module docker import net.unix import io import net.http import strings import net.urllib import json import util const ( socket = '/var/run/docker.sock' buf_len = 10 * 1024 http_separator = [u8(`\r`), `\n`, `\r`, `\n`] http_chunk_separator = [u8(`\r`), `\n`] timestamp_attr = 'timestamp' api_version = 'v1.41' ) [heap] pub struct DockerConn { mut: socket &unix.StreamConn reader &io.BufferedReader // Data for the request that's currently being constructed. method http.Method url string params map[string]string content_type string head http.Response body string } // new_conn creates a new connection to the Docker daemon. pub fn new_conn() !&DockerConn { s := unix.connect_stream(docker.socket)! d := &DockerConn{ socket: s reader: io.new_buffered_reader(reader: s) } return d } // close closes the underlying socket connection. pub fn (mut d DockerConn) close() ! { d.socket.close()! } // send_request sends an HTTP request without body. fn (mut d DockerConn) send_request(method http.Method, url_str string) ! { url := urllib.parse('/$docker.api_version$url_str')! req := '$method $url.request_uri() HTTP/1.1\nHost: localhost\n\n' d.socket.write_string(req)! // When starting a new request, the reader needs to be reset. d.reader = io.new_buffered_reader(reader: d.socket) } // send_request_with_body sends an HTTP request with the given body. fn (mut d DockerConn) send_request_with_body(method http.Method, url_str string, content_type string, body string) ! { url := urllib.parse('/$docker.api_version$url_str')! req := '$method $url.request_uri() HTTP/1.1\nHost: localhost\nContent-Type: $content_type\nContent-Length: $body.len\n\n$body\n\n' d.socket.write_string(req)! // When starting a new request, the reader needs to be reset. d.reader = io.new_buffered_reader(reader: d.socket) } // send_request_with_json is a convenience wrapper around // send_request_with_body that encodes the input as JSON. fn (mut d DockerConn) send_request_with_json(method http.Method, url_str string, data &T) ! { body := json.encode(data) return d.send_request_with_body(method, url_str, 'application/json', body) } // read_response_head consumes the socket's contents until it encounters // '\r\n\r\n', after which it parses the response as an HTTP response. // Importantly, this function never consumes the reader past the HTTP // separator, so the body can be read fully later on. fn (mut d DockerConn) read_response_head() ! { mut res := []u8{} util.read_until_separator(mut d.reader, mut res, docker.http_separator)! d.head = http.parse_response(res.bytestr())! } fn (mut d DockerConn) read_response_body() ! { if d.head.status() == .no_content { return } if d.head.header.get(http.CommonHeader.transfer_encoding) or { '' } == 'chunked' { mut builder := strings.new_builder(1024) mut body := d.get_chunked_response_reader() util.reader_to_writer(mut body, mut builder)! d.body = builder.str() return } content_length := d.head.header.get(.content_length)!.int() if content_length == 0 { return } mut buf := []u8{len: docker.buf_len} mut c := 0 mut builder := strings.new_builder(docker.buf_len) for builder.len < content_length { c = d.reader.read(mut buf)! builder.write(buf[..c])! } d.body = builder.str() } // read_response is a convenience function which always consumes the entire // response and loads it into memory. It should only be used when we're certain // that the result isn't too large, as even chunked responses will get fully // loaded into memory. fn (mut d DockerConn) read_response() ! { d.read_response_head()! d.check_error()! d.read_response_body()! } // read_json_response is a convenience function that runs read_response // before parsing its contents, which is assumed to be JSON, into a struct. fn (mut d DockerConn) read_json_response() !T { d.read_response()! data := json.decode(T, d.body)! //$for field in T.fields { //$if field.typ is time.Time { // data.$(field.name) = time.parse_rfc3339(data.$(field.name + '_str'))? //} //} return data } // get_chunked_response_reader returns a ChunkedResponseReader using the socket // as reader. fn (mut d DockerConn) get_chunked_response_reader() &ChunkedResponseReader { r := new_chunked_response_reader(d.reader) return r } // get_stream_format_reader returns a StreamFormatReader using the socket as // reader. fn (mut d DockerConn) get_stream_format_reader() &StreamFormatReader { r := new_chunked_response_reader(d.reader) r2 := new_stream_format_reader(r) return r2 } struct DockerError { pub: message string } // check_error should be called after read_response_head. If the status code of // the response is an error, the body is consumed and the Docker HTTP error is // returned as a V error. If the status isn't the error, this function is a // no-op. fn (mut d DockerConn) check_error() ! { if d.head.status().is_error() { d.read_response_body()! d_err := json.decode(DockerError, d.body)! return error_with_code('$d.head.status(): $d_err.message', d.head.status_code) } }