Difference between pages "Package:Boot-Update" and "Hostname"

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{{Ebuild
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==Introduction==
|Summary=Funtoo Core Boot Framework for global boot loader configuration
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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.
|CatPkg=sys-boot/boot-update
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==Configuration==
|Maintainer=Drobbins
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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:
|Repository=Funtoo Overlay
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|Organization=Funtoo Technologies
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|Overlay=Funtoo
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}}
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Funtoo boot-update provides a unified mechanism for configuring the GRUB 1.9x ({{Package|sys-boot/grub}}) and GRUB 0.97 ({{Package|sys-boot/grub-legacy}}) boot loaders. It is the recommended, official way to configure Funtoo Linux systems for booting.
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== Current Version ==
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* {{Package|sys-boot/boot-update}}
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== Man Pages ==
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Consult the following man pages for detailed, up-to-date information on configuration file settings and command-line arguments:
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* boot-update(8)
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* boot.conf(5)
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== GRUB 1.97+ Quick Start ==
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If using <code>sys-boot/grub-1.97</code> or later, perform the following steps:
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* Partition disk using GPT/GUID (recommended) or MBR partitions.
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* Install kernel/initrd to <code>/boot</code>
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<console>
 
<console>
###i## emerge sys-boot/boot-update
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localhost ~ # ##i## Hello :)
###i## grub-install --no-floppy /dev/sda
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</console>
 
</console>
Ensure that <code>/etc/fstab</code> is correct, and edit <code>/etc/boot.conf</code> to reflect your installation (see <code>/etc/boot.conf.example</code>). Then run:
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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>
 
<console>
###i## boot-update
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localhost ~ # ##i## nano /etc/conf.d/hostname
 
</console>
 
</console>
This will auto-generate the complex <code>/boot/grub/grub.cfg</code> required for booting. Re-run <code>boot-update</code> every time your available kernels/initrds or <code>/etc/boot.conf</code> configuration changes.
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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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= GRUB 0.97 (grub-legacy) Quick Start =
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If using <code>sys-boot/grub-legacy-0.97</code>, perform the following steps:
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* Partition disk using MBR partitions '''(GPT not supported)'''
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* Install kernel/initrd to <code>/boot</code>
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<console>
 
<console>
###i## emerge sys-boot/boot-update
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localhost ~ # ##i## service hostname restart
###i## emerge ">=sys-boot/grub-legacy-0.97-r11"
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###i## grub-install-legacy /dev/sda
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</console>
 
</console>
Due to an issue with <code>grub-legacy</code>, you may see the following message:
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Now, let's examine our changes, after a restarting a hostname
 
<console>
 
<console>
###i## grub-install-legacy /dev/sda
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oleg-stable ~ # ##i## Hello :)
The file /boot/grub-legacy/stage1 not read correctly.
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</console>
 
</console>
Should you receive this message, you will have to install <code>grub-legacy</code> from the grub shell.
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== Diving deeper==
Assuming <code>/boot</code> is the partition <code>/dev/sda1</code> and you want to install grub to the MBR, you would run the following:
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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:
 
<console>
 
<console>
###i## grub-legacy
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oleg-stable ~ # ##i## hostname
root (hd0,0)
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oleg-stable.host.funtoo.org
setup (hd0)
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quit
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</console>
 
</console>
When adjusting to fit your setup, remember 'root' is the location of your boot partition, 'setup' is where you want to install grub, and don't forget about grub's unique naming conventions for hard drives / partitions. For more information run:
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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.  
 
