Rework docker setup

platform/linux/Dockerfile

@@ -6,6 +6,7 @@ RUN    apt-get update \
         apt-transport-https \
         curl \
         gnupg \
+        sudo `# allows dev to install more packages without switching to root or rebuilding container` \
         build-essential \
         libsqlite3-dev \
         libcurl4-openssl-dev \
@@ -29,7 +30,24 @@ RUN curl -fsSL https://github.com/bazelbuild/bazelisk/releases/download/v1.20.0/
     && chmod +x /usr/local/bin/bazel \
     && :
 
-# When running docker with -u flag, the user should exist in the container to avoid various warnings
-RUN groupadd -f user && useradd -m -g user user
-
 WORKDIR /app
+
+ARG USERNAME=user
+ARG USER_UID=1000
+ARG USER_GID=$USER_UID
+
+# Create docker user as passed in by the build command
+# This was modeled on https://code.visualstudio.com/remote/advancedcontainers/add-nonroot-user
+RUN groupadd --gid $USER_GID $USERNAME \
+    && useradd --uid $USER_UID --gid $USER_GID -m $USERNAME \
+    && echo $USERNAME ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/$USERNAME \
+    && chmod 0440 /etc/sudoers.d/$USERNAME
+
+COPY startup.sh /usr/local/bin/startup.sh
+RUN chmod +x /usr/local/bin/startup.sh
+
+# This allows users to `docker run` without specifying -u and -g
+USER $USERNAME
+
+ENTRYPOINT ["/usr/local/bin/startup.sh"]
+CMD ["bash"]

platform/linux/Dockerfile.dockerignore

@@ -1,3 +1,4 @@
 # Exclude everything because we expect users to mount this dir as a volume,
 # so none of this repos' content should be part of the docker build context.
 *
+!startup.sh

platform/linux/README.md

@@ -30,23 +30,18 @@ You can use a Docker container to build MapLibre Native. Note that you cannot bu
 
 ```bash
 # Build docker image from the repo root
+# Specifying USER_ID and GROUP_ID allows container to create files with the same owner as the host user,
+# and avoids having to pass -u $(id -u):$(id -g) to docker run.  
 docker build \
   -t maplibre-native-image \
-  -f platform/linux/Dockerfile .
+  --build-arg USER_ID=$(id -u) \
+  --build-arg GROUP_ID=$(id -g) \
+  -f platform/linux/Dockerfile \
+  platform/linux
 
-# Run docker image as the current user.
-# This ensures that the files created in the container are owned by the current user.
-docker run --rm -it -v "$PWD:/app/" -v "$PWD/.docker_cache:/home/user/.cache" -u $(id -u):$(id -g) maplibre-native-image ___any_build_command___
-
-# You can also execute build commands from inside the docker container by starting it without parameters:
-docker run --rm -it -v "$PWD:/app/" -v "$PWD/.docker_cache:/home/user/.cache" -u $(id -u):$(id -g) maplibre-native-image
-```
-
-You can safely ignore this type of message and a missing username. It happens if your linux user was not the first one created on the system.
-
-```
-groups: cannot find name for group ID ....
-I have no name!@...:/root$ `
+# Run all build commands using the docker container.
+# You can also execute build commands from inside the docker container by starting it without the build command.
+docker run --rm -it -v "$PWD:/app/" -v "$PWD/.docker_cache:/home/user/.cache" maplibre-native-image ___any_build_command___
 ```
 
 ## Build
@@ -59,7 +54,6 @@ cmake -B build -GNinja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DC
 cmake --build build --target mbgl-render -j $(nproc 2>/dev/null || sysctl -n hw.ncpu 2>/dev/null)
 ```
 
-
 ## Running `mbgl-render`
 Running `mbgl-render --style https://raw.githubusercontent.com/maplibre/demotiles/gh-pages/style.json` should produce a map tile image with the default MapLibre styling from [the MapLibre demo](https://maplibre.org/).
 

platform/linux/startup.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+
+# This file will have any docker pre-installations
+
+exec "$@"