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<div class="moz-cite-prefix">On 23/07/14 15:50, Mark Heslin wrote:<br>
</div>
<blockquote cite="mid:53CFBDAC.4080503@redhat.com" type="cite">Martin,
Petr,
<br>
<br>
Thanks for helping me sort through the syntax. I have the entries
added properly:
<br>
<br>
# ipa dnsrecord-show example.com _foo.tcp
<br>
Record name: _foo.tcp
<br>
SRV record: 0 0 53 foo1.example.com., 0 0 53 foo2.example.com.
<br>
<br>
# host -t srv _foo.tcp
<br>
_foo.tcp.example.com has SRV record 0 0 53 foo2.example.com.
<br>
_foo.tcp.example.com has SRV record 0 0 53 foo1.example.com.
<br>
<br>
but how to I actually use the entry?
<br>
<br>
# nslookup _foo.tcp
<br>
Server: 10.19.140.101
<br>
Address: 10.19.140.101#53
<br>
<br>
*** Can't find _foo.tcp: No answer
<br>
<br>
# nslookup _foo.tcp.example.com.
<br>
Server: 10.19.140.101
<br>
Address: 10.19.140.101#53
<br>
<br>
*** Can't find _foo.tcp.example.com.: No answer
<br>
<br>
# ping _foo.tcp
<br>
ping: unknown host _foo.tcp
<br>
</blockquote>
<br>
Hi,<br>
<br>
try to use dig,<br>
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-qt-user-state:0;"><!--StartFragment--><a class="moz-txt-link-freetext" href="https://library.linode.com/linux-tools/common-commands/dig">https://library.linode.com/linux-tools/common-commands/dig</a><br>
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dig srv _foo.tcp.example.com.<br>
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<br>
<blockquote cite="mid:53CFBDAC.4080503@redhat.com" type="cite">
<br>
The point of this is to create a front-end to balance requests
from OpenShift clients
<br>
across a set of OpenShift brokers. Host "foo" would alternate
across the first broker
<br>
(foo1) and second broker (foo2).
<br>
<br>
-m
<br>
<br>
<br>
<br>
<br>
On 07/22/2014 08:06 AM, Mark Heslin wrote:
<br>
<blockquote type="cite">On 07/22/2014 08:00 AM, Mark Heslin wrote:
<br>
<blockquote type="cite">Martin, Petr,
<br>
<br>
I didn't see that missing dot "." - good catch. As always the
devil is in the details :-)
<br>
<br>
Two follow up questions:
<br>
<br>
1. I've set the priority and weighting equally here but I
will add a third host
<br>
so would it make sense to just set both priority and
weight to "0" for all three hosts?:
<br>
<br>
# ipa dnsrecord-add example.com _foo.tcp --srv-rec="0 0
53 foo1.example.com."
<br>
# ipa dnsrecord-add example.com _foo.tcp --srv-rec="0 0
53 foo2.example.com."
<br>
# ipa dnsrecord-add example.com _foo.tcp --srv-rec="0 0
53 foo3.example.com."
<br>
<br>
2. To Petr's point about registering the "_foo.tcp" service.
By definition this isn't really
<br>
a true "service" and more like "CNAME with benefits".
(Sorry, couldn't resist the bad dating reference ;-))
<br>
Do I actually still need to add this to /etc/services?
If so, then I'd have to do that for
<br>
all hosts in the environment, IdM servers, clients,
etc., correct?
<br>
<br>
Truth be told, this is just being used for an
alternative to a true h/w, s/w load balancer
<br>
for demonstration purposes so I'm sure adding it to the
services file makes sense.
<br>
</blockquote>
<br>
Gah! I meant to say I'm *not* sure adding it to the services
file makes sense.
<br>
<br>
<br>
<blockquote type="cite">
<br>
Thank you both!
<br>
<br>
-m
<br>
<br>
<br>
<br>
<br>
On 07/22/2014 03:16 AM, Petr Spacek wrote:
<br>
<blockquote type="cite">On 22.7.2014 00:13, Mark Heslin wrote:
<br>
<blockquote type="cite">Hi All,
<br>
<br>
I had some off-list exchanges with Petr Spacek on this but
am still trying to
<br>
work out the correct syntax.