<console>
 
<console>
###i## info grub-legacy
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oleg-stable ~ # ##i## hostname -s
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oleg-stable
 
</console>
 
</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.}}
  
Ensure that <code>/etc/fstab</code> is correct, and edit <code>/etc/boot.conf</code> to reflect your installation.
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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.
Ensure a <code>generate grub-legacy</code> setting in the <code>boot</code> section. Then run:
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==Hosts case==
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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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{{file|name=/etc/hosts|body=
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# 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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<console>
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oleg-stable ~ # ##i## echo 'aliases="10.1.12 oleg.distant.home"' >> /etc/conf.d/hostname
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oleg-stable ~ # ##i## service hostname restart
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</console>
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Examine our changes:
 
<console>
 
<console>
###i## boot-update
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oleg-stable ~ # ##i## cat /etc/hosts
 
</console>
 
</console>
This will auto-generate the <code>/boot/grub-legacy/grub.conf</code> required for booting. Note that <code>grub-legacy-0.97-r11</code> and later stores <code>grub.conf</code> in the <code>/boot/grub-legacy</code> directory.
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{{file|name=/etc/hosts|body=
 
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# Auto-generated hostname. Please do not remove this comment.
Re-run <code>boot-update</code> every time your available kernels / initrds or <code>/etc/boot.conf</code> configuration changes.
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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
[[Category:Projects]]
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::1            oleg-stable.host.funtoo.org oleg-stable localhost localhost.localdomain
[[Category:Funtoo features]]
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}}
{{EbuildFooter}}
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Revision as of 16:06, February 24, 2015

Introduction

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.

Configuration

In Funtoo Linux /etc/conf.d/hostname is the only configuration file for setting a hostname. In OpenRC framework /etc/conf.d/foo is the configuration file for a corresponding Init script /etc/init.d/foo. With the case of hostname, default value in /etc/conf.d/hostname is set to localhost, means when system boots and OpenRC's /etc/init.d/hostname 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:

localhost ~ #  Hello :)

Let's play a bit with a configuration. Open /etc/conf.d/hostname 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.

localhost ~ #  nano /etc/conf.d/hostname

Let's set it to hostname="oleg-stable.host.funtoo.org". Save the file and restart a hostname service:

localhost ~ #  service hostname restart

Now, let's examine our changes, after a restarting a hostname

oleg-stable ~ #  Hello :)

Diving deeper

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 PS1 set. To get nice promts, please, follow http://www.funtoo.org/Prompt_Magic 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:

oleg-stable ~ #  hostname
oleg-stable.host.funtoo.org

Now we see our fully qualified domain name hostname just how we configured it in /etc/conf.d/hostname in above paragraph. To get a short hostname we need to set -s (short) argument to hostname command.

oleg-stable ~ #  hostname -s
oleg-stable

Good! Hostname offers more then just displaying a system host name but can also set one. Let's try:

oleg-stable ~ #  hostname foo.bar.baz
oleg-stable ~ #  hostname 
foo.bar.baz

As you can see, we changed a hostname on-the-fly. This is not recommended way.

Warning

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 /etc/conf.d/hostname file with next system restart.

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.

Hosts case

As per man page hosts stands for static table lookup for hostnames and it's configuration file is /etc/hosts. Here is how it looks

/etc/hosts
# Auto-generated hostname. Please do not remove this comment.
127.0.0.1       oleg-stable.host.funtoo.org oleg-stable localhost localhost.localdomain
::1             oleg-stable.host.funtoo.org oleg-stable localhost localhost.localdomain

As you can see it has entries from our /etc/conf.d/hostname. As you may have guessed, in Funtoo Linux /etc/hosts file entries are auto-generated, when OpenRC hostname service starts. Previously, it is used to edit /etc/hosts manually. In Funtoo Linux there is no such need.

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 /etc/conf.d/hostname with adding following - my remote computer oleg.distant.home has an IP 10.1.1.2:

oleg-stable ~ #  echo 'aliases="10.1.12 oleg.distant.home"' >> /etc/conf.d/hostname
oleg-stable ~ #  service hostname restart
Examine our changes:
oleg-stable ~ #  cat /etc/hosts
/etc/hosts
# Auto-generated hostname. Please do not remove this comment.
10.1.1.2        oleg.distant.home
127.0.0.1       oleg-stable.host.funtoo.org oleg-stable localhost localhost.localdomain
::1             oleg-stable.host.funtoo.org oleg-stable localhost localhost.localdomain