Initial commit: OCI image mounting via containers-storage

slocker-lite validates an OCI Image Layout tar, imports its layers into containers-storage's layer store in order, and mounts the assembled image using fuse-overlayfs, printing the resulting merged path. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-10 08:12:50 +00:00
commit a301dfb44f
16 changed files with 1141 additions and 0 deletions
@@ -0,0 +1,13 @@
 # Meson build directory
 /buildDir/
 # Meson subprojects: keep the .wrap files, ignore fetched sources / download cache
 /subprojects/*/
 /subprojects/packagecache/
 /subprojects/.wraplock
 # JetBrains IDE
 .idea/
 # Claude Code session resume note (local-only, not part of the project)
 /RESUME
@@ -0,0 +1,57 @@
 # CLAUDE.md
 This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
 ## Project state
 `slocker-lite` (C++20, built with Meson) mounts an OCI Image Layout tar (`oci-layout` +
 `index.json` + `blobs/sha256/*`, as produced by `skopeo`/`podman save --format
 oci-archive`/modern `docker save`) using `containers-storage` and `fuse-overlayfs`. Given
 an image tar path, it validates the layout, imports each layer into containers-storage's
 layer store in order (chained by parent), mounts the assembled top layer, and prints the
 resulting merged path. There is no README or broader architecture doc yet — treat this
 repo as still early-stage.
 Source layout (all under `src/`):
 - `main.cpp` — CLI entry point, dependency checks, orchestration.
 - `oci_image.{h,cpp}` — validates/parses the OCI Image Layout tar (libarchive +
  nlohmann_json) and extracts layer blobs.
 - `containers_storage.{h,cpp}` — wraps the `containers-storage` CLI (`import-layer`,
  `mount`), forcing `fuse-overlayfs` as the overlay `mount_program`.
 - `process.{h,cpp}` — argv-based subprocess helper (fork/execvp/pipe, no shell).
 Errors are logged via `spdlog::error`; every external command is also traced at debug
 level in `run_process()` (`src/process.cpp`) — visible via `SPDLOG_LEVEL=debug`, since
 spdlog's default level is `info` — and a failed external command additionally logs a
 `spdlog::warn`, which is visible by default (no env var needed). The final "mounted
 image at: ..." success line is direct stdout program output, not a log.
 Because `containers-storage mount` runs rootless, the resulting mount lives in a private
 user+mount namespace; the printed path is only directly usable from within that same
 namespace (e.g. via `containers-storage unshare`), not from an arbitrary external shell.
 ## Build & test commands
 Build directory is `buildDir/` (already configured).
 - Configure (only needed if `buildDir/` is missing or deleted): `meson setup buildDir`
 - Build: `meson compile -C buildDir` (or `ninja -C buildDir`)
 - Run the executable: `./buildDir/slocker_lite <image.tar>`
 - Run tests: `meson test -C buildDir`
 ## Code style
 - Null-pointer checks: prefer `if (!ptr)` / `if (ptr)` over `if (ptr == nullptr)` / `if (ptr != nullptr)`.
 ## Licensing
 - Every `.c`/`.cpp`/`.h` file under `src/` must start with the GPLv2-or-later copyright
  header (see any existing file under `src/` for the exact text).
 - After adding a new source file under `src/`, run `./add-license.sh` from the repo
  root to prepend the header (it reads `copyright-header` and inserts it via `sed`,
  skipping files that already have it, so it's safe to re-run at any time).
 ## Build configuration notes
 - `meson.build` sets `warning_level=3` and `cpp_std=c++20` — keep new code warning-clean under `-Wall -Wextra -Wpedantic`-equivalent settings.
 - The single Meson `test()` target runs `slocker_lite` against a fixture OCI image tar generated at build time by `tests/gen_fixture.py` (a `custom_target`) and checks its exit code (no test framework is wired in yet).
