Loki

Start and configure a instance of Loki, a log aggregation system. The module use the Loki official docker image

Install

Instantiate the module, example:

add-module ghcr.io/nethserver/loki:latest 1

The output of the command will return the instance name. Output example:

{"module_id": "loki1", "image_name": "Loki log aggregation system", "image_url": "ghcr.io/nethserver/loki:latest"}

After the installation, the Loki server will listen on the IP address of the selected node's VPN interface, using the default fixed port 3100.

Usage

The instance can be queried with logcli. eg:

root@leader:~# add-module ghcr.io/nethserver/loki:latest 1
Extracting container filesystem ui to /var/lib/nethserver/cluster/ui/apps/loki1
ui/index.html
b89469d5a964b4e97ca2d40b25758cd2e06a96ebe6c00af7d95b1a2d5cf635a5
{"module_id": "loki1", "image_name": "Loki log aggregation system", "image_url": "ghcr.io/nethserver/loki:latest"}
root@leader:~# add-module ghcr.io/nethserver/promtail:latest 1
Extracting container filesystem ui to /var/lib/nethserver/cluster/ui/apps/promtail1
ui/index.html
fe8d71c5b5f0c579ba96e4a64660b275e3a667ffddcc576b1e4cab9f3a8bf9f8
{"module_id": "promtail1", "image_name": "Promtail logs collector for Loki", "image_url": "ghcr.io/nethserver/promtail:latest"}
root@leader:~# logcli labels -q
__name__
job
nodename
root@leader:~# logcli labels nodename -q
bullseye
leader
root@leader:~# logcli  query -q --no-labels -t '{nodename="leader"} | json | line_format "{{.MESSAGE}}"'
2021-05-28T15:49:27Z Created slice cgroup user-libpod_pod_d32e9a0f2237ca996c90f6790ca90447b3e8cbb30d16cc91701ab8257bb704d6.slice.
2021-05-28T15:49:27Z 2021-05-28 15:49:27.621079036 +0000 UTC m=+0.106351212 container create 6e51520a9fa4f63ac0f3dbbf89ef2ef075041dd90c5df952a35206a14691c654 (image=k8s.gcr.io/pause:3.2, name=d32e9a0f2237-infra)
2021-05-28T15:49:27Z 2021-05-28 15:49:27.62160088 +0000 UTC m=+0.106873062 pod create d32e9a0f2237ca996c90f6790ca90447b3e8cbb30d16cc91701ab8257bb704d6 (image=, name=loki)
2021-05-28T15:49:27Z d32e9a0f2237ca996c90f6790ca90447b3e8cbb30d16cc91701ab8257bb704d6
2021-05-28T15:49:27Z loki.service: Found left-over process 19008 (podman pause) in control group while starting unit. Ignoring.
2021-05-28T15:49:27Z This usually indicates unclean termination of a previous run, or service implementation deficiencies.

logcli will use the default Loki instance of the cluster, this can be changed using the environment variable LOKI_ADDR

APIs

The module provides some APIs to interact with the Loki instance:

• configure-module
• get-configuration

configure-module

Configure the Loki instance.

Parameters

• retention_days: The number of days to keep the logs.

Example

api-cli run module/loki1/configure-module '{"retention_days": 7}'

get-configuration

Get the Loki instance configuration.

Example

api-cli run module/loki1/get-configuration

{
  "retention_days": 7,
  "active_from": "2021-05-28T15:49:27Z+00:00",
  "active_to": "2021-05-28T15:49:27Z+00:00"
}

Note: active_to field WILL miss if the instance is still active.

Uninstall

To uninstall the instance:

remove-module loki1