crawler

README

A golang crawler

Requirements

• A working Go installation. Binaries can be downloaded from https://golang.org/dl/ and installation instructions are available here: https://golang.org/doc/install
• The GOPATH environment variable must be set

Getting started

You can grab this package with the following command:

go get gopkg.in/antoineaugusti/crawler.v0

And then build it:

cd ${GOPATH%/}/src/github.com/antoineaugusti/crawler
go build

Usage

A main file is provided to suit most needs. This is a web crawler that saves crawled HTML content to the disk, after removing the HTML tags (almost all of them) and keeping only the "meaningful" content. I highly advise you to custom this main file or to create your own fetcher or processor to suit your need. You can then reuse the crawler to do the work concurrently.

From the -h flag:

Usage of ./crawler:
  -start string
        address to start from (default "http://www.lemonde.fr/")
  -levels int
        depth of the web crawl (default 50)
  -savePath string
        where to saved crawled resources (default "/tmp/crawl/")
  -concurrentFetchers int
        number of fetchers to run concurrently (default 30)
  -fragment
        keep the fragment part of an URL. Example #top
  -query
        keep the query part of an URL. Example ?foo=bar
  -stayOnDomain
        do not crawl resources that are stored on another domain. (default true)

Interfaces

Some components are abstracted behind interfaces, or contracts as I like to call them. We have got 2 of them:

• A Fetcher is in charge of fetching a resource and finding children resources to explore after. The Fetcher is also in charge of determining if a children resource should be explored or not
• A Processor is in charge of processing a fetched resource

If you want to customise things, you will need to implement at least one of these 2 interfaces and write a custom main file. Of course you can use the provided main file and implementations to get you started.