docker/docker.v

187 lines
5.1 KiB
V

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<T> is a convenience wrapper around
// send_request_with_body that encodes the input as JSON.
fn (mut d DockerConn) send_request_with_json<T>(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<T> 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>() !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)
}
}