@@ -0,0 +1,338 @@
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@@ -0,0 +1,10 @@
 #! /bin/bash
 if [[ $1 = -f ]]; then
 	shift
 	for i in "$@"; do
 		grep -q 'GNU General Public License' "$i" || sed -i '0 r copyright-header' "$i"
 	done
 else
 	find src/ \( -name \*.c -o -name \*.cpp -o -name \*.h \) -exec "$0" -f {} +
 fi
@@ -0,0 +1,16 @@
 // Copyright (C) 2026 Viorel Munteanu
 //
 // 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
 // the Free Software Foundation; either version 2 of the License, or
 // (at your option) any later version.
 //
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 // GNU General Public License for more details.
 //
 // You should have received a copy of the GNU General Public License along
 // with this program; if not, write to the Free Software Foundation, Inc.,
 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
@@ -0,0 +1,29 @@
 project('slocker-lite', 'cpp',
        version : '0.0.1',
        default_options : ['warning_level=3', 'cpp_std=c++20'])
 fmt_dep = dependency('fmt')
 catch2_dep = dependency('catch2', required : get_option('enable_tests'))
 yaml_dep = dependency('yaml-0.1')
 archive_dep = dependency('libarchive')
 json_dep = dependency('nlohmann_json')
 spdlog_dep = dependency('spdlog')
 conf_data = configuration_data()
 conf_data.set_quoted('PACKAGE', meson.project_name())
 conf_data.set_quoted('VERSION', meson.project_version())
 conf_data.set10('ENABLE_TESTS', get_option('enable_tests'))
 configure_file(output : 'config.h', configuration : conf_data)
 slocker_lite = executable('slocker_lite',
    ['src/main.cpp', 'src/process.cpp', 'src/oci_image.cpp', 'src/containers_storage.cpp'],
    include_directories : include_directories('.'),
    dependencies : [fmt_dep, catch2_dep, yaml_dep, archive_dep, json_dep, spdlog_dep],
    install : true)
 fixture_tar = custom_target('oci-fixture',
    output : 'fixture.tar',
    command : [find_program('python3'), files('tests/gen_fixture.py'), '@OUTPUT@'])
 test('test', slocker_lite, args : [fixture_tar])
@@ -0,0 +1 @@
 option('enable_tests', type : 'boolean', value : true, description : 'Enable the Catch2 test dependency and -t test invocation')
@@ -0,0 +1,64 @@
 // Copyright (C) 2026 Viorel Munteanu
 //
 // 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
 // the Free Software Foundation; either version 2 of the License, or
 // (at your option) any later version.
 //
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 // GNU General Public License for more details.
 //
 // You should have received a copy of the GNU General Public License along
 // with this program; if not, write to the Free Software Foundation, Inc.,
 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #include "containers_storage.h"
 #include "process.h"
 namespace {
 std::string trim(const std::string& s) {
    size_t begin = s.find_first_not_of(" \t\r\n");
    if (begin == std::string::npos) {
        return "";
    }
    size_t end = s.find_last_not_of(" \t\r\n");
    return s.substr(begin, end - begin + 1);
 }
 }  // namespace
 std::string kMountProgram;
 std::optional<std::string> import_layer(const std::filesystem::path& diff_file,
                                         const std::string& parent_id) {
    std::vector<std::string> argv = {
        "containers-storage", "import-layer", "--file", diff_file.string(),
        "--storage-opt", "overlay.mount_program=" + kMountProgram};
    if (!parent_id.empty()) {
        argv.push_back(parent_id);
    }
    ProcessResult result = run_process(argv);
    std::string id = trim(result.stdout_output);
    if (result.exit_code != 0 || id.empty()) {
        return std::nullopt;
    }
    return id;
 }
 std::optional<std::string> mount_layer(const std::string& layer_id) {
    std::vector<std::string> argv = {
        "containers-storage", "mount", "--storage-opt",
        "overlay.mount_program=" + kMountProgram, layer_id};
    ProcessResult result = run_process(argv);
    std::string path = trim(result.stdout_output);
    if (result.exit_code != 0 || path.empty()) {
        return std::nullopt;
    }
    return path;
 }
@@ -0,0 +1,36 @@
 // Copyright (C) 2026 Viorel Munteanu
 //
 // 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
 // the Free Software Foundation; either version 2 of the License, or
 // (at your option) any later version.
