[PATCH] wait for db to become ready - WAS Re: [Ovirt-devel] Still having issues with the wui appliance install

[Perry N. Myers]

Alan Pevec wrote:
> Darryl L. Pierce wrote:
>> I ran through it again and it's still not creating the ovirt database 
>> or role. After it finished the full installation and restarted, I 
>> watched it as it tried to bring up the ovirt system it complained that 
>> the postgres database was not initialized. When I got to a command 
>> prompt, went into Postgres and listed databases with \l I only saw 
>> postgres, template0 and template1 listed.
> 
> This turned out to be a timing issue in ovirt-wui-install during first 
> boot, postgres was not ready immediately after 'service postgres start' 
> returned.
> PG initscript has optimistic sleep 2 after starting postmaster daemon 
> but this wui VM was created w/o KVM support (VT was not enabled in BIOS) 
> and running slooowly with qemu-system-x86_64
> With KVM it's fast enough so this doesn't happen.

We really should print a warning if create-wui-appliance doesn't detect 
hardware virt support or if the qemu process is not launched with 
qemu-kvm.  That way people will understand why things are so slow.

Though... create-wui-appliance will need to be rewritten once we start 
using livecd creator from the ADK to generate the appliance and this will 
be moot.

> Here's the patch which should fix this: wait until we can connect to the 
> database or timeout

Looks ok to me.  ACK.

Perry

> diff --git a/wui/scripts/ovirt-wui-install b/wui/scripts/ovirt-wui-install
> index 8d95d48..3891604 100755
> --- a/wui/scripts/ovirt-wui-install
> +++ b/wui/scripts/ovirt-wui-install
> @@ -135,6 +135,21 @@ echo "host all all 127.0.0.1 255.255.255.0 trust" 
>  >> /var/lib/pgsql/data/pg_hba.
> service postgresql stop > /dev/null 2>&1
> service postgresql start
> [ $? != 0 ] && echo "Failed to start database" && exit 1
> +declare -i timeout=10 +while [[ timeout -gt 0 ]]
> +do
> +  sleep 2
> +  psql -l -U postgres > /dev/null 2>&1
> +  rc=$?
> +  if [[ rc -eq 0 ]]
> +  then
> +     break
> +  else
> +     echo Database not ready yet, retrying...
> +  fi
> +  let timeout--
> +done
> +[[ timeout -eq 0 ]] && echo "Failed to start database" && exit 1
> 
> if [ -z $PASSWD ]; then
>     # generate random pg user password
> 
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