Ovirt devel - Apr 2008 - [PATCH] start init.d/ovirt-functions

a place to collect reusable shell functions for ovirt* scripts


diff --git a/ovirt-host-creator/common-post.ks
b/ovirt-host-creator/common-post.ks
index 146889a..fd373bd 100644
--- a/ovirt-host-creator/common-post.ks
+++ b/ovirt-host-creator/common-post.ks
@@ -10,6 +10,18 @@ cat > /etc/sysconfig/iptables << \EOF
 COMMIT
 EOF
 
+echo "Writing ovirt-functions script"
+# common functions
+cat > /etc/init.d/ovirt-functions << \EOF
+# -*-Shell-script-*-
+
+find_srv() {
+        local dnsreply=$(dig +short -t srv _$1._$2.$(dnsdomainname))
+        SRV_HOST=$(echo $dnsreply | awk 'NR==1 {print $4}')
+        SRV_PORT=$(echo $dnsreply | awk 'NR==1 {print $3}')
+}
+EOF
+
 echo "Writing ovirt-early init script"
 # next the dynamic bridge setup service
 cat > /etc/init.d/ovirt-early << \EOF
@@ -99,12 +111,11 @@ cat > /etc/init.d/ovirt << \EOF
 
 # Source functions library
 . /etc/init.d/functions
+. /etc/init.d/ovirt-functions
 
 start() {
     echo -n $"Starting ovirt: "
-    IPA=$(/usr/bin/dig +short -t srv _ipa._tcp.$(/bin/dnsdomainname))
-    HOST=$(echo $IPA | head -1 | awk '{print $4}')
-    PORT=$(echo $IPA | head -1 | awk '{print $3}')
+    find_srv ipa tcp
 
     mkdir -p /etc/libvirt
     # here, we wait for the "host-keyadd" service to finish adding
our
@@ -112,7 +123,7 @@ start() {
     # then give up
     tries=0
     while [ "$VAL" != "SUCCESS" -a $tries -lt 5 ]; do
-        VAL=`echo "KERB" | /usr/bin/nc $HOST 6666`
+        VAL=`echo "KERB" | /usr/bin/nc $SRV_HOST 6666`
         if [ "$VAL" == "SUCCESS" ]; then
             break
         fi
@@ -126,7 +137,7 @@ start() {
     fi
 
     if [ ! -s /etc/libvirt/krb5.tab ]; then
-        /usr/bin/wget -q http://$HOST:$PORT/config/$(/bin/hostname
-i)-libvirt.tab -O /etc/libvirt/krb5.tab
+        /usr/bin/wget -q http://$SRV_HOST:$SRV_PORT/config/$(/bin/hostname
-i)-libvirt.tab -O /etc/libvirt/krb5.tab
         if [ $? -ne 0 ]; then
             echo -n "Failed getting keytab" ; failure ; echo ; exit 1
         fi
@@ -134,7 +145,7 @@ start() {
 
     if [ ! -s /etc/krb5.conf ]; then
         rm -f /etc/krb5.conf
-        /usr/bin/wget -q http://$HOST:$PORT/config/krb5.ini -O /etc/krb5.conf
+        /usr/bin/wget -q http://$SRV_HOST:$SRV_PORT/config/krb5.ini -O
/etc/krb5.conf
         if [ "$?" -ne 0 ]; then
             echo "Failed getting krb5.conf" ; failure ; echo ; exit 1
         fi

Alan Pevec <apevec at redhat.com> wrote:
> a place to collect reusable shell functions for ovirt* scripts
>
> diff --git a/ovirt-host-creator/common-post.ks
b/ovirt-host-creator/common-post.ks
> index 146889a..fd373bd 100644
> --- a/ovirt-host-creator/common-post.ks
> +++ b/ovirt-host-creator/common-post.ks
> @@ -10,6 +10,18 @@ cat > /etc/sysconfig/iptables << \EOF
> COMMIT
> EOF
>
> +echo "Writing ovirt-functions script"
> +# common functions
> +cat > /etc/init.d/ovirt-functions << \EOF
> +# -*-Shell-script-*-
> +
> +find_srv() {
> +        local dnsreply=$(dig +short -t srv _$1._$2.$(dnsdomainname))
> +        SRV_HOST=$(echo $dnsreply | awk 'NR==1 {print $4}')
> +        SRV_PORT=$(echo $dnsreply | awk 'NR==1 {print $3}')
> +}
> +EOF
Hi Alan,

That looks like a fine change.  I don't know how robust we want things
like this to be, but it might be nice (at least for whomever is diagnosing
when things go wrong) if find_srv provided a way for callers to detect
when dig or dnsdomainname fails.

Actually, for simple parsing like that, there's a bourne shell idiom
that lets you avoids the cost (and risk of failure of) the two pipes
and uses of awk:
[ using "set" like this sets the shell's positional parameters,
$1, $2,
  etc.  The leading "_" is in case $dnsreply starts with
"-", which
  would make "set" do the wrong thing.  The following
"shift"
  removes the added "_" ]

    set _ $dnsreply; shift
    SRV_PORT=$3
    SRV_HOST=$4