The Logging Agent

This guide describes the Stackdriver Logging agent, an application based on fluentd that runs on your Google Compute Engine and Amazon EC2 virtual machine (VM) instances. The Logging agent streams logs from common third-party applications and system software to Stackdriver Logging. It is a best practice to install the Logging agent on all your VM instances.

To install the Logging agent, see Installing the Logging Agent.

Supported configurations

The Logging agent is compatible with the following environments.

Stackdriver service tiers

You can use the Logging agent with supported Amazon Web Services VM instances only if your AWS account is linked to a Stackdriver account in the Premium Service Tier.

You can use the Logging agent with supported Google Cloud Platform VM instances that are not linked with a Stackdriver account, or that are linked to an account in either the Basic or Premium tiers.

For more information about Stackdriver accounts and service tiers, see Stackdriver Pricing.

Virtual machine instances

By default, only virtual machine (VM) instances with external IP addresses can access Google APIs.

The Stackdriver Logging agent supports the following kinds of VM instances:

• Google Compute Engine instances. The Logging agent sends the logs to each instance's associated project. For instances without external IP addresses, you must enable Private Google Access to allow the Logging agent to send logs.

• Amazon Elastic Compute Cloud (EC2) instances. The Logging agent sends the logs to the AWS connector project for your Stackdriver account. Stackdriver creates this project for you when you connect your AWS account to a Stackdriver account. The account must be in the Premium service tier.

The following VM instances support Stackdriver Logging using their own software, possibly including custom versions or configurations of the Logging agent. Manually installing the Stackdriver Logging agent on them is not supported:

• Google App Engine includes built-in support for Stackdriver Logging in the standard environment. For more information, see Stackdriver Logging in App Engine Apps.

• Google App Engine flexible environments.

• Google Container Engine node instances. You can enable support for Stackdriver Logging on your new container clusters by selecting a checkbox.

Operating systems

The Logging agent supports the following operating systems on compatible VM instances:

• Amazon Linux AMI
• CentOS 7 and 6
• Debian 8 "Jessie", Debian 7 "Wheezy", and Debian-7-backports
• Red Hat Enterprise Linux 7 and 6
• Ubuntu LTS 12.04 "Precise", LTS 14.04 "Trusty", 14.10 "Utopic", 15.04 "Vivid", 15.10 "Wiley", LTS 16.04 "Xenial"
• Windows Server 2008 R2, 2012 R2, and 2016

Third party and system logs

By default, the Stackdriver Logging agent is configured to stream logs included in the list of supported logs. You can configure the agent to stream additional logs.

Installing the Logging agent

If you are ready to install the Logging agent, see Installing the Stackdriver Logging Agent.

Getting the Logging agent source code

The Logging agent is installed by a script described in the installation instructions. You do not need the information in this section unless you want to understand the source code or you have other special needs.

The Logging agent, google-fluentd, is a modified version of the fluentd log data collector. google-fluentd is distributed in two separate packages:

• A package named google-fluentd that includes the core fluentd program, the custom packaging scripts, and the output plugin for the Stackdriver Logging API.
  • The output plugin is packaged as a Ruby gem and is included in the google-fluentd package. It is also available separately at the Ruby gem hosting service at fluent-plugin-google-cloud.
• A package named fluentd-catch-all-config that includes the configuration files for the Logging agent and for the logs from various third-party software packages.

Here is where you can find additional Stackdriver Logging agent software:

• The sources for the custom packaging are at google-fluentd.
• The sources for the output plugin are at fluent-plugin-google-cloud.

Next steps

• Install the logging agent.