升级到 Python 3.6 后启动时无法启动 cloud-init
Failed to start cloud-init at startup after upgrading to Python 3.6
我在新的云服务器 (Ubuntu 16.04) 上安装了 Python 3.6 而不是默认的 3.5 版本。我重启服务器后，发现启动时无法执行cloud-init，在syslog.
中出现如下错误
Sep 20 16:16:14 cloud-init[1310]: Traceback (most recent call last):
Sep 20 16:16:14 cloud-init[1310]: File "/usr/bin/cloud-init", line 9, in <module>
Sep 20 16:16:14 cloud-init[1310]: load_entry_point('cloud-init==0.7.9', 'console_scripts', 'cloud-init')()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 570, in load_entry_point
Sep 20 16:16:14 cloud-init[1310]: return get_distribution(dist).load_entry_point(group, name)
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 2751, in load_entry_point
Sep 20 16:16:14 cloud-init[1310]: return ep.load()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 2405, in load
Sep 20 16:16:14 cloud-init[1310]: return self.resolve()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 2411, in resolve
Sep 20 16:16:14 cloud-init[1310]: module = __import__(self.module_name, fromlist=['__name__'], level=0)
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/cloudinit/cmd/main.py", line 27, in <module>
Sep 20 16:16:14 cloud-init[1310]: from cloudinit import stages
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/cloudinit/stages.py", line 21, in <module>
Sep 20 16:16:14 cloud-init[1310]: from cloudinit.handlers import cloud_config as cc_part
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/cloudinit/handlers/cloud_config.py", line 11, in <module>
Sep 20 16:16:14 cloud-init[1310]: import jsonpatch
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/jsonpatch.py", line 114, in <module>
Sep 20 16:16:14 cloud-init[1310]: json.load = get_loadjson()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/jsonpatch.py", line 108, in get_loadjson
Sep 20 16:16:14 cloud-init[1310]: argspec = inspect.getargspec(json.load)
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3.6/inspect.py", line 1072, in getargspec
Sep 20 16:16:14 cloud-init[1310]: raise ValueError("Function has keyword-only parameters or annotations"
Sep 20 16:16:14 cloud-init[1310]: ValueError: Function has keyword-only parameters or annotations, use getfullargspec() API which can support them
Sep 20 16:16:14 cloud-init[1310]: Error in sys.excepthook:
Sep 20 16:16:14 cloud-init[1310]: Traceback (most recent call last):
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook
Sep 20 16:16:14 cloud-init[1310]: from apport.fileutils import likely_packaged, get_recent_crashes
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>
Sep 20 16:16:14 cloud-init[1310]: from apport.report import Report
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>
Sep 20 16:16:14 cloud-init[1310]: import apport.fileutils
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>
Sep 20 16:16:14 cloud-init[1310]: from apport.packaging_impl import impl as packaging
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 23, in <module>
Sep 20 16:16:14 cloud-init[1310]: import apt
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>
Sep 20 16:16:14 cloud-init[1310]: import apt_pkg
Sep 20 16:16:14 cloud-init[1310]: ModuleNotFoundError: No module named 'apt_pkg'
Sep 20 16:16:14 cloud-init[1310]: Original exception was:
Sep 20 16:16:14 cloud-init[1310]: Traceback (most recent call last):
Sep 20 16:16:14 cloud-init[1310]: File "/usr/bin/cloud-init", line 9, in <module>
Sep 20 16:16:14 cloud-init[1310]: load_entry_point('cloud-init==0.7.9', 'console_scripts', 'cloud-init')()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 570, in load_entry_point
Sep 20 16:16:14 cloud-init[1310]: return get_distribution(dist).load_entry_point(group, name)
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 2751, in load_entry_point
Sep 20 16:16:14 cloud-init[1310]: return ep.load()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 2405, in load
Sep 20 16:16:14 cloud-init[1310]: return self.resolve()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 2411, in resolve
Sep 20 16:16:14 cloud-init[1310]: module = __import__(self.module_name, fromlist=['__name__'], level=0)
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/cloudinit/cmd/main.py", line 27, in <module>
Sep 20 16:16:14 cloud-init[1310]: from cloudinit import stages
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/cloudinit/stages.py", line 21, in <module>
Sep 20 16:16:14 cloud-init[1310]: from cloudinit.handlers import cloud_config as cc_part
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/cloudinit/handlers/cloud_config.py", line 11, in <module>
Sep 20 16:16:14 cloud-init[1310]: import jsonpatch
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/jsonpatch.py", line 114, in <module>
Sep 20 16:16:14 cloud-init[1310]: json.load = get_loadjson()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/jsonpatch.py", line 108, in get_loadjson
Sep 20 16:16:14 cloud-init[1310]: argspec = inspect.getargspec(json.load)
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3.6/inspect.py", line 1072, in getargspec
Sep 20 16:16:14 cloud-init[1310]: raise ValueError("Function has keyword-only parameters or annotations"
Sep 20 16:16:14 cloud-init[1310]: ValueError: Function has keyword-only parameters or annotations, use getfullargspec() API which can support them
Sep 20 16:16:14 systemd[1]: Started MySQL Community Server.
