Event handler to "unlock" GCPs Vertex.AI hyperparameter tuning service

Dear PyTorch team,

I have developed a custom event handler that would make ignite code (more specifically: MONAI code) accessible to hyperparamer tuning jobs in GCP Vertex AI. It is an Ignite-tified version of this Link. As you can see from the code in the link, the metrics are simply saved at a certain time, in a certain place with a certain syntax. Once this is possible the Vertex HPO orchestration kicks in. Input arguments are controlled via Vertex.AI custom training jobs and output model performance can be extracted from that output file written at the end of the training.

Why is this useful? With this handler Ignite code can be subject to "outsourced" hyperparameter screening with just adding this handler and a few lines of Vertex config files. I found the outsourcing of HPO to the cloud platform way easier than coding it myself.

If you want I can contribute my solution to the codebase via a PR. Just let me know.