 //
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 // GNU General Public License for more details.
 //
 // You should have received a copy of the GNU General Public License along
 // with this program; if not, write to the Free Software Foundation, Inc.,
 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #pragma once
 #include <filesystem>
 #include <optional>
 #include <string>
 // Absolute path to the fuse-overlayfs binary, passed to containers-storage as
 // overlay.mount_program so it performs the actual overlay mounting. Set once in main()
 // after find_in_path() resolves it.
 extern std::string kMountProgram;
 // Runs `containers-storage import-layer --storage-opt overlay.mount_program=<path>
 // [--file diff_file] [parent_id]`. Returns the new layer's ID (trimmed stdout) or
 // nullopt on failure (containers-storage's own stderr is inherited/visible).
 std::optional<std::string> import_layer(const std::filesystem::path& diff_file,
                                         const std::string& parent_id);
 // Runs `containers-storage mount --storage-opt overlay.mount_program=<path> <layer_id>`.
 // Returns the merged directory path (trimmed stdout) or nullopt on failure.
 std::optional<std::string> mount_layer(const std::string& layer_id);
@@ -0,0 +1,128 @@
 // Copyright (C) 2026 Viorel Munteanu
 //
 // 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
 // the Free Software Foundation; either version 2 of the License, or
 // (at your option) any later version.
 //
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 // GNU General Public License for more details.
 //
 // You should have received a copy of the GNU General Public License along
 // with this program; if not, write to the Free Software Foundation, Inc.,
 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #include <array>
 #include <cstdlib>
 #include <filesystem>
 #include <optional>
 #include <string_view>
 #include <unistd.h>
 #include <fmt/core.h>
 #include <spdlog/cfg/env.h>
 #include <spdlog/spdlog.h>
 #include "containers_storage.h"
 #include "oci_image.h"
 namespace {
 constexpr std::array<std::string_view, 2> kRequiredTools = {"containers-storage", "bwrap"};
 bool is_executable_file(const std::filesystem::path& path) {
    std::error_code ec;
    return std::filesystem::is_regular_file(path, ec) && access(path.c_str(), X_OK) == 0;
 }
 std::optional<std::filesystem::path> find_in_path(std::string_view name) {
    const char* path_env = std::getenv("PATH");
    if (!path_env) {
        return std::nullopt;
    }
    std::string_view path{path_env};
    for (size_t start = 0; start <= path.size();) {
        size_t end = path.find(':', start);
        if (end == std::string_view::npos) {
            end = path.size();
        }
        std::filesystem::path dir{path.substr(start, end - start)};
        if (!dir.empty()) {
            std::filesystem::path candidate = dir / name;
            if (is_executable_file(candidate)) {
                return candidate;
            }
        }
        start = end + 1;
    }
    return std::nullopt;
 }
 }  // namespace
 bool check_required_dependencies() {
    bool all_found = true;
    for (auto name : kRequiredTools) {
        if (!find_in_path(name)) {
            spdlog::error("required dependency not found in PATH: {}", name);
            all_found = false;
        }
    }
    return all_found;
 }
 int main(int argc, char* argv[]) {
    spdlog::cfg::load_env_levels();
    if (argc != 2) {
        spdlog::error("usage: {} <image.tar>", argv[0]);
        return 1;
    }
    const std::filesystem::path image_tar = argv[1];
    if (!check_required_dependencies()) {
        return 1;
    }
    auto mount_program = find_in_path("fuse-overlayfs");
    if (!mount_program) {
        spdlog::error("fuse-overlayfs not found in PATH");
        return 1;
    }
    kMountProgram = mount_program->string();
    auto layers = read_oci_layers(image_tar);
    if (!layers) {
        return 1;
    }
    std::string parent_id;
    for (const auto& layer : *layers) {
        std::filesystem::path tmp_file =
            std::filesystem::temp_directory_path() /
            fmt::format("slocker-lite-{}-{}", getpid(), oci_digest_hex(layer.digest));
        if (!extract_blob_to_file(image_tar, oci_digest_hex(layer.digest), tmp_file)) {
            return 1;
        }
        auto layer_id = import_layer(tmp_file, parent_id);
        std::filesystem::remove(tmp_file);
        if (!layer_id) {
            spdlog::error("failed to import layer {}", layer.digest);
            return 1;
        }
        parent_id = *layer_id;
    }
    auto merged = mount_layer(parent_id);
    if (!merged) {
        spdlog::error("failed to mount assembled image");
        return 1;
    }
    fmt::print("mounted image at: {}\n", *merged);
    return 0;
 }
@@ -0,0 +1,195 @@
 // Copyright (C) 2026 Viorel Munteanu
 //
 // 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
 // the Free Software Foundation; either version 2 of the License, or
 // (at your option) any later version.
