test app with postgres and redis healthchecks

2026-04-09 14:05:23 +03:00
commit db74b13ce2
6 changed files with 213 additions and 0 deletions
--- a/main.go
+++ b/main.go
@@ -0,0 +1,139 @@
+package main
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"time"
+
+	_ "github.com/lib/pq"
+	"github.com/redis/go-redis/v9"
+)
+
+type result struct {
+	Name    string
+	OK      bool
+	Message string
+}
+
+func env(key, fallback string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return fallback
+}
+
+func testPostgres() result {
+	dsn := fmt.Sprintf("host=%s port=%s user=%s password=%s dbname=%s sslmode=disable",
+		env("POSTGRES_HOST", "localhost"),
+		env("POSTGRES_PORT", "5432"),
+		env("POSTGRES_USER", "app"),
+		env("POSTGRES_PASSWORD", ""),
+		env("POSTGRES_DB", "app"),
+	)
+	db, err := sql.Open("postgres", dsn)
+	if err != nil {
+		return result{"PostgreSQL", false, fmt.Sprintf("open: %v", err)}
+	}
+	defer db.Close()
+	db.SetConnMaxLifetime(5 * time.Second)
+
+	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS healthcheck (id SERIAL PRIMARY KEY, checked_at TIMESTAMPTZ DEFAULT NOW(), msg TEXT)`)
+	if err != nil {
+		return result{"PostgreSQL", false, fmt.Sprintf("create table: %v", err)}
+	}
+
+	_, err = db.Exec(`INSERT INTO healthcheck (msg) VALUES ($1)`, fmt.Sprintf("ping at %s", time.Now().Format(time.RFC3339)))
+	if err != nil {
+		return result{"PostgreSQL", false, fmt.Sprintf("insert: %v", err)}
+	}
+
+	var count int
+	err = db.QueryRow(`SELECT COUNT(*) FROM healthcheck`).Scan(&count)
+	if err != nil {
+		return result{"PostgreSQL", false, fmt.Sprintf("count: %v", err)}
+	}
+
+	return result{"PostgreSQL", true, fmt.Sprintf("OK — %d rows in healthcheck", count)}
+}
+
+func testRedis() result {
+	addr := fmt.Sprintf("%s:%s",
+		env("REDIS_HOST", "localhost"),
+		env("REDIS_PORT", "6379"),
+	)
+	rdb := redis.NewClient(&redis.Options{Addr: addr})
+	defer rdb.Close()
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	err := rdb.Set(ctx, "test-key", "hello from test-app", 0).Err()
+	if err != nil {
+		return result{"Redis", false, fmt.Sprintf("SET: %v", err)}
+	}
+
+	val, err := rdb.Get(ctx, "test-key").Result()
+	if err != nil {
+		return result{"Redis", false, fmt.Sprintf("GET: %v", err)}
+	}
+
+	return result{"Redis", true, fmt.Sprintf("OK — GET test-key = %q", val)}
+}
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path == "/healthz" {
+		w.WriteHeader(200)
+		fmt.Fprint(w, "ok")
+		return
+	}
+
+	pg := testPostgres()
+	rd := testRedis()
+
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	fmt.Fprintf(w, `<!DOCTYPE html>
+<html>
+<head>
+  <title>StackOps Test App</title>
+  <style>
+    body { font-family: 'JetBrains Mono', monospace; background: #0a0a0a; color: #e5e5e5; padding: 40px; }
+    h1 { color: #4ade80; }
+    .test { margin: 16px 0; padding: 16px; border-radius: 8px; border: 1px solid #333; }
+    .ok { border-color: #166534; background: #052e16; }
+    .fail { border-color: #7f1d1d; background: #1c0a0a; }
+    .label { font-size: 14px; color: #9ca3af; }
+    .status { font-size: 18px; margin-top: 4px; }
+    .ok .status { color: #4ade80; }
+    .fail .status { color: #f87171; }
+    .time { color: #6b7280; font-size: 12px; margin-top: 24px; }
+  </style>
+</head>
+<body>
+  <h1>StackOps Test App</h1>
+  <p style="color:#9ca3af">Dependency connectivity checks</p>
+`)
+	for _, t := range []result{pg, rd} {
+		cls := "ok"
+		if !t.OK {
+			cls = "fail"
+		}
+		fmt.Fprintf(w, `  <div class="test %s">
+    <div class="label">%s</div>
+    <div class="status">%s</div>
+  </div>
+`, cls, t.Name, t.Message)
+	}
+	fmt.Fprintf(w, `  <div class="time">Checked at %s</div>
+</body>
+</html>`, time.Now().Format(time.RFC3339))
+}
+
+func main() {
+	http.HandleFunc("/", handler)
+	port := env("PORT", "8080")
+	log.Printf("test-app listening on :%s", port)
+	log.Fatal(http.ListenAndServe(":"+port, nil))
+}