package system import ( "bytes" "fmt" "net" "net/url" "os" "os/user" "regexp" "github.com/containers/common/pkg/config" "github.com/containers/libpod/cmd/podman/registry" "github.com/containers/libpod/libpod/define" "github.com/containers/libpod/pkg/domain/entities" "github.com/containers/libpod/pkg/terminal" "github.com/pkg/errors" "github.com/sirupsen/logrus" "github.com/spf13/cobra" "golang.org/x/crypto/ssh" "golang.org/x/crypto/ssh/agent" ) const schemaPattern = "^[A-Za-z][A-Za-z0-9+.-]*:" var ( // Skip creating engines since this command will obtain connection information to engine noOp = func(cmd *cobra.Command, args []string) error { return nil } connectionCmd = &cobra.Command{ Use: "connection [flags] DESTINATION", Args: cobra.ExactArgs(1), Long: `Store ssh destination information in podman configuration. "destination" is of the form [user@]hostname or an URI of the form ssh://[user@]hostname[:port] `, Short: "Record remote ssh destination", PersistentPreRunE: noOp, PersistentPostRunE: noOp, TraverseChildren: false, RunE: connection, Example: `podman system connection server.fubar.com podman system connection --identity ~/.ssh/dev_rsa ssh://root@server.fubar.com:2222 podman system connection --identity ~/.ssh/dev_rsa --port 22 root@server.fubar.com`, } cOpts = struct { Identity string Port int UDSPath string }{} ) func init() { registry.Commands = append(registry.Commands, registry.CliCommand{ Mode: []entities.EngineMode{entities.ABIMode, entities.TunnelMode}, Command: connectionCmd, Parent: systemCmd, }) flags := connectionCmd.Flags() flags.IntVarP(&cOpts.Port, "port", "p", 22, "port number for destination") flags.StringVar(&cOpts.UDSPath, "socket-path", "", "path to podman socket on remote host. (default '/run/podman/podman.sock' or '/run/user/{uid}/podman/podman.sock)") } func connection(cmd *cobra.Command, args []string) error { // Default to ssh: schema if none given dest := []byte(args[0]) if match, err := regexp.Match(schemaPattern, dest); err != nil { return errors.Wrapf(err, "internal regex error %q", schemaPattern) } else if !match { dest = append([]byte("ssh://"), dest...) } uri, err := url.Parse(string(dest)) if err != nil { return errors.Wrapf(err, "failed to parse %q", string(dest)) } if uri.User.Username() == "" { if uri.User, err = getUserInfo(uri); err != nil { return err } } if cmd.Flag("socket-path").Changed { uri.Path = cmd.Flag("socket-path").Value.String() } if cmd.Flag("port").Changed { uri.Host = net.JoinHostPort(uri.Hostname(), cmd.Flag("port").Value.String()) } if uri.Port() == "" { uri.Host = net.JoinHostPort(uri.Hostname(), cmd.Flag("port").DefValue) } if uri.Path == "" { if uri.Path, err = getUDS(cmd, uri); err != nil { return errors.Wrapf(err, "failed to connect to %q", uri.String()) } } custom, err := config.ReadCustomConfig() if err != nil { return err } if cmd.Flag("identity").Changed { custom.Engine.RemoteIdentity = cOpts.Identity } custom.Engine.RemoteURI = uri.String() return custom.Write() } func getUserInfo(uri *url.URL) (*url.Userinfo, error) { var ( usr *user.User err error ) if u, found := os.LookupEnv("_CONTAINERS_ROOTLESS_UID"); found { usr, err = user.LookupId(u) if err != nil { return nil, errors.Wrapf(err, "failed to find user %q", u) } } else { usr, err = user.Current() if err != nil { return nil, errors.Wrapf(err, "failed to obtain current user") } } pw, set := uri.User.Password() if set { return url.UserPassword(usr.Username, pw), nil } return url.User(usr.Username), nil } func getUDS(cmd *cobra.Command, uri *url.URL) (string, error) { var authMethods []ssh.AuthMethod passwd, set := uri.User.Password() if set { authMethods = append(authMethods, ssh.Password(passwd)) } ident := cmd.Flag("identity") if ident.Changed { auth, err := terminal.PublicKey(ident.Value.String(), []byte(passwd)) if err != nil { return "", errors.Wrapf(err, "Failed to read identity %q", ident.Value.String()) } authMethods = append(authMethods, auth) } if sock, found := os.LookupEnv("SSH_AUTH_SOCK"); found { logrus.Debugf("Found SSH_AUTH_SOCK %q, ssh-agent signer enabled", sock) c, err := net.Dial("unix", sock) if err != nil { return "", err } a := agent.NewClient(c) authMethods = append(authMethods, ssh.PublicKeysCallback(a.Signers)) } config := &ssh.ClientConfig{ User: uri.User.Username(), Auth: authMethods, HostKeyCallback: ssh.InsecureIgnoreHostKey(), } dial, err := ssh.Dial("tcp", uri.Host, config) if err != nil { return "", errors.Wrapf(err, "failed to connect to %q", uri.Host) } defer dial.Close() session, err := dial.NewSession() if err != nil { return "", errors.Wrapf(err, "failed to create new ssh session on %q", uri.Host) } defer session.Close() // Override podman binary for testing etc podman := "podman" if v, found := os.LookupEnv("PODMAN_BINARY"); found { podman = v } run := podman + " info --format=json" var buffer bytes.Buffer session.Stdout = &buffer if err := session.Run(run); err != nil { return "", errors.Wrapf(err, "failed to run %q", run) } var info define.Info if err := json.Unmarshal(buffer.Bytes(), &info); err != nil { return "", errors.Wrapf(err, "failed to parse 'podman info' results") } if info.Host.RemoteSocket == nil || len(info.Host.RemoteSocket.Path) == 0 { return "", fmt.Errorf("remote podman %q failed to report its UDS socket", uri.Host) } return info.Host.RemoteSocket.Path, nil }