mount: Move "just in time" sshfs logic to the daemon

src/client/cmd/common_cli.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2018 Canonical, Ltd.
+ * Copyright (C) 2018-2019 Canonical, Ltd.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -102,24 +102,3 @@ mp::ReturnCode cmd::standard_failure_handler_for(const std::string& command, std
 
     return return_code_for(status.error_code());
 }
-
-void cmd::install_sshfs_for(const std::string& instance_name, int verbosity_level, grpc::Channel* rpc_channel,
-                            mp::Rpc::Stub* stub, std::ostream& cout, std::ostream& cerr)
-{
-    std::vector<Command::UPtr> command;
-    command.push_back(std::make_unique<Exec>(*rpc_channel, *stub, cout, cerr));
-
-    auto args = QStringList() << "" // This is just a dummy string for the unnecessary binary name
-                              << "exec" << QString::fromStdString(instance_name) << "--"
-                              << "sudo"
-                              << "bash"
-                              << "-c"
-                              << "apt update && apt install -y sshfs";
-    ArgParser exec_parser{args, command, cout, cerr};
-    exec_parser.setVerbosityLevel(verbosity_level);
-    exec_parser.parse();
-
-    fmt::print(cerr, "The sshfs package is missing in \"{}\". Installing...\n", instance_name);
-    if (exec_parser.chosenCommand()->run(&exec_parser) == mp::ReturnCode::Ok)
-        fmt::print(cerr, "\n***Please re-run the mount command.\n");
-}

src/client/cmd/common_cli.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2018 Canonical, Ltd.
+ * Copyright (C) 2018-2019 Canonical, Ltd.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -41,8 +41,6 @@ ParseCode handle_format_option(ArgParser* parser, Formatter** chosen_formatter,
 std::string instance_action_message_for(const InstanceNames& instance_names, const std::string& action_name);
 ReturnCode standard_failure_handler_for(const std::string& command, std::ostream& cerr, const grpc::Status& status,
                                         const std::string& error_details = std::string());
-void install_sshfs_for(const std::string& instance_name, int verbosity_level, grpc::Channel* rpc_channel,
-                       Rpc::Stub* stub, std::ostream& cout, std::ostream& cerr);
 } // namespace cmd
 } // namespace multipass
 

src/client/cmd/mount.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017-2018 Canonical, Ltd.
+ * Copyright (C) 2017-2019 Canonical, Ltd.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -17,8 +17,8 @@
 
 #include "mount.h"
 #include "common_cli.h"
-#include "exec.h"
 
+#include "animated_spinner.h"
 #include <multipass/cli/argparser.h>
 #include <multipass/cli/client_platform.h>
 #include <multipass/logging/log.h>
@@ -59,29 +59,24 @@ mp::ReturnCode cmd::Mount::run(mp::ArgParser* parser)
         return parser->returnCodeFrom(ret);
     }
 
-    auto on_success = [](mp::MountReply& reply) {
+    mp::AnimatedSpinner spinner{cout};
+
+    auto on_success = [&spinner](mp::MountReply& reply) {
+        spinner.stop();
         return ReturnCode::Ok;
     };
 
-    auto on_failure = [this, &parser](grpc::Status& status) {
-        auto ret = standard_failure_handler_for(name(), cerr, status);
-        if (!status.error_details().empty())
-        {
-            mp::MountError mount_error;
-            mount_error.ParseFromString(status.error_details());
-
-            if (mount_error.error_code() == mp::MountError::SSHFS_MISSING)
-            {
-                cmd::install_sshfs_for(mount_error.instance_name(), parser->verbosityLevel(), rpc_channel, stub, cout,
-                                       cerr);
-            }
-        }
+    auto on_failure = [this, &spinner](grpc::Status& status) {
+        spinner.stop();
 
-        return ret;
+        return standard_failure_handler_for(name(), cerr, status);
     };
 
+    auto streaming_callback = [&spinner](mp::MountReply& reply) { spinner.start(reply.mount_message()); };
+
     request.set_verbosity_level(parser->verbosityLevel());
-    return dispatch(&RpcMethod::mount, request, on_success, on_failure);
+
+    return dispatch(&RpcMethod::mount, request, on_success, on_failure, streaming_callback);
 }
 
 std::string cmd::Mount::name() const { return "mount"; }

src/client/cmd/start.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017-2018 Canonical, Ltd.
+ * Copyright (C) 2017-2019 Canonical, Ltd.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -37,11 +37,13 @@ mp::ReturnCode cmd::Start::run(mp::ArgParser* parser)
         return parser->returnCodeFrom(ret);
     }
 
-    auto on_success = [](mp::StartReply& reply) {
+    AnimatedSpinner spinner{cout};
+
+    auto on_success = [&spinner](mp::StartReply& reply) {
+        spinner.stop();
         return ReturnCode::Ok;
     };
 
-    AnimatedSpinner spinner{cout};
     auto on_failure = [this, &spinner, &parser](grpc::Status& status) {
         spinner.stop();
         auto ret = standard_failure_handler_for(name(), cerr, status);
@@ -59,25 +61,19 @@ mp::ReturnCode cmd::Start::run(mp::ArgParser* parser)
                                "instance.\n");
                 }
             }
-            else
-            {
-                mp::MountError mount_error;
-                mount_error.ParseFromString(status.error_details());
-
-                if (mount_error.error_code() == mp::MountError::SSHFS_MISSING)
-                {
-                    cmd::install_sshfs_for(mount_error.instance_name(), parser->verbosityLevel(), rpc_channel, stub,
-                                           cout, cerr);
-                }
-            }
         }
 
         return ret;
     };
 