 //
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 // GNU General Public License for more details.
 //
 // You should have received a copy of the GNU General Public License along
 // with this program; if not, write to the Free Software Foundation, Inc.,
 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #include "oci_image.h"
 #include <archive.h>
 #include <archive_entry.h>
 #include <fmt/core.h>
 #include <nlohmann/json.hpp>
 #include <spdlog/spdlog.h>
 #include <fstream>
 #include <functional>
 namespace {
 using json = nlohmann::json;
 std::string_view normalize_entry_path(std::string_view name) {
    if (name.substr(0, 2) == "./") {
        name.remove_prefix(2);
    }
    return name;
 }
 // Reads a single tar entry's content, calling `sink` with each chunk of data as it's
 // read. `sink` is only invoked for the entry whose normalized path equals `target_name`.
 // Returns true if the entry was found (regardless of whether it was empty).
 bool for_each_chunk_in_entry(const std::filesystem::path& tar_path, std::string_view target_name,
                              const std::function<void(const char*, size_t)>& sink) {
    struct archive* a = archive_read_new();
    archive_read_support_filter_all(a);
    archive_read_support_format_tar(a);
    if (archive_read_open_filename(a, tar_path.c_str(), 65536) != ARCHIVE_OK) {
        archive_read_free(a);
        return false;
    }
    bool found = false;
    struct archive_entry* entry;
    while (archive_read_next_header(a, &entry) == ARCHIVE_OK) {
        if (normalize_entry_path(archive_entry_pathname(entry)) != target_name) {
            archive_read_data_skip(a);
            continue;
        }
        found = true;
        const void* buff;
        size_t size;
        int64_t offset;
        while (true) {
            int rc = archive_read_data_block(a, &buff, &size, &offset);
            if (rc == ARCHIVE_EOF) {
                break;
            }
            if (rc != ARCHIVE_OK) {
                found = false;
                break;
            }
            sink(static_cast<const char*>(buff), size);
        }
        break;
    }
    archive_read_free(a);
    return found;
 }
 std::optional<std::string> read_entry_to_string(const std::filesystem::path& tar_path,
                                                  std::string_view target_name) {
    std::string content;
    bool found = for_each_chunk_in_entry(tar_path, target_name, [&](const char* data, size_t size) {
        content.append(data, size);
    });
    if (!found) {
        return std::nullopt;
    }
    return content;
 }
 }  // namespace
 std::string oci_digest_hex(std::string_view digest) {
    constexpr std::string_view prefix = "sha256:";
    if (digest.substr(0, prefix.size()) == prefix) {
        digest.remove_prefix(prefix.size());
    }
    return std::string(digest);
 }
 bool extract_blob_to_file(const std::filesystem::path& tar_path, std::string_view digest_hex,
                           const std::filesystem::path& out_file) {
    std::string entry_name = fmt::format("blobs/sha256/{}", digest_hex);
    std::ofstream out(out_file, std::ios::binary | std::ios::trunc);
    if (!out) {
        spdlog::error("failed to open {} for writing", out_file.string());
        return false;
    }
    bool found = for_each_chunk_in_entry(tar_path, entry_name,
                                          [&](const char* data, size_t size) { out.write(data, static_cast<std::streamsize>(size)); });
    if (!found) {
        spdlog::error("blob {} not found in {}", entry_name, tar_path.string());
        return false;
    }
    return true;
 }
 std::optional<std::vector<OciLayer>> read_oci_layers(const std::filesystem::path& tar_path) {
