package crunchrun
import (
+ "context"
"crypto/hmac"
"crypto/rand"
"crypto/rsa"
"io"
"net"
"net/http"
+ "net/url"
"os"
"os/exec"
+ "strings"
"sync"
"syscall"
+ "time"
+ "git.arvados.org/arvados.git/lib/controller/rpc"
"git.arvados.org/arvados.git/lib/selfsigned"
+ "git.arvados.org/arvados.git/lib/webdavfs"
+ "git.arvados.org/arvados.git/sdk/go/arvados"
+ "git.arvados.org/arvados.git/sdk/go/auth"
"git.arvados.org/arvados.git/sdk/go/ctxlog"
"git.arvados.org/arvados.git/sdk/go/httpserver"
"github.com/creack/pty"
"github.com/google/shlex"
+ "github.com/hashicorp/yamux"
"golang.org/x/crypto/ssh"
- "golang.org/x/net/context"
+ "golang.org/x/net/webdav"
)
type GatewayTarget interface {
type Gateway struct {
ContainerUUID string
- Address string // listen host:port; if port=0, Start() will change it to the selected port
- AuthSecret string
- Target GatewayTarget
- Log interface {
+ // Caller should set Address to "", or "host:0" or "host:port"
+ // where host is a known external IP address; port is a
+ // desired port number to listen on; and ":0" chooses an
+ // available dynamic port.
+ //
+ // If Address is "", Start() listens only on the loopback
+ // interface (and changes Address to "127.0.0.1:port").
+ // Otherwise it listens on all interfaces.
+ //
+ // If Address is "host:0", Start() updates Address to
+ // "host:port".
+ Address string
+ AuthSecret string
+ Target GatewayTarget
+ Log interface {
Printf(fmt string, args ...interface{})
}
+ // If non-nil, set up a ContainerGatewayTunnel, so that the
+ // controller can connect to us even if our external IP
+ // address is unknown or not routable from controller.
+ ArvadosClient *arvados.Client
+
+ // When a tunnel is connected or reconnected, this func (if
+ // not nil) will be called with the InternalURL of the
+ // controller process at the other end of the tunnel.
+ UpdateTunnelURL func(url string)
+
+ // Source for serving WebDAV requests with
+ // X-Webdav-Source: /log
+ LogCollection arvados.CollectionFileSystem
sshConfig ssh.ServerConfig
requestAuth string
// from arvados-controller, and PORT is either the desired
// port where we should run our gateway server, or "0" if we
// should choose an available port.
- host, port, err := net.SplitHostPort(gw.Address)
+ extAddr := gw.Address
+ // Generally we can't know which local interface corresponds
+ // to an externally reachable IP address, so if we expect to
+ // be reachable by external hosts, we listen on all
+ // interfaces.
+ listenHost := ""
+ if extAddr == "" {
+ // If the dispatcher doesn't tell us our external IP
+ // address, controller will only be able to connect
+ // through the tunnel (see runTunnel), so our gateway
+ // server only needs to listen on the loopback
+ // interface.
+ extAddr = "127.0.0.1:0"
+ listenHost = "127.0.0.1"
+ }
+ extHost, extPort, err := net.SplitHostPort(extAddr)
if err != nil {
return err
}
srv := &httpserver.Server{
Server: http.Server{
- Handler: http.HandlerFunc(gw.handleSSH),
+ Handler: gw,
TLSConfig: &tls.Config{
Certificates: []tls.Certificate{cert},
},
},
- Addr: ":" + port,
+ Addr: net.JoinHostPort(listenHost, extPort),
}
err = srv.Start()
if err != nil {
return err
}
- // Get the port number we are listening on (the port might be
+ go func() {
+ err := srv.Wait()
+ gw.Log.Printf("gateway server stopped: %s", err)
+ }()
+ // Get the port number we are listening on (extPort might be
// "0" or a port name, in which case this will be different).
