allow override of gid/uid from the build command

It is useful when running from a development environment with
a setup identical to the CI.

Signed-off-by: Loïc Dachary <loic@dachary.org>

Dockerfile

@@ -1,13 +1,15 @@
 FROM golang:1.17-buster
+ARG GITEA_ID=1000
+ARG GITEA_GID=1000
 
 RUN addgroup \
-    --gid 1000 \
+    --gid $GITEA_GID \
     gitea && \
   adduser \
     --gecos '' \
     --shell /bin/bash \
-    --uid 1000 \
-    --gid 1000 \
+    --uid $GITEA_ID \
+    --gid $GITEA_GID \
     gitea
 
 # upgrade git to v2.33.0

README.md

@@ -6,3 +6,9 @@ A docker image for Gitea ci test
 - upgrade git to v2.33.0
 - install git-lfs
 - install [golangci-lint](https://github.com/golangci/golangci-lint) v1.43.0
+
+# development environment build
+
+In order to run from within a development environment at the root of the gitea repository with a command such as `docker run --volume $(pwd):/drone/src --workdir /drone/src --user gitea mytestenv ...` the id of the gitea user must match the id of the development environment.
+
+- docker build --tag mytestenv --build-arg GITEA_ID=$(id -u) --build-arg GITEA_GID=$(id -g) .