Set fixed Docker GID to avoid collisions with some groups

Author: ElsevierAlex

build/config.json

@@ -1,7 +1,8 @@
 {
   "user": {
     "user-id": 1001,
-    "group-id": 121
+    "group-id": 121,
+    "docker-group-id": 500
   },
   "install": [
     {

build/config.sh

@@ -13,6 +13,10 @@ function group_id() {
   jq -r '.user."group-id"' "$(config_file)"
 }
 
+function docker_group_id() {
+  jq -r '.user."docker-group-id"' "$(config_file)"
+}
+
 function apt_packages() {
   jq -r '.install[] | select(.source == "apt") | .packages[]' "$(config_file)" | paste -sd ' ' -
 }

build/tools.sh

@@ -38,11 +38,25 @@ function install_git-lfs() {
   rm -rf /tmp/lfs.tar.gz "/tmp/git-lfs-${GIT_LFS_VERSION}"
 }
 
+function configure_docker_group_id() {
+  local desired_gid="$(docker_group_id)"
+  local current_gid=$(getent group docker | cut -d: -f3)
+
+  if [[ "$current_gid" != "$desired_gid" ]]; then
+    # Expected to fail if the group already exists or the GID is already in use
+    groupadd --system --gid "$desired_gid" docker 2>/dev/null || true
+  fi
+}
+
 function install_docker-cli() {
+  configure_docker_group_id
+
   apt-get install -y docker-ce-cli --no-install-recommends --allow-unauthenticated
 }
 
 function install_docker() {
+  configure_docker_group_id
+
   apt-get install -y docker-ce docker-ce-cli docker-buildx-plugin containerd.io docker-compose-plugin --no-install-recommends --allow-unauthenticated
 
   echo -e '#!/bin/sh\ndocker compose --compatibility "$@"' > /usr/local/bin/docker-compose