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package client // import "github.com/docker/docker/client"
import (
"bytes"
"context"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"net"
"net/http"
"net/url"
"os"
"strings"
"github.com/docker/docker/api/types"
"github.com/docker/docker/api/types/versions"
"github.com/pkg/errors"
"golang.org/x/net/context/ctxhttp"
)
// serverResponse is a wrapper for http API responses.
type serverResponse struct {
body io.ReadCloser
header http.Header
statusCode int
reqURL *url.URL
}
// head sends an http request to the docker API using the method HEAD.
func (cli *Client) head(ctx context.Context, path string, query url.Values, headers map[string][]string) (serverResponse, error) {
return cli.sendRequest(ctx, "HEAD", path, query, nil, headers)
}
// get sends an http request to the docker API using the method GET with a specific Go context.
func (cli *Client) get(ctx context.Context, path string, query url.Values, headers map[string][]string) (serverResponse, error) {
return cli.sendRequest(ctx, "GET", path, query, nil, headers)
}
// post sends an http request to the docker API using the method POST with a specific Go context.
func (cli *Client) post(ctx context.Context, path string, query url.Values, obj interface{}, headers map[string][]string) (serverResponse, error) {
body, headers, err := encodeBody(obj, headers)
if err != nil {
return serverResponse{}, err
}
return cli.sendRequest(ctx, "POST", path, query, body, headers)
}
func (cli *Client) postRaw(ctx context.Context, path string, query url.Values, body io.Reader, headers map[string][]string) (serverResponse, error) {
return cli.sendRequest(ctx, "POST", path, query, body, headers)
}
// put sends an http request to the docker API using the method PUT.
func (cli *Client) put(ctx context.Context, path string, query url.Values, obj interface{}, headers map[string][]string) (serverResponse, error) {
body, headers, err := encodeBody(obj, headers)
if err != nil {
return serverResponse{}, err
}
return cli.sendRequest(ctx, "PUT", path, query, body, headers)
}
// putRaw sends an http request to the docker API using the method PUT.
func (cli *Client) putRaw(ctx context.Context, path string, query url.Values, body io.Reader, headers map[string][]string) (serverResponse, error) {
return cli.sendRequest(ctx, "PUT", path, query, body, headers)
}
// delete sends an http request to the docker API using the method DELETE.
func (cli *Client) delete(ctx context.Context, path string, query url.Values, headers map[string][]string) (serverResponse, error) {
return cli.sendRequest(ctx, "DELETE", path, query, nil, headers)
}
type headers map[string][]string
func encodeBody(obj interface{}, headers headers) (io.Reader, headers, error) {
if obj == nil {
return nil, headers, nil
}
body, err := encodeData(obj)
if err != nil {
return nil, headers, err
}
if headers == nil {
headers = make(map[string][]string)
}
headers["Content-Type"] = []string{"application/json"}
return body, headers, nil
}
func (cli *Client) buildRequest(method, path string, body io.Reader, headers headers) (*http.Request, error) {
expectedPayload := (method == "POST" || method == "PUT")
if expectedPayload && body == nil {
body = bytes.NewReader([]byte{})
}
req, err := http.NewRequest(method, path, body)
if err != nil {
return nil, err
}
req = cli.addHeaders(req, headers)
if cli.proto == "unix" || cli.proto == "npipe" {
// For local communications, it doesn't matter what the host is. We just
// need a valid and meaningful host name. (See #189)
req.Host = "docker"
}
req.URL.Host = cli.addr
req.URL.Scheme = cli.scheme
if expectedPayload && req.Header.Get("Content-Type") == "" {
req.Header.Set("Content-Type", "text/plain")
}
return req, nil
}
func (cli *Client) sendRequest(ctx context.Context, method, path string, query url.Values, body io.Reader, headers headers) (serverResponse, error) {
req, err := cli.buildRequest(method, cli.getAPIPath(path, query), body, headers)
if err != nil {
return serverResponse{}, err
}
resp, err := cli.doRequest(ctx, req)
if err != nil {
return resp, err
}
return resp, cli.checkResponseErr(resp)
}
func (cli *Client) doRequest(ctx context.Context, req *http.Request) (serverResponse, error) {
serverResp := serverResponse{statusCode: -1, reqURL: req.URL}
resp, err := ctxhttp.Do(ctx, cli.client, req)
if err != nil {
if cli.scheme != "https" && strings.Contains(err.Error(), "malformed HTTP response") {
return serverResp, fmt.Errorf("%v.\n* Are you trying to connect to a TLS-enabled daemon without TLS?", err)
}
if cli.scheme == "https" && strings.Contains(err.Error(), "bad certificate") {
return serverResp, fmt.Errorf("The server probably has client authentication (--tlsverify) enabled. Please check your TLS client certification settings: %v", err)
}
// Don't decorate context sentinel errors; users may be comparing to
// them directly.
