lazyraster

Lazyraster

A caching PDF rasterizer that uses a filecache and a hashring to distribute load.

MuPDF is the PDF engine that drives the rasterizer.

License Restriction

This project is released under an MIT license, but it relies on the AGPL code from lazypdf. Therefore, running it must comply with the terms and conditions from this license. Sorry about that!

Building It

You MUST first install and build LazyPdf

This requires some C library dependencies that are not vendored in this project. Install it in the correct location in your GOPATH so that it can be found in the correct location when building this project.

Once that is installed, if you have not already, you will need to install all of the dependencies in vendor/. This project uses the dep tool to manage dependencies. You must have that installed:

go get github.com/golang/dep/cmd/dep

Installing the dependencies is:

dep ensure

You can then build this project builds with a simple go build.

Running It

Simply call the executable. By default, it will run on port 8000 and serve pdfs located in the current directory. Configuration is done using environment variables. These include the following:

• RASTER_BASE_DIR: The location where cached files are to be stored and served (default .)
• RASTER_HTTP_PORT: The port to listen on for HTTP connections (default 8000)
• RASTER_ADVERTISE_HTTP_PORT: The advertised host port which gets mapped to RASTER_HTTP_PORT (default 8000)
• RASTER_AWS_REGION: The AWS Region fallback to use when S3 region lookup fails (default us-west-1)
• RASTER_CLUSTER_SEEDS: The seeds to use to start the gossip ring
• RASTER_CACHE_SIZE: The number of file objects to cache on disk at any one time. (default 512)
• RASTER_REDIS_PORT: The port on which to serve Redis protocol traffic (default 6379)
• RASTER_CLUSTER_NAME: The name of the Memberlist cluster (default default)
• RASTER_RING_TYPE: Use sidecar or memberlist backing for hash ring? (default: sidecar)
• RASTER_ADVERTISE_MEMBERLIST_HOST: The IP / hostname advertised by Memberlist
• RASTER_ADVERTISE_MEMBERLIST_PORT: The port advertised by Memberlist (default 7946)
• RASTER_SIDECAR_URL: The Sidecar state URL (default: http://192.168.168.168:7777/api/state.json)
• RASTER_SIDECAR_SERVICE_NAME: The name to lookup in Sidecar when using Sidecar backing (default lazyraster)
• RASTER_SIDECAR_SERVICE_PORT: The port to lookup in Sidecar when using Sidecar backing (default 10110)
• RASTER_URL_SIGNING_SECRET: A secret to use when validating signed URLs (default: deadbeef). Set it to empty string to disable signature validation.
• RASTER_RASTER_CACHE_SIZE: The number of Rasterizer objects to cache in memory at any one time (default 20)
• RASTER_RASTER_BUFFER_SIZE: The maximum number of raster requests to queue (default 10)
• RASTER_LOGGING_LEVEL: The cut off level for log messages. (debug, info, warn, error, default info)

In addition, the AWS APIs will require authorization in the form of the standard AWS environment variables:

• AWS_ACCESS_KEY_ID
• AWS_SECRET_ACCESS_KEY

If you are a New Relic customer and wish to monitor this using New Relic's service, the service includes the Gorelic platform agent. This is currently used in place of the New Relic go agent due to major licensing issues with the current Go agent. You may trigger the use of the New Relic agent by starting the service with:

• NEW_RELIC_LICENSE_KEY: the value is your current license key.
• SERVICE_NAME: the name of the application in New Relic (e.g. 'foo-service')
• ENVIRONMENT_NAME: appended to SERVICE_NAME (e.g. 'foo-service-prod')

Local Development

If you are running this locally for development purposes, you will probably want to use the following options to get started:

$ RASTER_RING_TYPE=memberlist RASTER_LOGGING_LEVEL=debug ./lazyraster

This will use the Memberlist clustering library and not require an external Sidecar service discovery system. It will also enable debug logging level which can help in understanding where things went wrong.

Copyright

Copyright (c) 2017-2018 Nitro Software.