working!

Dockerfile

 FROM python:3.7
 
 MAINTAINER root@recolic.net
+ARG GIT_REPO_TM_WEB
 
 EXPOSE 80/tcp
 
@@ -10,6 +11,8 @@ VOLUME /app/log
 VOLUME /app/keys
 WORKDIR /app
 
+RUN git clone "$GIT_REPO_TM_WEB" src 
+
 COPY entry.sh /app/entry.sh
 RUN chmod +x entry.sh
 

entry.sh

 #!/bin/bash
 
-[[ $1 == '' ]] && echo 'Usage: docker run ... image git://url_to_git_repo_of_tm.recolic.net_gitrepo' && exit 1
-
-git_="$1"
 mkdir -p ./keys ./log &&
-    git clone "$git_" src &&
-    touch ./keys/keys.list &&
-    ln -s $(pwd)/keys/keys.list ./src/keys.list &&
+    [[ -e ./keys/keys.list ]] || touch ./keys/keys.list &&
+    [[ -e ./src/keys.list ]] || ln -s $(pwd)/keys/keys.list ./src/keys.list &&
     cd /app/src &&
     unbuffer python3 ./daemon.py 80 >> ../log/tm.log 2>&1
 
 exit $?
 
-