#19 Health check (#24)

* Add health check endpoint (#19)

* Add healthy response (#19)

config/dev.yml

@@ -97,6 +97,8 @@ database:
   # Enable this if you need the user id in triggers, etc
   set_user_id: false
 
+  ping_timeout: 1m
+
   # Define additional variables here to be used with filters
   variables:
     admin_account_id: "5"

config/prod.yml

@@ -54,4 +54,6 @@ database:
 
   # Set session variable "user.id" to the user id
   # Enable this if you need the user id in triggers, etc
-  set_user_id: false
+  set_user_id: false
+
+  ping_timeout: 5m

serv/config.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"regexp"
 	"strings"
+	"time"
 	"unicode"
 
 	"github.com/gobuffalo/flect"
@@ -57,16 +58,17 @@ type config struct {
 	}
 
 	DB struct {
-		Type       string
-		Host       string
-		Port       uint16
-		DBName     string
-		User       string
-		Password   string
-		Schema     string
-		PoolSize   int32 `mapstructure:"pool_size"`
-		MaxRetries int   `mapstructure:"max_retries"`
-		SetUserID  bool  `mapstructure:"set_user_id"`
+		Type        string
+		Host        string
+		Port        uint16
+		DBName      string
+		User        string
+		Password    string
+		Schema      string
+		PoolSize    int32         `mapstructure:"pool_size"`
+		MaxRetries  int           `mapstructure:"max_retries"`
+		SetUserID   bool          `mapstructure:"set_user_id"`
+		PingTimeout time.Duration `mapstructure:"ping_timeout"`
 
 		Vars      map[string]string `mapstructure:"variables"`
 		Blocklist []string

serv/health.go

@@ -0,0 +1,30 @@
+package serv
+
+import (
+	"context"
+	"net/http"
+)
+
+var healthyResponse = []byte("All's Well")
+
+func health(w http.ResponseWriter, _ *http.Request) {
+	conn, err := db.Acquire(context.Background())
+	if err != nil {
+		errlog.Error().Err(err).Msg("error acquiring connection from pool")
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	ctx, _ := context.WithTimeout(context.Background(), conf.DB.PingTimeout)
+	if err := conn.Conn().Ping(ctx); err != nil {
+		errlog.Error().Err(err).Msg("error pinging database")
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	if _, err := w.Write(healthyResponse); err != nil {
+		errlog.Error().Err(err).Msg("error writing healthy response")
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+}

serv/serv.go

@@ -123,6 +123,8 @@ func startHTTP() {
 func routeHandler() http.Handler {
 	mux := http.NewServeMux()
 
+	mux.Handle("/health", http.HandlerFunc(health))
+
 	mux.Handle("/api/v1/graphql", withAuth(apiv1Http))
 
 	if conf.WebUI {