switch err {
case context.Canceled, context.DeadlineExceeded:
return serverResp, err
}
if nErr, ok := err.(*url.Error); ok {
if nErr, ok := nErr.Err.(*net.OpError); ok {
if os.IsPermission(nErr.Err) {
return serverResp, errors.Wrapf(err, "Got permission denied while trying to connect to the Docker daemon socket at %v", cli.host)
}
}
}
if err, ok := err.(net.Error); ok {
if err.Timeout() {
return serverResp, ErrorConnectionFailed(cli.host)
}
if !err.Temporary() {
if strings.Contains(err.Error(), "connection refused") || strings.Contains(err.Error(), "dial unix") {
return serverResp, ErrorConnectionFailed(cli.host)
}
}
}
// Although there's not a strongly typed error for this in go-winio,
// lots of people are using the default configuration for the docker
// daemon on Windows where the daemon is listening on a named pipe
// `//./pipe/docker_engine, and the client must be running elevated.
// Give users a clue rather than the not-overly useful message
// such as `error during connect: Get http://%2F%2F.%2Fpipe%2Fdocker_engine/v1.26/info:
// open //./pipe/docker_engine: The system cannot find the file specified.`.
// Note we can't string compare "The system cannot find the file specified" as
// this is localised - for example in French the error would be
// `open //./pipe/docker_engine: Le fichier spécifié est introuvable.`
if strings.Contains(err.Error(), `open //./pipe/docker_engine`) {
err = errors.New(err.Error() + " In the default daemon configuration on Windows, the docker client must be run elevated to connect. This error may also indicate that the docker daemon is not running.")
}
return serverResp, errors.Wrap(err, "error during connect")
}
if resp != nil {
serverResp.statusCode = resp.StatusCode
serverResp.body = resp.Body
serverResp.header = resp.Header
}
return serverResp, nil
}
func (cli *Client) checkResponseErr(serverResp serverResponse) error {
if serverResp.statusCode >= 200 && serverResp.statusCode < 400 {
return nil
}
body, err := ioutil.ReadAll(serverResp.body)
if err != nil {
return err
}
if len(body) == 0 {
return fmt.Errorf("request returned %s for API route and version %s, check if the server supports the requested API version", http.StatusText(serverResp.statusCode), serverResp.reqURL)
}
var ct string
if serverResp.header != nil {
ct = serverResp.header.Get("Content-Type")
}
var errorMessage string
if (cli.version == "" || versions.GreaterThan(cli.version, "1.23")) && ct == "application/json" {
var errorResponse types.ErrorResponse
if err := json.Unmarshal(body, &errorResponse); err != nil {
return fmt.Errorf("Error reading JSON: %v", err)
}
errorMessage = errorResponse.Message
} else {
errorMessage = string(body)
}
return fmt.Errorf("Error response from daemon: %s", strings.TrimSpace(errorMessage))
}
func (cli *Client) addHeaders(req *http.Request, headers headers) *http.Request {
// Add CLI Config's HTTP Headers BEFORE we set the Docker headers
// then the user can't change OUR headers
for k, v := range cli.customHTTPHeaders {
if versions.LessThan(cli.version, "1.25") && k == "User-Agent" {
continue
}
req.Header.Set(k, v)
}
if headers != nil {
for k, v := range headers {
req.Header[k] = v
}
}
return req
}
func encodeData(data interface{}) (*bytes.Buffer, error) {
params := bytes.NewBuffer(nil)
if data != nil {
if err := json.NewEncoder(params).Encode(data); err != nil {
return nil, err
}
}
return params, nil
}
func ensureReaderClosed(response serverResponse) {
if response.body != nil {
// Drain up to 512 bytes and close the body to let the Transport reuse the connection
io.CopyN(ioutil.Discard, response.body, 512)
response.body.Close()
}
}