Put devstack-version info into separate file

As a follow on to I4c269a7f3d63ee9a976e7c3636fc3e5e8dab9ae3; the
quoting gets tricky when putting arbitrary command-substitution
strings into saved echo-able strings.  As they say, "the only winning
move is not to play" :)

An alternative proposal is to not write this into a script but just
dump info into a file.  To my mind, this has several advantages --
avoid getting involved in quoting, not dropping a script into the
global environment -- it's just as easy to "cat" -- and the plain-text
file can be collected as an artifact during log collection (also moved
git commit line to separate line for easier parsing during log search,
etc).

Change-Id: Ic7391dd087657c0daf74046e4a052c53f4eb6e1a
(Cherry-picked from 07cbc44942)

functions

@@ -673,18 +673,16 @@ function enable_kernel_bridge_firewall {
     done
 }
 
+# Save some state information
+#
+# Write out various useful state information to /etc/devstack-version
 function write_devstack_version {
-    pushd $TOP_DIR
-    local git_version=""
-    git_version=$(git log --format="%H %ci" -1)
     cat - > /tmp/devstack-version <<EOF
-#!/bin/bash
-
-echo "DevStack Version: ${DEVSTACK_SERIES} - ${git_version}"
-echo "OS Version: ${os_VENDOR} ${os_RELEASE} ${os_CODENAME}"
-
+DevStack Version: ${DEVSTACK_SERIES}
+Change: $(git log --format="%H %s %ci" -1)
+OS Version: ${os_VENDOR} ${os_RELEASE} ${os_CODENAME}
 EOF
-    sudo install -m 755 /tmp/devstack-version /usr/local/bin/devstack-version
+    sudo install -m 644 /tmp/devstack-version /etc/devstack-version
     rm /tmp/devstack-version
 }
 

stack.sh

@@ -190,7 +190,7 @@ if [[ ! -r $TOP_DIR/stackrc ]]; then
 fi
 source $TOP_DIR/stackrc
 
-# this installs a devstack-version script to make it easy to report the version back
+# write /etc/devstack-version
 write_devstack_version
 
 # Warn users who aren't on an explicitly supported distro, but allow them to
@@ -1468,8 +1468,8 @@ if [[ -n "$DEPRECATED_TEXT" ]]; then
     echo
 fi
 
-# devstack version
-devstack-version
+# Useful info on current state
+cat /etc/devstack-version
 echo
 
 # Indicate how long this took to run (bash maintained variable ``SECONDS``)