Mailing-List: contact dev-help@brooklyn.incubator.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@brooklyn.incubator.apache.org
MIME-Version: 1.0
In-Reply-To: 
 <CADkof5btk7DTQC7Tuh2+OphFnSL1H2YLmj_z0T8Vx3-6qy-1QQ@mail.gmail.com>
References: 
 <CADkof5bXGFAH=Tt+29XvS84dK=23vUXrZ=pM0WaM4YhLvuc0nQ@mail.gmail.com>
	<CADkof5btk7DTQC7Tuh2+OphFnSL1H2YLmj_z0T8Vx3-6qy-1QQ@mail.gmail.com>
Date: Mon, 19 Jan 2015 10:34:31 +0000
Message-ID: 
 <CABQFKi1OhDdgXfzKKXCOsJaKtqAhEMvVUU3MgiVYCpEgetLGtA@mail.gmail.com>
Subject: Re: "force resolution of localhost to be loopback,
 otherwise we hit problems"
From: Richard Downer <richard@apache.org>
To: Brooklyn dev <dev@brooklyn.incubator.apache.org>
Content-Type: text/plain; charset=UTF-8

Sam,

I would guess that if the hostname/domain name are properly configured
everything should work. Unfortunately, it's easy to *not* quite
configure networking correctly.

My understanding of the canonical way to set the system hostname and
domain name is as follows:

/etc/hosts:

127.0.0.1  hostname hostname.domainname localhost
# that must be the first non-comment line

Configure the system hostname (without domainname); IIRC, on
Debian-derivatives you write it to the file /etc/hostname, and on
RedHat-derivatives there's a variable in /etc/sysconfig/network

Then either run "hostname newhostname" or "service network restart" or reboot.

Check it works:
# hostname
(returns the bare hostname)
# hostname --fqdn
(returns the hostname and DNS domainname)


On 18 January 2015 at 10:32, Sam Corbett <sam.corbett@cloudsoftcorp.com> wrote:
> BrooklynServiceAttributes defines the property and has a comment saying:
>
> /** in some cases localhost does not resolve correctly
>  * (e.g. to an interface which is defined locally but not in operation,
>  * or where multiple NICs are available and java's
> InetAddress.getLocalHost() strategy is not doing what is desired);
>  * use this to supply a specific address (e.g. "127.0.0.1" or a specific IP
> on a specific NIC or FW)
>  */
>
> I guess this answers my question but it doesn't give me much assurance.
>
> On 18 January 2015 at 10:02, Sam Corbett <sam.corbett@cloudsoftcorp.com>
> wrote:
>
>> Hi,
>>
>> The `brooklyn` launch script sets
>> `-Dbrooklyn.location.localhost.address=127.0.0.1` with the cryptic
>> explanation that 'otherwise we hit problems'. Can anybody explain what
>> problems are avoided? I have a case in which I'd like the hostname of a
>> localhost location to be the hostname of the machine, but I'd also like to
>> know what will happen if I change or remove the flag.
>>
>> Thanks,
>>
>> Sam
>>