func (s *Server) postContainersCreate(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
	if err := parseForm(r); err != nil {
		return err
	}
	if err := checkForJSON(r); err != nil {
		return err
	}
	var (
		warnings []string
		name     = r.Form.Get("name")
	)

	config, hostConfig, err := runconfig.DecodeContainerConfig(r.Body)
	if err != nil {
		return err
	}
	version := ctx.Version()
	adjustCPUShares := version.LessThan("1.19")

	container, warnings, err := s.daemon.ContainerCreate(name, config, hostConfig, adjustCPUShares)
	if err != nil {
		return err
	}

	return writeJSON(w, http.StatusCreated, &types.ContainerCreateResponse{
		ID:       container.ID,
		Warnings: warnings,
	})
}

func makeHttpHandler(logging bool, localMethod string, localRoute string, handlerFunc HttpApiFunc, corsHeaders string, dockerVersion version.Version) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		// log the request
		logrus.Debugf("Calling %s %s", localMethod, localRoute)

		if logging {
			logrus.Infof("%s %s", r.Method, r.RequestURI)
		}

		if strings.Contains(r.Header.Get("User-Agent"), "Docker-Client/") {
			userAgent := strings.Split(r.Header.Get("User-Agent"), "/")

			// v1.20 onwards includes the GOOS of the client after the version
			// such as Docker/1.7.0 (linux)
			if len(userAgent) == 2 && strings.Contains(userAgent[1], " ") {
				userAgent[1] = strings.Split(userAgent[1], " ")[0]
			}

			if len(userAgent) == 2 && !dockerVersion.Equal(version.Version(userAgent[1])) {
				logrus.Debugf("Warning: client and server don't have the same version (client: %s, server: %s)", userAgent[1], dockerVersion)
			}
		}
		version := version.Version(mux.Vars(r)["version"])
		if version == "" {
			version = api.Version
		}
		if corsHeaders != "" {
			writeCorsHeaders(w, r, corsHeaders)
		}

		if version.GreaterThan(api.Version) {
			http.Error(w, fmt.Errorf("client is newer than server (client API version: %s, server API version: %s)", version, api.Version).Error(), http.StatusBadRequest)
			return
		}
		if version.LessThan(api.MinVersion) {
			http.Error(w, fmt.Errorf("client is too old, minimum supported API version is %s, please upgrade your client to a newer version", api.MinVersion).Error(), http.StatusBadRequest)
			return
		}

		w.Header().Set("Server", "Docker/"+dockerversion.VERSION+" ("+runtime.GOOS+")")

		if err := handlerFunc(version, w, r, mux.Vars(r)); err != nil {
			logrus.Errorf("Handler for %s %s returned error: %s", localMethod, localRoute, err)
			httpError(w, err)
		}
	}
}