Migrate repos and groups from github to gitlab

migrate_to_gitlab.sh

#!/usr/bin/env bash
set -uo pipefail

VISIBILITY="${VISIBILITY:-private}"
WORKDIR="$HOME/dev/migrate/_mirror"
LOG="$HOME/dev/migrate/migrate.log"
SSH_HOST="${SSH_HOST_KEY:-gitlab.com}"

DRY_RUN=0
TEST=0
for arg in "$@"; do
  case "$arg" in
    --dry-run) DRY_RUN=1 ;;
    --test)    TEST=1 ;;
    -h|--help)
      cat <<EOF
Usage: $0 [--dry-run] [--test]
  --dry-run   List repos that would migrate, no changes made.
  --test      Migrate only the single smallest non-fork/non-archived repo
              from each source (ikouchiha47 user, go-batteries group).
  (no flag)   Full migration.
Env:
  VISIBILITY=private|public  (default: private)
EOF
      exit 0 ;;
  esac
done

mkdir -p "$WORKDIR"
[ "$DRY_RUN" -eq 1 ] || : > "$LOG"

list_repos() {
  local owner="$1"
  gh repo list "$owner" --limit 500 --json name,isFork,isArchived,diskUsage \
    -q '.[] | select(.isFork|not) | select(.isArchived|not) | select(.diskUsage > 0) | select(.name | startswith(".") | not) | "\(.diskUsage)\t\(.name)"' \
    | sort -n
}

migrate_repo() {
  local gh_owner="$1" gl_namespace="$2" name="$3"
  local gl_path="$gl_namespace/$name"

  if [ "$DRY_RUN" -eq 1 ]; then
    echo "DRY  $gh_owner/$name -> $gl_path"
    return 0
  fi

  local enc
  enc=$(printf '%s' "$gl_path" | jq -sRr @uri)

  if glab api "projects/$enc" >/dev/null 2>&1; then
    echo "SKIP exists: $gl_path" | tee -a "$LOG"
    return 0
  fi

  if [ "$gl_namespace" = "ikouchiha47" ]; then
    local priv=true
    [ "$VISIBILITY" = public ] && priv=false
    glab repo create "$name" --private="$priv" >/dev/null 2>>"$LOG" \
      || { echo "FAIL create $gl_path" | tee -a "$LOG"; return 1; }
  else
    local nsid
    nsid=$(glab api "groups/$gl_namespace" | jq .id)
    glab api -X POST projects \
      -f name="$name" -f path="$name" \
      -f namespace_id="$nsid" \
      -f visibility="$VISIBILITY" >/dev/null 2>>"$LOG" \
      || { echo "FAIL create $gl_path" | tee -a "$LOG"; return 1; }
  fi

  cd "$WORKDIR"
  rm -rf "$name.git"
  git clone --mirror "git@github.com:$gh_owner/$name.git" "$name.git" >>"$LOG" 2>&1 \
    || { echo "FAIL clone $gh_owner/$name" | tee -a "$LOG"; return 1; }
  cd "$name.git"
  if [ -z "$(git for-each-ref)" ]; then
    cd "$WORKDIR"; rm -rf "$name.git"
    echo "OK   $gh_owner/$name -> $gl_path (empty, project created)" | tee -a "$LOG"
    return 0
  fi
  git remote add gitlab "git@$SSH_HOST:$gl_path.git"
  git push --mirror gitlab >>"$LOG" 2>&1 \
    || { echo "FAIL push $gl_path" | tee -a "$LOG"; cd "$WORKDIR"; rm -rf "$name.git"; return 1; }
  cd "$WORKDIR"
  rm -rf "$name.git"
  echo "OK   $gh_owner/$name -> $gl_path" | tee -a "$LOG"
}

run_source() {
  local gh_owner="$1" gl_namespace="$2"
  if [ "$TEST" -eq 1 ]; then
    list_repos "$gh_owner" | head -1 | cut -f2 \
      | while read -r r; do migrate_repo "$gh_owner" "$gl_namespace" "$r"; done
  else
    list_repos "$gh_owner" | cut -f2 \
      | while read -r r; do migrate_repo "$gh_owner" "$gl_namespace" "$r"; done
  fi
}


echo "Done. Log: $LOG"