Add systemd unit files for malpd and support systemd socket activation

assets/page.erb

@@ -164,9 +164,13 @@
     fetch("?content", { credentials: "same-origin" })
       .then(function(response) {
         if (response.ok) return response.text();
+        throw new Error();
       })
       .then(function(html) {
-        if (html) document.getElementById("content").innerHTML = html;
+        document.getElementById("content").innerHTML = html;
+      })
+      .catch(function() {
+        document.getElementById("content").innerHTML = "Error";
       });
   </script>
 <% end %>

bin/malpd

@@ -62,12 +62,16 @@ if Process.uid != 0
   exit(1)
 end
 
-FileUtils.mkdir_p(File.dirname(SOCKET_PATH))
-FileUtils.rm_f(SOCKET_PATH)
+if ENV["LISTEN_FDS"]
+  server = UNIXServer.for_fd(3)
+else
+  FileUtils.mkdir_p(File.dirname(SOCKET_PATH))
+  FileUtils.rm_f(SOCKET_PATH)
 
-server = UNIXServer.new(SOCKET_PATH)
-File.chmod(0660, SOCKET_PATH)
-FileUtils.chown(nil, "apache", SOCKET_PATH)
+  server = UNIXServer.new(SOCKET_PATH)
+  File.chmod(0660, SOCKET_PATH)
+  FileUtils.chown(nil, "apache", SOCKET_PATH)
+end
 
 Signal.trap("TERM") { server.close }
 Signal.trap("INT") { server.close }

cgi-bin/malp.rb

@@ -3,7 +3,9 @@
 require "cgi"
 require "erb"
 require "digest"
+require "json"
 require "securerandom"
+require "socket"
 
 ASSETS_DIR = File.join(__dir__, "../assets")
 DATA_DIR = File.join(__dir__, "../data")
@@ -81,9 +83,39 @@ end
 
 if cgi.params.key?("content")
   if authenticated
-    sleep 5
+    html = ""
+
+    begin
+      sock = UNIXSocket.new("/run/malpd/malpd.sock")
+      sock.puts "info"
+      info = JSON.parse(sock.gets)
+      sock.close
+    rescue
       cgi.out("type" => "text/html", "charset" => "UTF-8") do
-      "<p>Content placeholder</p>"
+        "Could not connect to malpd socket"
+      end
+      exit
+    end
+
+    info.each do |entry|
+      case entry["type"]
+      when "drive"
+        dt = entry["drivetype"]
+        model = CGI.escapeHTML(entry["model"])
+        capacity = CGI.escapeHTML(entry["capacity"])
+        html << <<~HTML
+          <div class="card ok">
+            <div class="card-header">
+              <span class="card-title">#{model} <span class="drive-type #{dt}">#{dt.upcase}</span></span>
+            </div>
+            <div class="card-sub">#{capacity}</div>
+          </div>
+        HTML
+      end
+    end
+
+    cgi.out("type" => "text/html", "charset" => "UTF-8") do
+      html
     end
   else
     cgi.out("Status" => "403 Forbidden", "type" => "text/plain", "charset" => "UTF-8") do

systemd/malpd.service

@@ -0,0 +1,10 @@
+[Unit]
+Description=MALP monitoring daemon
+Requires=malpd.socket
+
+[Service]
+Type=simple
+ExecStart=/var/www/malp/bin/malpd
+
+[Install]
+WantedBy=multi-user.target

systemd/malpd.socket

@@ -0,0 +1,10 @@
+[Unit]
+Description=malpd Unix socket
+
+[Socket]
+ListenStream=/run/malpd/malpd.sock
+SocketGroup=apache
+SocketMode=0660
+
+[Install]
+WantedBy=sockets.target