embed (hidden) tailsql for debugging (#1663)

Signed-off-by: Kristoffer Dalby <kristoffer@dalby.cc>

hscontrol/tailsql.go

@@ -0,0 +1,99 @@
+package hscontrol
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"os"
+
+	"github.com/tailscale/tailsql/server/tailsql"
+	"tailscale.com/tsnet"
+	"tailscale.com/tsweb"
+	"tailscale.com/types/logger"
+)
+
+func runTailSQLService(ctx context.Context, logf logger.Logf, stateDir, dbPath string) error {
+	opts := tailsql.Options{
+		Hostname: "tailsql-headscale",
+		StateDir: stateDir,
+		Sources: []tailsql.DBSpec{
+			{
+				Source: "headscale",
+				Label:  "headscale - sqlite",
+				Driver: "sqlite",
+				URL:    fmt.Sprintf("file:%s?mode=ro", dbPath),
+				Named: map[string]string{
+					"schema": `select * from sqlite_schema`,
+				},
+			},
+		},
+	}
+
+	tsNode := &tsnet.Server{
+		Dir:      os.ExpandEnv(opts.StateDir),
+		Hostname: opts.Hostname,
+		Logf:     logger.Discard,
+	}
+	// if *doDebugLog {
+	// 	tsNode.Logf = logf
+	// }
+	defer tsNode.Close()
+
+	logf("Starting tailscale (hostname=%q)", opts.Hostname)
+	lc, err := tsNode.LocalClient()
+	if err != nil {
+		return fmt.Errorf("connect local client: %w", err)
+	}
+	opts.LocalClient = lc // for authentication
+
+	// Make sure the Tailscale node starts up. It might not, if it is a new node
+	// and the user did not provide an auth key.
+	if st, err := tsNode.Up(ctx); err != nil {
+		return fmt.Errorf("starting tailscale: %w", err)
+	} else {
+		logf("tailscale started, node state %q", st.BackendState)
+	}
+
+	// Reaching here, we have a running Tailscale node, now we can set up the
+	// HTTP and/or HTTPS plumbing for TailSQL itself.
+	tsql, err := tailsql.NewServer(opts)
+	if err != nil {
+		return fmt.Errorf("creating tailsql server: %w", err)
+	}
+
+	lst, err := tsNode.Listen("tcp", ":80")
+	if err != nil {
+		return fmt.Errorf("listen port 80: %w", err)
+	}
+
+	if opts.ServeHTTPS {
+		// When serving TLS, add a redirect from HTTP on port 80 to HTTPS on 443.
+		certDomains := tsNode.CertDomains()
+		if len(certDomains) == 0 {
+			fmt.Errorf("no cert domains available for HTTPS")
+		}
+		base := "https://" + certDomains[0]
+		go http.Serve(lst, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			target := base + r.RequestURI
+			http.Redirect(w, r, target, http.StatusPermanentRedirect)
+		}))
+		// log.Printf("Redirecting HTTP to HTTPS at %q", base)
+
+		// For the real service, start a separate listener.
+		// Note: Replaces the port 80 listener.
+		var err error
+		lst, err = tsNode.ListenTLS("tcp", ":443")
+		if err != nil {
+			return fmt.Errorf("listen TLS: %w", err)
+		}
+		logf("enabled serving via HTTPS")
+	}
+
+	mux := tsql.NewMux()
+	tsweb.Debugger(mux)
+	go http.Serve(lst, mux)
+	logf("ailSQL started")
+	<-ctx.Done()
+	logf("TailSQL shutting down...")
+	return tsNode.Close()
+}