[Pacemaker] RFC: Any interesting in 2.0.0 betas?

Vladislav Bogdanov bubble at hoster-ok.com
Fri Oct 26 10:57:54 UTC 2012


26.10.2012 13:38, Vladislav Bogdanov wrote:
> 26.10.2012 12:43, Andrew Beekhof wrote:
> ...
>>> May be also set it forcibly to uname if uname contains full lexem found
>>> in dns name?
>>
>> Run that past me again?
> 
> I mean that if ip address resolves to fqdn, and that fqdn begins with
> what uname call returns (so both node itself and DNS agree on a node
> name for a node with give IP address), then that value from uname could
> be safely used directly.

Ah, that is for local node only...
For remote nodes I would strip FQDN part which begins right at that dot
where FQDN of local node and its uname differ.

my_ring_address == 10.0.0.XXX
my_uname() == "host232"
getaddinfo(my_ring_address) == host232.some.very.long.domain.name.com.

my_node_name = "host232"
my_domain = "some.very.long.domain.name.com."

his_ring_address == 10.0.0.YYY
getaddinfo(his_ring_address) == host238.some.very.long.domain.name.com.

strstr("host238.some.very.long.domain.name.com.", my_domain) != NULL

his_node_name = "host238"


> 
> To illustrate:
> ring_address == 10.0.0.XXX
> uname() == "host232"
> getaddinfo(ring_address) == host232.some.very.long.domain.name.com.
> 
> then "host232" could be safely used as a node name (but not "host23" and
> not "host232.s")
> 
> Of course, it would be even more safe if gentnameinfo("host232") or
> getnameinfo("host232.some.very.long.domain.name.com.") returns
> 10.0.0.XXX, so additional check may be introduced.
> 
> That is normal for "correct" static DNS setups, where PTR record is
> consistent with what node has configured as a hostname internally.
> 
> That is also what I have for DHCP-based static address assignments
> (central configuration place for a whole cluster network), where node
> usually sets (or at least can be configured to set) its name to what
> DHCP server says. And DHCP server is usually set up to update A and PTR
> records in DNS zone.
> 
> Also that should work correctly when FQDN is used as an uname (long
> hostname), like redhat setups usually do.
> 
> Anyways, if FQDN does not begin with uname, then DNS info should be used
> for node name (like it is now), possibly with that "strip" hack. That
> could be useful for multi-ring setups I think.
> 
> Vladislav
> 
> 
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