use override file name in config

[qsh-zh]

Here is a toy example with the following config tree

├── config.yaml
├── net
│   ├── cnn.yaml
│   └── mlp.yaml
└── optimizer
    ├── adam.yaml
    └── sgd.yaml

And config.yaml reads

defaults:
  - net: cnn
  - optimizer: sgd
 
name: cnn_sgd

and example of cnn.yaml

_target_: SomeFancyCNN
num_layer: 3

Question

In the above example, we have totally 4 combinations~([cnn, mlp] x [sgd, adam]). Do we have a smart and automatic way to set name, for example,

python run.py net=mlp optimizer=adam # config.name -> mlp_adam
python run.py net=mlp optimizer=sgd # config.name -> mlp_sgd
python run.py net=cnn optimizer=sgd # config.name -> cnn_sgd

[Jasha10]

A few possibilities come to mind:

• You could use ${hydra:runtime.choices} to get a list of config group choices. This list could be further processed by a custom resolver to turn the list into a string.
• ${hydra:job.override_dirname} is a convenience providing a ready-to-use string representing the overrides used for the current job.