redmine2bugzilla is a simple script to export Redmine bugs to an XML format compatible with Bugzilla's importxml.pl script. It works by scraping public Redmine HTML for data, and converting that into a format readable by Bugzilla. It was tested extensively by exporting bugs from a Redmine 1.3.3 install into GNOME's Bugzilla, running version 3.4.13. I can't vouch for any other combination of installations.

• Python 2.6 or 2.7? Something relatively modern, but not too modern.
• Beautiful Soup 3
• html2text
• pytz
• tzlocal

In Ubuntu, these commands will give you the right packages:

$ sudo apt-get install python-beautifulsoup python-pip
$ sudo pip install html2text pytz tzlocal

If you're in a really old Ubuntu, you might also need:

$ sudo apt-get install python-argparse

To see the scraping in action, run something like

$ ./redmine2bugzilla.py --redmine-base http:https://redmine.example.com -s 1234

This will scrape bug 1234 in the redmine.example.com Redmine instance and print out the bug's data. You can use this to eyeball the script and make sure it's finding the correct fields.

To export Redmine bugs to Bugzilla-importable XML, use -e:

$ ./redmine2bugzilla.py --redmine-base http:https://redmine.example.com \
  --bugzilla-default-user [email protected] \
  --bugzilla-maintainer [email protected] -e 1234 > bugs.xml

This will scrape the same bug, but this time write importable XML to bugs.xml.

See ./redmine2bugzilla.py --help for full usage information.

To import into Bugzilla, transfer the export XML file to the Bugzilla server, then run something like:

$ ./importxml.pl -v bugs.xml

See the importxml.pl docs for more information.

Note that before you do the import, you'll want to set up all Bugzilla products, components, and versions to match exactly the Redmine projects, categories, and target versions, respectively.

I also highly recommend running an import in a testing environment before jumping in with production data. Bugzilla will tell you what went wrong for each bug, and this way you'll have a chance to fix it before any damage is done.

You may find it easier to simply edit the default config information at the top of the script than having to specify a bunch of long command line arguments. There are some things that I didn't bother making command line arguments for, like adding extra Bugzilla users, and editing the file is the only way to change.

Because this works by scraping the HTML, it only works for public bugs. It shouldn't be too hard to extend this with the proper cookie code to allow it to scrape bugs viewable only when logged in, but I didn't need that feature.

Because this pulls down the data for all attachments, you may want to run this on the server or somewhere close to it, where bandwidth won't be a concern.

There are a couple benefits to scraping the HTML over using the Redmine Ruby API:

• It gives you a little more flexibility in where you run it, so you could scrape bugs you may not have server access to.
• We pull the whole bug history div as one Bugzilla "comment", which is a nice compromise between readability and preservation of information.
• I found html2text more reliable than any textile to markdown converter I could find, especially because scraping makes it easy to control what data is being converted.

Please be warned that the mapping isn't 1:1 for all fields. Because there's no way of knowing which Redmine members also have Bugzilla accounts, maintaining any specific user information is tricky. Also, I didn't bother with fields like % Done, Due date, or Keywords, because we aren't using them. As I said before, try out the import in a test environment and make sure everything you care about is coming through.

• The Target version field in Redmine comes out as the Version field in Bugzilla. It should instead be mapped to the Target Milestone field. Fixing this should be easy, but I haven't bothered because our import was already done by the time I figured this out, and I didn't want to go through the trouble of testing any changes.

Here's what I learned about the XML format Bugzilla expects in its importxml.pl script. I could find no documentation about this format beyond "it's like when you click the XML link at the bottom of a bug listing". Many of the tags are obvious, but some aren't.

bugzilla tag attributes:

• version gets checked against the version of the destination Bugzilla database. It doesn't seem like the XML format has changed in years, though.
• urlbase should be set to the base URL of the bug database being exported. It gets concatenated with show_bug.cgi?id= and the bug's bug_id tag in some text describing where the bug came from. This is wrong for Redmine. Oh well. (It looks like in more modern versions of Bugzilla, the importxml.pl script accepts a --bug_page argument that can fix this.)
• maintainer should be set to an email addresses of an administrator of the exported bug database. importxml.pl can send this address a summary of the import process, and won't import without it set.
• exporter should be set to a valid user in the destination Bugzilla. importxml.pl can also send this address a summary of the import process, and again won't import without it set and valid.

bug tag children:

• bug_id should be set to the id of the bug being exported, whatever it is. See urlbase above.
• Attachments need to have a non-empty attachid tag. It seems to be ignored, and can be x. It just won't import the attachment without it set.
• The encoding attribute on attachments' data tag can have the value filename, in which case importxml.pl will open the specified file. This requires the --attach_path argument. I might be mistaken, but encoding="filename" appears to be a violation of the DTD. This script instead includes attachments inline, base64-encoded, so it's not an issue.

Everything else seemed fairly straightforward to me.

Good luck!