phase 0 complete

internal/httpserver/health.go

@@ -0,0 +1,75 @@
+package httpserver
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"time"
+
+	"solopm.com/solopm-server/internal/config"
+)
+
+// DBPinger is the subset of *pgxpool.Pool used for health checks.
+type DBPinger interface {
+	Ping(ctx context.Context) error
+}
+
+type healthResponse struct {
+	Status      string `json:"status"`
+	Version     string `json:"version"`
+	Database    string `json:"database"`
+	Meilisearch string `json:"meilisearch"`
+	SMTP        string `json:"smtp"`
+}
+
+func healthzHandler(cfg *config.Config, db DBPinger, version string) http.HandlerFunc {
+	httpClient := &http.Client{Timeout: 2 * time.Second}
+
+	return func(w http.ResponseWriter, r *http.Request) {
+		ctx, cancel := context.WithTimeout(r.Context(), 2*time.Second)
+		defer cancel()
+
+		resp := healthResponse{
+			Status:      "ok",
+			Version:     version,
+			Meilisearch: "absent",
+			SMTP:        "absent",
+		}
+
+		if err := db.Ping(ctx); err != nil {
+			resp.Status = "error"
+			resp.Database = "unreachable"
+		} else {
+			resp.Database = "ok"
+		}
+
+		if cfg.SearchEnabled() {
+			req, err := http.NewRequestWithContext(ctx, http.MethodGet, cfg.MeiliURL+"/health", nil)
+			if err == nil {
+				if hr, err := httpClient.Do(req); err == nil {
+					_ = hr.Body.Close()
+					if hr.StatusCode == http.StatusOK {
+						resp.Meilisearch = "ok"
+					} else {
+						resp.Meilisearch = "unreachable"
+					}
+				} else {
+					resp.Meilisearch = "unreachable"
+				}
+			}
+		}
+
+		if cfg.EmailEnabled() {
+			resp.SMTP = "ok"
+		}
+
+		status := http.StatusOK
+		if resp.Status != "ok" {
+			status = http.StatusServiceUnavailable
+		}
+
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(status)
+		_ = json.NewEncoder(w).Encode(resp)
+	}
+}