devcontainer: expose host config, fix mac screen issues (#29932)

* export host config via .host/.env file. fix mac display issues

* append instead of replace for bashrc

* Log when mac display override happens

* Update xauthority path in json

.devcontainer/.gitignore

@@ -1 +1,3 @@
-.Xauthority
+.Xauthority
+.env
+.host/

.devcontainer/container_post_create.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+
+source .devcontainer/.host/.env
+
+# override display flag for mac
+if [[ $HOST_OS == darwin ]]; then
+  echo "Setting up DISPLAY override for macOS..."
+  cat <<EOF >> /root/.bashrc
+if [ -n "\$DISPLAY" ]; then
+  DISPLAY_NUM=\$(echo "\$DISPLAY" | awk -F: '{print \$NF}')
+  export DISPLAY=host.docker.internal:\$DISPLAY_NUM
+fi
+EOF
+fi

.devcontainer/container_post_start.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+# setup safe directories for submodules
+SUBMODULE_DIRS=$(git config --file .gitmodules --get-regexp path | awk '{ print $2 }')
+for DIR in $SUBMODULE_DIRS; do 
+  git config --global --add safe.directory "$PWD/$DIR"
+done

.devcontainer/devcontainer.json

@@ -3,9 +3,9 @@
   "build": {
     "dockerfile": "Dockerfile"
   },
-  "postCreateCommand": "bash -c 'if [[ $DISPLAY == *xquartz* ]]; then echo \"export DISPLAY=host.docker.internal:0\" >> /root/.bashrc; fi'",
-  "postStartCommand": "git config --file .gitmodules --get-regexp path | awk '{ print $2 }' | xargs -I{} git config --global --add safe.directory \"$PWD/{}\"",
-  "initializeCommand": ".devcontainer/setup_host.sh",
+  "postCreateCommand": ".devcontainer/container_post_create.sh",
+  "postStartCommand": ".devcontainer/container_post_start.sh",
+  "initializeCommand": ".devcontainer/host_setup.sh",
   "privileged": true,
   "containerEnv": {
     "DISPLAY": "${localEnv:DISPLAY}",
@@ -14,7 +14,7 @@
   },
   "runArgs": [
     "--volume=/tmp/.X11-unix:/tmp/.X11-unix",
-    "--volume=${localWorkspaceFolder}/.devcontainer/.Xauthority:/root/.Xauthority",
+    "--volume=${localWorkspaceFolder}/.devcontainer/.host/.Xauthority:/root/.Xauthority",
     "--volume=${localEnv:HOME}/.comma:/root/.comma",
     "--volume=/tmp/comma_download_cache:/tmp/comma_download_cache",
     "--volume=/tmp/devcontainer_scons_cache:/tmp/scons_cache",

.devcontainer/host_setup.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+# setup .host dir
+mkdir -p .devcontainer/.host
+
+# setup links to Xauthority
+XAUTHORITY_LINK=".devcontainer/.host/.Xauthority"
+rm -f $XAUTHORITY_LINK
+if [[ -z $XAUTHORITY ]]; then
+  echo "XAUTHORITY not set. Fallback to ~/.Xauthority ..."
+  if ! [[ -f $HOME/.Xauthority ]]; then
+    echo "~/.XAuthority file does not exist. GUI tools may not work properly."
+    touch $XAUTHORITY_LINK # dummy file to satisfy container volume mount
+  else
+    ln -sf $HOME/.Xauthority $XAUTHORITY_LINK
+  fi
+else
+    ln -sf $XAUTHORITY $XAUTHORITY_LINK
+fi
+
+# setup host env file
+HOST_INFO_FILE=".devcontainer/.host/.env"
+SYSTEM=$(uname -s | tr '[:upper:]' '[:lower:]')
+echo "HOST_OS=\"$SYSTEM\"" > $HOST_INFO_FILE