distribution/docs/endpoint.go
Victor Vieux 5685221c5f Merge pull request #8387 from vbatts/vbatts-registry_test_enpoint
registry/endpoint: make it testable
2014-10-29 13:36:17 -07:00

136 lines
3.7 KiB
Go

package registry
import (
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"net/http"
"net/url"
"strings"
log "github.com/Sirupsen/logrus"
)
// scans string for api version in the URL path. returns the trimmed hostname, if version found, string and API version.
func scanForAPIVersion(hostname string) (string, APIVersion) {
var (
chunks []string
apiVersionStr string
)
if strings.HasSuffix(hostname, "/") {
chunks = strings.Split(hostname[:len(hostname)-1], "/")
apiVersionStr = chunks[len(chunks)-1]
} else {
chunks = strings.Split(hostname, "/")
apiVersionStr = chunks[len(chunks)-1]
}
for k, v := range apiVersions {
if apiVersionStr == v {
hostname = strings.Join(chunks[:len(chunks)-1], "/")
return hostname, k
}
}
return hostname, DefaultAPIVersion
}
func NewEndpoint(hostname string) (*Endpoint, error) {
endpoint, err := newEndpoint(hostname)
if err != nil {
return nil, err
}
endpoint.URL.Scheme = "https"
if _, err := endpoint.Ping(); err != nil {
log.Debugf("Registry %s does not work (%s), falling back to http", endpoint, err)
// TODO: Check if http fallback is enabled
endpoint.URL.Scheme = "http"
if _, err = endpoint.Ping(); err != nil {
return nil, errors.New("Invalid Registry endpoint: " + err.Error())
}
}
return endpoint, nil
}
func newEndpoint(hostname string) (*Endpoint, error) {
var (
endpoint Endpoint
trimmedHostname string
err error
)
if !strings.HasPrefix(hostname, "http") {
hostname = "https://" + hostname
}
trimmedHostname, endpoint.Version = scanForAPIVersion(hostname)
endpoint.URL, err = url.Parse(trimmedHostname)
if err != nil {
return nil, err
}
return &endpoint, nil
}
type Endpoint struct {
URL *url.URL
Version APIVersion
}
// Get the formated URL for the root of this registry Endpoint
func (e Endpoint) String() string {
return fmt.Sprintf("%s/v%d/", e.URL.String(), e.Version)
}
func (e Endpoint) VersionString(version APIVersion) string {
return fmt.Sprintf("%s/v%d/", e.URL.String(), version)
}
func (e Endpoint) Ping() (RegistryInfo, error) {
if e.String() == IndexServerAddress() {
// Skip the check, we now this one is valid
// (and we never want to fallback to http in case of error)
return RegistryInfo{Standalone: false}, nil
}
req, err := http.NewRequest("GET", e.String()+"_ping", nil)
if err != nil {
return RegistryInfo{Standalone: false}, err
}
resp, _, err := doRequest(req, nil, ConnectTimeout)
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
}