Merge pull request #522 from nkryuchkov/feature/exec-on-visor

Implement arbitrary command execution on visor from hypervisor

cmd/skywire-cli/commands/node/app.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"strconv"
+	"strings"
 	"text/tabwriter"
 
 	"github.com/spf13/cobra"
@@ -18,6 +19,7 @@ func init() {
 		startAppCmd,
 		stopAppCmd,
 		setAppAutostartCmd,
+		execCmd,
 	)
 }
 
@@ -82,3 +84,14 @@ var setAppAutostartCmd = &cobra.Command{
 		fmt.Println("OK")
 	},
 }
+
+var execCmd = &cobra.Command{
+	Use:   "exec <command>",
+	Short: "Executes the given command",
+	Args:  cobra.MinimumNArgs(1),
+	Run: func(_ *cobra.Command, args []string) {
+		out, err := rpcClient().Exec(strings.Join(args, " "))
+		internal.Catch(err)
+		fmt.Println(string(out))
+	},
+}

pkg/hypervisor/hypervisor.go

@@ -129,6 +129,7 @@ func (m *Node) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 			}
 			r.Get("/user", m.users.UserInfo())
 			r.Post("/change-password", m.users.ChangePassword())
+			r.Post("/exec", m.exec())
 			r.Get("/nodes", m.getNodes())
 			r.Get("/nodes/{pk}", m.getNode())
 			r.Get("/nodes/{pk}/apps", m.getApps())
@@ -150,6 +151,30 @@ func (m *Node) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	r.ServeHTTP(w, req)
 }
 
+// executes a command and returns its output
+func (m *Node) exec() http.HandlerFunc {
+	return m.withCtx(m.nodeCtx, func(w http.ResponseWriter, r *http.Request, ctx *httpCtx) {
+		var reqBody struct {
+			Command string `json:"command"`
+		}
+		if err := httputil.ReadJSON(r, &reqBody); err != nil {
+			httputil.WriteJSON(w, r, http.StatusBadRequest, err)
+			return
+		}
+
+		out, err := ctx.RPC.Exec(reqBody.Command)
+		if err != nil {
+			httputil.WriteJSON(w, r, http.StatusInternalServerError, err)
+			return
+		}
+
+		output := struct {
+			Output string `json:"output"`
+		}{string(out)}
+		httputil.WriteJSON(w, r, http.StatusOK, output)
+	})
+}
+
 type summaryResp struct {
 	TCPAddr string `json:"tcp_addr"`
 	*visor.Summary

pkg/visor/rpc.go

@@ -92,6 +92,13 @@ func (r *RPC) Summary(_ *struct{}, out *Summary) error {
 	return nil
 }
 
+// Exec executes a given command in cmd and writes its output to out.
+func (r *RPC) Exec(cmd *string, out *[]byte) error {
+	var err error
+	*out, err = r.node.Exec(*cmd)
+	return err
+}
+
 /*
 	<<< APP MANAGEMENT >>>
 */

pkg/visor/rpc_client.go

@@ -19,6 +19,7 @@ import (
 // RPCClient represents a RPC Client implementation.
 type RPCClient interface {
 	Summary() (*Summary, error)
+	Exec(command string) ([]byte, error)
 
 	Apps() ([]*AppState, error)
 	StartApp(appName string) error
@@ -64,6 +65,13 @@ func (rc *rpcClient) Summary() (*Summary, error) {
 	return out, err
 }
 
+// Exec calls Exec.
+func (rc *rpcClient) Exec(command string) ([]byte, error) {
+	output := make([]byte, 0)
+	err := rc.Call("Exec", &command, &output)
+	return output, err
+}
+
 // Apps calls Apps.
 func (rc *rpcClient) Apps() ([]*AppState, error) {
 	states := make([]*AppState, 0)
@@ -277,6 +285,11 @@ func (mc *mockRPCClient) Summary() (*Summary, error) {
 	return &out, err
 }
 
+// Exec implements RPCClient.
+func (mc *mockRPCClient) Exec(command string) ([]byte, error) {
+	return []byte("mock"), nil
+}
+
 // Apps implements RPCClient.
 func (mc *mockRPCClient) Apps() ([]*AppState, error) {
 	var apps []*AppState

pkg/visor/rpc_test.go

@@ -180,6 +180,22 @@ func TestRPC(t *testing.T) {
 		// })
 	})
 
+	t.Run("Exec", func(t *testing.T) {
+		command := "echo 1"
+
+		t.Run("RPCServer", func(t *testing.T) {
+			var out []byte
+			require.NoError(t, gateway.Exec(&command, &out))
+			assert.Equal(t, []byte("1\n"), out)
+		})
+
+		// t.Run("RPCClient", func(t *testing.T) {
+		// 	out, err := client.Exec(command)
+		// 	require.NoError(t, err)
+		// 	assert.Equal(t, []byte("1\n"), out)
+		// })
+	})
+
 	t.Run("Apps", func(t *testing.T) {
 		test := func(t *testing.T, apps []*AppState) {
 			assert.Len(t, apps, 2)

pkg/visor/visor.go

@@ -355,6 +355,13 @@ func (node *Node) Close() (err error) {
 	return err
 }
 
+// Exec executes a shell command. It returns combined stdout and stderr output and an error.
+func (node *Node) Exec(command string) ([]byte, error) {
+	args := strings.Split(command, " ")
+	cmd := exec.Command(args[0], args[1:]...) // nolint: gosec
+	return cmd.CombinedOutput()
+}
+
 // Apps returns list of AppStates for all registered apps.
 func (node *Node) Apps() []*AppState {
 	res := make([]*AppState, 0)