Installation and Usage of Python Plugins¤
Plugins are a released as parts of Python packages. They can but do not need to be open-source and published on pypi.org (a widely used Python Package Index). One package can contain of multiple plugins.
If you want to install a python plugin package, you need to use cmemc’s admin workspace python command group.
The following shell commands demonstrate the basic workflow:
$ cmemc admin workspace python install cmem-plugin-graphql Install package cmem-plugin-graphql ... done
$ cmemc admin workspace python list-plugins ID Type Label --------------------------------- -------------- ------------- cmem_plugin_graphql-GraphQLPlugin WorkflowPlugin GraphQL query
You can get a list of all installed python packages: (1)
- This list contains all installed packages in the python environment, not just your plugin packages.
$ cmemc admin workspace python list Name Version ------------------ ----------- certifi 2022.5.18.1 charset-normalizer 2.0.12 cmem-cmempy 22.1.1 cmem-plugin-base 1.2.0 idna 3.3 isodate 0.6.1 jep 4.0.2 pip 20.3.4 pyparsing 3.0.9 rdflib 6.1.1 requests 2.27.1 requests-toolbelt 0.9.1 setuptools 52.0.0 six 1.16.0 urllib3 1.26.9 wheel 0.34.2
You also can (un-)install packages in a specific version or from a source distribution file. Please have a look at the admin workspace python command group for a complete documentation of the package / plugin commands.
Depending on the plugin type, an installed plugin can appear in different parts of the Build workbench:
Workflow Plugins are listed in the Create new item dialog in the Task category. From there, you can create a task in your project and use it in a workflow.
Transform Plugins are listed in the sidebar of the Value formula editor and the Linking editor in the Transform tab. Drag and drop it on the canvas, and connect it with ingoing and / or outgoing links to other elements.
PYTHONPATH via NFS
PYTHONPATH is the location where the installed python plugins and their dependencies are stored for DataIntegration.
When you share this path via NFS, there are issues with open file locks which will sometimes break the plugin installation requests.
A workaround for this is to install or upgrade plugins right after rebooting DataIntergration (and before you start a workflow that uses a python plugin).
We currently advise against using NFS on this path directly.
The problem is known by the python community but there is no fix or workaround available yet.