Clarify graph view dynamic task labels

[bbovenzi]

Fixing an issue reported in #28973
Closes: #29105

Skipped dynamic tasks put us in a position where a task was mapped but it had not mapped states and updating the graph labels would fail.

Also, handling mapped tasks vs mapped task groups were confusing. This PR aims to simplify that.

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[talnagar]

hi
Is there a way we can patch this fix in the airflow docker image we are using?
we would really like to patch it till the next version is released since it really bothers some of our users.
the js files go through some build process, can we simulate it somehow?
thanks

[potiuk]

Sure. You can build your own airflow package and install it. Look at the INSTALL and https://github.com/apache/airflow/blob/main/INSTALL#L114 . You can also use breeze CLI https://github.com/apache/airflow/blob/main/BREEZE.rst#preparing-airflow-packages to build packages in consistent way.

[talnagar]

thanks @potiuk

[KarthikRajashekaran]

I have cherry-picked the commit and applied it to the docker image, still I don't see the graph
Below is sample of the DockerFile

# Global Docker Build arguments
ARG AIRFLOW_VERSION=2.5.1
ARG PYTHON_RUNTIME_VERSION=3.8
FROM apache/airflow:${AIRFLOW_VERSION}-python${PYTHON_RUNTIME_VERSION}
SHELL ["/bin/bash", "-o", "pipefail", "-e", "-u", "-x", "-c"]
# Cherry pick the changes into the Dockerfile
RUN curl -o /home/airflow/.local/lib/python3.8/site-packages/airflow/www/static/js/graph.js https://raw.githubusercontent.com/apache/airflow/main/airflow/www/static/js/graph.js
......
......

[pierrejeambrun]

Hello @KarthikRajashekaran,

Front end assets are built/bundled using webpack. So you would need to rebuild this part in your image for it to work. (python setup.py compile_assets command pointed by Jarek or directly using yarn)

As Jarek mentioned, you can also use breeze to build docker images and python packages in a consistent way. Here you could rebuild your own version of the airflow package with this patch, then extend your docker image to use this patched airflow version.

I believe you could also directly build the docker image from the patched source by customising your image. But keeping a version of the patched package is preferable I think.

Hope this helps.