template.Clusters {
+			data.ClusterID = name
+			break
+		}
+	}
+
+	return func(w http.ResponseWriter, r *http.Request) {
+		defer r.Body.Close()
+
+		write(w, data, http.StatusOK)
+	}
+}
+
+func write(w http.ResponseWriter, data interface{}, httpStatus int) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	w.WriteHeader(httpStatus)
+	json.NewEncoder(w).Encode(data) // nolint: gosec
+}

handlers/client/client_test.go

@@ -0,0 +1,88 @@
+/*
+Copyright 2018 Planet Labs Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+implied. See the License for the specific language governing permissions
+and limitations under the License.
+*/
+
+package client
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/go-test/deep"
+	"k8s.io/client-go/tools/clientcmd/api"
+)
+
+
+const (
+	testCluster = "test"
+)
+
+var (
+	testDuration, _ = time.ParseDuration("10h")
+	testTemplate = &api.Config {
+		Clusters: map[string]*api.Cluster {
+			testCluster: &api.Cluster {
+			},
+		},
+	}
+)
+
+func TestHandler(t *testing.T) {
+	cases := map[string]struct {
+		lifetime time.Duration
+		template *api.Config
+		rsp  		 *rsp
+	}{
+		"Default Cluster": {
+			lifetime: testDuration,
+			rsp:      &rsp{
+				MaxLifetime: testDuration.Hours(),
+				ClusterID:   defaultClusterId,
+			},
+		},
+		"Template Cluster": {
+			lifetime: testDuration,
+			template: testTemplate,
+			rsp:      &rsp{
+				MaxLifetime: testDuration.Hours(),
+				ClusterID:   testCluster,
+			},
+		},
+	}
+	for testName, tt := range cases {
+		t.Run(testName, func(t *testing.T) {
+			w := httptest.NewRecorder()
+			r := httptest.NewRequest("GET", "/", nil)
+			Handler(tt.lifetime, tt.template)(w, r)
+
+			expectedStatus := http.StatusOK
+			if w.Code != expectedStatus {
+				t.Errorf("w.Code: want %v, got %v", expectedStatus, w.Code)
+			}
+
+			rsp := &rsp{}
+			if err := json.Unmarshal(w.Body.Bytes(), rsp); err != nil {
+				t.Fatalf("json.Unmarshal(%v, %s): %v", w.Body, rsp, err)
+			}
+
+			if diff := deep.Equal(tt.rsp, rsp); diff != nil {
+				t.Errorf("want != got: %v", diff)
+			}
+		})
+	}
+}