diff options
Diffstat (limited to 'azurelinuxagent/common/utils/restutil.py')
| -rw-r--r-- | azurelinuxagent/common/utils/restutil.py | 386 |
1 files changed, 270 insertions, 116 deletions
diff --git a/azurelinuxagent/common/utils/restutil.py b/azurelinuxagent/common/utils/restutil.py index 49d2d68..ddd930b 100644 --- a/azurelinuxagent/common/utils/restutil.py +++ b/azurelinuxagent/common/utils/restutil.py @@ -17,20 +17,74 @@ # Requires Python 2.4+ and Openssl 1.0+ # +import os import time +import traceback import azurelinuxagent.common.conf as conf import azurelinuxagent.common.logger as logger -from azurelinuxagent.common.exception import HttpError -from azurelinuxagent.common.future import httpclient, urlparse +import azurelinuxagent.common.utils.textutil as textutil -""" -REST api util functions -""" +from azurelinuxagent.common.exception import HttpError, ResourceGoneError +from azurelinuxagent.common.future import httpclient, urlparse, ustr +from azurelinuxagent.common.version import PY_VERSION_MAJOR -RETRY_WAITING_INTERVAL = 3 -secure_warning = True +SECURE_WARNING_EMITTED = False + +DEFAULT_RETRIES = 3 + +SHORT_DELAY_IN_SECONDS = 5 +LONG_DELAY_IN_SECONDS = 15 + +RETRY_CODES = [ + httpclient.RESET_CONTENT, + httpclient.PARTIAL_CONTENT, + httpclient.FORBIDDEN, + httpclient.INTERNAL_SERVER_ERROR, + httpclient.NOT_IMPLEMENTED, + httpclient.BAD_GATEWAY, + httpclient.SERVICE_UNAVAILABLE, + httpclient.GATEWAY_TIMEOUT, + httpclient.INSUFFICIENT_STORAGE, + 429, # Request Rate Limit Exceeded +] + +RESOURCE_GONE_CODES = [ + httpclient.BAD_REQUEST, + httpclient.GONE +] + +OK_CODES = [ + httpclient.OK, + httpclient.CREATED, + httpclient.ACCEPTED +] + +THROTTLE_CODES = [ + httpclient.FORBIDDEN, + httpclient.SERVICE_UNAVAILABLE +] + +RETRY_EXCEPTIONS = [ + httpclient.NotConnected, + httpclient.IncompleteRead, + httpclient.ImproperConnectionState, + httpclient.BadStatusLine +] + +HTTP_PROXY_ENV = "http_proxy" +HTTPS_PROXY_ENV = "https_proxy" + + +def _is_retry_status(status, retry_codes=RETRY_CODES): + return status in retry_codes + +def _is_retry_exception(e): + return len([x for x in RETRY_EXCEPTIONS if isinstance(e, x)]) > 0 + +def _is_throttle_status(status): + return status in THROTTLE_CODES def _parse_url(url): o = urlparse(url) @@ -45,46 +99,57 @@ def _parse_url(url): return o.hostname, o.port, secure, rel_uri -def get_http_proxy(): - """ - Get http_proxy and https_proxy from environment variables. - Username and password is not supported now. - """ +def _get_http_proxy(secure=False): + # Prefer the configuration settings over environment variables host = conf.get_httpproxy_host() - port = conf.get_httpproxy_port() + port = None + + if not host is None: + port = conf.get_httpproxy_port() + + else: + http_proxy_env = HTTPS_PROXY_ENV if secure else HTTP_PROXY_ENV + http_proxy_url = None + for v in [http_proxy_env, http_proxy_env.upper()]: + if v in os.environ: + http_proxy_url = os.environ[v] + break + + if not http_proxy_url is None: + host, port, _, _ = _parse_url(http_proxy_url) + return host, port def _http_request(method, host, rel_uri, port=None, data=None, secure=False, headers=None, proxy_host=None, proxy_port=None): - url, conn = None, None + + headers = {} if headers is None else headers + use_proxy = proxy_host is not None and proxy_port is not None + + if port is None: + port = 443 if secure else 80 + + if use_proxy: + conn_host, conn_port = proxy_host, proxy_port + scheme = "https" if secure else "http" + url = "{0}://{1}:{2}{3}".format(scheme, host, port, rel_uri) + + else: + conn_host, conn_port = host, port + url = rel_uri + if secure: - port = 443 if port is None else port - if proxy_host is not None and proxy_port is not None: - conn = httpclient.HTTPSConnection(proxy_host, - proxy_port, - timeout=10) + conn = httpclient.HTTPSConnection(conn_host, + conn_port, + timeout=10) + if use_proxy: conn.set_tunnel(host, port) - # If proxy is used, full url is needed. - url = "https://{0}:{1}{2}".format(host, port, rel_uri) - else: - conn = httpclient.HTTPSConnection(host, - port, - timeout=10) - url = rel_uri + else: - port = 80 if port is None else port - if proxy_host is not None and proxy_port is not None: - conn = httpclient.HTTPConnection(proxy_host, - proxy_port, - timeout=10) - # If proxy is used, full url is needed. - url = "http://{0}:{1}{2}".format(host, port, rel_uri) - else: - conn = httpclient.HTTPConnection(host, - port, - timeout=10) - url = rel_uri + conn = httpclient.HTTPConnection(conn_host, + conn_port, + timeout=10) logger.verbose("HTTP connection [{0}] [{1}] [{2}] [{3}]", method, @@ -92,49 +157,70 @@ def _http_request(method, host, rel_uri, port=None, data=None, secure=False, data, headers) - headers = {} if headers is None else headers conn.request(method=method, url=url, body=data, headers=headers) - resp = conn.getresponse() - return resp + return conn.getresponse() -def http_request(method, url, data, headers=None, max_retry=3, - chk_proxy=False): - """ - Sending http request to server - On error, sleep 10 and retry max_retry times. - """ +def http_request(method, + url, data, headers=None, + use_proxy=False, + max_retry=DEFAULT_RETRIES, + retry_codes=RETRY_CODES, + retry_delay=SHORT_DELAY_IN_SECONDS): + + global SECURE_WARNING_EMITTED + host, port, secure, rel_uri = _parse_url(url) - global secure_warning - # Check proxy + # Use the HTTP(S) proxy proxy_host, proxy_port = (None, None) - if chk_proxy: - proxy_host, proxy_port = get_http_proxy() + if use_proxy: + proxy_host, proxy_port = _get_http_proxy(secure=secure) - # If httplib module is not built with ssl support. Fallback to http + if proxy_host or proxy_port: + logger.verbose("HTTP proxy: [{0}:{1}]", proxy_host, proxy_port) + + # If httplib module is not built with ssl support, + # fallback to HTTP if allowed if secure and not hasattr(httpclient, "HTTPSConnection"): + if not conf.get_allow_http(): + raise HttpError("HTTPS is unavailable and required") + secure = False - if secure_warning: - logger.warn("httplib is not built with ssl support") - secure_warning = False + if not SECURE_WARNING_EMITTED: + logger.warn("Python does not include SSL support") + SECURE_WARNING_EMITTED = True + + # If httplib module doesn't support HTTPS tunnelling, + # fallback to HTTP if allowed + if secure and \ + proxy_host is not None and \ + proxy_port is not None \ + and not hasattr(httpclient.HTTPSConnection, "set_tunnel"): + + if not conf.get_allow_http(): + raise HttpError("HTTPS tunnelling is unavailable and required") - # If httplib module doesn't support https tunnelling. Fallback to http - if secure and proxy_host is not None and proxy_port is not None \ - and not hasattr(httpclient.HTTPSConnection, "set_tunnel"): secure = False - if secure_warning: - logger.warn("httplib does not support https tunnelling " - "(new in python 2.7)") - secure_warning = False - - if proxy_host or proxy_port: - logger.verbose("HTTP proxy: [{0}:{1}]", proxy_host, proxy_port) - - retry_msg = '' - log_msg = "HTTP {0}".format(method) - for retry in range(0, max_retry): - retry_interval = RETRY_WAITING_INTERVAL + if not SECURE_WARNING_EMITTED: + logger.warn("Python does not support HTTPS tunnelling") + SECURE_WARNING_EMITTED = True + + msg = '' + attempt = 0 + delay = retry_delay + + while attempt < max_retry: + if attempt > 0: + logger.info("[HTTP Retry] Attempt {0} of {1}: {2}", + attempt+1, + max_retry, + msg) + time.sleep(delay) + + attempt += 1 + delay = retry_delay + try: resp = _http_request(method, host, @@ -145,55 +231,123 @@ def http_request(method, url, data, headers=None, max_retry=3, headers=headers, proxy_host=proxy_host, proxy_port=proxy_port) - logger.verbose("HTTP response status: [{0}]", resp.status) + logger.verbose("[HTTP Response] Status Code {0}", resp.status) + + if request_failed(resp): + if _is_retry_status(resp.status, retry_codes=retry_codes): + msg = '[HTTP Retry] HTTP {0} Status Code {1}'.format( + method, resp.status) + if _is_throttle_status(resp.status): + delay = LONG_DELAY_IN_SECONDS + logger.info("[HTTP Delay] Delay {0} seconds for " \ + "Status Code {1}".format( + delay, resp.status)) + continue + + if resp.status in RESOURCE_GONE_CODES: + raise ResourceGoneError() + return resp + except httpclient.HTTPException as e: - retry_msg = 'HTTP