Allow to configure the running user inside the docker container

Dockerfile

@@ -15,7 +15,6 @@ ENV LOGS_DIR /srv/logs
 ENV USERSCRIPTS_DIR /srv/userscripts
 
 ENV DEBIAN_FRONTEND noninteractive
-ENV USER root
 
 # Configurable environment variables
 ####################################
@@ -129,6 +128,14 @@ ENV REPO_INIT_ARGS ""
 # Allowed values: positive, non-null integers
 ENV RETRY_FETCHES=
 
+# You can specify the user name, user id and group id of the linux user inside the docker container executing the build.
+# In windows environments docker maps volume folders / files for the current windows user to the root inside the docker container.
+# In *nix like environments the uid and gid of the volume folders / files will be identical on the host and inside the container.
+# You can use these settings in such environments to match the volume folder / file owners your user on the host.
+# If you use 0 as UID it is mandatory to also use the root USER, otherwise the USER name can be arbitrary and does not need to match the host.
+ENV USER root
+ENV UID 0
+ENV GID 0
 
 # variables to control whether or not tasks are implemented
 ENV INIT_MIRROR true
@@ -204,4 +211,4 @@ RUN ln -sf /proc/1/fd/1 /var/log/docker.log
 
 # Set the entry point to init.sh
 ################################
-ENTRYPOINT /root/init.sh
+ENTRYPOINT /root/root_init.sh

README.md

@@ -241,6 +241,8 @@ Other useful settings are:
    cores on your machine. Reducing this number can help keeping it responsive for other tasks.
  * `RETRY_FETCHES`: Set the number of retries for the fetch during `repo sync`. By default, this value is unset (default `repo sync` retry behavior).
    Positive values greater than 0 are allowed.
+ * `USER (root)`, `UID (0)`, `GID (0)`: Change this in unix like systems to match the docker volume owner with your host
+   owner.
 
 The full list of settings, including the less interesting ones not mentioned in
 this guide, can be found in the [Dockerfile][dockerfile].

src/root_init.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+# Docker init script
+# Copyright (c) 2017 Julian Xhokaxhiu
+# Copyright (C) 2017-2018 Nicola Corna <[email protected]>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+echo "Preparing user: ${USER} with UID: ${UID}, GID: ${GID}"
+
+if ! id -u "$USER" >/dev/null 2>&1 && [ ! -z "${UID}" ] && [ "${UID}" != "0" ]; then \
+  groupadd -g ${GID} -o ${USER} && \
+  useradd -m -u ${UID} -g ${GID} -o -s /bin/bash ${USER}; \
+fi
+
+chown -R ${USER}:${USER} /root
+
+exec su -c /root/init.sh ${USER}