setup-env: only allow slaves with large amounts of RAM to mount tmpfs

Signed-off-by: Derek Straka <derek@asterius.io>

scripts/cleanup-env.sh

@@ -1,5 +1,8 @@
 #!/bin/bash -e
 
-sudo umount build
+# Only attempt to unmount if the directory is already mounted
+if mountpoint -q `pwd`/build; then
+    sudo umount build
+fi
 
 exit 0

scripts/setup-env.sh

@@ -2,6 +2,11 @@
 
 mkdir -p build
 
-sudo mount -t tmpfs -o size=64G,mode=755,uid=${UID} tmpfs build
+total_mem=`grep MemTotal /proc/meminfo | awk '{print $2}'`
+
+# Only have the slaves with large amounts of RAM mount the tmpfs
+if [ "$total_mem" -ge "67108864" ]; then
+    sudo mount -t tmpfs -o size=64G,mode=755,uid=${UID} tmpfs build
+fi
 
 exit 0