DiscoverEvent Plugin Loki

author: alexwanglei

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The plug-in implements sending service event logs to the Loki log system, and retrieves and visualizes the logs in Loki through Grafana.

1. Preparation

Install and deploy loki

Download binary package

$ curl -O -L "https://github.com/grafana/loki/releases/download/v2.6.1/loki-linux-amd64.zip"
# extract the binary
$ unzip "loki-linux-amd64.zip"
# make sure it is executable
$ chmod a+x "loki-linux-amd64"

Download configuration file

$ wget https://raw.githubusercontent.com/grafana/loki/v2.6.0/cmd/loki/loki-local-config.yaml

Run Loki Server

$ nohup ./loki-linux-amd64 -config.file=loki-local-config.yaml > ./loki.log 2>&1 &

For more installation methods, please refer to Loki official installation documentation

Install and deploy Grafana

RPM package installation

$ wget https://dl.grafana.com/enterprise/release/grafana-enterprise-9.1.6-1.x86_64.rpm
$ sudo yum install grafana-enterprise-9.1.6-1.x86_64.rpm

Start the Grafana service

$ sudo systemctl daemon-reload
$ sudo systemctl start grafana-server
$ sudo systemctl status grafana-server

For more installation methods, please refer to Grafana official installation documentation

2. Plug-in configuration and use

Compile the plugin

1. Git clone https://github.com/polarismesh/polaris.git
2. Go to the polaris directory
3. Execute go get github.com/polaris-contrib/polaris-server-plugin-discoverevent-loki
4. Execute go mod tidy -compat=1.17
5. Edit polaris/plugin.go, add in the import block

   import (
        ...
        _ "github.com/polarismesh/polaris/plugin/discoverevent/loki" # Introduce the plugin and trigger the plugin's automatic registration logic
   )

6. Execute build.sh to build polaris-server

enable in polaris-server

In the polaris-server.yaml configuration file, in the plugin configuration section, the discoverEvent plugin configuration block is set as follows:

plugin:
  discoverEvent:
    name: discoverEventLoki                              # [必填]插件名称
    option:
      queueSize: 1024                                    # [必填]日志缓存队列长度
      pushURL: http://127.0.0.1:3100/loki/api/v1/push    # [必填]loki push 接口地址
      tenantID: "test"                                   # [可选]设置loki日志租户
      labels:                                            # [可选]自定义日志标签
        key1: "value1"
        key2: "value2"

After polaris-server starts, the plugin will be loaded according to the configuration file, and service discovery events will be reported to the Loki log system through the plugin.

3. Grafana query Loki log

Grafana configure Loki data source

Click the configuration icon on the Grafana page, click Data Sources, and add the Loki data source:

• Name: Set the data source name
• URL: set the address of the Loki instance

After the configuration is complete, click the Save & Test button at the bottom of the page. If the Loki system is running and a log is reported to the system, it will prompt that the data source is connected and the tag is found.

Query Loki logs

Click the Explore button to query the Loki log, and log filtering can be done according to the tag. The plugin will set two tags, source and event_type by default. The value of source is the plugin name discoverEventLoki, and event_type is the service discovery event type.

For more configuration and usage, please refer to Using Loki in Grafana