From e676503f65ca26b51210c3f1fca585d9f6255e10 Mon Sep 17 00:00:00 2001
From: Michael Serajnik <ms@mserajnik.at>
Date: Sun, 5 Jan 2020 20:49:12 +0100
Subject: [PATCH] feat: add ability to define custom UID/GID at container
 creation

---
 CHANGELOG.md         |  5 +++++
 Dockerfile           | 25 ++++++-------------------
 README.md            | 39 +++++++++++++++++++++------------------
 docker-entrypoint.sh | 15 ++++++---------
 docker-start.sh      | 13 +++++++++++++
 5 files changed, 51 insertions(+), 46 deletions(-)
 create mode 100644 docker-start.sh

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b44be30..de160a9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+### Added
+
++ Added the ability to define custom UID and GID for the Docker container at
+  container creation
+
 ## [3.21.0] - 2020-01-02
 
 ### Changed
diff --git a/Dockerfile b/Dockerfile
index 44893d5..2b97d9e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,35 +1,20 @@
 FROM python:3.8-slim-buster
 
-ARG HOST_USER_ID=1000
-ARG HOST_GROUP_ID=1000
-
-ENV HOST_USER_ID=$HOST_USER_ID
-ENV HOST_GROUP_ID=$HOST_GROUP_ID
-
-RUN \
-  if [ $(getent group ${HOST_GROUP_ID}) ]; then \
-    useradd -r -u ${HOST_USER_ID} hydrus; \
-  else \
-    groupadd -g ${HOST_GROUP_ID} hydrus && \
-    useradd -r -u ${HOST_USER_ID} -g hydrus hydrus; \
-  fi
-
 WORKDIR /usr/src/app
 
 COPY ./hydrus .
 COPY ./deb .
 
 RUN \
-  chown -R hydrus:hydrus /usr/src/app && \
   chmod +x \
     server.py \
     bin/swfrender_linux \
     bin/upnpc_linux && \
   mkdir /data && \
-  chown -R hydrus:hydrus /data && \
   apt-get update && apt-get install --no-install-recommends -y \
     build-essential \
     ffmpeg \
+    gosu \
     multiarch-support \
     wget && \
   dpkg -i libjpeg8_8d-2_amd64.deb && \
@@ -59,7 +44,10 @@ RUN \
   rm -rf /var/lib/apt/lists/*
 
 COPY docker-entrypoint.sh /usr/local/bin/docker-entrypoint
-RUN chmod +x /usr/local/bin/docker-entrypoint
+COPY docker-start.sh /usr/local/bin/docker-start
+RUN \
+  chmod +x /usr/local/bin/docker-entrypoint && \
+  chmod +x /usr/local/bin/docker-start
 
 EXPOSE 45870/tcp 45871/tcp 45872/tcp
 
@@ -69,6 +57,5 @@ HEALTHCHECK --interval=1m --timeout=10s --retries=3 \
 
 VOLUME /data
 
-USER hydrus
-
 ENTRYPOINT ["docker-entrypoint"]
+CMD ["docker-start"]
diff --git a/README.md b/README.md
index d2b5fa4..e234484 100644
--- a/README.md
+++ b/README.md
@@ -15,8 +15,9 @@ The latest build runs [hydrus server version 379][hydrus-server-version].
     + [Upgrading from 2.x to 3.x](#upgrading-from-2x-to-3x)
     + [Upgrading from 1.x to 2.x](#upgrading-from-1x-to-2x)
 + [Usage](#usage)
-  + [Additional configuration when building](#additional-configuration-when-building)
-    + [UID/GID](#uidgid)
+  + [Ports](#ports)
+  + [Storage](#storage)
+  + [UID/GID](#uidgid)
 + [Donate](#donate)
 + [Maintainer](#maintainer)
 + [Contribute](#contribute)
@@ -87,6 +88,8 @@ making it easier to adapt for future changes/dependencies.
 
 ## Usage
 
+### Ports
+
 First, you need to bind the exposed ports. This can be done automatically
 using `-P` but it is recommended to bind them manually instead since having
 changing ports every time you run a new container might be annoying when used
@@ -103,6 +106,8 @@ for the server administration service while `45871` and `45872` are used for
 repositories. You will generally have two (one for tags and one for files), but
 if you add more, you will also need to expose additional ports.
 
+### Storage
+
 Per default, hydrus-server-docker stores its databases and media inside the
 `/data` directory which is a mount point that is persisted as a volume. A new
 volume will be created every time a container is created, making it less ideal
@@ -113,11 +118,22 @@ mount that over it:
 user@local:~$ docker volume create hydrus-server-data
 ```
 
-After creating your named volume, you can run the container. Here is a full
-example with all the options mentioned above:
+### UID/GID
+
+The user that owns the data and runs the server inside the container has the
+UID `1000` and the GID `1000` by default. You can change these by providing the
+environment variables `CUSTOM_UID` and `CUSTOM_GID` when creating a container.
+
+This is useful if you want to access the data outside the container with a user
+with different IDs without hassle. In such a case, `CUSTOM_UID` and
+`CUSTOM_GID` should match the user that is going to access the data on the
+host.
+
+Here is a full example for running the container with all the options mentioned
+above:
 
 ```zsh
-user@local:~$ docker run -p 45870:45870 -p 45871:45871 -p 45872:45872 -v hydrus-server-data:/data -d mserajnik/hydrus-server-docker
+user@local:~$ docker run -p 45870:45870 -p 45871:45871 -p 45872:45872 -v hydrus-server-data:/data -e CUSTOM_UID=1000 -e CUSTOM_GID=1000 -d mserajnik/hydrus-server-docker
 ```
 
 Specifying the same named volume every time a container is created gives each
@@ -127,19 +143,6 @@ Of course, using a bind mount instead of a named volume is also possible but
 for performance reasons only recommended if you need easy access to the data on
 the host machine.
 
-### Additional configuration when building
-
-#### UID/GID
-
-By default, the user that owns the data and runs the server inside the
-container has the UID `1000` and the GID `1000`. You can make a build providing
-the arguments `HOST_USER_ID` and `HOST_GROUP_ID` to change these defaults.
-
-This is useful if you want to access the data outside the container with a user
-with different ID's without hassle. In such a case, `HOST_USER_ID` and
-`HOST_GROUP_ID` should match the user that is going to access the data on the
-host.
-
 ## Donate
 
 If you like hydrus-server-docker and want to buy me a coffee, feel free to
diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
index 2369c66..62937a4 100644
--- a/docker-entrypoint.sh
+++ b/docker-entrypoint.sh
@@ -1,13 +1,10 @@
 #!/bin/bash
 
-. venv/bin/activate
+USER_ID=${CUSTOM_UID:-1000}
+GROUP_ID=${CUSTOM_GID:-1000}
 
-stop() {
-  ./server.py stop -d="/data"
-}
+echo "Setting permissions to UID/GID ${USER_ID}/${GROUP_ID}."
+chown ${USER_ID}:${GROUP_ID} -R /usr/src/app
+chown ${USER_ID}:${GROUP_ID} -R /data
 
-trap "stop" SIGTERM
-
-./server.py -d="/data" &
-
-wait $!
+exec gosu ${USER_ID}:${GROUP_ID} "$@"
diff --git a/docker-start.sh b/docker-start.sh
new file mode 100644
index 0000000..2369c66
--- /dev/null
+++ b/docker-start.sh
@@ -0,0 +1,13 @@
+#!/bin/bash
+
+. venv/bin/activate
+
+stop() {
+  ./server.py stop -d="/data"
+}
+
+trap "stop" SIGTERM
+
+./server.py -d="/data" &
+
+wait $!