    auto layout = read_entry_to_string(tar_path, "oci-layout");
    if (!layout) {
        spdlog::error("not an OCI image tar: missing oci-layout");
        return std::nullopt;
    }
    try {
        [[maybe_unused]] json parsed_layout = json::parse(*layout);
    } catch (const json::parse_error& e) {
        spdlog::error("oci-layout is not valid JSON: {}", e.what());
        return std::nullopt;
    }
    auto index_content = read_entry_to_string(tar_path, "index.json");
    if (!index_content) {
        spdlog::error("not an OCI image tar: missing index.json");
        return std::nullopt;
    }
    json index;
    try {
        index = json::parse(*index_content);
    } catch (const json::parse_error& e) {
        spdlog::error("index.json is not valid JSON: {}", e.what());
        return std::nullopt;
    }
    std::string manifest_digest;
    for (const auto& m : index.value("manifests", json::array())) {
        if (m.value("mediaType", "") == "application/vnd.oci.image.manifest.v1+json") {
            manifest_digest = m.value("digest", "");
            break;
        }
    }
    if (manifest_digest.empty()) {
        spdlog::error("index.json has no OCI image manifest entry");
        return std::nullopt;
    }
    std::string manifest_entry = fmt::format("blobs/sha256/{}", oci_digest_hex(manifest_digest));
    auto manifest_content = read_entry_to_string(tar_path, manifest_entry);
    if (!manifest_content) {
        spdlog::error("missing image manifest blob {}", manifest_digest);
        return std::nullopt;
    }
    json manifest;
    try {
        manifest = json::parse(*manifest_content);
    } catch (const json::parse_error& e) {
        spdlog::error("image manifest {} is not valid JSON: {}", manifest_digest, e.what());
        return std::nullopt;
    }
    std::vector<OciLayer> layers;
    for (const auto& l : manifest.value("layers", json::array())) {
        OciLayer layer;
        layer.digest = l.value("digest", "");
        layer.media_type = l.value("mediaType", "");
        if (layer.digest.empty()) {
            spdlog::error("image manifest {} has a layer with no digest", manifest_digest);
            return std::nullopt;
        }
        layers.push_back(std::move(layer));
    }
    if (layers.empty()) {
        spdlog::error("image manifest {} has no layers", manifest_digest);
        return std::nullopt;
    }
    return layers;
 }
@@ -0,0 +1,44 @@
 // Copyright (C) 2026 Viorel Munteanu
 //
 // 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
 // the Free Software Foundation; either version 2 of the License, or
 // (at your option) any later version.
 //
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 // GNU General Public License for more details.
 //
 // You should have received a copy of the GNU General Public License along
 // with this program; if not, write to the Free Software Foundation, Inc.,
 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #pragma once
 #include <filesystem>
 #include <optional>
 #include <string>
 #include <string_view>
 #include <vector>
 struct OciLayer {
    std::string digest;      // "sha256:<hex>", as it appears in the manifest
    std::string media_type;
 };
 // Validates that `tar_path` is an OCI Image Layout tar (oci-layout + index.json +
 // a referenced blobs/sha256/<digest> image manifest) and returns its layers in
 // base-to-top order. Logs a specific error via fmt and returns nullopt if anything
 // required is missing or malformed.
 std::optional<std::vector<OciLayer>> read_oci_layers(const std::filesystem::path& tar_path);
 // Extracts the raw bytes of blobs/sha256/<digest_hex> from `tar_path` into `out_file`.
