Log Monitoring in Docker
Dynatrace log monitoring supports the collection of logs from non-orchestrated Docker environments via OneAgent. To learn more about log monitoring in orchestrated platforms, such as Kubernetes and OpenShift, that use Docker as the Container Runtime Interface (CRI), see Log Monitoring in Kubernetes.
How autodiscovery works
OneAgent autodiscovers log messages written to the containerized application's stdout/stderr streams. The Docker logging driver saves these log streams in a file located in the /var/lib/docker/containers directory on the host running the containers. OneAgent autodiscovers log files from that path.
OneAgent does not discover logs written directly to the container's file system.
Autodiscovery requirements
Requirements for autodiscovery of Docker logs:
- The process running in the container is an important process.
- The container uses a
json-filelogging driver. - Logs are written to the container's
stdout/stderrstreams. - The log file in
/var/lib/docker/containersexists for a minimum of one minute after container execution is finished.
Connecting logs with Docker properties and annotations
As OneAgent discovers logs from the /var/lib/docker/containers path on a host running in a non-orchestrated Docker environment, it connects specific logs to a corresponding container based on the container ID from the file path.
In addition, OneAgent enhances these logs with the following Docker metadata:
container.namecontainer.idcontainer.image.name