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ASF GitHub Bot commented on NUTCH-2144: --------------------------------------- Github user sebastian-nagel commented on a diff in the pull request: https://github.com/apache/nutch/pull/89#discussion_r52833909 --- Diff: conf/db-ignore-external-exemptions.txt --- @@ -0,0 +1,37 @@ +# Licensed to the Apache Software Foundation (ASF) under one or more +# contributor license agreements. See the NOTICE file distributed with +# this work for additional information regarding copyright ownership. +# The ASF licenses this file to You under the Apache License, Version 2.0 +# (the "License"); you may not use this file except in compliance with +# the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# +# +# Exemption rules to db.ignore.external.links +# +# Format : +#-------- +# UrlRegex1 +# UrlRegex2 +# UrlRegex3 + + +# NOTE :: +# 1. When the url matches any of the regex then that url is exempted. +# 2. # in the beginning makes it a comment line +# 3. To Test the regex, update this file and use the below command +# bin/nutch plugin urlfilter-ignoreexempt org.apache.nutch.urlfilter.ignoreexempt.ExemptionUrlFilter <URL> +# 4. Dont forget to enable this plugin in nutch-site.xml + + +# Example 1: +#---------- +# To exempt urls ending with image extensions, uncomment the below line +#.*\.(jpg|JPG|png$|PNG|gif|GIF)$ --- End diff -- Regex could be simplified to `#(?i).*\.(?:jpg|png|gif)` (or `#(?i)\.(?:jpg|png|gif)$` if Pattern.find() is used). `(?i)` makes the pattern case insensitive, cf. [NUTCH-2035](https://issues.apache.org/jira/browse/NUTCH-2035) > Plugin to override db.ignore.external to exempt interesting external domain > URLs > -------------------------------------------------------------------------------- > > Key: NUTCH-2144 > URL: https://issues.apache.org/jira/browse/NUTCH-2144 > Project: Nutch > Issue Type: New Feature > Components: crawldb, fetcher > Reporter: Thamme Gowda N > Assignee: Chris A. Mattmann > Priority: Minor > Fix For: 1.12 > > Attachments: ignore-exempt.patch, ignore-exempt.patch > > > Create a rule based urlfilter plugin that allows focused crawler > (db.ignore.external.links=true) to fetch static resources from external > domains. > The generalized version of this: This plugin should permit interesting URLs > from external domains (by overriding db.ignore.external). The interesting > urls are decided from a combination of regex and mime-type rules. > Concrete use case: > When using Nutch to crawl images from a set of domains, the crawler needs > to fetch all images which may be linked from CDNs and other domains. In this > scenario, allowing all external links and then writing hundreds of regular > expressions is not feasible for large number of domains. -- This message was sent by Atlassian JIRA (v6.3.4#6332)