Change kernel building docker arguments

This was needed because the Ubuntu docker image overwrites the UID
argument with a blank string, so we need to rename the variable to
something else.

Signed-off-by: Sergiu Weisz <sergiu121@gmail.com>

Author: sergiu121

tools/labs/Makefile

@@ -36,7 +36,7 @@ docker-docs:
 	cd docker && UID=$(shell id -u) GID=$(shell id -g) docker-compose run docs-build bash -c "cd /linux/tools/labs && make docs"
 
 docker-kernel:
-	cd docker && UID=$(shell id -u) GID=$(shell id -g) docker-compose build kernel-build
+	cd docker && ARG_UID=$(shell id -u) ARG_GID=$(shell id -g) docker-compose build kernel-build
 	cd docker && docker-compose up -d kernel-build
 	cd docker && docker-compose exec -u ubuntu kernel-build bash
 

tools/labs/docker/docker-compose.yml

@@ -13,11 +13,12 @@ services:
   kernel-build:
     privileged: true
     tty: true
+    hostname: "so2"
     build:
       context: .
       dockerfile: ./kernel/Dockerfile
       args:
-              UID: ${UID}
-              GID: ${GID}
+              ARG_UID: ${ARG_UID}
+              ARG_GID: ${ARG_GID}
     volumes:
       - ../../../:/linux

tools/labs/docker/kernel/Dockerfile

@@ -28,11 +28,11 @@ RUN apt-get -y clean
 
 RUN rm -rf /var/lib/apt/lists/*
 
-ARG UID
-ARG GID
+ARG ARG_UID
+ARG ARG_GID
 
-RUN groupadd -g $GID ubuntu
-RUN useradd -u $UID -g $GID -ms /bin/bash ubuntu && adduser ubuntu sudo && echo -n 'ubuntu:ubuntu' | chpasswd
+RUN groupadd -g $ARG_GID ubuntu
+RUN useradd -u $ARG_UID -g $ARG_GID -ms /bin/bash ubuntu && adduser ubuntu sudo && echo -n 'ubuntu:ubuntu' | chpasswd
 
 # Enable passwordless sudo for users under the "sudo" group
 RUN sed -i.bkp -e \