DevStack部署报错求助：执行./stack.sh时出现Python2.7(Django)错误

Hey there! Let's work through that Python 2.7/Django error you're hitting with DevStack's ./stack.sh script. This is a super common issue, especially since modern DevStack versions have fully moved to Python 3—here's how to fix it step by step:

1. Check Your DevStack Branch Compatibility #

First off, most newer DevStack branches (like stable/ussuri and later) no longer support Python 2.7. If you're using an older branch (e.g., stable/queens or earlier), those do rely on Python 2, but they're no longer maintained (no security patches, bug fixes, etc.).

• To check your current branch:

  git branch
  

• If you can, switch to a Python 3-compatible branch:

  git checkout stable/ussuri
  git submodule update --init
  

2. Force DevStack to Use Python 3 #

If you absolutely need to stick with your current branch (though I strongly advise against it for security reasons), you can override the Python version in your local.conf file:

• Edit devstack/local.conf and add these lines:

  USE_PYTHON3=True
  FORCE_PYTHON3=True
  

This tells DevStack to prioritize Python 3 for all dependency installs, so it won't pull in Python 2-specific Django versions.

3. Clean Up Old Python 2 Environment Residues #

Leftover Python 2 packages or cached environments can mess up the installation. Let's wipe those out:

• Stop any running DevStack services:

  ./unstack.sh
  

• Run the official cleanup script to remove old dependencies and virtual environments:

  ./clean.sh
  

• If your system has pip2 installed, manually uninstall any Python 2 Django packages:

  sudo pip2 uninstall django -y
  

4. Set Python 3 as Your System Default #

Make sure your system's default Python points to a 3.x version (not 2.7):

• Check your current default:

  python --version
  

• If it's still Python 2, use update-alternatives to switch (adjust the path to your Python 3 version if needed):

  sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.8 1
  sudo update-alternatives --config python
  

Select the Python 3 option when prompted.

5. (Last Resort) Match Django Version to Python 2 #

If you must use an old DevStack branch that requires Python 2, you'll need to install a Django version that supports Python 2 (the last one is Django 1.11.29):

• Create a custom requirements directory (e.g., ~/devstack-custom-requirements)
• Inside it, create a global-requirements.txt file with:

  django==1.11.29
  

• Edit devstack/local.conf to point to this directory:

  REQUIREMENTS_DIR=~/devstack-custom-requirements
  

A Quick Note of Caution #

Using Python 2 or unsupported Django versions is a huge security risk—these haven't received security patches in years. If at all possible, upgrading to a modern, supported DevStack branch is the best long-term fix.

内容的提问来源于stack exchange，提问作者rania triki