- _, port, err = net.SplitHostPort(srv.Addr)
+ _, listenPort, err := net.SplitHostPort(srv.Addr)
if err != nil {
return err
}
- // When changing state to Running, we will set
- // gateway_address to "HOST:PORT" where HOST is our
- // external hostname/IP as provided by arvados-dispatch-cloud,
- // and PORT is the port number we ended up listening on.
- gw.Address = net.JoinHostPort(host, port)
+ // When changing state to Running, the caller will want to set
+ // gateway_address to a "HOST:PORT" that, if controller
+ // connects to it, will reach this gateway server.
+ //
+ // The most likely thing to work is: HOST is our external
+ // hostname/IP as provided by the caller
+ // (arvados-dispatch-cloud) or 127.0.0.1 to indicate
+ // non-tunnel connections aren't available; and PORT is the
+ // port number we are listening on.
+ gw.Address = net.JoinHostPort(extHost, listenPort)
+ gw.Log.Printf("gateway server listening at %s", gw.Address)
+ if gw.ArvadosClient != nil {
+ go gw.maintainTunnel(gw.Address)
+ }
return nil
}
+func (gw *Gateway) maintainTunnel(addr string) {
+ for ; ; time.Sleep(5 * time.Second) {
+ err := gw.runTunnel(addr)
+ gw.Log.Printf("runTunnel: %s", err)
+ }
+}
+
+// runTunnel connects to controller and sets up a tunnel through
+// which controller can connect to the gateway server at the given
+// addr.
+func (gw *Gateway) runTunnel(addr string) error {
+ ctx := auth.NewContext(context.Background(), auth.NewCredentials(gw.ArvadosClient.AuthToken))
+ arpc := rpc.NewConn("", &url.URL{Scheme: "https", Host: gw.ArvadosClient.APIHost}, gw.ArvadosClient.Insecure, rpc.PassthroughTokenProvider)
+ tun, err := arpc.ContainerGatewayTunnel(ctx, arvados.ContainerGatewayTunnelOptions{
+ UUID: gw.ContainerUUID,
+ AuthSecret: gw.AuthSecret,
+ })
+ if err != nil {
+ return fmt.Errorf("error creating gateway tunnel: %w", err)
+ }
+ mux, err := yamux.Client(tun.Conn, nil)
+ if err != nil {
+ return fmt.Errorf("error setting up mux client end: %s", err)
+ }
+ if url := tun.Header.Get("X-Arvados-Internal-Url"); url != "" && gw.UpdateTunnelURL != nil {
+ gw.UpdateTunnelURL(url)
+ }
+ for {
+ muxconn, err := mux.AcceptStream()
+ if err != nil {
+ return err
+ }
+ gw.Log.Printf("tunnel connection %d started", muxconn.StreamID())
+ go func() {
+ defer muxconn.Close()
+ gwconn, err := net.Dial("tcp", addr)
+ if err != nil {
+ gw.Log.Printf("tunnel connection %d: error connecting to %s: %s", muxconn.StreamID(), addr, err)
+ return
+ }
+ defer gwconn.Close()
+ var wg sync.WaitGroup
+ wg.Add(2)
+ go func() {
+ defer wg.Done()
+ _, err := io.Copy(gwconn, muxconn)
+ if err != nil {
+ gw.Log.Printf("tunnel connection %d: mux end: %s", muxconn.StreamID(), err)
+ }
+ gwconn.Close()
+ }()
+ go func() {
+ defer wg.Done()
+ _, err := io.Copy(muxconn, gwconn)