+    auto streaming_callback = [&spinner](mp::StartReply& reply) {
+        spinner.stop();
+        spinner.start(reply.start_message());
+    };
+
     spinner.start(instance_action_message_for(request.instance_names(), "Starting "));
     request.set_verbosity_level(parser->verbosityLevel());
-    return dispatch(&RpcMethod::start, request, on_success, on_failure);
+    return dispatch(&RpcMethod::start, request, on_success, on_failure, streaming_callback);
 }
 
 std::string cmd::Start::name() const { return "start"; }

src/daemon/daemon.cpp

@@ -299,11 +299,8 @@ auto validate_create_arguments(const mp::LaunchRequest* request)
 
 auto grpc_status_for_mount_error(const std::string& instance_name)
 {
-    mp::MountError mount_error;
-    mount_error.set_error_code(mp::MountError::SSHFS_MISSING);
-    mount_error.set_instance_name(instance_name);
-
-    return grpc::Status(grpc::StatusCode::FAILED_PRECONDITION, "Mount failed", mount_error.SerializeAsString());
+    return grpc::Status(grpc::StatusCode::FAILED_PRECONDITION,
+                        fmt::format("Error enabling mount support in '{}'", instance_name));
 }
 
 auto grpc_status_for(fmt::memory_buffer& errors)
@@ -1260,7 +1257,18 @@ try // clang-format on
             }
             catch (const mp::SSHFSMissingError&)
             {
-                return grpc_status_for_mount_error(name);
+                try
+                {
+                    MountReply mount_reply;
+                    mount_reply.set_mount_message("Enabling support for mounting");
+                    server->Write(mount_reply);
+                    install_sshfs(vm, name);
+                    start_mount(vm, name, request->source_path(), target_path, gid_map, uid_map);
+                }
+                catch (const mp::SSHFSMissingError&)
+                {
+                    return grpc_status_for_mount_error(name);
+                }
             }
             catch (const std::exception& e)
             {
@@ -1470,7 +1478,18 @@ try // clang-format on
             }
             catch (const mp::SSHFSMissingError&)
             {
-                return grpc_status_for_mount_error(name);
+                try
+                {
+                    StartReply start_reply;
+                    start_reply.set_start_message("Enabling support for mounting");
+                    server->Write(start_reply);
+                    install_sshfs(vm, name);
+                    start_mount(vm, name, source_path, target_path, gid_map, uid_map);
+                }
+                catch (const mp::SSHFSMissingError&)
+                {
+                    return grpc_status_for_mount_error(name);
+                }
             }
             catch (const std::exception& e)
             {
@@ -2034,3 +2053,38 @@ grpc::Status mp::Daemon::cmd_vms(const std::vector<std::string>& tgts, std::func
 
     return grpc::Status::OK;
 }
+
+void mp::Daemon::install_sshfs(const VirtualMachine::UPtr& vm, const std::string& name)
+{
+    auto& key_provider = *config->ssh_key_provider;
+
+    SSHSession session{vm->ssh_hostname(), vm->ssh_port(), vm->ssh_username(), key_provider};
+
+    mpl::log(mpl::Level::info, category, fmt::format("Installing sshfs in \'{}\'", name));
+
+    int retries{0};
+    while (++retries <= 3)
+    {
+        try
+        {
+            auto proc = session.exec("sudo apt update && sudo apt install -y sshfs");
+            if (proc.exit_code(std::chrono::minutes(5)) != 0)
+            {
+                auto error_msg = proc.read_std_error();
+                mpl::log(mpl::Level::warning, category,
+                         fmt::format("Failed to install 'sshfs', error message: '{}'", mp::utils::trim_end(error_msg)));
+            }
+            else
+            {
+                break;
+            }
+        }
+        catch (const mp::ExitlessSSHProcessException&)
+        {
+            mpl::log(mpl::Level::info, category, fmt::format("Timeout while installing 'sshfs' in '{}'", name));
+        }
+    }
+
+    if (retries > 3)
+        throw mp::SSHFSMissingError();
+}

src/daemon/daemon.h

@@ -139,6 +139,7 @@ public slots:
     grpc::Status shutdown_vm(VirtualMachine& vm, const std::chrono::milliseconds delay);
     grpc::Status cancel_vm_shutdown(const VirtualMachine& vm);
     grpc::Status cmd_vms(const std::vector<std::string>& tgts, std::function<grpc::Status(VirtualMachine&)> cmd);
+    void install_sshfs(const VirtualMachine::UPtr& vm, const std::string& name);
 
     std::unique_ptr<const DaemonConfig> config;
     std::unordered_map<std::string, VMSpecs> vm_instance_specs;

src/rpc/multipass.proto

@@ -1,4 +1,4 @@
-// Copyright © 2017-2018 Canonical Ltd.
+// Copyright © 2017-2019 Canonical Ltd.
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License version 3 as
@@ -217,16 +217,6 @@ message TargetPathInfo {
     string target_path = 2;
 }
 
-message MountError {
-    enum ErrorCode {
-        OK = 0;
-        SSHFS_MISSING = 1;
-        OTHER = 2;
-    }
-    string instance_name = 1;
-    ErrorCode error_code = 2;
-}
-
 message MountRequest {
     string source_path = 1;
     repeated TargetPathInfo target_paths = 2;
@@ -236,6 +226,7 @@ message MountRequest {
 
 message MountReply {
     string log_line = 1;
+    string mount_message = 2;
 }
 
 message PingRequest {
@@ -288,6 +279,7 @@ message StartRequest {
 
 message StartReply {
     string log_line = 1;
+    string start_message = 2;
 }
 
 message StopRequest {