From 85a0f4f44f82402088363a2feb025093c348a232 Mon Sep 17 00:00:00 2001
From: Steve Kowalik <steven@wedontsleep.org>
Date: Thu, 4 Jun 2015 15:30:55 +1000
Subject: [PATCH] Switch to using $() for subshells, part 1

Cleanup every use of `` for subshells in the nodepool and tools
directory , replacing them with $(), and finally making the scripts
consistent.

Change-Id: I2b05cd20f9c9a30ab88f8db235aa81da93b1fad3
---
 nodepool/elements/puppet/pre-install.d/10-preseed | 4 ++--
 nodepool/scripts/install_devstack_dependencies.sh | 2 +-
 nodepool/scripts/multinode_setup.sh               | 4 ++--
 nodepool/scripts/prepare_devstack.sh              | 2 +-
 tools/check_valid_gerrit_config.sh                | 2 +-
 tools/mount-image.sh                              | 2 +-
 tools/run-compare-xml.sh                          | 2 +-
 7 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/nodepool/elements/puppet/pre-install.d/10-preseed b/nodepool/elements/puppet/pre-install.d/10-preseed
index 4c5dbef515..71d623d011 100755
--- a/nodepool/elements/puppet/pre-install.d/10-preseed
+++ b/nodepool/elements/puppet/pre-install.d/10-preseed
@@ -23,11 +23,11 @@
 set -e
 
 # If lsb_release is missing, just do nothing.
-DISTRO=`lsb_release -si` || true
+DISTRO=$(lsb_release -si) || true
 
 case $DISTRO in
     'Ubuntu'|'Debian')
-    PRESEED=`mktemp`
+    PRESEED=$(mktemp)
     cat > $PRESEED <<EOF
 d-i iptables-persistent/autosave_done boolean true
 d-i iptables-persistent/autosave_v4 boolean false
diff --git a/nodepool/scripts/install_devstack_dependencies.sh b/nodepool/scripts/install_devstack_dependencies.sh
index 2c295600fc..2c09fd4f1c 100755
--- a/nodepool/scripts/install_devstack_dependencies.sh
+++ b/nodepool/scripts/install_devstack_dependencies.sh
@@ -43,7 +43,7 @@ elif [ -f /usr/bin/apt-get ]; then
         sudo DEBIAN_FRONTEND=noninteractive apt-get \
             --option "Dpkg::Options::=--force-confold" \
             --assume-yes install build-essential python-dev \
-            python-software-properties linux-headers-virtual linux-headers-`uname -r`
+            python-software-properties linux-headers-virtual linux-headers-$(uname -r)
     fi
 else
     echo "Unsupported distro."
diff --git a/nodepool/scripts/multinode_setup.sh b/nodepool/scripts/multinode_setup.sh
index 61a12f8ef4..704351140a 100755
--- a/nodepool/scripts/multinode_setup.sh
+++ b/nodepool/scripts/multinode_setup.sh
@@ -18,7 +18,7 @@
 
 export PATH=$PATH:/usr/local/sbin:/usr/sbin
 
-for ip in `cat /etc/nodepool/primary_node /etc/nodepool/sub_nodes /etc/nodepool/primary_node_private /etc/nodepool/sub_nodes_private | sort -u`; do
+for ip in $(cat /etc/nodepool/primary_node /etc/nodepool/sub_nodes /etc/nodepool/primary_node_private /etc/nodepool/sub_nodes_private | sort -u); do
     sudo iptables -I openstack-INPUT 1 -s $ip -j ACCEPT
 done
 
@@ -26,7 +26,7 @@ echo "" >> /home/jenkins/.ssh/authorized_keys
 cat /etc/nodepool/id_rsa.pub >> /home/jenkins/.ssh/authorized_keys
 echo "" >> /home/jenkins/.ssh/authorized_keys
 
-ROLE=`cat /etc/nodepool/role`
+ROLE=$(cat /etc/nodepool/role)
 if [ $ROLE == "primary" ]; then
     cp /etc/nodepool/id_rsa /home/jenkins/.ssh/id_rsa
     chmod 0600 /home/jenkins/.ssh/id_rsa
diff --git a/nodepool/scripts/prepare_devstack.sh b/nodepool/scripts/prepare_devstack.sh
index f6abfedfcf..92327817ea 100755
--- a/nodepool/scripts/prepare_devstack.sh
+++ b/nodepool/scripts/prepare_devstack.sh
@@ -18,7 +18,7 @@
 
 cd /opt/nodepool-scripts/
 ./install_devstack_dependencies.sh
-DISTRIB_CODENAME=`lsb_release -sc`
+DISTRIB_CODENAME=$(lsb_release -sc)
 python ./cache_devstack.py $DISTRIB_CODENAME
 
 sync
diff --git a/tools/check_valid_gerrit_config.sh b/tools/check_valid_gerrit_config.sh
index ae9478b838..3a87c3877d 100755
--- a/tools/check_valid_gerrit_config.sh
+++ b/tools/check_valid_gerrit_config.sh
@@ -2,7 +2,7 @@
 
 # It checks that *.config files respect certain gerrit ACL rules
 
-export TMPDIR=`/bin/mktemp -d`
+export TMPDIR=$(/bin/mktemp -d)
 trap "rm -rf $TMPDIR" EXIT
 
 pushd $TMPDIR
diff --git a/tools/mount-image.sh b/tools/mount-image.sh
index f184467d93..faaadb59a1 100644
--- a/tools/mount-image.sh
+++ b/tools/mount-image.sh
@@ -22,7 +22,7 @@ rm -rf /tmp/newimage
 mkdir -p /tmp/newimage
 
 #qemu-nbd needs the absolute path of the image
-qemu-nbd -c /dev/nbd1 `readlink -e $IMAGE`
+qemu-nbd -c /dev/nbd1 $(readlink -e $IMAGE)
 
 #mount the first partition
 mount /dev/nbd1p1 /tmp/newimage
diff --git a/tools/run-compare-xml.sh b/tools/run-compare-xml.sh
index 1b65c3b6c4..49e210f025 100755
--- a/tools/run-compare-xml.sh
+++ b/tools/run-compare-xml.sh
@@ -28,7 +28,7 @@ mkdir -p .test/new/config
 mkdir -p .test/new/out
 cd ../..
 
-GITHEAD=`git rev-parse HEAD`
+GITHEAD=$(git rev-parse HEAD)
 
 # First generate output from HEAD~1
 git checkout HEAD~1