+ if err != nil {
+ gw.Log.Printf("tunnel connection %d: gateway end: %s", muxconn.StreamID(), err)
+ }
+ muxconn.Close()
+ }()
+ wg.Wait()
+ gw.Log.Printf("tunnel connection %d finished", muxconn.StreamID())
+ }()
+ }
+}
+
+var webdavMethod = map[string]bool{
+ "GET": true,
+ "OPTIONS": true,
+ "PROPFIND": true,
+}
+
+func (gw *Gateway) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+ w.Header().Set("Vary", "X-Arvados-Authorization, X-Arvados-Container-Gateway-Uuid, X-Webdav-Prefix, X-Webdav-Source")
+ reqUUID := req.Header.Get("X-Arvados-Container-Gateway-Uuid")
+ if reqUUID == "" {
+ // older controller versions only send UUID as query param
+ req.ParseForm()
+ reqUUID = req.Form.Get("uuid")
+ }
+ if reqUUID != gw.ContainerUUID {
+ http.Error(w, fmt.Sprintf("misdirected request: meant for %q but received by crunch-run %q", reqUUID, gw.ContainerUUID), http.StatusBadGateway)
+ return
+ }
+ if req.Header.Get("X-Arvados-Authorization") != gw.requestAuth {
+ http.Error(w, "bad X-Arvados-Authorization header", http.StatusUnauthorized)
+ return
+ }
+ w.Header().Set("X-Arvados-Authorization-Response", gw.respondAuth)
+ switch {
+ case req.Method == "POST" && req.Header.Get("Upgrade") == "ssh":
+ gw.handleSSH(w, req)
+ case req.Header.Get("X-Webdav-Source") == "/log":
+ if !webdavMethod[req.Method] {
+ http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+ return
+ }
+ gw.handleLogsWebDAV(w, req)
+ default:
+ http.Error(w, "path not found", http.StatusNotFound)
+ }
+}
+
+func (gw *Gateway) handleLogsWebDAV(w http.ResponseWriter, r *http.Request) {
+ prefix := r.Header.Get("X-Webdav-Prefix")
+ if !strings.HasPrefix(r.URL.Path, prefix) {
+ http.Error(w, "X-Webdav-Prefix header is not a prefix of the requested path", http.StatusBadRequest)
+ return
+ }
+ if gw.LogCollection == nil {
+ http.Error(w, "Not found", http.StatusNotFound)
+ return
+ }
+ wh := webdav.Handler{
+ Prefix: prefix,
+ FileSystem: &webdavfs.FS{
+ FileSystem: gw.LogCollection,
+ Prefix: "",
+ Writing: false,
+ AlwaysReadEOF: r.Method == "PROPFIND",
+ },
+ LockSystem: webdavfs.NoLockSystem,
+ Logger: gw.webdavLogger,
+ }
+ wh.ServeHTTP(w, r)
+}
+
+func (gw *Gateway) webdavLogger(r *http.Request, err error) {
+ if err != nil && !os.IsNotExist(err) {
+ ctxlog.FromContext(r.Context()).WithError(err).Info("error reported by webdav handler")
+ } else {
+ ctxlog.FromContext(r.Context()).WithError(err).Debug("webdav request log")
+ }
+}
+
// handleSSH connects to an SSH server that allows the caller to run
// interactive commands as root (or any other desired user) inside the
// container. The tunnel itself can only be created by an
// X-Arvados-Login-Username: argument to "docker exec --user": account
// used to run command(s) inside the container.
