feat: adding embedded db-studio

Signed-off-by: allanice001 <allanice001@gmail.com>

internal/web/pgweb_proxy.go

@@ -0,0 +1,106 @@
+package web
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"os"
+	"os/exec"
+	"time"
+)
+
+type Pgweb struct {
+	cmd  *exec.Cmd
+	host string
+	port string
+	bin  string
+}
+
+func StartPgweb(dbURL, host, port string, readonly bool, user, pass string) (*Pgweb, error) {
+	// pick random port if 0/empty
+	if port == "" || port == "0" {
+		l, err := net.Listen("tcp", net.JoinHostPort(host, "0"))
+		if err != nil {
+			return nil, err
+		}
+		defer l.Close()
+		_, p, _ := net.SplitHostPort(l.Addr().String())
+		port = p
+	}
+
+	args := []string{
+		"--url", dbURL,
+		"--bind", host,
+		"--listen", port,
+		"--skip-open",
+	}
+	if readonly {
+		args = append(args, "--readonly")
+	}
+	if user != "" && pass != "" {
+		args = append(args, "--auth-user", user, "--auth-pass", pass)
+	}
+
+	pgwebBinary, err := ExtractPgweb()
+	if err != nil {
+		return nil, fmt.Errorf("pgweb extract: %w", err)
+	}
+
+	cmd := exec.Command(pgwebBinary, args...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	if err := cmd.Start(); err != nil {
+		return nil, err
+	}
+
+	// wait for port to be ready
+	deadline := time.Now().Add(4 * time.Second)
+	for time.Now().Before(deadline) {
+		c, err := net.DialTimeout("tcp", net.JoinHostPort(host, port), 200*time.Millisecond)
+		if err == nil {
+			_ = c.Close()
+			return &Pgweb{cmd: cmd, host: host, port: port}, nil
+		}
+		time.Sleep(120 * time.Millisecond)
+	}
+	// still return object so caller can Stop()
+	//return &Pgweb{cmd: cmd, host: host, port: port, bin: pgwebBinary}, nil
+	return nil, fmt.Errorf("pgweb did not become ready on %s:%s", host, port)
+}
+
+func (p *Pgweb) Proxy() http.HandlerFunc {
+	target, _ := url.Parse("http://" + net.JoinHostPort(p.host, p.port))
+	proxy := httputil.NewSingleHostReverseProxy(target)
+	proxy.FlushInterval = 100 * time.Millisecond
+	return func(w http.ResponseWriter, r *http.Request) {
+		r.Host = target.Host
+		// Let pgweb handle its paths; we mount it at a prefix.
+		proxy.ServeHTTP(w, r)
+	}
+}
+
+func (p *Pgweb) Stop(ctx context.Context) error {
+	if p == nil || p.cmd == nil || p.cmd.Process == nil {
+		return nil
+	}
+	_ = p.cmd.Process.Kill()
+	done := make(chan struct{})
+	go func() { _, _ = p.cmd.Process.Wait(); close(done) }()
+	select {
+	case <-done:
+		if p.bin != "" {
+			_ = CleanupPgweb(p.bin)
+		}
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+	return nil
+}
+
+func (p *Pgweb) Port() string {
+	return p.port
+}