Add --version to dockerc and --dockerc-version to runtime

build.zig

@@ -18,6 +18,10 @@ pub fn build(b: *std.Build) void {
     const optimize = b.standardOptimizeOption(.{});
 
     const skip_crun_build = b.option(bool, "skip_crun_build", "Skip crun build") orelse false;
+    const dockerc_version = b.option([]const u8, "dockerc_version", "Set dockerc version") orelse "HEAD";
+
+    const build_info = b.addOptions();
+    build_info.addOption([]const u8, "dockerc_version", dockerc_version);
 
     const zstd = b.createModule(.{});
     zstd.addAssemblyFile(b.path("zstd/lib/decompress/huf_decompress_amd64.S"));
@@ -184,6 +188,8 @@ pub fn build(b: *std.Build) void {
         .link_libc = true,
     });
 
+    runtime.addOptions("build_info", build_info);
+
     runtime.addImport("zstd", zstd);
     runtime.addImport("fuse-overlayfs", fuse_fss);
 
@@ -404,6 +410,8 @@ pub fn build(b: *std.Build) void {
         .link_libc = true,
     });
 
+    dockerc.root_module.addOptions("build_info", build_info);
+
     dockerc.addIncludePath(b.path("zstd/lib"));
     dockerc.root_module.addImport("zstd", zstd);
     dockerc.addCSourceFiles(.{

src/dockerc.zig

@@ -2,6 +2,7 @@ const builtin = @import("builtin");
 const std = @import("std");
 const clap = @import("clap");
 const common = @import("common.zig");
+const build_info = @import("build_info");
 
 const mkdtemp = common.mkdtemp;
 const extract_file = common.extract_file;
@@ -48,6 +49,7 @@ pub fn main() !void {
 
     const params = comptime clap.parseParamsComptime(
         \\-h, --help               Display this help and exit.
+        \\--version                Display dockerc version.
         \\-i, --image <str>        Image to pull.
         \\-o, --output <str>       Output file.
         \\--arch <str>             Architecture (amd64, arm64).
@@ -66,6 +68,11 @@ pub fn main() !void {
     };
     defer res.deinit();
 
+    if (res.args.version != 0) {
+        std.debug.print("dockerc version: {s}\n", .{build_info.dockerc_version});
+        return;
+    }
+
     if (res.args.help != 0) {
         try clap.help(io.getStdErr().writer(), clap.Help, &params, .{});
         return;

src/main.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 const assert = std.debug.assert;
 const common = @import("common.zig");
+const build_info = @import("build_info");
 
 const mkdtemp = common.mkdtemp;
 const extract_file = common.extract_file;
@@ -356,6 +357,16 @@ fn umount(path: [*:0]const u8) void {
 }
 
 pub fn main() !u8 {
+    var args = std.process.args();
+    const executable_path = args.next() orelse @panic("unreachable: there must be a executable name");
+
+    while (args.next()) |arg| {
+        if (eql(u8, arg, "--dockerc-version")) {
+            std.debug.print("dockerc version: {s}\n", .{build_info.dockerc_version});
+            return 0;
+        }
+    }
+
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
     defer _ = gpa.deinit();
     const allocator = gpa.allocator();
@@ -485,9 +496,6 @@ pub fn main() !u8 {
         std.posix.close(read_fd);
     }
 
-    var args = std.process.args();
-    const executable_path = args.next() orelse unreachable;
-
     var temp_dir_path = "/tmp/dockerc-XXXXXX".*;
     try mkdtemp(&temp_dir_path);