dotweaks

#!/bin/sh
set -eux

export LOG_NAME="$(pwd)/vpp-daily-tweaks/RUN-LOG.md"
echo "  - Started at $(date)" >"${LOG_NAME}"

export SECRET_GERRIT_KEY_FILE="$(pwd)/secret_gerrit_key"

export VPP_ROOT="$(pwd)/vpp"
export SAVE_DIR_ROOT="$(pwd)"

# $ echo -n | git hash-object --stdin
# e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
NO_CHANGE_HASH="e69de29bb2d1d6434b8b29ae775ad8c2e48c5391"

cd "${VPP_ROOT}"
git config user.name "GH Actions"
git config user.email "ayourtch@icloud.com"
cd "${SAVE_DIR_ROOT}"

# Go into the "volatile" copy of tweaks, possibly we will be modifying data
cd vpp-daily-tweaks/tweaks
for TWEAK_NAME in [0-9]*; do
            echo "    - Running tweak ${TWEAK_NAME}..." >>"${LOG_NAME}"

            # run each tweak on its own vpp branch
            BRANCH_NAME="ayourtch-${TWEAK_NAME}"
            (cd "${VPP_ROOT}"; git branch -D "${BRANCH_NAME}" || true)
            (cd "${VPP_ROOT}"; git checkout -b "${BRANCH_NAME}")

            # get the last known hash of the diff seen and the last known change ID
            SAVE_DIR_TWEAKS="$(pwd)"
            cd "${TWEAK_NAME}"
            LAST_HASH_FILENAME="$(pwd)/last-diff-hash"
            CHANGE_ID_FILENAME="$(pwd)/last-change-id"
            COMMIT_MSG_FILENAME="$(pwd)/commit-message"

            # get the saved hash from previous time
            if [ -f  "${LAST_HASH_FILENAME}" ]; then
                LAST_HASH="$(cat "${LAST_HASH_FILENAME}")"
                echo "Last seen diff hash: ${LAST_HASH}"
            else
                LAST_HASH="${NO_CHANGE_HASH}"
                echo "Not seen a diff before, so assign  a 'no-diff' hash of ${LAST_HASH}"
            fi

            # what is the change ID that we have been working with before...
            if [ -f  "${CHANGE_ID_FILENAME}" ]; then
                CHANGE_ID="$(cat "${CHANGE_ID_FILENAME}")"
                echo "Last change id: ${CHANGE_ID}"

                # check if it has been merged already and if so, pick a new one
                if (cd "${VPP_ROOT}"; git log --grep="${CHANGE_ID}" | grep "${CHANGE_ID}"); then
                     CHANGE_ID=$( (whoami ; hostname ; date; echo $LAST_HASH) | git hash-object --stdin)
                     echo "Merged already, pick a new one: ${CHANGE_ID}"
                fi
            else
                # no change ID submitted before, so pick a random new in case we have to
                CHANGE_ID=$( (whoami ; hostname ; date; echo $LAST_HASH) | git hash-object --stdin)
                echo "New change ID: ${CHANGE_ID}"
            fi
            TEMP_FILENAME="/tmp/change-${CHANGE_ID}"
            bash action
            cd "${SAVE_DIR_TWEAKS}"

            # see if there is anything to submit
            cd "${VPP_ROOT}"
            CHANGE_HASH="$(git diff | git hash-object --stdin)"
            if [ "${CHANGE_HASH}" != "${NO_CHANGE_HASH}" ] && [ "${CHANGE_HASH}" != "${LAST_HASH}" ]; then

                # this is not an empty diff *and* it is not the same diff as we have last seen and submitted

                # leave some trace in the version-controlled log
                echo '```' >>"${LOG_NAME}"
                echo "Found something to submit after ${TWEAK_NAME}:" >>"${LOG_NAME}"
                git branch >> "${LOG_NAME}"
                git diff >> "${LOG_NAME}"
                echo '```' >>"${LOG_NAME}"

                # fixup the commit message and save it into version-controlled space
                git interpret-trailers --if-exists replace --trailer "Change-Id: I${CHANGE_ID}" < "${COMMIT_MSG_FILENAME}" >"${TEMP_FILENAME}"

                mv "${TEMP_FILENAME}" "${COMMIT_MSG_FILENAME}"
                git commit -a -F "${COMMIT_MSG_FILENAME}"

                # Upload the new or updated change to gerrit
                ssh-agent bash -c 'ssh-add "${SECRET_GERRIT_KEY_FILE}"; GIT_SSH_COMMAND="ssh -o StrictHostKeyChecking=no" git push fdio.origin HEAD:refs/for/master'

                # save the state of the change in the to-be-updated tweaks repo and come back to VPP repo
                cd "${SAVE_DIR_TWEAKS}"
                echo "${CHANGE_HASH}" >"${LAST_HASH_FILENAME}"
                git add "${LAST_HASH_FILENAME}"
                echo "${CHANGE_ID}" >"${CHANGE_ID_FILENAME}"
                git add "${CHANGE_ID_FILENAME}"
                cd "${VPP_ROOT}"
            fi
            # reset back to master
            git checkout -f master
            cd "${SAVE_DIR_TWEAKS}"
done
cd "${SAVE_DIR_ROOT}"
echo "  - Last done at $(date)" >>"${LOG_NAME}"