dinit: supervise real Kandelo service processes

Formula/dinit.rb

@@ -0,0 +1,202 @@
+require (Tap.fetch("automattic", "kandelo-homebrew").path/"Kandelo/formula_support/kandelo_formula_support").to_s
+
+class Dinit < Formula
+  include KandeloFormulaSupport
+
+  desc "Service manager and process supervisor for Kandelo"
+  homepage "https://davmac.org/projects/dinit/"
+  url "https://github.com/davmac314/dinit/archive/refs/tags/v0.19.4.tar.gz"
+  sha256 "3c0f624eb958f8e884631be4ef687da1e475ebaa6241e7ee330b864e6cd9e30b"
+  license "Apache-2.0"
+
+  depends_on "binaryen" => :build
+  depends_on "m4" => :build
+  depends_on "wabt" => :build
+  depends_on "automattic/kandelo-homebrew/libcxx"
+
+  skip_clean "bin/dinit"
+  skip_clean "bin/dinitctl"
+  skip_clean "bin/dinitcheck"
+  skip_clean "bin/dinit-monitor"
+
+  GUEST_OPT_PREFIX = "/home/linuxbrew/.linuxbrew/opt/dinit".freeze
+  GUEST_LIBCXX_PREFIX = "/home/linuxbrew/.linuxbrew/opt/libcxx".freeze
+
+  # LLVM lowers Wasm setjmp/longjmp through exceptions. An exception escaping
+  # these noexcept event loops is otherwise intercepted by C++ termination
+  # cleanup before the generated setjmp dispatch can receive it.
+  patch :DATA
+
+  def install
+    kandelo_require_arch!("wasm32")
+    libcxx = formula_opt_prefix("automattic/kandelo-homebrew/libcxx")
+    build_cxx = kandelo_host_cxx
+
+    # Dinit uses this native generator to produce its target configuration
+    # header. Build it in Kandelo's canonical native dev shell so target libcxx
+    # dependency paths cannot enter the host compiler environment.
+    system build_cxx,
+      "-DNDEBUG", "-std=c++14", "-O2", "-pthread",
+      "build/tools/mconfig-gen.cc", "-o", "build/tools/mconfig-gen"
+
+    kandelo_wasm_build do |root|
+      prefix_maps = [
+        "-ffile-prefix-map=#{buildpath}=/usr/src/dinit",
+        "-fdebug-prefix-map=#{buildpath}=/usr/src/dinit",
+        "-fmacro-prefix-map=#{buildpath}=/usr/src/dinit",
+        "-ffile-prefix-map=#{root}=/usr/src/kandelo",
+        "-fdebug-prefix-map=#{root}=/usr/src/kandelo",
+        "-fmacro-prefix-map=#{root}=/usr/src/kandelo",
+        "-ffile-prefix-map=#{libcxx}=#{GUEST_LIBCXX_PREFIX}",
+        "-fdebug-prefix-map=#{libcxx}=#{GUEST_LIBCXX_PREFIX}",
+        "-fmacro-prefix-map=#{libcxx}=#{GUEST_LIBCXX_PREFIX}",
+      ]
+      target_cxxflags = [
+        "-std=c++14",
+        "-O2",
+        "-fwasm-exceptions",
+        "-nostdinc++",
+        "-isystem #{libcxx}/include/c++/v1",
+        *prefix_maps,
+      ].join(" ")
+      target_ldflags = "-L#{libcxx}/lib -lc++ -lc++abi"
+
+      ENV["CXXFLAGS"] = target_cxxflags
+      ENV["TEST_CXXFLAGS"] = target_cxxflags
+      ENV["CPPFLAGS"] = "-D_POSIX_C_SOURCE=200809L"
+      ENV["LDFLAGS"] = target_ldflags
+      ENV["TEST_LDFLAGS"] = target_ldflags
+      ENV["CXX_FOR_BUILD"] = build_cxx.to_s
+      ENV["CXXFLAGS_FOR_BUILD"] = "-std=c++14 -O2"
+      ENV["CPPFLAGS_FOR_BUILD"] = "-DNDEBUG"
+      ENV["LDFLAGS_FOR_BUILD"] = "-pthread"
+
+      system "./configure",
+        "--platform=Linux",
+        "--prefix=#{GUEST_OPT_PREFIX}",
+        "--exec-prefix=#{GUEST_OPT_PREFIX}",
+        "--sbindir=#{GUEST_OPT_PREFIX}/bin",
+        "--mandir=#{GUEST_OPT_PREFIX}/share/man",
+        "--syscontrolsocket=/run/dinitctl",
+        "--disable-strip",
+        "--disable-shutdown",
+        "--disable-cgroups",
+        "--disable-utmpx",
+        "--default-auto-restart=on-failure"
+      system "make", "-j#{ENV.make_jobs}"
+
+      # LLVM already optimized each translation unit. A post-link Binaryen pass
+      # increases this program's fork-replay surface, so instrument the linked
+      # fork callers directly and leave instrumentation as the final transform.
+      fork_programs = %w[dinit dinit-monitor]
+      fork_programs.each { |program| kandelo_fork_instrument(buildpath/"src"/program) }
+
+      programs = %w[dinit dinitctl dinitcheck dinit-monitor]
+      programs.each do |program|
+        fork_policy = fork_programs.include?(program) ? :required : :forbidden
+        kandelo_validate_wasm_artifact(buildpath/"src"/program, fork: fork_policy)
+      end
+
+      program_paths = programs.map { |program| (buildpath/"src"/program).to_s.shellescape }.join(" ")
+      system "bash", "-c", <<~SH
+        set -euo pipefail
+        for program in #{program_paths}; do
+          unexpected_env_imports=$(wasm-objdump -x "$program" |
