Redmine SVN to Git Migrator

redmine_svn_to_git_migrator.rb

#!/usr/bin/ruby

#
# Migration Tool for Redmine issue and time entry comments from SVN revisions to Git (i.e. r1234 => commit:abcdef789)
# ==============================
# (c) 2009 Christoph Olszowka & Sebastian Georgi, Capita Unternehmensberatung
#
# We used this when we migrated two of our main repositories from svn to git (see http://gist.github.com/139478)
# and wanted to have our revision links in Redmine reflect that change, too.
#
# WARNING: This worked for us, but you better backup your database before letting this off! 
# Provided "as is", no waranties, blah!
#
#
# Please make sure you have grit installed before launching: sudo gem install grit
#
# Simply run this with:
#   $ ./redmine_svn_to_git_migrator.rb ./path/to/a/proper/git_clone/of_your_repo REDMINE_PROJECT_ID
#
# NOTE:
# If you want to check the conversions first, put a "if 1 == 2" behind journal.save! and te.save!
# The result will be a "dry run", only displaying the changes that would be done, without actually touching things
#

require 'rubygems'
require 'grit'
require 'pp'
include Grit

def migrate(repo_path, project_id)
  project = Project.find(project_id)

  if __FILE__ == $0
    puts "", ""
    print "Working with directory #{repo_path} and project #{project.name}. Continue? "
    foo = STDIN.gets
  end

  repo = Repo.new(repo_path)

  def extract_svn_revision(message)
    match = message.match(/; revision=(\d+)/)
    if match 
      match[2].strip.chomp
    else
      nil
    end
  rescue => err
    raise "Failed to extract from #{message}"
  end

  read_commits = {} # map from git commit to svn revision
  revisions = {} # map from svn revision to git commit(s)
  repo.heads().each do |head|
    puts "Reading branch #{head.name}"
    offset = 0
    limit = 50
    # read commits in batches
    while commits = repo.commits(head.name, limit, offset) and not commits.empty?
      commits.each do |commit|
        c = "commit:#{commit.to_s[0..8]}"
        if !read_commits[c]
          # extract svn revision from commit message
          svn_revision = extract_svn_revision(commit.message)

          if svn_revision = extract_svn_revision(commit.message)
            revision = "r#{svn_revision}"
            if (revisions[revision])
              if !revisions[revision].index(c)
                revisions[revision] = revisions[revision] + " #{c}"
                puts "[WARNING] Revision #{revision} is ambiguous, poiting to #{revisions[revision]}"
              end
            else
              revisions[revision] = c
            end
            read_commits[c] = svn_revision
          else
            puts "[WARNING] #{commit} does not have svn revision"
            puts commit.message
            puts
          end
        end
      end
      offset += limit
    end
  end

  puts "Found #{revisions.size} revision mappings..."

  # Fix issues
  project.issues.each do |issue|
    puts "Working on issue #{issue.id}: #{issue.subject}"
    issue.journals.each do |journal|
      puts "  Journal \##{journal.journalized_id}"
      revisions.each do |svn_revision, git_commit|
        svn_regexp = /#{svn_revision}([^\d])/
        if journal.notes =~ svn_regexp
          puts "Match found for #{svn_revision}:"
          puts "#{journal.notes}"
          puts "  converted to"
          converted_notes = "#{journal.notes.gsub(svn_regexp, "#{git_commit}#{$1}")}"
          puts converted_notes

          # Update notes
          journal.notes = converted_notes
          journal.save!
        end
      end
    end
    puts "", "="*80, ""
  end

  # Fix time entries
  project.time_entries.each do |te|
    puts "Working on time entry #{te.id}"
    revisions.each do |svn_revision, git_commit|
      svn_regexp = /#{svn_revision}([^\d])/
      if te.comments =~ svn_regexp
        puts "Match found for #{svn_revision}:"
        puts "#{te.comments}"
        puts "  converted to"
        converted_comments = "#{te.comments.gsub(svn_regexp, "#{git_commit}#{$1}")}"
        puts converted_comments

        # Update notes
        te.comments = converted_comments
        te.save!
        puts "", "="*80, ""
      end
    end
  end
end

if __FILE__ == $0
  repo_path = ARGV[0].strip.chomp
  project_id = ARGV[1].strip.chomp
  puts "Loading environment..."
  RAILS_ENV = 'production'
  require '/var/www/redmine/config/environment' # Replace with path to your actual Redmine install

  migrate(repo_path, project_id)
end

Changes from the original script:

• changed the revision pattern
• changed the default environment path
• getting repo commits from every branch instead of just 'master'
• dealing with ambiguous svn revisions