add possibility to download compose file

setup.sh

@@ -2,20 +2,44 @@
 # env setup script for step-ca docker compose
 # 2023-01-06 by dede & dany
 
-echo "step-ca docker compose setup"
+# variables setup
-echo "> env setup for step-ca with docker compose..."
+PROJECT_NAME=step-ca
+#COMPOSE_DOWNLOAD_URL=
+
+# starting the setup
+echo "$PROJECT_NAME docker compose setup"
+echo "> env setup for $PROJECT_NAME with docker compose"
+
+# check for existing compose file to not break an existing setup
+if [ -n "$COMPOSE_DOWNLOAD_URL" ]; then
+  if [[ -f "docker-compose.yml" ]]; then
+    echo "> docker-compose.yml file already exists. setup will not run"
+    exit 1
+  else
+    echo "> downloading docker-compose.yml file from $COMPOSE_DOWNLOAD_URL"
+    wget -O docker-compose.yml "$COMPOSE_DOWNLOAD_URL"
+  fi
+fi
 
 # check for existing .env file to not break an existing setup
 if [[ -f .env ]]; then
   echo "> .env file already exists. setup will not run. either rename or delete it first."
+  echo -n "do you want to continue anyway and create a new .env file? [y/N]: "
+  read -r continue
+  if [[ $continue =~ ^([yY])$ ]]; then
+    mv ".env" ".env_backup"
+    echo "> saved existing .env file to .env_backup"
+  else
     exit 1
+  fi
 elif [[ ! -f env.sample ]]; then
   echo "> env.sample file is missing. cannot run."
   exit 2
 fi
 
 # create .env file
-echo -e "# file generated by ${0##*/} on $(date +"%F %H:%M") by $USER\n" > .env
+echo -e "# env file for $PROJECT_NAME compose project" > .env
+echo -e "# generated by ${0##*/} on $(date +"%F %H:%M") by $USER\n" >> .env
 
 # step through the list of lines and ask for each key to use default value or set value
 # for each line in configfile