mantis explorer server

docker/mantis-explorer.nix

@@ -0,0 +1,20 @@
+{ lib, mkEnv, buildLayeredImage, writeShellScript, mantis-explorer
+, mantis-explorer-server }:
+let
+  entrypoint = writeShellScript "mantis-explorer-server" ''
+    set -exuo pipefail
+
+    exec mantis-explorer-server \
+      --root ${mantis-explorer} \
+      --port "$NOMAD_PORT_http" \
+      --host 0.0.0.0
+  '';
+in {
+  mantis-explorer-server = buildLayeredImage {
+    name = "docker.mantis.ws/mantis-explorer-server";
+    config = {
+      Entrypoint = [ entrypoint ];
+      Env = mkEnv { PATH = lib.makeBinPath [ mantis-explorer-server ]; };
+    };
+  };
+}

flake.nix

@@ -10,6 +10,7 @@
     terranix.follows = "bitte/terranix";
     utils.url = "github:numtide/flake-utils";
     ops-lib.url = "github:input-output-hk/ops-lib/zfs-image?dir=zfs";
+    inclusive.follows = "bitte/inclusive";
     midnight-automation = {
       url =
         "git+ssh://github.com/input-output-hk/midnight-automation?ref=etcm-99-mantis-agen";

jobs/mantis.nix

@@ -369,11 +369,11 @@ let
       };
 
       config = {
-        image = dockerImages.darkhttpd.id;
+        image = dockerImages.mantis-explorer-server.id;
         ports = [ "http" ];
         labels = [{
           inherit namespace name;
-          imageTag = dockerImages.darkhttpd.image.imageTag;
+          imageTag = dockerImages.mantis-explorer-server.image.imageTag;
         }];
 
         logging = {
@@ -596,7 +596,7 @@ let
               }
             }
           '';
-          changeMode = "noop";
+          changeMode = "restart";
           destination = "local/faucet.conf";
         }
         genesisJson

overlay.nix

@@ -29,6 +29,10 @@ in {
 
   mantis-faucet = import final.mantis-faucet-source { inherit system; };
 
+  mantis-explorer-server = prev.callPackage ./pkgs/mantis-explorer-server.nix {
+    inherit (self.inputs.inclusive.lib) inclusive;
+  };
+
   # Any:
   # - run of this command with a parameter different than the testnet (currently 10)
   # - change in the genesis file here
@@ -275,6 +279,9 @@ in {
       final.nixFlakes
       final.jq
       final.fd
+      # final.crystal
+      # final.pkgconfig
+      # final.openssl
     ];
   };
 

