Difference between pages "Hostname" and "User:Ivanvcouso"

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(Hosts case)
 
 
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w.i.p
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{{Person
==Introduction==
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|Geoloc=40.4167754, -3.7037902
A hostname is a unique name created to identify a machine on a network. In computer networking, a hostname  is a label that is assigned to a device connected to a computer network and that is used to identify the device in various forms of electronic communication such as the World Wide Web, e-mail or Usenet. Hostnames may be simple names consisting of a single word or phrase, or they may be structured.
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|Location name=Madrid, Spain
==Configuration==
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|Blogs=
In Funtoo Linux <code>/etc/conf.d/hostname</code> is the only configuration file for setting a hostname. In OpenRC framework <code>/etc/conf.d/foo</code> is the configuration file for a corresponding Init script <code>/etc/init.d/foo</code>.  With the case of hostname, default value in <code>/etc/conf.d/hostname</code> is set to ''localhost'', means when system boots and OpenRC's <code>/etc/init.d/hostname</code> script started a hostname getting only ''localhost'' name.  How it looks?  In your shell promt this will look in following way, an example for root:
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}}
<console>
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Hi! I'm a Python & Java web developer from Spain! Also interested in Operating Systems, Artificial Intelligence and Software Craftmanship.
localhost ~ # ##i## Hello :)
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</console>
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Let's play a bit with a configuration. Open <code>/etc/conf.d/hostname</code> with your favorite editor and set a hostname of your choice.  Below, I will use a real examples  from one of my working test boxes.
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<console>
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localhost ~ # ##i## nano /etc/conf.d/hostname
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</console>
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Let's set it to hostname="oleg-stable.host.funtoo.org". Save the file and restart  a hostname service:
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<console>
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localhost ~ # ##i## service hostname restart
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</console>
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Now, let's examine our changes, after a restarting a hostname
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<console>
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oleg-stable ~ # ##i## Hello :)
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</console>
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== Diving deeper==
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Notice, that in above output we seeing a shortened hostname and not a FQDN (Fully Qualified Domain Name). Don't be frustrated. This is  how  default bash promt <code>PS1</code> set. To get nice promts, please, follow http://www.funtoo.org/Prompt_Magic
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Another way to test our settings is using a '''hostname''' command. Here we will show only  some of it's features. Let's try to execute '''hostname''' command:
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<console>
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oleg-stable ~ # ##i## hostname
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oleg-stable.host.funtoo.org
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</console>
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Now we see our fully qualified domain name hostname just how we configured it in <code>/etc/conf.d/hostname</code> in above paragraph. To get a short hostname we need to set '''-s ''' (short) argument to hostname command.
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<console>
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oleg-stable ~ # ##i## hostname -s
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oleg-stable
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</console>
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Good! Hostname offers more then just displaying a system host name but can also set one. Let's try:
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<console>
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oleg-stable ~ # ##i## hostname foo.bar.baz
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oleg-stable ~ # ##i## hostname
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foo.bar.baz
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</console>
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As you can see, we changed a hostname on-the-fly. This is not recommended way.
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{{fancywarning|Please, notice that using '''hostname''' command to configure will work temporary for a current session and will be reverted back to a value set in <code>/etc/conf.d/hostname</code> file with next system restart.}}
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Now that we got a brief description of a hostname and basic configuration steps, its time to reflect another important case which is directly related to a Funtoo Linux hostname generation, a hosts.
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Devices:
  
==Hosts case==
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Asha:
As per man page <code>hosts</code> stands for static table lookup for hostnames and it's configuration file is <code>/etc/hosts</code>. Here is how it looks
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Macbook Pro 6.1 - Core i7 M 620 - 4 GB RAM - 500 GB HDD
{{file|name=/etc/hosts|body=
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EFI Boot with Grub2, only funtoo in a luks/lvm.
# Auto-generated hostname. Please do not remove this comment.
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127.0.0.1       oleg-stable.host.funtoo.org oleg-stable localhost localhost.localdomain
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::1            oleg-stable.host.funtoo.org oleg-stable localhost localhost.localdomain
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}}
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As you can see it has entries from our <code>/etc/conf.d/hostname</code>. As you may have guessed, in Funtoo Linux <code>/etc/hosts</code> file entries are auto-generated, when OpenRC hostname service starts. Previously, it is used to edit <code>/etc/hosts</code> manually. In Funtoo Linux there is no such need.
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What about custom hosts entries? This can be easily configured with 'aliases'. For example you want to have a hosts for your remote router or a computer in home LAN. Let's try to modify <code>/etc/conf.d/hostname</code> with adding following - my remote computer oleg.distant.home has an IP 10.1.1.2:
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Freya:
<console>
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EeePc 1008HA - Atom N720 - 1 GB RAM
oleg-stable ~ # ##i## echo 'aliases="10.1.12 oleg.distant.home"' >> /etc/conf.d/hostname
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/dev/sda1 boot
oleg-stable ~ # ##i## service hostname restart
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/dev/sda2 root
</console>
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/dev/sda3 fat32 (EeePc Boot Booster)
Examine our changes:
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<console>
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oleg-stable ~ # ##i## cat /etc/hosts
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</console>
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{{file|name=/etc/hosts|body=
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# Auto-generated hostname. Please do not remove this comment.
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10.1.1.2        oleg.distant.home
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127.0.0.1      oleg-stable.host.funtoo.org oleg-stable localhost localhost.localdomain
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::1            oleg-stable.host.funtoo.org oleg-stable localhost localhost.localdomain
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}}
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Revision as of 23:23, March 26, 2015

Iván Valderrábano Couso

Contact

Location

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Madrid, Spain (40° 24' 59", -3° 42' 13")



Hi! I'm a Python & Java web developer from Spain! Also interested in Operating Systems, Artificial Intelligence and Software Craftmanship.

Devices:

Asha: Macbook Pro 6.1 - Core i7 M 620 - 4 GB RAM - 500 GB HDD EFI Boot with Grub2, only funtoo in a luks/lvm.

Freya: EeePc 1008HA - Atom N720 - 1 GB RAM /dev/sda1 boot /dev/sda2 root /dev/sda3 fat32 (EeePc Boot Booster)