Add support for placeholder in the Dashboards CRD

deploy/kustomize/crds/kobs.io_applications.yaml

@@ -50,6 +50,10 @@ spec:
                       type: string
                     namespace:
                       type: string
+                    placeholders:
+                      additionalProperties:
+                        type: string
+                      type: object
                     title:
                       type: string
                   required:

deploy/kustomize/crds/kobs.io_dashboards.yaml

@@ -43,6 +43,17 @@ spec:
                 type: string
               namespace:
                 type: string
+              placeholders:
+                items:
+                  properties:
+                    description:
+                      type: string
+                    name:
+                      type: string
+                  required:
+                  - name
+                  type: object
+                type: array
               rows:
                 items:
                   properties:

deploy/kustomize/crds/kobs.io_teams.yaml

@@ -48,6 +48,10 @@ spec:
                       type: string
                     namespace:
                       type: string
+                    placeholders:
+                      additionalProperties:
+                        type: string
+                      type: object
                     title:
                       type: string
                   required:

pkg/api/apis/dashboard/v1beta1/types.go

@@ -27,12 +27,18 @@ type DashboardList struct {
 }
 
 type DashboardSpec struct {
-	Cluster     string `json:"cluster,omitempty"`
-	Namespace   string `json:"namespace,omitempty"`
-	Name        string `json:"name,omitempty"`
-	Title       string `json:"title,omitempty"`
+	Cluster      string        `json:"cluster,omitempty"`
+	Namespace    string        `json:"namespace,omitempty"`
+	Name         string        `json:"name,omitempty"`
+	Title        string        `json:"title,omitempty"`
+	Description  string        `json:"description,omitempty"`
+	Placeholders []Placeholder `json:"placeholders,omitempty"`
+	Rows         []Row         `json:"rows"`
+}
+
+type Placeholder struct {
+	Name        string `json:"name"`
 	Description string `json:"description,omitempty"`
-	Rows        []Row  `json:"rows"`
 }
 
 type Row struct {
@@ -56,9 +62,10 @@ type Plugin struct {
 }
 
 type Reference struct {
-	Cluster     string `json:"cluster,omitempty"`
-	Namespace   string `json:"namespace,omitempty"`
-	Name        string `json:"name"`
-	Title       string `json:"title"`
-	Description string `json:"description,omitempty"`
+	Cluster      string            `json:"cluster,omitempty"`
+	Namespace    string            `json:"namespace,omitempty"`
+	Name         string            `json:"name"`
+	Title        string            `json:"title"`
+	Description  string            `json:"description,omitempty"`
+	Placeholders map[string]string `json:"placeholders,omitempty"`
 }

pkg/app/app.go

@@ -89,8 +89,12 @@ func New(isDevelopment bool) (*Server, error) {
 
 		staticHandler := http.StripPrefix("/", http.FileServer(http.Dir(assetsDir)))
 		router.HandleFunc("/*", func(w http.ResponseWriter, r *http.Request) {
+			// When kobs is run in development mode and the request path starts with "/api", we redirect these requests
+			// to the port, where the API is running ("15220"). We have to return 307 as status code, to preserve the
+			// used http method. This can be used to test the production build of the React app locally without the need
+			// of another proxy, which handles the redirect.
 			if isDevelopment && strings.HasPrefix(r.URL.Path, "/api") {
-				http.Redirect(w, r, "http://localhost:15220"+r.URL.Path+"?"+r.URL.RawQuery, http.StatusMovedPermanently)
+				http.Redirect(w, r, "http://localhost:15220"+r.URL.Path+"?"+r.URL.RawQuery, http.StatusTemporaryRedirect)
 				return
 			}
 

plugins/dashboards/dashboards.go

@@ -8,6 +8,7 @@ import (
 	"github.com/kobsio/kobs/pkg/api/clusters"
 	"github.com/kobsio/kobs/pkg/api/middleware/errresponse"
 	"github.com/kobsio/kobs/pkg/api/plugins/plugin"
+	"github.com/kobsio/kobs/plugins/dashboards/pkg/placeholders"
 
 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/render"
@@ -79,8 +80,8 @@ func (router *Router) getDashboards(w http.ResponseWriter, r *http.Request) {
 
 	// Loop through all the provided references and set the cluster and namespace from the defaults, when it is not
 	// provided. Then we are using the GetDashboard function for a cluster to get the dashboard by namespace and name.
-	// Finally we are adding the title from the reference as dashboard title and we are adding the dashboard to a list
-	// of dashboards.
+	// Finally we are replacing the placeholders in a dashboard with the provided values and we are adding the title
+	// from the reference as dashboard title and we are adding the dashboard to a list of dashboards.
 	for _, reference := range data.References {
 		if reference.Cluster == "" {
 			reference.Cluster = data.Defaults.Cluster
@@ -102,6 +103,14 @@ func (router *Router) getDashboards(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 
+		if reference.Placeholders != nil {
+			dashboard, err = placeholders.Replace(reference.Placeholders, *dashboard)
+			if err != nil {
+				render.Render(w, r, errresponse.Render(err, http.StatusBadRequest, "could not replace placeholders"))
+				return
+			}
+		}
+
 		dashboard.Title = reference.Title
 		dashboards = append(dashboards, dashboard)
 	}

plugins/dashboards/pkg/placeholders/helpers.go

@@ -0,0 +1,40 @@
+package placeholders
+
+import (
+	"bytes"
+	"encoding/json"
+	"html/template"
+
+	dashboard "github.com/kobsio/kobs/pkg/api/apis/dashboard/v1beta1"
+)
+
+// Replace replaces the placeholders in a dashboard, with the provided values from the placeholders map. The
+// placeholders must use the following format in the dashboard to be replaced: "{% .placeholder %}".
+// To replace the placeholders we have to convert the dashboard to it's json string representation, which is then passed
+// to the template together with the placeholders. The result is then unmarshaled back to the dashboard struct and
+// returned.
+func Replace(placeholders map[string]string, dash dashboard.DashboardSpec) (*dashboard.DashboardSpec, error) {
+	out, err := json.Marshal(dash)
+	if err != nil {
+		return nil, err
+	}
+
+	tpl, err := template.New("dashboard").Delims("{%", "%}").Parse(string(out))
+	if err != nil {
+		return nil, err
+	}
+
+	var buf bytes.Buffer
+	err = tpl.Execute(&buf, placeholders)
+	if err != nil {
+		return nil, err
+	}
+
+	var dashPlaceholders dashboard.DashboardSpec
+	err = json.Unmarshal([]byte(buf.String()), &dashPlaceholders)
+	if err != nil {
+		return nil, err
+	}
+
+	return &dashPlaceholders, nil
+}

plugins/dashboards/src/utils/interfaces.ts

@@ -4,9 +4,15 @@ export interface IDashboard {
   name: string;
   title: string;
   description?: string;
+  placeholders?: IPlaceholder[];
   rows: IRow[];
 }
 
+export interface IPlaceholder {
+  name: string;
+  description?: string;
+}
+
 export interface IRow {
   title?: string;
   description?: string;
@@ -34,4 +40,9 @@ export interface IReference {
   name: string;
   title: string;
   description?: string;
+  placeholders?: IPlaceholders;
+}
+
+export interface IPlaceholders {
+  [key: string]: string;
 }