Improve configuration handling with KServe

[sgaist]

🐛 Describe the bug

The current implementation of the configuration file loading when using the KServe wrapper is sub-optimal.

Based on the content of the __main__.py file, there are several defaults values that are in use however, if any of the corresponding keys are missing from the configuration file, a KeyError will get triggered and thus the execution will never reach the default value handling code.

The configuration loading also does not ignore lines starting with # as the file format defines.

Error logs

INFO:root:Wrapper: loading configuration from ts-config.conf
Traceback (most recent call last):
File "/path/to/pytorch-serve/kubernetes/kserve/kserve_wrapper/main.py", line 103, in
) = parse_config()
File "/path/to/pytorch-serve/kubernetes/kserve/kserve_wrapper/main.py", line 46, in parse_config
keys["model_snapshot"] = json.loads(keys["model_snapshot"])
KeyError: 'model_snapshot'

Installation instructions

Installed torchserve from sources

Model Packaing

Using the mnist example

config.properties

enable_envvars_config=true

Versions

---

Environment headers

Torchserve branch:

torchserve==0.9.0
torch-model-archiver==0.9.0b20240224

Python version: 3.10 (64-bit runtime)
Python executable: /Users/home/miniconda3/envs/pytorch-serve-dev/bin/python

Versions of relevant python libraries:
captum==0.6.0
numpy==1.24.3
pillow==10.2.0
psutil==5.9.8
pygit2==1.13.3
pylint==3.0.3
pytest==7.3.1
pytest-cov==4.1.0
pytest-mock==3.12.0
requests==2.31.0
requests-oauthlib==1.3.1
requests-toolbelt==1.0.0
torch==2.2.1
torch-model-archiver==0.9.0b20240224
torch-workflow-archiver==0.2.11b20240224
torchaudio==2.2.1
torchdata==0.7.1
torchpippy==0.1.1
torchserve==0.9.0
torchtext==0.17.1
torchvision==0.17.1
transformers==4.38.1
wheel==0.42.0
torch==2.2.1
torchtext==0.17.1
torchvision==0.17.1
torchaudio==2.2.1

Java Version:

OS: Mac OSX 13.6.4 (arm64)
GCC version: N/A
Clang version: 15.0.0 (clang-1500.1.0.2.5)
CMake version: version 3.28.3

Versions of npm installed packages:
**Warning: newman, newman-reporter-html markdown-link-check not installed...

Repro instructions

Follow the mnist example and start torchserve

Create the properties file

Start the kserve wrapper

 CONFIG_PATH=./ts-config.conf python3 kubernetes/kserve/kserve_wrapper/__main__.py

Possible Solution

For the default part, refactor the properties handling so that if a key is missing, the default value is used.

For the # add a check for that character before handling the line.