Sep 20 16:16:14 systemd[1]: cloud-config.service: Main process exited, code=exited, status=1/FAILURE
Sep 20 16:16:14 systemd[1]: Failed to start Apply the settings specified in cloud-config.
Sep 20 16:16:14 systemd[1]: cloud-config.service: Unit entered failed state.
Sep 20 16:16:14 systemd[1]: cloud-config.service: Failed with result 'exit-code'.
显然有两个问题：
ModuleNotFoundError: No module named 'apt_pkg'
ValueError: Function has keyword-only parameters or annotations, use getfullargspec() API which can support them
所以我运行apt-get install python3-apt，但是包已经安装好了。然后我运行apt-get install python3-jsonpatch，就成功了。不幸的是，问题没有得到解决。
最后我用 pip 升级 jsonpatch 包解决了这个问题。
$ pip3 install --upgrade jsonpatch
这是旧版本 jsonpatch 上的一个已知错误（兼容性问题）（参见 https://github.com/stefankoegl/python-json-patch/issues/56）。我必须通过 pip 而不是 apt-get 来升级软件包。这可以修复这两个错误。
我在新的云服务器 (Ubuntu 16.04) 上安装了 Python 3.6 而不是默认的 3.5 版本。我重启服务器后，发现启动时无法执行cloud-init，在syslog.
Sep 20 16:16:14 cloud-init[1310]: Traceback (most recent call last):
Sep 20 16:16:14 cloud-init[1310]: File "/usr/bin/cloud-init", line 9, in <module>
Sep 20 16:16:14 cloud-init[1310]: load_entry_point('cloud-init==0.7.9', 'console_scripts', 'cloud-init')()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 570, in load_entry_point
Sep 20 16:16:14 cloud-init[1310]: return get_distribution(dist).load_entry_point(group, name)
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 2751, in load_entry_point
Sep 20 16:16:14 cloud-init[1310]: return ep.load()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 2405, in load
Sep 20 16:16:14 cloud-init[1310]: return self.resolve()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 2411, in resolve
Sep 20 16:16:14 cloud-init[1310]: module = __import__(self.module_name, fromlist=['__name__'], level=0)
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/cloudinit/cmd/main.py", line 27, in <module>
Sep 20 16:16:14 cloud-init[1310]: from cloudinit import stages
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/cloudinit/stages.py", line 21, in <module>
Sep 20 16:16:14 cloud-init[1310]: from cloudinit.handlers import cloud_config as cc_part
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/cloudinit/handlers/cloud_config.py", line 11, in <module>
Sep 20 16:16:14 cloud-init[1310]: import jsonpatch
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/jsonpatch.py", line 114, in <module>
Sep 20 16:16:14 cloud-init[1310]: json.load = get_loadjson()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/jsonpatch.py", line 108, in get_loadjson
Sep 20 16:16:14 cloud-init[1310]: argspec = inspect.getargspec(json.load)
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3.6/inspect.py", line 1072, in getargspec
Sep 20 16:16:14 cloud-init[1310]: raise ValueError("Function has keyword-only parameters or annotations"
Sep 20 16:16:14 cloud-init[1310]: ValueError: Function has keyword-only parameters or annotations, use getfullargspec() API which can support them
Sep 20 16:16:14 cloud-init[1310]: Error in sys.excepthook:
Sep 20 16:16:14 cloud-init[1310]: Traceback (most recent call last):
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook
Sep 20 16:16:14 cloud-init[1310]: from apport.fileutils import likely_packaged, get_recent_crashes
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>
Sep 20 16:16:14 cloud-init[1310]: from apport.report import Report
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>
Sep 20 16:16:14 cloud-init[1310]: import apport.fileutils