pkgs/mantis-explorer-server.cr

@@ -0,0 +1,147 @@
+require "http/server"
+require "uri"
+require "mime"
+require "digest/md5"
+require "option_parser"
+
+class HTTP::ExplorerFileHandler
+  include HTTP::Handler
+
+  @public_dir : Path
+
+  # Creates a handler that will serve files in the given *public_dir*, after
+  # expanding it (using `File#expand_path`).
+  #
+  # If *fallthrough* is `false`, this handler does not call next handler when
+  # request method is neither GET or HEAD, then serves `405 Method Not Allowed`.
+  # Otherwise, it calls next handler.
+  def initialize(public_dir : String, fallthrough = true)
+    @public_dir = Path.new(public_dir).expand
+    @fallthrough = !!fallthrough
+  end
+
+  def call(context)
+    unless context.request.method.in?("GET", "HEAD")
+      if @fallthrough
+        call_next(context)
+      else
+        context.response.status = :method_not_allowed
+        context.response.headers.add("Allow", "GET, HEAD")
+      end
+      return
+    end
+
+    original_path = context.request.path.not_nil!
+    is_dir_path = original_path.ends_with?("/")
+    request_path = URI.decode(original_path)
+
+    # File path cannot contains '\0' (NUL) because all filesystem I know
+    # don't accept '\0' character as file name.
+    if request_path.includes? '\0'
+      context.response.respond_with_status(:bad_request)
+      return
+    end
+
+    request_path = Path.posix(request_path)
+    expanded_path = request_path.expand("/")
+
+    file_path = @public_dir.join(expanded_path.to_kind(Path::Kind.native))
+    is_dir = Dir.exists? file_path
+    is_file = !is_dir && File.exists?(file_path)
+
+    if request_path != expanded_path || is_dir && !is_dir_path
+      redirect_path = expanded_path
+      if is_dir && !is_dir_path
+        # Append / to path if missing
+        redirect_path = expanded_path.join("")
+      end
+      redirect_to context, redirect_path
+      return
+    end
+
+    unless is_file
+      file_path = @public_dir.join(Path.posix("/index.html").to_kind(Path::Kind.native))
+      is_file = File.exists?(file_path)
+      is_dir = Dir.exists? file_path
+    end
+
+    if is_file
+      hash = file_hash(file_path)
+      add_cache_headers(context.response.headers, hash)
+
+      if cache_request?(context, hash)
+        context.response.status = :not_modified
+        return
+      end
+
+      context.response.content_type = MIME.from_filename(file_path.to_s, "application/octet-stream")
+      context.response.content_length = File.size(file_path)
+      File.open(file_path) do |file|
+        IO.copy(file, context.response)
+      end
+    else
+      call_next(context)
+    end
+  end
+
+  private def redirect_to(context, url)
+    context.response.status = :found
+
+    url = URI.encode(url.to_s)
+    context.response.headers.add "Location", url
+  end
+
+  private def add_cache_headers(response_headers : HTTP::Headers, hash : String) : Nil
+    response_headers["Etag"] = etag(hash)
+  end
+
+  private def cache_request?(context : HTTP::Server::Context, hash : String) : Bool
+    # According to RFC 7232:
+    # A recipient must ignore If-Modified-Since if the request contains an If-None-Match header field
+    if if_none_match = context.request.if_none_match
+      match = {"*", context.response.headers["Etag"]}
+      if_none_match.any? { |etag| match.includes?(etag) }
+    else
+      false
+    end
+  end
+
+  private def etag(file_hash)
+    %{"#{file_hash}"}
+  end
+
+  private def file_hash(file_path)
+    Digest::MD5.hexdigest(File.read(file_path))
+  end
+end
+
+root = ENV["ROOT"]? || "."
+host = ENV["HOST"]? || "127.0.0.1"
+port = (ENV["PORT"]? || "3000").to_i
+
+OptionParser.parse do |parser|
+  parser.banner = "Usage: mantis-explorer-server [arguments]"
+  parser.on("-r", "--root=ROOT", "directory root (default: #{root})") { |v| root = v }
+  parser.on("-h", "--host=HOST", "Listening host (default: #{host})") { |v| host = v }
+  parser.on("-p", "--port=PORT", "Listening port (default: #{port})") { |v| port = v.to_i }
+  parser.on("--help", "Show this help") do
+    puts parser
+    exit
+  end
+  parser.invalid_option do |flag|
+    STDERR.puts "ERROR: #{flag} is not a valid option."
+    STDERR.puts parser
+    exit(1)
+  end
+end
+
+server = HTTP::Server.new([
+  HTTP::ErrorHandler.new,
+  HTTP::LogHandler.new,
+  HTTP::CompressHandler.new,
+  HTTP::ExplorerFileHandler.new(root),
+])
+
+server.bind_tcp host, port
+puts "Listening at #{host}:#{port}"
+server.listen

pkgs/mantis-explorer-server.nix

@@ -0,0 +1,20 @@
+{ removeReferencesTo, inclusive, pkgconfig, openssl, crystal }:
+crystal.buildCrystalPackage {
+  pname = "mantis-explorer-server";
+  version = "0.0.1";
+  format = "crystal";
+
+  src = inclusive ./. [ ./mantis-explorer-server.cr ];
+
+  nativeBuildInputs = [ removeReferencesTo ];
+  buildInputs = [ openssl pkgconfig ];
+
+  postInstall = ''
+    remove-references-to -t ${crystal.lib} $out/bin/*
+  '';
+
+  crystalBinaries.mantis-explorer-server = {
+    src = "mantis-explorer-server.cr";
+    options = [ "--verbose" "--release" ];
+  };
+}