standardize apt-get

root/etc/cont-init.d/94-mesa-repo

@@ -0,0 +1,7 @@
+#!/usr/bin/with-contenv bash
+
+if [ ! -f "/etc/apt/sources.list.d/kisak-mesa-focal.list" ]; then
+    echo "**** Adding kisak-mesa repo ****"
+    apt-key adv --keyserver keyserver.ubuntu.com --recv-keys F63F0F2B90935439
+    echo "deb http://ppa.launchpad.net/kisak/kisak-mesa/ubuntu focal main" > /etc/apt/sources.list.d/kisak-mesa-focal.list
+fi

root/etc/cont-init.d/95-apt-get

@@ -0,0 +1,3 @@
+#!/usr/bin/with-contenv bash
+
+apt-get update

root/etc/cont-init.d/98-mesa

@@ -19,8 +19,5 @@ done
 
 if "$install"; then
     echo "**** Installing mesa ****"
-    apt-key adv --keyserver keyserver.ubuntu.com --recv-keys F63F0F2B90935439
-    echo "deb http://ppa.launchpad.net/kisak/kisak-mesa/ubuntu focal main" > /etc/apt/sources.list.d/kisak-mesa-focal.list
-    apt-get update
     apt-get install -y $pkgs
 fi