SVN-to-GitHub.bash

#!/bin/bash
# ----------------------------------------------------------------------------
# SVN-to-GitHub.bash
# ----------------------------------------------------------------------------
export SVNREPO="$1"

export GITPERLLIB=/usr/local/Cellar/git/2.35.1/share/perl5:/usr/local/lib/perl5/site_perl/5.30.3/darwin-thread-multi-2level

SOURCE=${BASH_SOURCE[0]}
while [ -h "${SOURCE}" ]; do
    DIR=$(cd -P "$( dirname "${SOURCE}" )" >/dev/null 2>&1 && pwd)
    SOURCE=$(readlink "${SOURCE}")
    [[ ${SOURCE} != /* ]] && SOURCE=${DIR}/${SOURCE}
done
DIR=$(cd -P "$(dirname "${SOURCE}")" >/dev/null 2>&1 && pwd)

url="$(svn info --show-item url ${SVNREPO})"
export SVNURL="${url}"
export SVNURL="${SVNURL%/trunk}"
export SVNURL="${SVNURL%/branches}"
export SVNURL="${SVNURL%/tags}"

if [ "${SVNURL}" != "${url}" ]; then
    export STDLAYOUT=true
else
    export STDLAYOUT=false
fi
unset url

export REPONAME="${SVNURL##*/}"
export SVNCLONEREPO="$(pwd)/${REPONAME}-clone"
export GITREPO="$(pwd)/${REPONAME}.git"

#svn log -q ${SVNURL} \
#    | awk -F '|' '/^r/ {sub("^ ", "", $2); sub(" $", "", $2); print $2" = "$2" <"$2">"}' \
#    | sort -u > "${DIR}/authors-file.txt"
#sed -i '' 's/<ball>/Allen D. Ball <ball@hcf.dev>/g' "${DIR}/authors-file.txt"
#
# Create clone of Subversion repository:
#
defaultBranch="$(git config --global --get init.defaultBranch)"

git config --global init.defaultBranch "${defaultBranch:=trunk}"

mkdir ${SVNCLONEREPO}

if [ "${STDLAYOUT}" = true ]; then
    layoutargs="--stdlayout"
fi

git svn clone --prefix svn/ --authors-file ${DIR}/authors-file.txt \
              ${layoutargs} ${SVNURL} ${SVNCLONEREPO}
#
# Add .gitignore
#
cd ${SVNCLONEREPO}
git svn show-ignore > .gitignore
git add .gitignore
git commit --message "Convert svn:ignore properties to .gitignore."
#
# Create new bare repository and push
#
git init --bare ${GITREPO}
cd ${GITREPO}

if [ "${STDLAYOUT}" = true ]; then
    git symbolic-ref HEAD refs/heads/${defaultBranch}
fi

cd ${SVNCLONEREPO}
git remote add bare ${GITREPO}
git config remote.bare.push 'refs/remotes/*:refs/heads/*'
git push bare
#
# Rename tags and branches
#
cd ${GITREPO}

branches=$(git branch --list)

for branch in ${branches}; do
    target="${branch##*/}"

    case ${target} in
        ([0-9]*)
            target="v${target}"
            ;;

        (*)
            ;;
    esac

    case ${branch} in
        (${defaultBranch})
            ;;

        (svn/git-svn | svn/${defaultBranch})
            git branch --move "${branch}" "${defaultBranch}"
            ;;

        (svn/*@*)
            git branch --delete --force "${branch}"
            ;;

        (svn/tags/*)
            git branch --move "${branch}" "${target}"
            ;;

        (svn/*)
            git branch --delete --force "${branch}"
            ;;

        (*)
            git branch --delete --force "${branch}"
            ;;
    esac
done
#
# Convert bare repository to regular repository
#
cd ${GITREPO}
mkdir .git
mv * .git
git config --local --bool core.bare false
git reset --hard
git gc --aggressive
git checkout "${defaultBranch}"
#
# Create a gh-pages (orphan) branch
#
cd ${GITREPO}
git checkout --orphan gh-pages
git rm -rf .
cat > .gitignore <<EOF
_site
.sass-cache
.jekyll-cache
.jekyll-metadata
vendor
EOF
git add .gitignore
git commit --all --message "Created gh-pages branch."
#
# Push to GitHub
#
export GITHUB_USER="$(gh api /user | jq -r .login)"

cd ${GITREPO}
gh repo create --private "${GITHUB_USER}/${REPONAME}"
git remote add origin "https://github.com/${GITHUB_USER}/${REPONAME}.git"
git push origin --all
git push origin --tags

SVN-to-GitHub.md

SVN to GitHub Migration Script

Before running, create an authors-file.txt in the same directory as the script:

svn log -q ${SVNURL} \
    | awk -F '|' '/^r/ {sub("^ ", "", $2); sub(" $", "", $2); print $2" = "$2" <"$2">"}' \
    | sort -u > authors-file.txt

To get something like:

ball = ball <ball>

And then replace with actual e'mail addresses:

sed -i '' 's/<ball>/Allen D. Ball <ball@hcf.dev>/g' authors-file.txt

ball = ball Allen D. Ball <ball@hcf.dev>

Make sure git and gh are configured. To run:

bash SVN-to-GitHub.bash [SVNURL | local copy]

Argument can either be an SVN repository URL or a working directory. The script attempts to detect if the repository is in the "standard layout." To aid the detection process when specifying a URL, append /trunk if the repository is in the standard layout.

For repositories in "standard layout," branches are ultimately ignored but tags are preserved as git branches. An orphaned gh-pages branch is also created.