<br>
I have 2 hosts:
<br>
<br>
- foo1.example.com
<br>
- foo2.example.com
<br>
<br>
and would like to create a round-robin DNS srv record for
both called
<br>
foo.example.com
<br>
<br>
I already have DNS entries for both hosts in IPA:
<br>
<br>
# ipa dnsrecord-show example.com foo1
<br>
Record name: foo1
<br>
A record: 10.0.0.1
<br>
# ipa dnsrecord-show example.com foo2
<br>
Record name: foo2
<br>
A record: 10.0.0.2
<br>
<br>
I'd like to get the correct syntax for adding the srv
record for foo.
<br>
My understanding is that it should be something like this:
<br>
<br>
# ipa dnsrecord-add example.com _foo.tcp --srv-rec="0
50 53 foo1.example.com"
<br>
Record name: _foo.tcp
<br>
SRV record: 0 50 53 foo1.example.com
<br>
# ipa dnsrecord-add example.com _foo.tcp --srv-rec="0
50 53 foo2.example.com"
<br>
Record name: _foo.tcp
<br>
SRV record: 0 50 53 foo2.example.com
<br>
<br>
which seemed to be added ok but on second glance I think
not:
<br>
<br>
# host -t srv _foo.tcp.example.com
<br>
_foo.tcp..example.com has SRV record 0 50 53
foo1.example.com.example.com.
<br>
_foo.tcp..example.com has SRV record 0 50 53
foo2.example.com.example.com.
<br>
<br>
In looking over the description of rfc2782
<br>
<a class="moz-txt-link-rfc2396E" href="http://en.wikipedia.org/wiki/SRV_record"><http://en.wikipedia.org/wiki/SRV_record></a> it appears
the IPA syntax is a
<br>
little different,
<br>
</blockquote>
<br>
I don't think so :-)
<br>
<br>
Please note the trailing dot in "target" part of
<a class="moz-txt-link-freetext" href="http://en.wikipedia.org/wiki/SRV_record#Record_format">http://en.wikipedia.org/wiki/SRV_record#Record_format</a>.
<br>
<br>
IPA behaves in the same way as BIND 9: All domain names
without trailing dot are automatically extended with zone
origin, i.e. "example.com.".
<br>
<br>
You have two options:
<br>
# ipa dnsrecord-add example.com _foo.tcp --srv-rec="0 50 53
foo1" (DNS server will automatically append "example.com.")
<br>
<br>
or
<br>
<br>
# ipa dnsrecord-add example.com _foo.tcp --srv-rec="0 50 53
foo1.example.com."
<br>
(please note the trailing dot)
<br>
<br>
<br>
<br>
Another note is about "_foo". "foo" should be "service name"
according to
<br>
<a class="moz-txt-link-freetext" href="http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml">http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml</a>
<br>
<br>
It will probably not cause any problems if you invent your
own name (preferably prefixed with x- to avoid collisions in
future, e.g. "_x-foo"), but it will not hurt you if you
register your protocol into the registry :-)
<br>
See <a class="moz-txt-link-freetext" href="http://tools.ietf.org/html/rfc6335">http://tools.ietf.org/html/rfc6335</a>
<br>
<br>
<blockquote type="cite">and the documentation is scarce so
admittedly I'm taking a swag at this ;-)
<br>
<br>
I can do this fine without srv but don't have enough
familiarity with DNS srv
<br>
here.
<br>
Can anyone help clarify what I'm missing? I'd like to have
equal weighting,
<br>
priority
<br>
to both hosts - I'm assuming the port (53) is correct for
DNS here as well.
<br>
</blockquote>
What are you trying to achieve? The port number refers to
port used by your application, not to DNS.
<br>
<br>
</blockquote>
<br>
<br>
</blockquote>
<br>
<br>
</blockquote>
<br>
<br>
</blockquote>
<br>
<br>
<pre class="moz-signature" cols="72">--
Martin Basti</pre>
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