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从环境变量加载机密信息

使用环境变量将密钥排除在源代码之外

从环境变量加载机密信息 是 CoddyKit 上的免费 Flask Academy 课时。这是第 2 节课，共 4 节。你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。这是 Flask Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Flask Academy 课程共包含 4 节课。

本课时的部分内容尚未翻译，以英文显示。

Secrets Do Not Belong in Code

API keys and passwords pasted into source files leak the moment you push to Git. Keep secrets out of your repository entirely.

The Twelve-Factor Idea

The twelve-factor approach stores config in the environment, so the same code ships everywhere with no edits.

Read One with os.environ

Use os.environ to read a variable. It raises a clear error if the key is missing, which is great for required secrets.

import os
key = os.environ["SECRET_KEY"]

Optional Values with get

Use os.environ.get for optional settings and supply a fallback so your app still boots in development.

debug = os.environ.get("DEBUG", "0")

Wire It into a Config Class

Read env vars right inside your Config class so every environment gets its secrets from the system, not the source.

SECRET_KEY = os.environ.get("SECRET_KEY")

Set a Variable in the Shell

On your machine, export the value before running. The process inherits it, and Flask picks it up.

export SECRET_KEY=super-secret

Everything Is a String

Env vars arrive as strings. Convert numbers and booleans yourself, since "0" is truthy in Python.

port = int(os.environ.get("PORT", "5000"))

Fail Fast on Missing Secrets

In production, a missing secret should crash on startup, not midway. Fail fast so the problem is obvious immediately.

if not SECRET_KEY:
    raise RuntimeError("SECRET_KEY required")

Where the Platform Sets Them

Hosts like Heroku, Docker, and Kubernetes inject env vars at deploy time, so no secret ever sits in your image.

Generate a Strong Key

A SECRET_KEY should be long and random. Generate one with secrets.token_hex and store it as an env var.

import secrets
secrets.token_hex(32)

Never Log a Secret

Avoid printing config that holds secrets. A stray log line in a dashboard exposes the very value you protected.

Quick Check

How should you handle a required secret that is missing in production?

Recap: Env Secrets

You read secrets from os.environ, gave optional ones defaults, converted types, and failed fast when required keys were missing. 🔐

常见问题解答

「从环境变量加载机密信息」课时是免费的吗？

是的 — 「从环境变量加载机密信息」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Flask Academy 课程的其余内容，请升级到 CoddyKit PRO。 Flask Academy 课程共包含 4 节课。

「从环境变量加载机密信息」这节课中我会学到什么？

使用环境变量将密钥排除在源代码之外你通过在浏览器中直接运行的动手代码来练习 Flask Academy，全天候 AI 导师会在你学习这节课的过程中回答你的问题。

学习 Flask Academy 需要有经验吗？

无需任何先前经验。CoddyKit 上的 Flask Academy 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。这是第 2 节课，共 4 节。

「从环境变量加载机密信息」课时需要多长时间？

大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。

我能在这节 Flask Academy 课中编写并运行代码吗？

能。每节 Flask Academy 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。

此课程中的所有课时

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