feature:inject-config

Introduction

feature:inject-config writes your feature’s config.py from the environment variables its code reads. The framework calls its inject_config(app) when it loads the feature, so every variable lands in app.config with its default. Run it after you add an os.getenv.

splent feature:inject-config splent_feature_followers

  feature:inject-config — splent_feature_followers

  Detected 2 env var(s):
    FOLLOWERS_DIGEST_HOUR               default: "8"
    FOLLOWERS_MAX_PER_DAY               default: "50"

  ✅ config.py created.

"""
followers feature configuration.

Auto-generated by `splent feature:inject-config`.
Injects environment variables into Flask app.config.
"""

import os


def inject_config(app):
    app.config.update({
        "FOLLOWERS_DIGEST_HOUR": int(os.getenv("FOLLOWERS_DIGEST_HOUR", "8")),
        "FOLLOWERS_MAX_PER_DAY": int(os.getenv("FOLLOWERS_MAX_PER_DAY", "50")),
    })

Previewing and updating

splent feature:inject-config splent_feature_followers --dry-run

--dry-run prints the file and writes nothing. Run without it after you read a new variable, and the whole file is generated again (config.py updated (1 new var(s)).). When nothing is missing, it prints config.py is already up to date.

Replacing a config.py you wrote by hand

splent feature:inject-config splent_feature_followers --force

A config.py without the Auto-generated line, and that is not the empty scaffold of feature:create, was written by hand. The command refuses to regenerate it and exits 1, so add the variables yourself or pass --force.

What it detects

It reads every .py file of the package except config.py and migrations/. It finds os.getenv, os.environ.get and os.environ[...] with an uppercase name. Without a default, the default is "".

Default in the code	In `config.py`
`True`, `False`, `"true"`, `"false"`	`os.getenv("KEY", "True").lower() == "true"`
An integer, or a string of digits	`int(os.getenv("KEY", "3600"))`
Another literal, or a call on `os` or a builtin	`os.getenv("KEY", <default>)`
A name `config.py` does not import	`os.getenv("KEY") # default in source: <expr>`, with a warning

Reference

Argument or option	Description
`FEATURE_REF`	`splent_feature_followers` or `<namespace>/splent_feature_followers`. The editable copy at the workspace root
`--dry-run`	Print the generated `config.py` without writing it
`--force`	Replace a `config.py` written by hand

It exits 1 when the feature is not at the workspace root, when config.py was written by hand and --force is missing, or when the generated file is not valid Python.

Requirements

A selected product (SPLENT_APP).