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, `
StackOps Test App
StackOps Test App
Dependency connectivity checks
`)
for _, t := range []result{pg, rd} {
cls := "ok"
if !t.OK {
cls = "fail"
}
fmt.Fprintf(w, `
`, cls, t.Name, t.Message)
}
fmt.Fprintf(w, ` Checked at %s
`, 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))
}