Convert a subversion repo to git

svn-to-git.sh

#!/bin/sh -ex
# Convert a subversion repo to git
# according to this link http://john.albin.net/git/convert-subversion-to-git

if [ $# -eq 0 ]; then
    echo "Usage: $0 [svn repo url]"
    exit 1
fi

# Checkout an svn repo
# $1 - The svn repo url
# $2 - The directory to checkout
checkout_svn_repo() {
    local svn_repo_url="$1"
    local dest_svn_dir="$(basename ${svn_repo_url}).svn"

    svn checkout ${svn_repo_url} ${dest_svn_dir}
}

# Create an authors file from the svn repo
# $1 - The svn repo url
transform_authors() {
    local svn_repo_url="$1"
    local svn_checkout_dir="$(basename ${svn_repo_url}).svn"

    checkout_svn_repo ${svn_repo_url}

    cd ${svn_checkout_dir}

    SVN_ROOT=`svn info "${SVN_URL}" | grep '^Repository.Root' | sed -e 's/^Repository.Root: //'`

    svn log -q "${SVN_ROOT}" | awk -F '|' '/^r/ {sub("^ ", "", $2); sub(" $", "", $2); print $2" = "$2" <"$2"@google.com>"}' | sort -u > ../${svn_checkout_dir}-authors-transform.txt

    cd -
}

# Clone a svn repo to git
# $1 - The svn repo url
# $2 - The authors transform file
clone_svn_to_git() {
    local svn_repo_url="$1"
    local authors_transform_file="$2"
    local dest_git_dir="$(basename ${svn_repo_url}).git"

    if [ -z ${authors_transform_file} ]; then
        git svn clone ${svn_repo_url} --stdlayout ${dest_git_dir}
    else
        git svn clone ${svn_repo_url} -A ${authors_transform_file} --stdlayout ${dest_git_dir}
    fi

    cd ${dest_git_dir}
    ls -la
    cd -
}

# Create a bare git repo and push the changes there
# $1 - The svn repo url
create_bare_and_push_to_bare() {
    local svn_repo_url="$1"
    local git_dir="$(basename ${svn_repo_url}).git"
    local git_bare_dir="$(basename ${svn_repo_url})-bare.git"

    if [ ! -d ${git_dir} ]; then
        echo "Git directory doesn't exist..."
        exit 1
    fi

    # Create bare git repo
    if [ ! -d ${git_bare_dir} ]; then
        git init --bare ${git_bare_dir}
    fi
    cd ${git_bare_dir}
    git symbolic-ref HEAD refs/heads/trunk
    cd -

    # Push to bare repo
    cd ${git_dir}
    git remote add bare "../${git_bare_dir}"
    git config remote.bare.push "refs/remotes/*:refs/heads/*"
    git push bare
    cd -

    cd ${git_bare_dir}
    # Rename trunk to master
    git branch -m trunk master

    # Cleanup branches and tags
    git for-each-ref --format='%(refname)' refs/heads/tags | cut -d / -f 4 |
    while read ref
    do
        git tag "$ref" "refs/heads/tags/$ref";
        git branch -D "tags/$ref";
    done
    cd -
}


authors_transform="$(basename ${1}).svn-authors-transform.txt"

# If the file of authors doesn't exist
# create it
if [ ! -f ${authors_transform} ]; then
    transform_authors ${1}
fi

clone_svn_to_git ${1} ${authors_transform}

create_bare_and_push_to_bare ${1}