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>
Sep 20 16:16:14 cloud-init[1310]: from apport.packaging_impl import impl as packaging
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 23, in <module>
Sep 20 16:16:14 cloud-init[1310]: import apt
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>
Sep 20 16:16:14 cloud-init[1310]: import apt_pkg
Sep 20 16:16:14 cloud-init[1310]: ModuleNotFoundError: No module named 'apt_pkg'
Sep 20 16:16:14 cloud-init[1310]: Original exception was:
Sep 20 16:16:14 cloud-init[1310]: Traceback (most recent call last):
Sep 20 16:16:14 cloud-init[1310]: File "/usr/bin/cloud-init", line 9, in <module>
Sep 20 16:16:14 cloud-init[1310]: load_entry_point('cloud-init==0.7.9', 'console_scripts', 'cloud-init')()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 570, in load_entry_point
Sep 20 16:16:14 cloud-init[1310]: return get_distribution(dist).load_entry_point(group, name)
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 2751, in load_entry_point
Sep 20 16:16:14 cloud-init[1310]: return ep.load()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 2405, in load
Sep 20 16:16:14 cloud-init[1310]: return self.resolve()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py", line 2411, in resolve
Sep 20 16:16:14 cloud-init[1310]: module = __import__(self.module_name, fromlist=['__name__'], level=0)
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/cloudinit/cmd/main.py", line 27, in <module>
Sep 20 16:16:14 cloud-init[1310]: from cloudinit import stages
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/cloudinit/stages.py", line 21, in <module>
Sep 20 16:16:14 cloud-init[1310]: from cloudinit.handlers import cloud_config as cc_part
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/cloudinit/handlers/cloud_config.py", line 11, in <module>
Sep 20 16:16:14 cloud-init[1310]: import jsonpatch
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/jsonpatch.py", line 114, in <module>
Sep 20 16:16:14 cloud-init[1310]: json.load = get_loadjson()
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3/dist-packages/jsonpatch.py", line 108, in get_loadjson
Sep 20 16:16:14 cloud-init[1310]: argspec = inspect.getargspec(json.load)
Sep 20 16:16:14 cloud-init[1310]: File "/usr/lib/python3.6/inspect.py", line 1072, in getargspec
Sep 20 16:16:14 cloud-init[1310]: raise ValueError("Function has keyword-only parameters or annotations"
Sep 20 16:16:14 cloud-init[1310]: ValueError: Function has keyword-only parameters or annotations, use getfullargspec() API which can support them
Sep 20 16:16:14 systemd[1]: Started MySQL Community Server.
Sep 20 16:16:14 systemd[1]: cloud-config.service: Main process exited, code=exited, status=1/FAILURE
Sep 20 16:16:14 systemd[1]: Failed to start Apply the settings specified in cloud-config.
Sep 20 16:16:14 systemd[1]: cloud-config.service: Unit entered failed state.
Sep 20 16:16:14 systemd[1]: cloud-config.service: Failed with result 'exit-code'.
显然有两个问题：
ModuleNotFoundError: No module named 'apt_pkg'
ValueError: Function has keyword-only parameters or annotations, use getfullargspec() API which can support them
所以我运行apt-get install python3-apt，但是包已经安装好了。然后我运行apt-get install python3-jsonpatch，就成功了。不幸的是，问题没有得到解决。
最后我用 pip 升级 jsonpatch 包解决了这个问题。
$ pip3 install --upgrade jsonpatch
这是旧版本 jsonpatch 上的一个已知错误（兼容性问题）（参见 https://github.com/stefankoegl/python-json-patch/issues/56）。我必须通过 pip 而不是 apt-get 来升级软件包。这可以修复这两个错误。