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moby--moby/registry/endpoint.go
Derek McGowan 55f0ca94e5 Use request factory for registry ping
Currently when the registry ping is sent, it creates the request directly from http.NewRequest instead of from the http request factory. The request factory adds useful header information such as user agent which is needed by the registry.

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
2015-03-16 14:21:00 -07:00

264 lines
7.8 KiB
Go

package registry
import (
"encoding/json"
"fmt"
"io/ioutil"
"net"
"net/http"
"net/url"
"strings"
log "github.com/Sirupsen/logrus"
"github.com/docker/docker/registry/v2"
"github.com/docker/docker/utils"
)
// for mocking in unit tests
var lookupIP = net.LookupIP
// scans string for api version in the URL path. returns the trimmed address, if version found, string and API version.
func scanForAPIVersion(address string) (string, APIVersion) {
var (
chunks []string
apiVersionStr string
)
if strings.HasSuffix(address, "/") {
address = address[:len(address)-1]
}
chunks = strings.Split(address, "/")
apiVersionStr = chunks[len(chunks)-1]
for k, v := range apiVersions {
if apiVersionStr == v {
address = strings.Join(chunks[:len(chunks)-1], "/")
return address, k
}
}
return address, APIVersionUnknown
}
// NewEndpoint parses the given address to return a registry endpoint.
func NewEndpoint(index *IndexInfo) (*Endpoint, error) {
// *TODO: Allow per-registry configuration of endpoints.
endpoint, err := newEndpoint(index.GetAuthConfigKey(), index.Secure)
if err != nil {
return nil, err
}
if err := validateEndpoint(endpoint); err != nil {
return nil, err
}
return endpoint, nil
}
func validateEndpoint(endpoint *Endpoint) error {
log.Debugf("pinging registry endpoint %s", endpoint)
// Try HTTPS ping to registry
endpoint.URL.Scheme = "https"
if _, err := endpoint.Ping(); err != nil {
if endpoint.IsSecure {
// If registry is secure and HTTPS failed, show user the error and tell them about `--insecure-registry`
// in case that's what they need. DO NOT accept unknown CA certificates, and DO NOT fallback to HTTP.
return fmt.Errorf("invalid registry endpoint %s: %v. If this private registry supports only HTTP or HTTPS with an unknown CA certificate, please add `--insecure-registry %s` to the daemon's arguments. In the case of HTTPS, if you have access to the registry's CA certificate, no need for the flag; simply place the CA certificate at /etc/docker/certs.d/%s/ca.crt", endpoint, err, endpoint.URL.Host, endpoint.URL.Host)
}
// If registry is insecure and HTTPS failed, fallback to HTTP.
log.Debugf("Error from registry %q marked as insecure: %v. Insecurely falling back to HTTP", endpoint, err)
endpoint.URL.Scheme = "http"
var err2 error
if _, err2 = endpoint.Ping(); err2 == nil {
return nil
}
return fmt.Errorf("invalid registry endpoint %q. HTTPS attempt: %v. HTTP attempt: %v", endpoint, err, err2)
}
return nil
}
func newEndpoint(address string, secure bool) (*Endpoint, error) {
var (
endpoint = new(Endpoint)
trimmedAddress string
err error
)
if !strings.HasPrefix(address, "http") {
address = "https://" + address
}
trimmedAddress, endpoint.Version = scanForAPIVersion(address)
if endpoint.URL, err = url.Parse(trimmedAddress); err != nil {
return nil, err
}
endpoint.IsSecure = secure
return endpoint, nil
}
func (repoInfo *RepositoryInfo) GetEndpoint() (*Endpoint, error) {
return NewEndpoint(repoInfo.Index)
}
// Endpoint stores basic information about a registry endpoint.
type Endpoint struct {
URL *url.URL
Version APIVersion
IsSecure bool
AuthChallenges []*AuthorizationChallenge
URLBuilder *v2.URLBuilder
}
// Get the formated URL for the root of this registry Endpoint
func (e *Endpoint) String() string {
return fmt.Sprintf("%s/v%d/", e.URL, e.Version)
}
// VersionString returns a formatted string of this
// endpoint address using the given API Version.
func (e *Endpoint) VersionString(version APIVersion) string {
return fmt.Sprintf("%s/v%d/", e.URL, version)
}
// Path returns a formatted string for the URL
