Guest environment release notes

This page documents updates to the guest environment, which is a set of scripts, daemons, and binaries that read metadata server content to ensure instances function correctly on Compute Engine. The central component of the guest environment is the guest agent, which handles tasks like account management, OS Login integration, and network interface management. For more information about the guest environment, see Guest environment.

Check this page for announcements about new or updated features, bug fixes, known issues, and deprecated functionality.

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September 18, 2025

Version 20250918.01 of the guest agent is now available. This guest agent version introduces the plugin-based architecture to the following Debian and Enterprise Linux 10 operating systems:

  • Red Hat Enterprise Linux (RHEL) 10
  • Rocky Linux 10
  • CentOS Stream 10
  • Debian 13

For more information about the plugin-based architecture, see Guest agent.

Version 20250918.01 includes the following fixes for issues found in plugin-based architecture. For more information about the plugin-based architecture, see Guest agent.

  • Corrects an issue in the OS Login module that was incorrectly writing perm_denied=die PAM module configuration when two-factor authentication isn't enabled.
  • Fixes an issue in the metadata-based SSH module where re-adding a user didn't add the user to the sudoers group.

September 09, 2025

Version 20250907.00 of the guest agent, which introduces the plugin-based architecture to Enterprise Linux 8 operating systems, is now available. For more information about the plugin-based architecture, see Guest agent.

With this version, the plugin-based guest agent is now also available for the following operating systems:

  • Red Hat Enterprise Linux (RHEL) 8
  • Rocky Linux 8
  • CentOS Stream 8
  • Oracle Linux 8
  • AlmaLinux 8

Version 20250907.00 includes the following fixes for issues found in guest agent version 20250901.00:

  • Corrects an issue in the OS Login module that was incorrectly handling optional runtime systemd dependencies and causing an error log.
  • Fixes a bug that could cause the metadata SSH key module to enter an infinite loop when setting up SSH keys. This occurred if an initial setup attempt failed and the metadata server returned the SSH keys in a different order on a subsequent retry.

September 03, 2025

Starting with version 20250901.00, the guest agent is migrated to a new plugin-based architecture to improve modularity. You can revert to the previous version by setting the metadata attribute enable-guest-agent-core-plugin to FALSE. For more information about the plugin-based architecture, see Guest agent.

This plugin-based guest agent is available for the following operating systems:

  • Red Hat Enterprise Linux (RHEL) 9
  • Rocky Linux 9
  • CentOS Stream 9
  • Oracle Linux 9
  • AlmaLinux 9

With the introduction of the plugin-based architecture, the guest agent includes the following updates:

  • A new command-line tool, ggactl_plugin, is available to manage and restart the guest agent core plugin. To restart the agent, run:

    ggactl_plugin coreplugin restart

    For more information, see Restarting the guest agent.

  • All guest agent components now use a new logging framework. This framework lets you set the logging level in the guest agent configuration file. For more information about the logging options, see core settings in the configuration options table.

  • The workload refresh service gce-workload-cert-refresher is now part of the guest agent's core plugin. It is no longer a separate systemd service.

  • The guest agent updates the metadata script runner and the Authorized Keys binary (Windows only) to use the new, configurable logging framework. Compatibility managers are included to facilitate the migration.

An issue is fixed where network routes were not consistently applied (GitHub Issue #516). The system now consistently applies network routes by monitoring the route table and re-adding routes when they disappear.