Linux Guest Environment for Google Compute Engine

This repository stores the collection of packages installed on Google supported Compute Engine images.

Table of Contents

• Background
• Packaging
  • Version Updates
  • Package Distribution
• Troubleshooting
• Contributing
• License

Background

The Linux guest environment denotes the Google provided configuration and tooling inside of a Google Compute Engine (GCE) virtual machine. The metadata server is a communication channel for transferring information from a client into the guest. The Linux guest environment includes a set of scripts and daemons (long-running processes) that read the content of the metadata server to make a virtual machine run properly on our platform.

Packaging

The guest Python code is packaged as a compliant PyPI Python package that can be used as a library or run independently. In addition to the Python package, deb and rpm packages are created with appropriate init configuration for supported GCE distros. The packages are targeted towards distribution provided Python versions.

Distro	Package Type	Python Version	Init System
SLES 12	rpm	2.7	systemd
SLES 15	rpm	3.6	systemd
CentOS 6	rpm	2.6	upstart
CentOS 7	rpm	2.7	systemd
RHEL 6	rpm	2.6	upstart
RHEL 7	rpm	2.7	systemd
RHEL 8	rpm	3.6	systemd
Ubuntu 14.04	deb	2.7	upstart
Ubuntu 16.04	deb	3.5 or 2.7	systemd
Ubuntu 18.04	deb	3.6	systemd
Ubuntu 19.04	deb	3.7	systemd
Debian 9	deb	3.5 or 2.7	systemd
Debian 10	deb	3.7	systemd

We build the following packages for the Linux guest environment.

• google-compute-engine
  • System init scripts (systemd, upstart, or sysvinit).
  • Includes udev rules, sysctl rules, rsyslog configs, dhcp configs for hostname setting.
  • Entry point scripts created by the Python package located in /usr/bin.
  • Includes bash scripts used by instance_setup.
• python-google-compute-engine
  • The Python 2 package for Linux daemons and libraries.
• python3-google-compute-engine
  • The Python 3 package for Linux daemons and libraries.
• google-compute-engine-oslogin
  • The PAM and NSS modules for OS Login
• gce-disk-expand
  • The on-boot resize scripts for root partition.

The package sources (RPM spec files and Debian packaging directories) are also included in this project. There are also Daisy workflows for spinning up GCE VM's to automatically build the packages for Debian, Red Hat, and CentOS. See the README in the packaging directory for more details.

Version Updates

Versions are described as 1:YYYYMMDD.NN-gN, meaning epoch 1 to denote from a distro maintained package which will be 0, a date string formatted as year, month, day, an incrementing minor release, and gN representing the Google package release. Debian, Ubuntu, and SUSE maintain distro packages which may be out of date, have different versioning, or naming.

The method for making version updates differs by package.

• All packages need the VERSION variable set in the setup_{deb,rpm}.sh build scripts.
• All packages need the debian/changelog file updated. Please use dch(1) to update it.
• python-google-compute-engine additionally needs the version specified in setup.py. This is used for entry points through the Python egg and PyPI.
• google-compute-engine-oslogin needs the version also updated in the Makefile.

Package Distribution

The deb and rpm packages are published to Google Cloud repositories. Debian, CentOS, and RHEL use these repositories to install and update the google-compute-engine, google-compute-engine-oslogin and python-google-compute-engine (and python3-google-compute-engine for Python 3) packages. If you are creating a custom image, you can also use these repositories in your image.

For Debian, run the following commands as root:

Add the public repo key to your system:

curl https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -

Add a source list file /etc/apt/sources.list.d/google-cloud.list and change DIST to either stretch for Debian 9 or buster for Debian 10:

DIST=stretch
sudo tee /etc/apt/sources.list.d/google-cloud.list << EOM
deb http://packages.cloud.google.com/apt google-compute-engine-${DIST}-stable main
deb http://packages.cloud.google.com/apt google-cloud-packages-archive-keyring-${DIST} main
EOM

Install the packages to maintain the public key over time:

sudo apt update; sudo apt install -y google-cloud-packages-archive-keyring

You are then able to install any of the packages from this repo.

For RedHat based distributions, run the following commands as root:

Add the yum repo to a repo file /etc/yum.repos.d/google-cloud.repo for EL6, EL7, or EL8. Change DIST to either 6, 7, or 8 respectively:

DIST=7
tee /etc/yum.repos.d/google-cloud.repo << EOM
[google-compute-engine]
name=Google Compute Engine
baseurl=https://packages.cloud.google.com/yum/repos/google-compute-engine-el${DIST}-x86_64-stable
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
       https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOM

You are then able to install any of the packages from this repo.

Troubleshooting

Deprecated Packages

Deprecated Package	Replacement
google-compute-engine-jessie	google-compute-engine and python-google-compute-engine
google-compute-engine-stretch	google-compute-engine and python-google-compute-engine
google-compute-engine-init	google-compute-engine
google-compute-engine-init-jessie	google-compute-engine
google-compute-engine-init-stretch	google-compute-engine
google-config	google-compute-engine
google-config-jessie	google-compute-engine
google-config-stretch	google-compute-engine
google-compute-daemon	python-google-compute-engine
google-startup-scripts	google-compute-engine

An old CentOS 6 image fails to install the packages with an error on SCL

CentOS 6 images prior to v20160526 may fail to install the package with the error:

http://mirror.centos.org/centos/6/SCL/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"

Remove the stale repository file: sudo rm -f /etc/yum.repos.d/CentOS-SCL.repo

On some CentOS or RHEL 6 systems, extraneous python egg directories can cause the python daemons to fail.

In /usr/lib/python2.6/site-packages look for google_compute_engine-2.4.1-py27.egg-info directories and google_compute_engine-2.5.2.egg-info directories and delete them if you run into this problem.

Using boto with virtualenv

Specific to running boto inside of a Python virtualenv, virtual environments are isolated from system site-packages. This includes the installed Linux guest environment libraries that are used to configure boto credentials. There are two recommended solutions:

• Create a virtual environment with virtualenv venv --system-site-packages.
• Install boto via the Linux guest environment PyPI package using pip install google-compute-engine.

Contributing

Have a patch that will benefit this project? Awesome! Follow these steps to have it accepted.

1. Please sign our Contributor License Agreement.
2. Fork this Git repository and make your changes.
3. Create a Pull Request against the development branch.
4. Incorporate review feedback to your changes.
5. Accepted!

License

All files in this repository are under the Apache License, Version 2.0 unless noted otherwise.