- 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).
The hosts plugins transforms the information of this file to the following structure. The keys directly below ipv4 or ipv6 are host names of IPv4 or IPv6 addresses, respectively. The keys directly below these keys are aliases. The IP addresses themselves are stored as values.
Special values
Hostnames
Canonical hostnames are stored as key base names with their IP addresses as value.
Aliases
Aliases are stored as keys directly below canonical hostnames 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:
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
