Logproxy plugins

This projects contains a number of logproxy plugins

Plugins are compiled binaries running alongside the main logproxy process which manages the complete lifecycle. It detects and loads any plugins found in the search paths. The mechanism is based on Hashicorp's Go plugin system. Some use cases for writing a plugin:

• Dropping verbose or high frequency logs which are not interesting (saving costs)
• Trigger events (e.g. send an email, call a webhook) when certain patterns in your logs are detected
• Controlled forwarding of logs to other systems
• Log enrichment e.g. by parsing fields or adding data from external systems

Plugin interface

Plugins implement a single method from the Filter interface

package main

import (
  "github.com/philips-software/go-hsdp-api/logging"
)

type Filter interface {
    Filter(in logging.Resource) (out logging.Resource, drop bool, modified bool, err error)
}

The incoming Resource is a single log message. You can examine its content and decide to leave it as is, drop it, or make changes to various fields. Setting the drop boolean true to true will instruct Logproxy to discard the message without further processing. If the message contains modifications set the modified boolean to true as well as returning the modified message.

Note on aggregation in filters

When you want to aggregate data (e.g. a counter) over a number of messages, or trigger events, keep in mind there might be multiple Logproxy instances running, each with their own copy of the plugin running. You will need to use a backing store service, e.g. Redis or PostgreSQL, to synchronize across instances.

Building and deploying your plugin

The quickest way to build and deploy your plugin is using a well crafted Dockerfile. We will build the plugin using Docker.

Naming

Your plugin binary should follow the logproxy-filter-* glob naming convention. In future we might support other types of plugins.

Dockerfile

We use the official Logproxy Docker image as base and simply copy the plugin binary to the app folder. When the image starts your plugin will be auto-detected. Example:

FROM golang:1.17.3-alpine3.13 as build_base
RUN apk add --no-cache git openssh gcc musl-dev
WORKDIR /plugin
COPY go.mod .
COPY go.sum .

# Get plugin dependancies
RUN go mod download
LABEL builder=true

# Build
FROM build_base AS builder
WORKDIR /plugin
COPY . .
RUN go build .

FROM philipssoftware/logproxy:latest
COPY --from=builder /plugin/logproxy-filter-myplugin /app

Build and push your Docker image to a registry and you are now ready to deploy. Please see the Logproxy project for details on the configuration, specifically the required ENV variables.

Contact / Getting help

Andy Lo-A-Foe [email protected]

License

License is MIT