Experimenting with listing containers

main.vala

@@ -0,0 +1,119 @@
+namespace Docker {
+    public class Container: Object {}
+
+    public class Connection: Object {
+        public string socket {
+            get;
+            set;
+            default = "/var/run/docker.sock";
+        }
+
+        private GLib.UnixSocketAddress address;
+        private GLib.SocketClient client;
+        private GLib.SocketConnection conn;
+
+        private int status = 0;
+        private string? status_message = null;
+        private int content_length = 0;
+        private bool headers_received = false;
+        private string? contents = null;
+
+        public Connection(string socket = "/var/run/docker.sock") {
+            Object(socket: socket);
+
+            address =  new GLib.UnixSocketAddress(socket);
+            client = new SocketClient();
+            conn = client.connect(address);
+        }
+
+        public async List<Container>
+        list_containers() {
+            var message = "GET /containers/json HTTP/1.1\r\nHost: v1.27\r\n\r\n";
+            yield conn.output_stream.write_async(message.data,
+                                                 Priority.DEFAULT);
+
+            var input = new DataInputStream(conn.input_stream);
+            input.set_newline_type(GLib.DataStreamNewlineType.CR_LF);
+
+            while (!headers_received) {
+                message = input.read_line(null).strip();
+
+                if ((status == 0) && (message.has_prefix("HTTP/1.1 "))) {
+                    status = message.slice(9, 12).to_int();
+                    status_message =  message.slice(13, message.length);
+                    // Reset some variables
+                    headers_received = false;
+                    content_length = 0;
+                    contents = null;
+
+                    // TODO: Handle error codes
+                } else if (message.down().has_prefix("content-length: ")) {
+                    content_length = message.slice(16, message.length).to_int();
+                } else if (message.length == 0) {
+                    headers_received = true;
+                    contents = "";
+                } else {
+                    // TODO: Handle other headers
+                }
+            }
+
+            stdout.printf("Got headers\n");
+            yield;
+
+            input.set_newline_type(GLib.DataStreamNewlineType.LF);
+
+            while (content_length > 0) {
+                size_t read_len;
+                var line = input.read_line_utf8(out read_len);
+                // read_len doesn’t contain the newline at the end of the line
+                read_len++;
+                contents += line;
+
+                if (read_len == content_length) {
+                    break;
+                } else {
+                    content_length -= (int)read_len;
+                }
+            }
+            stdout.printf("Got contents\n");
+            yield;
+
+            var parser = new Json.Parser();
+            parser.load_from_data(contents, -1);
+            stdout.printf("Parsing done\n");
+            yield;
+
+            var root_array = parser.get_root().get_array();
+            var result = new List<Container>();
+
+            foreach (var data in root_array.get_elements()) {
+                var container = new Container();
+                result.prepend(container);
+
+                stdout.printf("A container!\n");
+            }
+
+            stdout.printf("Yielding…\n");
+            yield;
+            stdout.printf("Returning…\n");
+            return result;
+        }
+    }
+}
+
+public static int
+main(string[] args) {
+    var loop = new MainLoop();
+    var docker =  new Docker.Connection();
+
+    docker.list_containers.begin((obj, res) => {
+            stdout.printf("Done!\n");
+            var containers = docker.list_containers.end(res);
+
+            stdout.printf("Done!\n");
+        });
+
+    loop.run();
+
+    return 0;
+}