 // Returns false (and logs) if the entry isn't found.
 bool extract_blob_to_file(const std::filesystem::path& tar_path,
                           std::string_view digest_hex,
                           const std::filesystem::path& out_file);
 // Strips the "sha256:" algorithm prefix from a digest string, e.g.
 // "sha256:abcd" -> "abcd". Returns the input unchanged if there is no such prefix.
 std::string oci_digest_hex(std::string_view digest);
@@ -0,0 +1,78 @@
 // Copyright (C) 2026 Viorel Munteanu
 //
 // 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
 // the Free Software Foundation; either version 2 of the License, or
 // (at your option) any later version.
 //
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 // GNU General Public License for more details.
 //
 // You should have received a copy of the GNU General Public License along
 // with this program; if not, write to the Free Software Foundation, Inc.,
 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #include "process.h"
 #include <sys/wait.h>
 #include <unistd.h>
 #include <cstring>
 #include <fmt/ranges.h>
 #include <spdlog/spdlog.h>
 ProcessResult run_process(const std::vector<std::string>& argv) {
    spdlog::debug("running external command: {}", fmt::join(argv, " "));
    int stdout_pipe[2];
    if (pipe(stdout_pipe) != 0) {
        return {-1, ""};
    }
    pid_t pid = fork();
    if (pid < 0) {
        close(stdout_pipe[0]);
        close(stdout_pipe[1]);
        return {-1, ""};
    }
    if (pid == 0) {
        close(stdout_pipe[0]);
        dup2(stdout_pipe[1], STDOUT_FILENO);
        close(stdout_pipe[1]);
        std::vector<char*> c_argv;
        c_argv.reserve(argv.size() + 1);
        for (const auto& arg : argv) {
            c_argv.push_back(const_cast<char*>(arg.c_str()));
        }
        c_argv.push_back(nullptr);
        execvp(c_argv[0], c_argv.data());
        const char* msg = "run_process: execvp failed\n";
        write(STDERR_FILENO, msg, std::strlen(msg));
        _exit(127);
    }
    close(stdout_pipe[1]);
    std::string output;
    char buffer[4096];
    ssize_t n;
    while ((n = read(stdout_pipe[0], buffer, sizeof(buffer))) > 0) {
        output.append(buffer, static_cast<size_t>(n));
    }
    close(stdout_pipe[0]);
    int status = 0;
    waitpid(pid, &status, 0);
    int exit_code = WIFEXITED(status) ? WEXITSTATUS(status) : -1;
    if (exit_code != 0) {
        spdlog::warn("external command failed (exit code {}): {}", exit_code, fmt::join(argv, " "));
    }
    return {exit_code, output};
 }
@@ -0,0 +1,29 @@
 // Copyright (C) 2026 Viorel Munteanu
 //
 // 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
 // the Free Software Foundation; either version 2 of the License, or
 // (at your option) any later version.
 //
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 // GNU General Public License for more details.
 //
 // You should have received a copy of the GNU General Public License along
 // with this program; if not, write to the Free Software Foundation, Inc.,
 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #pragma once
 #include <string>
 #include <vector>
 struct ProcessResult {
    int exit_code;
    std::string stdout_output;
 };
 // Runs argv[0] with the given arguments via fork/execvp, capturing stdout.
 // stderr is inherited so the child's own error messages reach the user directly.
