add branches info to buildinfo file

Author: timofeyturenko

.drone.jsonnet

@@ -830,11 +830,19 @@ local Pipeline(branch, platform, event, arch='amd64', server='10.6-enterprise')
                status: ['success', 'failure'],
              },
              volumes: [pipeline._volumes.mdb],
+             environment: {
+               SERVER_REF: '${SERVER_REF:-' + server + '}',
+               SERVER_REMOTE: '${SERVER_REMOTE:-' + server_remote + '}',
+             },
              commands: [
                'cd /mdb/' + builddir,
                'echo "engine: $DRONE_COMMIT" > buildinfo.txt',
                'echo "server: $$(git rev-parse HEAD)" >> buildinfo.txt',
                'echo "buildNo: $DRONE_BUILD_NUMBER" >> buildinfo.txt',
+               'echo "serverBranch: $$SERVER_REF" >> buildinfo.txt',
+               'echo "serverRepo: $$SERVER_REMOTE" >> buildinfo.txt',
+               'echo "engineBranch: $DRONE_SOURCE_BRANCH" >> buildinfo.txt',
+               'echo "engineRepo: https://github.com/$DRONE_REPO" >> buildinfo.txt',
                'mv buildinfo.txt ./%s/' % result,
                'yes | cp -vr ./%s/. /drone/src/%s/' % [result, result],
                'ls -l /drone/src/' + result,