Instead of silently skipping user creation, it renames the existing "ubuntu" user/group to "vscode" so that USER vscode resolves correctly

Author: c-schuler

.devcontainer/Dockerfile

@@ -44,8 +44,18 @@ RUN curl -fsSL https://archive.apache.org/dist/maven/maven-3/${MAVEN_VERSION}/bi
 ARG USERNAME=vscode
 ARG USER_UID=1000
 ARG USER_GID=$USER_UID
-RUN if ! getent group $USER_GID >/dev/null; then groupadd --gid $USER_GID $USERNAME; fi && \
-    if ! getent passwd $USER_UID >/dev/null; then useradd --uid $USER_UID --gid $USER_GID -m $USERNAME; fi && \
+RUN EXISTING_GROUP=$(getent group $USER_GID | cut -d: -f1 || echo ""); \
+    EXISTING_USER=$(getent passwd $USER_UID | cut -d: -f1 || echo ""); \
+    if [ -n "$EXISTING_GROUP" ] && [ "$EXISTING_GROUP" != "$USERNAME" ]; then \
+        groupmod -n $USERNAME $EXISTING_GROUP; \
+    elif [ -z "$EXISTING_GROUP" ]; then \
+        groupadd --gid $USER_GID $USERNAME; \
+    fi && \
+    if [ -n "$EXISTING_USER" ] && [ "$EXISTING_USER" != "$USERNAME" ]; then \
+        usermod -l $USERNAME -d /home/$USERNAME -m $EXISTING_USER; \
+    elif [ -z "$EXISTING_USER" ]; then \
+        useradd --uid $USER_UID --gid $USER_GID -m $USERNAME; \
+    fi && \
     echo $USERNAME ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/$USERNAME && \
     chmod 0440 /etc/sudoers.d/$USERNAME