coldmod-py 0.1.1

find cold code

README

Coldmod-py is a tracing library for collecting runtime data from python code, and a CLI for configuration and codemods.

It's implemented with, and test against, the Python version found in .python-version.

Tracing is implemented using "sys.settrace" - built into CPython.

The CLI, which is implemented with Python Fire, can be used to inspect configuration and apply code mods.

Installation

pip install coldmod-py

Setup

The CLI and tracing require these environment variables to be set

COLDMOD_GRPC_HOST
COLDMOD_TLS_CA
COLDMOD_WEB_HOST
COLDMOD_API_KEY
COLDMOD_INSECURE

See Env.md for details on how these environment variables are used.

Tracing

• toml file

(two threads)

CLI

---

Cacheing

• parsing is expensive so trace srcs are cached per file, key by a digest of the relative path+contents

• if the file changes you get a cache miss

• the cache can be cleared with the cli

• Get into the poetry env: poetry shell

• Run a sample: python -m coldmod_py.samples.trace_target_1

• Test command: pytest[-watch]

• Run the cli: python -m coldmod <tracefile> <sourcepath>

• to debug just add breakpoint()

Development

ENV

COLDMOD_GRPC_HOST
COLDMOD_WEB_HOST
COLDMOD_CA
COLDMOD_API_KEY

Editable install

CLI

The CLI is used to apply code mods and check trace configuration.

Installation

Man page:

insert generated man page here

pyright

run it with brew install, it uses node... so I don't want to make every install it as a dep

• vendors coldmod-msg
• coldmod-msg dependencies are a subset of coldmod-py dependencies

setting up in an app via editable install of local checkout

• checkout the __coldmod branch (has a pyproject.toml which has coldmod-py as an editable install)
• activate an env for the app (see __coldmod branch)
• in that shell, go to the root of the app
• poetry install
• pip install -r requirements.txt
• add a line to the entrypoint import coldmod_py; coldmod_py.tracing.start()
• add a coldmod.toml
• start the app
• if coldmod-d isn't running the app should carry on and start but with no tracing
• start coldmod-d
• restart the app

TODO:

• sender architecture
• caching
  • commands
• connect
• ignoring
• about coldmod.rootmarker
• what happens in the web UI we the heatmap is truncated because of ignore.
• limitations of Remove (references)
• strategies of tracing (settrace vs modding, version drift)