// of this endpoint with the given path appended.
func (e *Endpoint) Path(path string) string {
return fmt.Sprintf("%s/v%d/%s", e.URL, e.Version, path)
}
func (e *Endpoint) Ping() (RegistryInfo, error) {
// The ping logic to use is determined by the registry endpoint version.
factory := HTTPRequestFactory(nil)
switch e.Version {
case APIVersion1:
return e.pingV1(factory)
case APIVersion2:
return e.pingV2(factory)
}
// APIVersionUnknown
// We should try v2 first...
e.Version = APIVersion2
regInfo, errV2 := e.pingV2(factory)
if errV2 == nil {
return regInfo, nil
}
// ... then fallback to v1.
e.Version = APIVersion1
regInfo, errV1 := e.pingV1(factory)
if errV1 == nil {
return regInfo, nil
}
e.Version = APIVersionUnknown
return RegistryInfo{}, fmt.Errorf("unable to ping registry endpoint %s\nv2 ping attempt failed with error: %s\n v1 ping attempt failed with error: %s", e, errV2, errV1)
}
func (e *Endpoint) pingV1(factory *utils.HTTPRequestFactory) (RegistryInfo, error) {
log.Debugf("attempting v1 ping for registry endpoint %s", e)
if e.String() == IndexServerAddress() {
// Skip the check, we know this one is valid
// (and we never want to fallback to http in case of error)
return RegistryInfo{Standalone: false}, nil
}
req, err := factory.NewRequest("GET", e.Path("_ping"), nil)
if err != nil {
return RegistryInfo{Standalone: false}, err
}
resp, _, err := doRequest(req, nil, ConnectTimeout, e.IsSecure)
if err != nil {
return RegistryInfo{Standalone: false}, err
}
defer resp.Body.Close()
jsonString, err := ioutil.ReadAll(resp.Body)
if err != nil {
return RegistryInfo{Standalone: false}, fmt.Errorf("error while reading the http response: %s", err)
}
// If the header is absent, we assume true for compatibility with earlier
// versions of the registry. default to true
info := RegistryInfo{
Standalone: true,
}
if err := json.Unmarshal(jsonString, &info); err != nil {
log.Debugf("Error unmarshalling the _ping RegistryInfo: %s", err)
// don't stop here. Just assume sane defaults
}
if hdr := resp.Header.Get("X-Docker-Registry-Version"); hdr != "" {
log.Debugf("Registry version header: '%s'", hdr)
info.Version = hdr
}
log.Debugf("RegistryInfo.Version: %q", info.Version)
standalone := resp.Header.Get("X-Docker-Registry-Standalone")
log.Debugf("Registry standalone header: '%s'", standalone)
// Accepted values are "true" (case-insensitive) and "1".
if strings.EqualFold(standalone, "true") || standalone == "1" {
info.Standalone = true
} else if len(standalone) > 0 {
// there is a header set, and it is not "true" or "1", so assume fails
info.Standalone = false
}
log.Debugf("RegistryInfo.Standalone: %t", info.Standalone)
return info, nil
}
func (e *Endpoint) pingV2(factory *utils.HTTPRequestFactory) (RegistryInfo, error) {
log.Debugf("attempting v2 ping for registry endpoint %s", e)
req, err := factory.NewRequest("GET", e.Path(""), nil)
if err != nil {
return RegistryInfo{}, err
}
resp, _, err := doRequest(req, nil, ConnectTimeout, e.IsSecure)
if err != nil {
return RegistryInfo{}, err
}
defer resp.Body.Close()
// The endpoint may have multiple supported versions.
// Ensure it supports the v2 Registry API.
var supportsV2 bool
HeaderLoop:
for _, supportedVersions := range resp.Header[http.CanonicalHeaderKey("Docker-Distribution-API-Version")] {
for _, versionName := range strings.Fields(supportedVersions) {
if versionName == "registry/2.0" {
supportsV2 = true
break HeaderLoop
}
}
}
if !supportsV2 {
return RegistryInfo{}, fmt.Errorf("%s does not appear to be a v2 registry endpoint", e)
}
if resp.StatusCode == http.StatusOK {
// It would seem that no authentication/authorization is required.
// So we don't need to parse/add any authorization schemes.
return RegistryInfo{Standalone: true}, nil
}
if resp.StatusCode == http.StatusUnauthorized {
// Parse the WWW-Authenticate Header and store the challenges
// on this endpoint object.
e.AuthChallenges = parseAuthHeader(resp.Header)
return RegistryInfo{}, nil
}
return RegistryInfo{}, fmt.Errorf("v2 registry endpoint returned status %d: %q", resp.StatusCode, http.StatusText(resp.StatusCode))
}