错误信息
在使用Dockerfile建立Docker镜像的时候，使用pip下载安装numpy时，出现以下error，Record！
ERROR: Exception:
Traceback (most recent call last):
File "/opt/conda/lib/python3.6/site-packages/pip/_vendor/urllib3/response.py", line 437, in _error_catcher
yield
File "/opt/conda/lib/python3.6/site-packages/pip/_vendor/urllib3/response.py", line 519, in read
data = self._fp.read(amt) if not fp_closed else b""
File "/opt/conda/lib/python3.6/site-packages/pip/_vendor/cachecontrol/filewrapper.py", line 62, in read
data = self.__fp.read(amt)
File "/opt/conda/lib/python3.6/http/client.py", line 449, in read
n = self.readinto(b)
File "/opt/conda/lib/python3.6/http/client.py", line 493, in readinto
n = self.fp.readinto(b)
File "/opt/conda/lib/python3.6/socket.py", line 586, in readinto
return self._sock.recv_into(b)
File "/opt/conda/lib/python3.6/ssl.py", line 1012, in recv_into
return self.read(nbytes, buffer)
File "/opt/conda/lib/python3.6/ssl.py", line 874, in read
return self._sslobj.read(len, buffer)
File "/opt/conda/lib/python3.6/ssl.py", line 631, in read
v = self._sslobj.read(len, buffer)
socket.timeout: The read operation timed out
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/opt/conda/lib/python3.6/site-packages/pip/_internal/cli/base_command.py", line 228, in _main
status = self.run(options, args)
File "/opt/conda/lib/python3.6/site-packages/pip/_internal/cli/req_command.py", line 182, in wrapper
return func(self, options, args)
File "/opt/conda/lib/python3.6/site-packages/pip/_internal/commands/install.py", line 324, in run
reqs, check_supported_wheels=not options.target_dir
File "/opt/conda/lib/python3.6/site-packages/pip/_internal/resolution/legacy/resolver.py", line 183, in resolve
discovered_reqs.extend(self._resolve_one(requirement_set, req))
File "/opt/conda/lib/python3.6/site-packages/pip/_internal/resolution/legacy/resolver.py", line 388, in _resolve_one
abstract_dist = self._get_abstract_dist_for(req_to_install)
File "/opt/conda/lib/python3.6/site-packages/pip/_internal/resolution/legacy/resolver.py", line 340, in _get_abstract_dist_for
abstract_dist = self.preparer.prepare_linked_requirement(req)
File "/opt/conda/lib/python3.6/site-packages/pip/_internal/operations/prepare.py", line 469, in prepare_linked_requirement
hashes=self._get_linked_req_hashes(req)
File "/opt/conda/lib/python3.6/site-packages/pip/_internal/operations/prepare.py", line 259, in unpack_url
hashes=hashes,
File "/opt/conda/lib/python3.6/site-packages/pip/_internal/operations/prepare.py", line 130, in get_http_url
link, downloader, temp_dir.path, hashes
File "/opt/conda/lib/python3.6/site-packages/pip/_internal/operations/prepare.py", line 282, in _download_http_url
for chunk in download.chunks:
File "/opt/conda/lib/python3.6/site-packages/pip/_internal/cli/progress_bars.py", line 168, in iter
for x in it:
File "/opt/conda/lib/python3.6/site-packages/pip/_internal/network/utils.py", line 88, in response_chunks
decode_content=False,
File "/opt/conda/lib/python3.6/site-packages/pip/_vendor/urllib3/response.py", line 576, in stream
data = self.read(amt=amt, decode_content=decode_content)
File "/opt/conda/lib/python3.6/site-packages/pip/_vendor/urllib3/response.py", line 541, in read
raise IncompleteRead(self._fp_bytes_read, self.length_remaining)
File "/opt/conda/lib/python3.6/contextlib.py", line 99, in __exit__
self.gen.throw(type, value, traceback)
File "/opt/conda/lib/python3.6/site-packages/pip/_vendor/urllib3/response.py", line 442, in _error_catcher
raise ReadTimeoutError(self._pool, None, "Read timed out.")
pip._vendor.urllib3.exceptions.ReadTimeoutError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Read timed out.原因
由于国内网络原因，pip下载会非常耗时。
解决
添加参数：--default-timeout=1000 --no-cache-dir。
即 pip install --default-timeout=1000 --no-cache-dir -r /app/requirements.txt \