add flutter user

Dockerfile

@@ -26,6 +26,9 @@ RUN wget "$GLIBC_URL/glibc-2.35-r1.apk" --directory-prefix $TMP_DEPENDENCIES_DIR
 FROM alpine:3.20
 
 ARG DEPENDENCY_DIR
+ARG USER_UID="1000"
+ARG USER_GID=${USER_UID}
+ARG USERNAME="flutter"
 
 ENV FLUTTER_HOME="/flutter"
 ENV PATH=$PATH:$FLUTTER_HOME/bin
@@ -35,5 +38,11 @@ COPY --from=download $DEPENDENCY_DIR /
 RUN wget -q -O /etc/apk/keys/sgerrand.rsa.pub https://alpine-pkgs.sgerrand.com/sgerrand.rsa.pub \
     && apk add --no-cache --force-overwrite curl bash git tmp/glibc-2.35-r1.apk tmp/glibc-bin-2.35-r1.apk \
     && rm -r /tmp/* \
-    && dart --disable-analytics && flutter config --no-analytics \
+    && addgroup ${USERNAME} -g ${USER_GID} \
+    && adduser ${USERNAME} --uid ${USER_UID} --ingroup ${USERNAME} --disabled-password \
+    && chown -R ${USERNAME}:${USERNAME} ${FLUTTER_HOME}
+
+USER ${USERNAME}
+
+RUN dart --disable-analytics && flutter config --no-analytics \
     && flutter precache --universal