git-semver-install

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

# install a git repo at a tag matching the given semver
# git-semver-install semver git-url dir git-clone-args*
#
# optionally use x as semver placeholder e.g. 0.x.x same as 0.x same as 0

SEMVER=$1
shift
GIT_URL=$1
shift
DIR=$1
shift

SEMVER_ARR=${SEMVER}
SEMVER_ARR=${SEMVER_ARR//x/}
# shellcheck disable=2206
SEMVER_ARR=( ${SEMVER_ARR//./ } )
SEMVER_MAJOR="${SEMVER_ARR[0]:-[0-9]\\+}"
SEMVER_MINOR="${SEMVER_ARR[1]:-[0-9]\\+}"
SEMVER_PATCH="${SEMVER_ARR[2]:-[0-9]\\+}"

function get_current_tag() {
    git -C "${DIR}" describe --tags --exact-match | \
        grep "^v\?${SEMVER_MAJOR}\.${SEMVER_MINOR}\.${SEMVER_PATCH}$"
}

function get_remote_tag() {
    git ls-remote --tags --sort=version:refname "${GIT_URL}" | \
        cut -d$'\t' -f2 | \
        grep -v "\^{}" | \
        grep "refs/tags/" | \
        sed "s|^refs/tags/||g" | \
        grep "^v\?${SEMVER_MAJOR}\.${SEMVER_MINOR}\.${SEMVER_PATCH}$" | \
        tail -n1
}

[[ -d "${DIR}/.git" ]] || {
    rm -rf "${DIR}"
    >&2 echo "[INFO]" "Checking for remote tag ${GIT_TAG} matching ${SEMVER} for ${GIT_URL}..."
    GIT_TAG=$(git_remote_tag || true)
    [[ -n "${GIT_TAG}" ]] || {
        >&2 echo "[ERR ]" "Found no remote tag matching ${SEMVER} for ${GIT_URL}."
        exit 1
    }
    >&2 echo "[INFO]" "Found remote tag ${GIT_TAG} matching ${SEMVER} for ${GIT_URL}."
    >&2 echo "[INFO]" "Cloning ${GIT_URL}..."
    git clone --branch "${GIT_TAG}" "$@" "${GIT_URL}" "${DIR}"
    exit 0
}

>&2 echo "[INFO]" "Folder ${DIR} exists. Skipping cloning."
GIT_TAG=$(get_current_tag || true)
if [[ -n "${GIT_TAG}" ]]; then
  >&2 echo "[INFO ]" "Found current tag ${GIT_TAG} matching ${SEMVER} for ${GIT_URL}."
else
    >&2 echo "[INFO]" "Checking for remote tag ${GIT_TAG} matching ${SEMVER} for ${GIT_URL}..."
    GIT_TAG=$(git_remote_tag || true)
    [[ -n "${GIT_TAG}" ]] || {
        >&2 echo "[ERR ]" "Found no remote tag matching ${SEMVER} for ${GIT_URL}."
        exit 1
    }
    >&2 echo "[INFO ]" "Found remote tag ${GIT_TAG} matching ${SEMVER} for ${GIT_URL}."
    git -C "${DIR}" fetch
    >&2 echo "[INFO]" "Checking out ${GIT_TAG} for ${DIR}..."
    git -C "${DIR}" checkout "${GIT_TAG}"
fi
>&2 echo "[INFO]" "Resetting folder ${DIR} to ${GIT_TAG}..."
git -C "${DIR}" reset --hard "${GIT_TAG}"
git -C "${DIR}" clean -xdf