/mwscrape

Download rendered articles from MediaWiki API to CouchDB

Primary LanguagePythonMozilla Public License 2.0MPL-2.0

mwscrape downloads rendered articles from MediaWiki sites via web API and stores them in CouchDB to enable further offline processing.

Installation

mwscrape depends on the following:

Consult your operating system documentation and these projects’ websites for installation instructions.

For example, on Ubuntu 18.04, the following command installs required packages:

sudo apt-get install python3 python3-venv

To install CouchDB first enable the Apache CouchDB package repository:

echo "deb https://apache.bintray.com/couchdb-deb bionic main" | sudo tee -a /etc/apt/sources.list

Then install the repository key:

curl -L https://couchdb.apache.org/repo/bintray-pubkey.asc | sudo apt-key add -

And finally update the repository cache and install the package:

sudo apt-get update && sudo apt-get install couchdb

Alternatively, run CouchDB with docker:

docker run --detach --rm --name couchdb \
-v $(PWD)/.couchdb:/opt/couchdb/data \
-p 5984:5984 \
couchdb:2

See CouchDB Docker image docs for more details.

Note that starting with CouchDB 3.0 an admin user must be set up. See CouchDB documentation.

With docker:

docker run --detach --rm --name couchdb \
-e COUCHDB_USER=admin \
-e COUCHDB_PASSWORD=secret \
-v $(PWD)/.couchdb:/opt/couchdb/data \
-p 5984:5984 \
couchdb:3

By default CouchDB uses snappy for file compression. Change file_compression configuration parameter in couchdb config section to deflate_6 (Maximum is deflate_9). This reduces database disc space usage significantly.

Create new Python virtual environment:

python3 -m venv env-mwscrape

Activate it:

source env-mwscrape/bin/activate

Install mwscrape from source:

pip install https://github.com/itkach/mwscrape/tarball/master

Usage

usage: mwscrape [-h] [--site-path SITE_PATH] [--site-ext SITE_EXT] [-c COUCH]
                [--db DB] [--titles TITLES [TITLES ...]] [--start START]
                [--changes-since CHANGES_SINCE] [--recent-days RECENT_DAYS]
                [--recent] [--timeout TIMEOUT] [-S] [-r [SESSION ID]]
                [--sessions-db-name SESSIONS_DB_NAME] [--desc]
                [--delete-not-found] [--speed {0,1,2,3,4,5}]
                [site]

positional arguments:
  site                  MediaWiki site to scrape (host name), e.g.
                        en.wikipedia.org

optional arguments:
  -h, --help            show this help message and exit
  --site-path SITE_PATH
                        MediaWiki site API path. Default: /w/
  --site-ext SITE_EXT   MediaWiki site API script extension. Default: .php
  -c COUCH, --couch COUCH
                        CouchDB server URL. Default: http://localhost:5984
  --db DB               CouchDB database name. If not specified, the name will
                        be derived from Mediawiki host name.
  --titles TITLES [TITLES ...]
                        Download article pages with these names (titles). It
                        name starts with @ it is interpreted as name of file
                        containing titles, one per line, utf8 encoded.
  --start START         Download all article pages beginning with this name
  --changes-since CHANGES_SINCE
                        Download all article pages that change since specified
                        time. Timestamp format is yyyymmddhhmmss. See
                        https://www.mediawiki.org/wiki/Timestamp. Hours,
                        minutes and seconds can be omited
  --recent-days RECENT_DAYS
                        Number of days to look back for recent changes
  --recent              Download recently changed articles only
  --timeout TIMEOUT     Network communications timeout. Default: 30.0s
  -S, --siteinfo-only   Fetch or update siteinfo, then exit
  -r [SESSION ID], --resume [SESSION ID]
                        Resume previous scrape session. This relies on stats
                        saved in mwscrape database.
  --sessions-db-name SESSIONS_DB_NAME
                        Name of database where session info is stored.
                        Default: mwscrape
  --desc                Request all pages in descending order
  --delete-not-found    Remove non-existing pages from the database
  --speed {0,1,2,3,4,5}
                        Scrape speed
  --delay
                        Pause before requesting rendered article for 
                        this many seconds.
                        Some sites limit request rate so that even
                        single-threaded, request-at-a-time scrapes
                        are too fast and additional delay needs
                        to be introduced
  --namespace           ID of MediaWiki namespace to " "scrape.
  --user-agent          HTTP user agent string.

The following examples are for with CouchDB < 3.0 running in admin party mode.

To get English Wiktionary:

mwscrape en.wiktionary.org

To get the same but work through list of titles in reverse order:

mwscrape en.wiktionary.org --desc

Some sites expose Mediawiki API at path different from Wikipedia’s default, specify it with --site-path:

mwscrape lurkmore.to --site-path=/

For CouchDB with admin user admin and password secret specify credentials as part of CouchDB URL:

mwscrape -c http://admin:secret@localhost:5984 en.wiktionary.org

mwscrape compares page revisions reported by MediaWiki API with revisions of previously scraped pages in CouchDB and requests parsed page data if new revision is available.

mwscrape also creates a CouchDB design document w with show function html to allow viewing article html returned by MediaWiki API and navigating to html of other collected articles. For example, to view rendered html for article A in database simple-wikipedia-org, in a web browser go to the following address (assuming CouchDB is running on localhost):

http://127.0.0.1:5984/simple-wikipedia-org/_design/w/_show/html/A

If databases are combined via replication articles with the same title will be stored as conflicts. mwresolvec script is provided to merge conflicting versions (combine aliases, select highest MediaWiki article revision, discard other revisions). Usage:

mwresolvec [-h] [-s START] [-b BATCH_SIZE] [-w WORKERS] [-v] couch_url

positional arguments:
  couch_url

optional arguments:
  -h, --help            show this help message and exit
  -s START, --start START
  -b BATCH_SIZE, --batch-size BATCH_SIZE
  -w WORKERS, --workers WORKERS
  -v, --verbose

Example:

mwresolvec http://localhost:5984/en-m-wikipedia-org