Day 1: Add a compose.yaml to test my fastCGI application

Signed-off-by: Aaron Fischer <mail@aaron-fischer.net>

README

@@ -1,3 +1,16 @@
 # December Adventure 2024
 
 This is my little #decemberAdventure for 2024. I try to get some real coding done with the Zig programming language. My adventure can be found [here](https://okoyono.de/~f/december-adventure-2024.gmi).
+
+## Build
+
+```
+zig build
+```
+
+
+## Run tests
+
+```
+zig build test
+```

build.zig

@@ -0,0 +1,91 @@
+const std = @import("std");
+
+// Although this function looks imperative, note that its job is to
+// declaratively construct a build graph that will be executed by an external
+// runner.
+pub fn build(b: *std.Build) void {
+    // Standard target options allows the person running `zig build` to choose
+    // what target to build for. Here we do not override the defaults, which
+    // means any target is allowed, and the default is native. Other options
+    // for restricting supported target set are available.
+    const target = b.standardTargetOptions(.{});
+
+    // Standard optimization options allow the person running `zig build` to select
+    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
+    // set a preferred release mode, allowing the user to decide how to optimize.
+    const optimize = b.standardOptimizeOption(.{});
+
+    const lib = b.addStaticLibrary(.{
+        .name = "december-adventure-2024",
+        // In this case the main source file is merely a path, however, in more
+        // complicated build scripts, this could be a generated file.
+        .root_source_file = b.path("src/root.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    // This declares intent for the library to be installed into the standard
+    // location when the user invokes the "install" step (the default step when
+    // running `zig build`).
+    b.installArtifact(lib);
+
+    const exe = b.addExecutable(.{
+        .name = "december-adventure-2024",
+        .root_source_file = b.path("src/main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    // This declares intent for the executable to be installed into the
+    // standard location when the user invokes the "install" step (the default
+    // step when running `zig build`).
+    b.installArtifact(exe);
+
+    // This *creates* a Run step in the build graph, to be executed when another
+    // step is evaluated that depends on it. The next line below will establish
+    // such a dependency.
+    const run_cmd = b.addRunArtifact(exe);
+
+    // By making the run step depend on the install step, it will be run from the
+    // installation directory rather than directly from within the cache directory.
+    // This is not necessary, however, if the application depends on other installed
+    // files, this ensures they will be present and in the expected location.
+    run_cmd.step.dependOn(b.getInstallStep());
+
+    // This allows the user to pass arguments to the application in the build
+    // command itself, like this: `zig build run -- arg1 arg2 etc`
+    if (b.args) |args| {
+        run_cmd.addArgs(args);
+    }
+
+    // This creates a build step. It will be visible in the `zig build --help` menu,
+    // and can be selected like this: `zig build run`
+    // This will evaluate the `run` step rather than the default, which is "install".
+    const run_step = b.step("run", "Run the app");
+    run_step.dependOn(&run_cmd.step);
+
+    // Creates a step for unit testing. This only builds the test executable
+    // but does not run it.
+    const lib_unit_tests = b.addTest(.{
+        .root_source_file = b.path("src/root.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    const run_lib_unit_tests = b.addRunArtifact(lib_unit_tests);
+
+    const exe_unit_tests = b.addTest(.{
+        .root_source_file = b.path("src/main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
+
+    // Similar to creating the run step earlier, this exposes a `test` step to
+    // the `zig build --help` menu, providing a way for the user to request
+    // running the unit tests.
+    const test_step = b.step("test", "Run unit tests");
+    test_step.dependOn(&run_lib_unit_tests.step);
+    test_step.dependOn(&run_exe_unit_tests.step);
+}

