1 /*
2  * Copyright (C) 2023 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "host/commands/snapshot_util_cvd/snapshot_taker.h"
18 
19 #include <cstdlib>
20 #include <string>
21 #include <string_view>
22 #include <unordered_map>
23 
24 #include <android-base/file.h>
25 #include <android-base/strings.h>
26 
27 #include "common/libs/fs/shared_buf.h"
28 #include "common/libs/fs/shared_fd.h"
29 #include "common/libs/utils/environment.h"
30 #include "common/libs/utils/files.h"
31 #include "common/libs/utils/json.h"
32 #include "common/libs/utils/result.h"
33 #include "common/libs/utils/users.h"
34 #include "host/libs/command_util/snapshot_utils.h"
35 #include "host/libs/config/cuttlefish_config.h"
36 
37 namespace cuttlefish {
38 
39 /**
40  * cp -r <cuttlefish home dir> <snapshot_path>
41  * write meta info for cvd: i.e. HOME, group name, instance names
42  * returns the path of generated snapshot json file
43  */
HandleHostGroupSnapshot(const std::string & path)44 Result<std::string> HandleHostGroupSnapshot(const std::string& path) {
45   const auto cuttlefish_home = StringFromEnv("HOME", "");
46   CF_EXPECT(!cuttlefish_home.empty(),
47             "\"HOME\" environment variable must be set.");
48 
49   const std::string snapshot_path = CF_EXPECT(EmulateAbsolutePath(InputPathForm{
50       .current_working_dir = CurrentDirectory(),
51       .home_dir = CF_EXPECT(SystemWideUserHome()),
52       .path_to_convert = path,
53       .follow_symlink = false,
54   }));
55 
56   auto* cuttlefish_config = CuttlefishConfig::Get();
57   CF_EXPECT(cuttlefish_config != nullptr, "Cannot find cuttlefish_config.json");
58 
59   const auto cuttlefish_root = cuttlefish_config->root_dir();
60   CF_EXPECTF(android::base::StartsWith(cuttlefish_root, cuttlefish_home),
61              "Cuttlefish Root directory \"{}\" "
62              "is not subdirectory of cuttlefish home \"{}\".",
63              cuttlefish_root, cuttlefish_home);
64 
65   // cp -r HOME snapshot_path
66   auto always_true = [](const std::string&) -> bool { return true; };
67   CF_EXPECTF(CopyDirectoryRecursively(cuttlefish_root, snapshot_path,
68                                       /* verify_dest_dir_empty */ true,
69                                       /* predicate */ std::move(always_true)),
70              "\"cp -r {} {} failed.\"", cuttlefish_root, snapshot_path);
71 
72   const auto meta_json =
73       CF_EXPECTF(CreateMetaInfo(*cuttlefish_config, snapshot_path),
74                  "Failed to create ", kMetaInfoJsonFileName);
75   const auto serialized_meta_json = meta_json.toStyledString();
76   LOG(DEBUG) << "Generated " << kMetaInfoJsonFileName << ": " << std::endl
77              << std::endl
78              << serialized_meta_json;
79 
80   // write meta_json to file
81   const auto meta_json_path = SnapshotMetaJsonPath(snapshot_path);
82   CF_EXPECTF(
83       android::base::WriteStringToFile(serialized_meta_json, meta_json_path,
84                                        /* follow_symlinks */ true),
85       "Failed to write the meta information in json to \"{}\"", meta_json_path);
86 
87   // mkdir guest_snapshot under the snapshot directory
88   CF_EXPECT(meta_json.isMember(kGuestSnapshotField));
89   auto meta_json_guest_snapshot = meta_json[kGuestSnapshotField];
90   for (const auto& instance : cuttlefish_config->Instances()) {
91     CF_EXPECT(meta_json_guest_snapshot.isMember(instance.id()));
92     const std::string new_dir_path =
93         snapshot_path + "/" +
94         meta_json_guest_snapshot[instance.id()].asString();
95     CF_EXPECTF(EnsureDirectoryExists(new_dir_path),
96                "Failed to create instance guest snapshot directory {}",
97                new_dir_path);
98   }
99   return meta_json_path;
100 }
101 
102 }  // namespace cuttlefish
103