feat: add badge endpoint for shields.io (#25)

* feat: add badge endpoint for shields.io

* docs: update readme

Author: steveiliop56

README.md

@@ -27,6 +27,7 @@ The server is configured using environment variables, the following options are
 | `CORS_ALLOWED_ORIGINS` | string/array | Comma-separated list of allowed CORS origins. | `*`                  |
 | `TRUSTED_PROXIES`      | string/array | Comma-separated list of trusted proxy IPs.    | ``                   |
 | `DASHBOARD_ENABLED`     | boolean      | Whether to enable the dashboard.              | `true`               |
+| `BADGE_ENABLED`         | boolean      | Whether to enable the badge endpoint.         | `true`               |
 
 ## Contributing
 

badge_handler.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+
+	_ "embed"
+
+	"github.com/go-chi/render"
+	"github.com/tinyauthapp/analytics/queries"
+)
+
+type BadgeHandler struct {
+	queries *queries.Queries
+}
+
+func NewBadgeHandler(queries *queries.Queries) *BadgeHandler {
+	return &BadgeHandler{
+		queries: queries,
+	}
+}
+
+type shieldsioData struct {
+	SchemaVersion int    `json:"schemaVersion"`
+	Label         string `json:"label"`
+	Message       string `json:"message"`
+	Color         string `json:"color,omitempty"`
+	LabelColor    string `json:"labelColor,omitempty"`
+	IsError       bool   `json:"isError,omitempty"`
+	NamedLogo     string `json:"namedLogo,omitempty"`
+	LogoSvg       string `json:"logoSvg,omitempty"`
+	LogoColor     string `json:"logoColor,omitempty"`
+	LogoSize      string `json:"logoSize,omitempty"`
+	Style         string `json:"style,omitempty"`
+}
+
+func (h *BadgeHandler) Badge(w http.ResponseWriter, r *http.Request) {
+	instanceCount, err := h.queries.GetInstanceCount(r.Context())
+
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	badgeData := shieldsioData{
+		SchemaVersion: 1,
+		Label:         "Active Instances",
+		Message:       fmt.Sprintf("%d", instanceCount),
+		Color:         "brightgreen",
+		LabelColor:    "grey",
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	render.JSON(w, r, badgeData)
+}

dashboard_handler.go

@@ -12,9 +12,6 @@ import (
 //go:embed dashboard.html
 var dashboardTemplate string
 
-//go:embed favicon.ico
-var faviconData []byte
-
 type DashboardHandler struct {
 	queries *queries.Queries
 }
@@ -88,15 +85,3 @@ func (h *DashboardHandler) Dashboard(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 }
-
-func (h *DashboardHandler) Favicon(w http.ResponseWriter, r *http.Request) {
-	w.Header().Set("Content-Type", "image/x-icon")
-	w.WriteHeader(http.StatusOK)
-	w.Write(faviconData)
-}
-
-func (h *DashboardHandler) Robots(w http.ResponseWriter, r *http.Request) {
-	w.Header().Set("Content-Type", "text/plain")
-	w.WriteHeader(http.StatusOK)
-	w.Write([]byte("User-agent: *\nDisallow: /"))
-}

main.go

@@ -16,8 +16,13 @@ import (
 	"github.com/go-chi/cors"
 	"github.com/spf13/viper"
 	_ "modernc.org/sqlite"
+
+	_ "embed"
 )
 
+//go:embed favicon.ico
+var faviconData []byte
+
 var version = "development"
 
 type Config struct {
@@ -28,6 +33,7 @@ type Config struct {
 	TrustedProxies     []string `mapstructure:"trusted_proxies"`
 	CORSAllowedOrigins []string `mapstructure:"cors_allowed_origins"`
 	DashboardEnabled   bool     `mapstructure:"dashboard_enabled"`
+	BadgeEnabled       bool     `mapstructure:"badge_enabled"`
 }
 
 func main() {
@@ -40,6 +46,7 @@ func main() {
 	v.SetDefault("trusted_proxies", []string{""})
 	v.SetDefault("cors_allowed_origins", []string{"*"})
 	v.SetDefault("dashboard_enabled", true)
+	v.SetDefault("badge_enabled", true)
 
 	v.AutomaticEnv()
 
@@ -84,7 +91,6 @@ func main() {
 
 	instancesHandler := NewInstancesHandler(queries)
 	healthHandler := NewHealthHandler()
-	dashboardHandler := NewDashboardHandler(queries)
 
 	router.Get("/v1/healthz", healthHandler.Health)
 
@@ -100,12 +106,27 @@ func main() {
 		r.Post("/v1/instances/heartbeat", instancesHandler.Heartbeat)
 	})
 
+	router.Get("/robots.txt", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/plain")
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte("User-agent: *\nDisallow: /"))
+	})
+
 	if config.DashboardEnabled {
+		dashboardHandler := NewDashboardHandler(queries)
 		router.Get("/dashboard", dashboardHandler.Dashboard)
+		router.Get("/favicon.ico", func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Content-Type", "image/x-icon")
+			w.WriteHeader(http.StatusOK)
+			w.Write(faviconData)
+		})
+
 	}
 
-	router.Get("/favicon.ico", dashboardHandler.Favicon)
-	router.Get("/robots.txt", dashboardHandler.Robots)
+	if config.BadgeEnabled {
+		badgeHandler := NewBadgeHandler(queries)
+		router.Get("/v1/badge", badgeHandler.Badge)
+	}
 
 	srv := &http.Server{
 		Addr:    fmt.Sprintf("%s:%d", config.Address, config.Port),

queries.sql

@@ -25,3 +25,6 @@ WHERE uuid = ?;
 DELETE FROM instances
 WHERE last_seen < ? OR version = '' OR uuid = ''
 RETURNING *;
+
+-- name: GetInstanceCount :one
+SELECT COUNT(*) AS count FROM instances;