build.zig.zon

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+.{
+    // This is the default name used by packages depending on this one. For
+    // example, when a user runs `zig fetch --save <url>`, this field is used
+    // as the key in the `dependencies` table. Although the user can choose a
+    // different name, most users will stick with this provided value.
+    //
+    // It is redundant to include "zig" in this name because it is already
+    // within the Zig package namespace.
+    .name = "december-adventure-2024",
+
+    // This is a [Semantic Version](https://semver.org/).
+    // In a future version of Zig it will be used for package deduplication.
+    .version = "0.0.0",
+
+    // This field is optional.
+    // This is currently advisory only; Zig does not yet do anything
+    // with this value.
+    //.minimum_zig_version = "0.11.0",
+
+    // This field is optional.
+    // Each dependency must either provide a `url` and `hash`, or a `path`.
+    // `zig build --fetch` can be used to fetch all dependencies of a package, recursively.
+    // Once all dependencies are fetched, `zig build` no longer requires
+    // internet connectivity.
+    .dependencies = .{
+        // See `zig fetch --save <url>` for a command-line interface for adding dependencies.
+        //.example = .{
+        //    // When updating this field to a new URL, be sure to delete the corresponding
+        //    // `hash`, otherwise you are communicating that you expect to find the old hash at
+        //    // the new URL.
+        //    .url = "https://example.com/foo.tar.gz",
+        //
+        //    // This is computed from the file contents of the directory of files that is
+        //    // obtained after fetching `url` and applying the inclusion rules given by
+        //    // `paths`.
+        //    //
+        //    // This field is the source of truth; packages do not come from a `url`; they
+        //    // come from a `hash`. `url` is just one of many possible mirrors for how to
+        //    // obtain a package matching this `hash`.
+        //    //
+        //    // Uses the [multihash](https://multiformats.io/multihash/) format.
+        //    .hash = "...",
+        //
+        //    // When this is provided, the package is found in a directory relative to the
+        //    // build root. In this case the package's hash is irrelevant and therefore not
+        //    // computed. This field and `url` are mutually exclusive.
+        //    .path = "foo",
+
+        //    // When this is set to `true`, a package is declared to be lazily
+        //    // fetched. This makes the dependency only get fetched if it is
+        //    // actually used.
+        //    .lazy = false,
+        //},
+    },
+
+    // Specifies the set of files and directories that are included in this package.
+    // Only files and directories listed here are included in the `hash` that
+    // is computed for this package. Only files listed here will remain on disk
+    // when using the zig package manager. As a rule of thumb, one should list
+    // files required for compilation plus any license(s).
+    // Paths are relative to the build root. Use the empty string (`""`) to refer to
+    // the build root itself.
+    // A directory listed here means that all files within, recursively, are included.
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+        "src",
+        // For example...
+        //"LICENSE",
+        //"README.md",
+    },
+}

gemini-server-test/compose.yaml

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+services:
+  server:
+    image: git.okoyono.de/f/twins:latest
+    restart: unless-stopped
+    ports:
+      - 1965:1965
+    volumes:
+      - ./config:/app/config
+      - ./public_gmi:/public_gmi
+
+  december-adventure:
+    image: alpine:latest
+    restart: unless-stopped
+    ports:
+      - 9001:9001
+    volumes:
+      - ../zig-out/bin/:/run
+    command: ["sh", "-c", "cd /run && ./december-adventure-2024"]

gemini-server-test/config/twins.ini

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+listen: :1965
+
+hosts:
+  default:
+    paths:
+      -
+        path: /
+        root: /public_gmi
+        fastcgi: tcp://december-adventure:9001

gemini-server-test/public_gmi/index.gmi

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+# December Adventure 2024

src/main.zig

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+const std = @import("std");
+const net = std.net;
+const posix = std.posix;
+
+pub fn main() !void {
+    const address = try std.net.Address.parseIp("127.0.0.1", 5882);
+
+    const tpe: u32 = posix.SOCK.STREAM;
+    const protocol = posix.IPPROTO.TCP;
+    const listener = try posix.socket(address.any.family, tpe, protocol);
+    defer posix.close(listener);
+
+    try posix.setsockopt(listener, posix.SOL.SOCKET, posix.SO.REUSEADDR, &std.mem.toBytes(@as(c_int, 1)));
+    try posix.bind(listener, &address.any, address.getOsSockLen());
+    try posix.listen(listener, 128);
+
+    var buf: [128]u8 = undefined;
+    while (true) {
+        var client_address: net.Address = undefined;
+        var client_address_len: posix.socklen_t = @sizeOf(net.Address);
+        const socket = posix.accept(listener, &client_address.any, &client_address_len, 0) catch |err| {
+            // Rare that this happens, but in later parts we'll
+            // see examples where it does.
+            std.debug.print("error accept: {}\n", .{err});
+            continue;
+        };
+        defer posix.close(socket);
+
+        std.debug.print("{} connected\n", .{client_address});
+
+        const timeout = posix.timeval{.tv_sec = 2, .tv_usec = 500_000};
+        try posix.setsockopt(socket, posix.SOL.SOCKET, posix.SO.RCVTIMEO, &std.mem.toBytes(timeout));
+        try posix.setsockopt(socket, posix.SOL.SOCKET, posix.SO.SNDTIMEO, &std.mem.toBytes(timeout));
+
+        // we've changed everything from this point on
+        const stream = std.net.Stream{.handle = socket};
+
+        const read = try stream.read(&buf);
+        if (read == 0) {
+            continue;
+        }
+        try stream.writeAll(buf[0..read]);
+    }
+}

src/root.zig

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+const std = @import("std");
+const testing = std.testing;
+
+export fn add(a: i32, b: i32) i32 {
+    return a + b;
+}
+
+test "basic add functionality" {
+    try testing.expect(add(3, 7) == 10);
+}