misc lil cleanups (#582)

* cleanup apt hook

* Move VERSION into rootfs overlay

* Use broad rootfs overlay copy

userspace/root/VERSION

@@ -0,0 +1 @@
+18.2

userspace/root/etc/apt/apt.conf

@@ -0,0 +1,17 @@
+APT::Install-Suggests “0”;
+APT::Install-Recommends “0”;
+
+APT::Install {
+  Pre-Invoke { "/usr/comma/apt_setup.sh"; };
+  Post-Invoke { "/usr/comma/apt_teardown.sh"; };
+};
+
+APT::Update {
+  Pre-Invoke { "/usr/comma/apt_setup.sh"; };
+  Post-Invoke { "/usr/comma/apt_teardown.sh"; };
+};
+
+DPkg {
+  Pre-Invoke { "/usr/comma/apt_setup.sh"; };
+  Post-Invoke { "/usr/comma/apt_teardown.sh"; };
+};

userspace/root/usr/comma/apt_setup.sh

@@ -1,5 +1,10 @@
 #!/bin/bash -e
 
+# Skip while Docker is assembling the image.
+if [ -f /.dockerenv ]; then
+  exit 0
+fi
+
 sudo mount -o rw,remount /
 sudo resize2fs $(findmnt -n -o SOURCE /) &>/dev/null || sudo resize2fs $(findmnt -n -o SOURCE /)
 sudo mount -o remount,size=1500M /var

userspace/root/usr/comma/apt_teardown.sh

@@ -1,3 +1,8 @@
 #!/bin/bash
 
+# Skip while Docker is assembling the image.
+if [ -f /.dockerenv ]; then
+  exit 0
+fi
+
 sudo mount -o ro,remount / || true