+            awk '/<- env[.]/ { sub(/^.*<- env[.]/, ""); print $1 }' |
+            grep -Ev '^(__channel_base|memory|setjmp|longjmp)$' || true)
+          if [ -n "$unexpected_env_imports" ]; then
+            echo "ERROR: $program contains unresolved non-ABI env imports" >&2
+            echo "$unexpected_env_imports" >&2
+            exit 1
+          fi
+        done
+      SH
+    end
+
+    %w[dinit dinitctl dinitcheck dinit-monitor].each do |program|
+      kandelo_install_bin(buildpath/"src", program, program)
+    end
+    man5.install "doc/manpages/dinit-service.5"
+    man8.install "doc/manpages/dinit.8",
+      "doc/manpages/dinitctl.8",
+      "doc/manpages/dinitcheck.8",
+      "doc/manpages/dinit-monitor.8"
+  end
+
+  test do
+    assert_match(/Dinit version 0\.19\.4/, kandelo_run_wasm(bin/"dinit", ["--version"]))
+    assert_match(/Dinit version 0\.19\.4/, kandelo_run_wasm(bin/"dinitctl", ["--version"]))
+    assert_match(/Dinit version 0\.19\.4/, kandelo_run_wasm(bin/"dinit-monitor", ["--version"]))
+    assert_includes kandelo_run_wasm(bin/"dinitcheck", ["--help"]), "dinitcheck"
+
+    probe_service = testpath/"probe.service"
+    probe_service.write <<~EOS
+      type = internal
+    EOS
+    monitor_service = testpath/"monitor.service"
+    monitor_service.write <<~EOS
+      type = process
+      command = #{GUEST_OPT_PREFIX}/bin/dinit-monitor --socket-path /tmp/dinitctl --initial --exit --command "#{GUEST_OPT_PREFIX}/bin/dinitcheck --help" probe
+      restart = false
+    EOS
+
+    # dinit-monitor's --initial --exit path returns only after its notification
+    # command has forked, exec'd, exited, and been waited for.
+    output = kandelo_run_wasm(
+      bin/"dinit",
+      [
+        "--container",
+        "--services-dir", "/etc/dinit.d",
+        "--socket-path", "/tmp/dinitctl",
+        "monitor"
+      ],
+      exec_programs: {
+        "#{GUEST_OPT_PREFIX}/bin/dinit-monitor" => bin/"dinit-monitor",
+        "#{GUEST_OPT_PREFIX}/bin/dinitcheck"    => bin/"dinitcheck",
+      },
+      guest_files:   {
+        "/etc/dinit.d/monitor" => monitor_service,
+        "/etc/dinit.d/probe"   => probe_service,
+      },
+    )
+    assert_match(/\[\s*OK\s*\] monitor/, output)
+    assert_match(/\[STOPPD\] monitor/, output)
+
+    %w[dinit dinitctl dinitcheck dinit-monitor].each do |program|
+      binary = File.binread(bin/program)
+      refute_includes binary, prefix.to_s
+      refute_includes binary, "/nix/store/"
+      refute_match %r{/private/tmp/[^/]+/}, binary
+      refute_match %r{/Users/[^/]+/}, binary
+    end
+    assert_includes File.binread(bin/"dinit"), "#{GUEST_OPT_PREFIX}/bin"
+  end
+end
+
+__END__
+diff --git a/dasynq/include/dasynq/pselect.h b/dasynq/include/dasynq/pselect.h
+index d370be6..578ab39 100644
+--- a/dasynq/include/dasynq/pselect.h
++++ b/dasynq/include/dasynq/pselect.h
+@@ -225,7 +225,7 @@ template <class Base> class pselect_events : public signal_events<Base, false>
+     //
+     //  do_wait - if false, returns immediately if no events are
+     //            pending.
+-    void pull_events(bool do_wait) noexcept
++    void pull_events(bool do_wait)
+     {
+         struct timespec ts;
+         struct timespec *wait_ts = nullptr;
+diff --git a/dasynq/include/dasynq/select.h b/dasynq/include/dasynq/select.h
+index 5aae627..b6edc3e 100644
+--- a/dasynq/include/dasynq/select.h
++++ b/dasynq/include/dasynq/select.h
+@@ -283,7 +283,7 @@ template <class Base> class select_events : public signal_events<Base, true>
+     //
+     //  do_wait - if false, returns immediately if no events are
+     //            pending.
+-    void pull_events(bool do_wait) noexcept
++    void pull_events(bool do_wait)
+     {
+         struct timeval ts;
+         struct timeval *wait_ts = nullptr;

README.md

@@ -42,6 +42,7 @@ Current migration controls and pilots include:
 - `asa`, FreeBSD's POSIX carriage-control translator for FORTRAN output;
 - `m4`, the GNU macro processor with process-executing builtins backed by the tap's Dash shell;
 - `gawk`, GNU's pattern scanning and text-processing language;
+- `dinit`, the service manager, control client, configuration checker, and process monitor;
 - `binutils`, GNU's native WebAssembly archive, symbol, and inspection suite,
   with exact trailing/representable `.wasm.*` custom-section and strip transforms,
   plus explicit rejection of relocatable, dynamic, cross-format, or lossy rewrites;