func (gw *Gateway) handleSSH(w http.ResponseWriter, req *http.Request) {
- // In future we'll handle browser traffic too, but for now the
- // only traffic we expect is an SSH tunnel from
- // (*lib/controller/localdb.Conn)ContainerSSH()
- if req.Method != "GET" || req.Header.Get("Upgrade") != "ssh" {
- http.Error(w, "path not found", http.StatusNotFound)
- return
- }
- if want := req.Header.Get("X-Arvados-Target-Uuid"); want != gw.ContainerUUID {
- http.Error(w, fmt.Sprintf("misdirected request: meant for %q but received by crunch-run %q", want, gw.ContainerUUID), http.StatusBadGateway)
- return
- }
- if req.Header.Get("X-Arvados-Authorization") != gw.requestAuth {
- http.Error(w, "bad X-Arvados-Authorization header", http.StatusUnauthorized)
- return
- }
- detachKeys := req.Header.Get("X-Arvados-Detach-Keys")
- username := req.Header.Get("X-Arvados-Login-Username")
+ req.ParseForm()
+ detachKeys := req.Form.Get("detach_keys")
+ username := req.Form.Get("login_username")
if username == "" {
username = "root"
}
defer netconn.Close()
w.Header().Set("Connection", "upgrade")
w.Header().Set("Upgrade", "ssh")
- w.Header().Set("X-Arvados-Authorization-Response", gw.respondAuth)
netconn.Write([]byte("HTTP/1.1 101 Switching Protocols\r\n"))
w.Header().Write(netconn)
netconn.Write([]byte("\r\n"))
ctx := req.Context()
conn, newchans, reqs, err := ssh.NewServerConn(netconn, &gw.sshConfig)
- if err != nil {
+ if err == io.EOF {
+ return
+ } else if err != nil {
gw.Log.Printf("ssh.NewServerConn: %s", err)
return
}
func (gw *Gateway) handleSession(ctx context.Context, newch ssh.NewChannel, detachKeys, username string) {
ch, reqs, err := newch.Accept()
if err != nil {
- gw.Log.Printf("accept session channel: %s", err)
+ gw.Log.Printf("error accepting session channel: %s", err)
return
}
+ defer ch.Close()
+
var pty0, tty0 *os.File
// Where to send errors/messages for the client to see
logw := io.Writer(ch.Stderr())
eol := "\n"
// Env vars to add to child process
termEnv := []string(nil)
- for req := range reqs {
+
+ started := 0
+ wantClose := make(chan struct{})
+ for {
+ var req *ssh.Request
+ select {
+ case r, ok := <-reqs:
+ if !ok {
+ return
+ }
+ req = r
+ case <-wantClose:
+ return
+ }
ok := false
switch req.Type {
case "shell", "exec":
+ if started++; started != 1 {
+ // RFC 4254 6.5: "Only one of these
+ // requests can succeed per channel."
+ break
+ }
ok = true
var payload struct {
Command string
}
defer func() {
ch.SendRequest("exit-status", false, ssh.Marshal(&resp))
- ch.Close()
+ close(wantClose)
}()
cmd, err := gw.Target.InjectCommand(ctx, detachKeys, username, tty0 != nil, execargs)
resp.Status = 1
return
}
- cmd.Stdin = ch
- cmd.Stdout = ch
- cmd.Stderr = ch.Stderr()
if tty0 != nil {
cmd.Stdin = tty0
cmd.Stdout = tty0
cmd.Stderr = tty0
- var wg sync.WaitGroup
- defer wg.Wait()
- wg.Add(2)
- go func() { io.Copy(ch, pty0); wg.Done() }()
- go func() { io.Copy(pty0, ch); wg.Done() }()
+ go io.Copy(ch, pty0)
+ go io.Copy(pty0, ch)
// Send our own debug messages to tty as well.
logw = tty0
+ } else {
+ // StdinPipe may seem
+ // superfluous here, but it's
+ // not: it causes cmd.Run() to
+ // return when the subprocess
+ // exits. Without it, Run()
+ // waits for stdin to close,
+ // which causes "ssh ... echo
+ // ok" (with the client's
+ // stdin connected to a
+ // terminal or something) to
+ // hang.
+ stdin, err := cmd.StdinPipe()
+ if err != nil {
+ fmt.Fprintln(ch.Stderr(), err)
+ ch.CloseWrite()
+ resp.Status = 1
+ return
+ }
+ go func() {
+ io.Copy(stdin, ch)
+ stdin.Close()
+ }()
+ cmd.Stdout = ch
+ cmd.Stderr = ch.Stderr()
}
cmd.SysProcAttr = &syscall.SysProcAttr{
Setctty: tty0 != nil,
// would be a gaping security
// hole).
default:
- // fmt.Fprintf(logw, "declining %q req"+eol, req.Type)
+ // fmt.Fprintf(logw, "declined request %q on ssh channel"+eol, req.Type)
}
if req.WantReply {
req.Reply(ok, nil)