exception: {0} {1}'.format(log_msg, e) - retry_interval = 5 + msg = '[HTTP Failed] HTTP {0} HttpException {1}'.format(method, e) + if _is_retry_exception(e): + continue + break + except IOError as e: - retry_msg = 'IO error: {0} {1}'.format(log_msg, e) - # error 101: network unreachable; when the adapter resets we may - # see this transient error for a short time, retry once. - if e.errno == 101: - retry_interval = RETRY_WAITING_INTERVAL - max_retry = 1 + msg = '[HTTP Failed] HTTP {0} IOError {1}'.format(method, e) + continue + + raise HttpError(msg) + + +def http_get(url, headers=None, use_proxy=False, + max_retry=DEFAULT_RETRIES, + retry_codes=RETRY_CODES, + retry_delay=SHORT_DELAY_IN_SECONDS): + return http_request("GET", + url, None, headers=headers, + use_proxy=use_proxy, + max_retry=max_retry, + retry_codes=retry_codes, + retry_delay=retry_delay) + + +def http_head(url, headers=None, use_proxy=False, + max_retry=DEFAULT_RETRIES, + retry_codes=RETRY_CODES, + retry_delay=SHORT_DELAY_IN_SECONDS): + return http_request("HEAD", + url, None, headers=headers, + use_proxy=use_proxy, + max_retry=max_retry, + retry_codes=retry_codes, + retry_delay=retry_delay) + + +def http_post(url, data, headers=None, use_proxy=False, + max_retry=DEFAULT_RETRIES, + retry_codes=RETRY_CODES, + retry_delay=SHORT_DELAY_IN_SECONDS): + return http_request("POST", + url, data, headers=headers, + use_proxy=use_proxy, + max_retry=max_retry, + retry_codes=retry_codes, + retry_delay=retry_delay) + + +def http_put(url, data, headers=None, use_proxy=False, + max_retry=DEFAULT_RETRIES, + retry_codes=RETRY_CODES, + retry_delay=SHORT_DELAY_IN_SECONDS): + return http_request("PUT", + url, data, headers=headers, + use_proxy=use_proxy, + max_retry=max_retry, + retry_codes=retry_codes, + retry_delay=retry_delay) + + +def http_delete(url, headers=None, use_proxy=False, + max_retry=DEFAULT_RETRIES, + retry_codes=RETRY_CODES, + retry_delay=SHORT_DELAY_IN_SECONDS): + return http_request("DELETE", + url, None, headers=headers, + use_proxy=use_proxy, + max_retry=max_retry, + retry_codes=retry_codes, + retry_delay=retry_delay) + +def request_failed(resp, ok_codes=OK_CODES): + return not request_succeeded(resp, ok_codes=ok_codes) + +def request_succeeded(resp, ok_codes=OK_CODES): + return resp is not None and resp.status in ok_codes + +def read_response_error(resp): + result = '' + if resp is not None: + try: + result = "[HTTP Failed] [{0}: {1}] {2}".format( + resp.status, + resp.reason, + resp.read()) + + # this result string is passed upstream to several methods + # which do a raise HttpError() or a format() of some kind; + # as a result it cannot have any unicode characters + if PY_VERSION_MAJOR < 3: + result = ustr(result, encoding='ascii', errors='ignore') else: - retry_interval = 0 - max_retry = 0 - - if retry < max_retry: - logger.info("Retry [{0}/{1} - {3}]", - retry+1, - max_retry, - retry_interval, - retry_msg) - time.sleep(retry_interval) - - raise HttpError("{0} failed".format(log_msg)) - - -def http_get(url, headers=None, max_retry=3, chk_proxy=False): - return http_request("GET", url, data=None, headers=headers, - max_retry=max_retry, chk_proxy=chk_proxy) - - -def http_head(url, headers=None, max_retry=3, chk_proxy=False): - return http_request("HEAD", url, None, headers=headers, - max_retry=max_retry, chk_proxy=chk_proxy) - - -def http_post(url, data, headers=None, max_retry=3, chk_proxy=False): - return http_request("POST", url, data, headers=headers, - max_retry=max_retry, chk_proxy=chk_proxy) - - -def http_put(url, data, headers=None, max_retry=3, chk_proxy=False): - return http_request("PUT", url, data, headers=headers, - max_retry=max_retry, chk_proxy=chk_proxy) - + result = result\ + .encode(encoding='ascii', errors='ignore')\ + .decode(encoding='ascii', errors='ignore') -def http_delete(url, headers=None, max_retry=3, chk_proxy=False): - return http_request("DELETE", url, None, headers=headers, - max_retry=max_retry, chk_proxy=chk_proxy) + result = textutil.replace_non_ascii(result) -# End REST api util functions + except Exception: + logger.warn(traceback.format_exc()) + return result |