distribution/docs/registry.go
Aaron Lehmann 4bb475cd3c Push/pull errors improvement and cleanup
Several improvements to error handling:

- Introduce ImageConfigPullError type, wrapping errors related to
  downloading the image configuration blob in schema2. This allows for a
  more descriptive error message to be seen by the end user.

- Change some logrus.Debugf calls that display errors to logrus.Errorf.
  Add log lines in the push/pull fallback cases to make sure the errors
  leading to the fallback are shown.

- Move error-related types and functions which are only used by the
  distribution package out of the registry package.

Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
2016-02-11 16:28:56 -08:00

187 lines
5 KiB
Go

// Package registry contains client primitives to interact with a remote Docker registry.
package registry
import (
"crypto/tls"
"crypto/x509"
"errors"
"fmt"
"io/ioutil"
"net"
"net/http"
"os"
"path/filepath"
"runtime"
"strings"
"time"
"github.com/Sirupsen/logrus"
"github.com/docker/distribution/registry/client/transport"
"github.com/docker/go-connections/tlsconfig"
)
var (
// ErrAlreadyExists is an error returned if an image being pushed
// already exists on the remote side
ErrAlreadyExists = errors.New("Image already exists")
)
func init() {
if runtime.GOOS != "linux" {
V2Only = true
}
}
func newTLSConfig(hostname string, isSecure bool) (*tls.Config, error) {
// PreferredServerCipherSuites should have no effect
tlsConfig := tlsconfig.ServerDefault
tlsConfig.InsecureSkipVerify = !isSecure
if isSecure && CertsDir != "" {
hostDir := filepath.Join(CertsDir, cleanPath(hostname))
logrus.Debugf("hostDir: %s", hostDir)
if err := ReadCertsDirectory(&tlsConfig, hostDir); err != nil {
return nil, err
}
}
return &tlsConfig, nil
}
func hasFile(files []os.FileInfo, name string) bool {
for _, f := range files {
if f.Name() == name {
return true
}
}
return false
}
// ReadCertsDirectory reads the directory for TLS certificates
// including roots and certificate pairs and updates the
// provided TLS configuration.
func ReadCertsDirectory(tlsConfig *tls.Config, directory string) error {
fs, err := ioutil.ReadDir(directory)
if err != nil && !os.IsNotExist(err) {
return err
}
for _, f := range fs {
if strings.HasSuffix(f.Name(), ".crt") {
if tlsConfig.RootCAs == nil {
// TODO(dmcgowan): Copy system pool
tlsConfig.RootCAs = x509.NewCertPool()
}
logrus.Debugf("crt: %s", filepath.Join(directory, f.Name()))
data, err := ioutil.ReadFile(filepath.Join(directory, f.Name()))
if err != nil {
return err
}
tlsConfig.RootCAs.AppendCertsFromPEM(data)
}
if strings.HasSuffix(f.Name(), ".cert") {
certName := f.Name()
keyName := certName[:len(certName)-5] + ".key"
logrus.Debugf("cert: %s", filepath.Join(directory, f.Name()))
if !hasFile(fs, keyName) {
return fmt.Errorf("Missing key %s for client certificate %s. Note that CA certificates should use the extension .crt.", keyName, certName)
}
cert, err := tls.LoadX509KeyPair(filepath.Join(directory, certName), filepath.Join(directory, keyName))
if err != nil {
return err
}
tlsConfig.Certificates = append(tlsConfig.Certificates, cert)
}
if strings.HasSuffix(f.Name(), ".key") {
keyName := f.Name()
certName := keyName[:len(keyName)-4] + ".cert"
logrus.Debugf("key: %s", filepath.Join(directory, f.Name()))
if !hasFile(fs, certName) {
return fmt.Errorf("Missing client certificate %s for key %s", certName, keyName)
}
}
}
return nil
}
// DockerHeaders returns request modifiers with a User-Agent and metaHeaders
func DockerHeaders(userAgent string, metaHeaders http.Header) []transport.RequestModifier {
modifiers := []transport.RequestModifier{}
if userAgent != "" {
modifiers = append(modifiers, transport.NewHeaderRequestModifier(http.Header{
"User-Agent": []string{userAgent},
}))
}
if metaHeaders != nil {
modifiers = append(modifiers, transport.NewHeaderRequestModifier(metaHeaders))
}
return modifiers
}
// HTTPClient returns a HTTP client structure which uses the given transport
// and contains the necessary headers for redirected requests
func HTTPClient(transport http.RoundTripper) *http.Client {
return &http.Client{
Transport: transport,
CheckRedirect: addRequiredHeadersToRedirectedRequests,
}
}
func trustedLocation(req *http.Request) bool {
var (
trusteds = []string{"docker.com", "docker.io"}
hostname = strings.SplitN(req.Host, ":", 2)[0]
)
if req.URL.Scheme != "https" {
return false
}
for _, trusted := range trusteds {
if hostname == trusted || strings.HasSuffix(hostname, "."+trusted) {
return true
}
}
return false
}
// addRequiredHeadersToRedirectedRequests adds the necessary redirection headers
// for redirected requests
func addRequiredHeadersToRedirectedRequests(req *http.Request, via []*http.Request) error {
if via != nil && via[0] != nil {
if trustedLocation(req) && trustedLocation(via[0]) {
req.Header = via[0].Header
return nil
}
for k, v := range via[0].Header {
if k != "Authorization" {
for _, vv := range v {
req.Header.Add(k, vv)
}
}
}
}
return nil
}
// NewTransport returns a new HTTP transport. If tlsConfig is nil, it uses the
// default TLS configuration.
func NewTransport(tlsConfig *tls.Config) *http.Transport {
if tlsConfig == nil {
var cfg = tlsconfig.ServerDefault
tlsConfig = &cfg
}
return &http.Transport{
Proxy: http.ProxyFromEnvironment,
Dial: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
DualStack: true,
}).Dial,
TLSHandshakeTimeout: 10 * time.Second,
TLSClientConfig: tlsConfig,
// TODO(dmcgowan): Call close idle connections when complete and use keep alive
DisableKeepAlives: true,
}
}