From b5120790a4942caf8e10fe236c76fa69d314167a Mon Sep 17 00:00:00 2001
From: Jonathan Chan <jonathanhwchan@gmail.com>
Date: Sat, 6 Sep 2025 02:45:24 +0200
Subject: [PATCH] Add `UID` and `GID` arguments to Dockerfile
Change-Id: pqwwuswvnlxvspzkrxrkuokorlvvkpxn

`UID` and `GID` args can now be set during build,
so following the example command in the README should fix
[#2](https://tangled.sh/@tangled.sh/knot-docker/issues/2)
by providing a `UID` and `GID` that exist on the host
so that the directories owned by git in the container
can be bind mounted on the host.
---
 Dockerfile         |  7 ++++++-
 docker-compose.yml |  6 +++++-
 readme.md          | 18 ++++++++++++++++--
 3 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 4aab26b..610cbcb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -20,11 +20,16 @@ label org.opencontainers.image.url='https://tangled.sh'
 label org.opencontainers.image.vendor='tangled.sh'
 label org.opencontainers.image.licenses='MIT'
 
+arg UID=1000
+arg GID=1000
+
 copy rootfs .
 run chmod 755 /etc
 run chmod -R 755 /etc/s6-overlay
 run apk add shadow s6-overlay execline openssl openssh git curl bash
-run useradd -d /home/git git && openssl rand -hex 16 | passwd --stdin git
+run groupadd -g $GID -f git
+run useradd -u $UID -g $GID -d /home/git git
+run openssl rand -hex 16 | passwd --stdin git
 run mkdir -p /home/git/repositories && chown -R git:git /home/git
 copy --from=builder /usr/bin/knot /usr/bin
 run mkdir /app && chown -R git:git /app
diff --git a/docker-compose.yml b/docker-compose.yml
index 0ac7811..69b34b7 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,6 +1,10 @@
 services:
   knot:
-    build: .
+    build:
+      context: .
+      args:
+        UID: 1000
+        GID: 1000
     environment:
       KNOT_SERVER_HOSTNAME: ${KNOT_SERVER_HOSTNAME}
       KNOT_SERVER_OWNER: ${KNOT_SERVER_OWNER}
diff --git a/readme.md b/readme.md
index d77f4aa..a39d6de 100644
--- a/readme.md
+++ b/readme.md
@@ -29,15 +29,29 @@ docker build -t knot:latest --build-arg TAG=master .
 The command above for example will build the latest commit on the `master`
 branch.
 
+By default it will also create a `git` user with user and group ID 1000:1000,
+but you can change it with the `UID` and `GID` build arguments.
+
+```sh
+docker build -t knot:latest --build-arg UID=$(id -u) GID=$(id -g)
+```
+
+The command above for example will create a user with the host user's UID and GID.
+This is useful if you are bind mounting the repositories and app folder on the host,
+as in the provided `docker-compose.yml` file.
+
 <hr style="margin-bottom: 20px; margin-top: 10px" />
 
-When using compose, it can be specified as a build argument which will be
+When using compose, these can be specified as build arguments which will be
 passed to the builder.
 
 ```yaml
 build:
   context: .
-  args: { TAG: master }
+  args:
+    TAG: master
+    UID: 1000
+    GID: 1000
 ```
 
 This will for example tell docker to build it using the `master` branch like
-- 
2.51.0