Central Logging with Loki
Adding the pre-configured stack
When Overnode is installed or upgraded, it also does the same for Loki driver for Docker automatically. This enables containers to stream stdout / stderr logs to the Loki server.
First, it is necessary to add the Loki stack to a project:
Adjust the downloaded settings as required. Default settings should work fine for a start. The stack opens 3100 port on localhost interface on each node. The server on the port forwards traffic to the Loki server using the network of a cluster.
The default configuration also enables logs collection from /var/logs on each host.
Configuring logging per containers
To opt in containers to log to Loki, add logging section to the required services, like the following:
Browsing logs in Loki using Grafana
To browse logs, add the pre-configured Grafana stack:
Adjust the downloaded settings as required. Default settings should work fine for a start. The stack opens port 4431 on each host. The server uses self-signed certificate. And the Basic HTTP username/password is configured to admin/admin.