英文:
How to wait till POST request is finished in GO?
问题
你好，我正在使用GO创建一个POST请求，但是它在实际完成之前就终止了。例如，我正在尝试使用curl拉取一个Docker镜像，可以使用以下命令完成：
curl -X POST https://address/images/create?fromImage=imagename
这将返回以下内容：
{"status":"Pulling from imagename","id":"latest"}
{"status":"Already exists","progressDetail":{},"id":"3d30e94188f7"}
{"status":"Already exists","progressDetail":{},"id":"bf4e27765153"}
{"status":"Already exists","progressDetail":{},"id":"67280fd39fba"}
.... 许多类似的输出
{"status":"Pull complete","progressDetail":{},"id":"21c062e2346f"}
{"status":"Digest: sha256:24f26a1344fca6d5ee1adcdsf2d01b20d7823c560ed9d2193466e36bd1f049088"}
{"status":"Pulling from imagename","id":"20161005"}
{"status":"Digest: sha256:f527dsfds88676eb25d8f7de5406f46cbc3a995345ddb4bb3d08fcf110458fe3cf"}
{"status":"Status: Downloaded newer image for imagename"}
并且成功拉取了镜像。
但是，如果我尝试使用GO来实现：
func PullImage(imagename string, uuid string) error {
logFields := log.Fields{
"handler": "PullImage",
"uuid": uuid,
}
log.WithFields(logFields).Debugf("imagename:%v", imagename)
url := fmt.Sprintf("https://%s/images/create?fromImage%s", sconf.Docker.Endpoint, imagename)
req, err := http.NewRequest("POST", url, nil)
req.Header.Set("Content-Type", "application/json")
resp, err := client.Do(req)
log.WithFields(logFields).Infof("call url:%s", url)
if err != nil {
log.WithFields(logFields).Errorf("Error in call url (%s) :%s", url, err)
return errors.New(fmt.Sprintf("Error in call url (%s) :%s", url, err))
}
var pullresbody interface{}
err = json.NewDecoder(resp.Body).Decode(&pullresbody)
if err != nil {
log.WithFields(logFields).Errorf("Could not unmarshal json: %s", err)
return errors.New(fmt.Sprintf("Could not unmarshal json: %s", err))
}
log.WithFields(logFields).Infof("response of url %s:%+v", url, resp)
log.WithFields(logFields).Infof("response body:%+v", pullresbody)
return nil
}
然后在日志中我得到了这个：
map[status:Pulling from imagename]
并且镜像没有被拉取，所以连接在真正完成之前就被停止了。我该如何解决这个问题？
英文:
Hi I am creating a POST request in GO but it terminates before actually finishing, for example I am trying to pull a docker image and this can be done with curl by the following:
curl -X POST https://address/images/create?fromImage=imagename
this returns the following
{"status":"Pulling from imagename","id":"latest"}
{"status":"Already exists","progressDetail":{},"id":"3d30e94188f7"}
{"status":"Already exists","progressDetail":{},"id":"bf4e27765153"}
{"status":"Already exists","progressDetail":{},"id":"67280fd39fba"}
.... many of those
{"status":"Pull complete","progressDetail":{},"id":"21c062e2346f"}
{"status":"Digest: sha256:24f26a1344fca6d5ee1adcdsf2d01b20d7823c560ed9d2193466e36bd1f049088"}
{"status":"Pulling from imagename","id":"20161005"}
{"status":"Digest: sha256:f527dsfds88676eb25d8f7de5406f46cbc3a995345ddb4bb3d08fcf110458fe3cf"}
{"status":"Status: Downloaded newer image for imagename"}
and the image is pulled successfully
but If I try from go
func PullImage(imagename string, uuid string) error {
logFields := log.Fields{
"handler": "PullImage",
"uuid": uuid,
}
log.WithFields(logFields).Debugf("imagename:%v", imagename)
url := fmt.Sprintf("https://%s/images/create?fromImage%s", sconf.Docker.Endpoint, imagename)
req, err := http.NewRequest("POST", url, nil)
req.Header.Set("Content-Type", "application/json")
resp, err := client.Do(req)
log.WithFields(logFields).Infof("call url:%s", url)
if err != nil {
log.WithFields(logFields).Errorf("Error in call url (%s) :%s", url, err)
return errors.New(fmt.Sprintf("Error in call url (%s) :%s", url, err))
}
var pullresbody interface{}
err = json.NewDecoder(resp.Body).Decode(&pullresbody)
if err != nil {
log.WithFields(logFields).Errorf("Could not unmarshal json: %s", err)
return errors.New(fmt.Sprintf("Could not unmarshal json: %s", err))
}
log.WithFields(logFields).Infof("response of url %s:%+v", url, resp)
log.WithFields(logFields).Infof("response body:%+v", pullresbody)
return nil
}
then I get this in the logs:
map[status:Pulling from imagename]
and the image is not pulled so the connection is stopped before really finishing how can I fix this?
答案1
得分: 3
Decoder每次只能从流中解码一个对象。要获取所有的对象，你需要像下面这样做：
var pullRespBody interface{}
dec := json.NewDecoder(resp.Body)
var err error
for err == nil {
err = dec.Decode(&pullRespBody)
// 检查 err...
log.WithFields(logFields).Infof("response body:%+v", pullRespBody)
// 对 pullRespBody 进行其他操作...
}
// 处理 err...
这段代码使用了json包中的Decoder来解码JSON对象。通过循环调用Decode方法，可以逐个获取所有的对象。在每次解码后，你可以对pullRespBody进行其他操作。最后，你可以处理可能出现的错误（err）。
英文:
The Decoder will only decode one object from a stream at a time. To get all objects, you'll need something like
var pullRespBody interface{}
dec := json.NewDecoder(resp.Body)
var err error
for err == nil {
err = dec.Decode(&pullRespBody)
// Check err...
log.WithFields(logFields).Infof("response body:%+v", pullRespBody)
// Do something else with pullRespBody...
}
// Deal with err...
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论