Plugin: hosts

• infos = Information about hosts plugin is in keys below
• infos/author = Markus Raab elekt.nosp@m.ra@l.nosp@m.ibele.nosp@m.ktra.nosp@m..org
• infos/licence = BSD
• infos/provides = storage/hosts
• infos/needs =
• infos/recommends = glob error network
• infos/placements = getstorage setstorage
• infos/status = maintained unittest nodep libc limited
• infos/metadata = order comment/# comment/#/start comment/#/space
• infos/description = This plugin reads and writes /etc/hosts files.

Introduction

The /etc/hosts file is a simple text file that associates IP addresses with hostnames, one line per IP address. The format is described in hosts(5).

Special values

Hostnames

Canonical hostnames are stored as key names with their IP address as value.

Aliases

Aliases are stored as sub keys with a read only duplicate of the associated IP address as value.

Comments

Comments are stored according to the comment metadata specification (see /doc/METADATA.ini for more information).

Ordering

The ordering of the hosts is stored in metakeys of type order. The value is an ascending number. Ordering of aliases is not preserved.

Examples

Mount the plugin:

sudo kdb mount --with-recommends /etc/hosts system/hosts hosts

Print out all known hosts and their aliases:

kdb ls system/hosts

Get IP address of ipv4 host "localhost":

kdb get system/hosts/ipv4/localhost

Check if a comment is belonging to host "localhost":

kdb meta-ls system/hosts/ipv4/localhost

Try to change the host "localhost", should fail because it is not an IPv4 address:

sudo kdb set system/hosts/ipv4/localhost ::1

```

Backup-and-Restore:/tests/hosts

sudo kdb mount –with-recommends hosts /tests/hosts hosts

Create hosts file for testing

echo '127.0.0.1 localhost' > kdb file /tests/hosts echo '::1 localhost' >> kdb file /tests/hosts

Check the file

cat kdb file /tests/hosts #> 127.0.0.1 localhost #> ::1 localhost

Check if the values are read correctly

kdb get /tests/hosts/ipv4/localhost #> 127.0.0.1 kdb get /tests/hosts/ipv6/localhost #> ::1

Should both fail with error 04200 and return 5

kdb set /tests/hosts/ipv4/localhost ::1

RET:5

ERROR:C03200

kdb set /tests/hosts/ipv6/localhost 127.0.0.1

RET:5

ERROR:C03200

cleanup

kdb rm -r /tests/hosts sudo kdb umount /tests/hosts ```

Limitations

• host names are not validated (see https://issues.libelektra.org/2185)