journald
Overview
Systemd-journald is a system service that collects and stores logging data.
It creates and maintains structured, indexed journals based on logging information from a variety of sources.
Setup
Installation
The journald check is included in the Datadog Agent package.
No additional installation is needed on your server.
Configuration
Journal files, by default, are owned and readable by the systemd-journal system group. To start collecting your journal logs, you need to:
- Install the Agent on the instance running the journal.
- Add the
dd-agent
user to the systemd-journal
group by running: usermod -a -G systemd-journal dd-agent
To configure this check for an Agent running on a host:
Edit the journald.d/conf.yaml
file, in the conf.d/
folder at the root of your Agent’s configuration directory to start collecting logs.
Log collection
Collecting logs is disabled by default in the Datadog Agent, you need to enable it in the datadog.yaml
with:
Then add this configuration block to your journald.d/conf.yaml
file to start collecting your Logs:
logs:
- type: journald
container_mode: true
To fill source
and service
attributes, the Agent collects SYSLOG_IDENTIFIER
, _SYSTEMD_UNIT
and _COMM
and set them to the first non empty value. To take advantage of the integration pipelines, Datadog recommends setting the SyslogIdentifier
parameter in the systemd
service file directly, or in a systemd
service override file. Their location depends on your distribution, but you can find the location of the systemd
service file by using the command systemctl show -p FragmentPath <unit_name>
.
Note: With Agent 7.17+, if container_mode
is set to true
, the default behavior changes for logs coming from Docker containers. The source
attribute of your logs is automatically set to the corresponding short image name of the container instead of simply docker
.
Restart the Agent.
For containerized environments, see the Autodiscovery Integration Templates for guidance on applying the parameters below.
Log collection
Collecting logs is disabled by default in the Datadog Agent. To enable it, see Kubernetes Log Collection.
Parameter | Value |
---|
<LOG_CONFIG> | {"source": "journald", "service": "<YOUR_APP_NAME>"} |
Advanced features
Change journal location
By default the Agent looks for the journal at the following locations:
/var/log/journal
/run/log/journal
If your journal is located elsewhere, add a path
parameter with the corresponding journal path.
Filter journal units
It’s possible to filter in and out specific units by using these parameters:
include_units
: Includes all units specified.exclude_units
: Excludes all units specified.
Example:
logs:
- type: journald
path: /var/log/journal/
include_units:
- docker.service
- sshd.service
Tags are critical for finding information in highly dynamic containerized environments, which is why the Agent can collect container tags in journald logs.
This works automatically when the Agent is running from the host. If you are using the containerized version of the Datadog Agent, mount your journal path and the following file:
/etc/machine-id
: this ensures that the Agent can query the journal that is stored on the host.
Validation
Run the Agent’s status subcommand and look for journald
under the Logs Agent section.
Data Collected
Metrics
journald does not include any metrics.
Service Checks
journald does not include any service checks.
Events
journald does not include any events.
Troubleshooting
Need help? Contact Datadog support.