 ProcessResult run_process(const std::vector<std::string>& argv);
@@ -0,0 +1,14 @@
 [wrap-file]
 directory = spdlog-1.17.0
 source_url = https://github.com/gabime/spdlog/archive/refs/tags/v1.17.0.tar.gz
 source_filename = spdlog-1.17.0.tar.gz
 source_hash = d8862955c6d74e5846b3f580b1605d2428b11d97a410d86e2fb13e857cd3a744
 source_fallback_url = https://wrapdb.mesonbuild.com/v2/spdlog_1.17.0-2/get_source/spdlog-1.17.0.tar.gz
 patch_filename = spdlog_1.17.0-2_patch.zip
 patch_url = https://wrapdb.mesonbuild.com/v2/spdlog_1.17.0-2/get_patch
 patch_fallback_url = https://github.com/mesonbuild/wrapdb/releases/download/spdlog_1.17.0-2/spdlog_1.17.0-2_patch.zip
 patch_hash = f5dd3aead18a790b5463f1af514eec63d06893d860966771375d77fd4d9e4acf
 wrapdb_version = 1.17.0-2
 [provide]
 dependency_names = spdlog
@@ -0,0 +1,89 @@
 #!/usr/bin/env python3
 """Writes a minimal one-layer OCI Image Layout tar to the path given as argv[1].
 Used by meson.build to produce a fixture for the `meson test` smoke test.
 """
 import gzip
 import hashlib
 import io
 import json
 import sys
 import tarfile
 def sha256_hex(data: bytes) -> str:
    return hashlib.sha256(data).hexdigest()
 def add_bytes(tar: tarfile.TarFile, name: str, data: bytes) -> None:
    info = tarfile.TarInfo(name=name)
    info.size = len(data)
    tar.addfile(info, io.BytesIO(data))
 def main() -> None:
    out_path = sys.argv[1]
    # Uncompressed layer content: a tiny tar with a single file.
    layer_tar_buf = io.BytesIO()
    with tarfile.open(fileobj=layer_tar_buf, mode="w") as layer_tar:
        add_bytes(layer_tar, "hello.txt", b"hello from slocker-lite fixture\n")
    layer_tar_bytes = layer_tar_buf.getvalue()
    diff_id = sha256_hex(layer_tar_bytes)
    layer_gz_bytes = gzip.compress(layer_tar_bytes)
    layer_digest = sha256_hex(layer_gz_bytes)
    config = {
        "architecture": "amd64",
        "os": "linux",
        "config": {},
        "rootfs": {"type": "layers", "diff_ids": [f"sha256:{diff_id}"]},
    }
    config_bytes = json.dumps(config).encode()
    config_digest = sha256_hex(config_bytes)
    manifest = {
        "schemaVersion": 2,
        "mediaType": "application/vnd.oci.image.manifest.v1+json",
        "config": {
            "mediaType": "application/vnd.oci.image.config.v1+json",
            "digest": f"sha256:{config_digest}",
            "size": len(config_bytes),
        },
        "layers": [
            {
                "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip",
                "digest": f"sha256:{layer_digest}",
                "size": len(layer_gz_bytes),
            }
        ],
    }
    manifest_bytes = json.dumps(manifest).encode()
    manifest_digest = sha256_hex(manifest_bytes)
    index = {
        "schemaVersion": 2,
        "manifests": [
            {
                "mediaType": "application/vnd.oci.image.manifest.v1+json",
                "digest": f"sha256:{manifest_digest}",
                "size": len(manifest_bytes),
            }
        ],
    }
    index_bytes = json.dumps(index).encode()
    oci_layout_bytes = json.dumps({"imageLayoutVersion": "1.0.0"}).encode()
    with tarfile.open(out_path, mode="w") as tar:
        add_bytes(tar, "oci-layout", oci_layout_bytes)
        add_bytes(tar, "index.json", index_bytes)
        add_bytes(tar, f"blobs/sha256/{config_digest}", config_bytes)
        add_bytes(tar, f"blobs/sha256/{manifest_digest}", manifest_bytes)
        add_bytes(tar, f"blobs/sha256/{layer_digest}", layer_gz_bytes)
 if __name__ == "__main__":
    main()
		`@@ -0,0 +1 @@`
							`option('enable_tests', type : 'boolean', value : true, description : 'Enable the Catch2 test dependency and -t test invocation')`