- See also: Portal:Cloud VPS/Infrastructure#dns
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Within Cloud VPS, each instance has a name like
<instancename>.<projectname>.eqiad.wmflabs. For historical reasons we also create
<instancename>.eqiad.wmflabs DNS entries for each instance. This legacy behavior may be discontinued in the future.
Public DNS (e.g. tools-login.wmflabs.org) is currently handled by labs-ns0 and labs-ns1 running pdns with ldap. Soon this will move to a Horizon/Designate system using the new pdns server labs-ns2.
Cloud VPS DNS is PowerDNS, backed by ldap served by opendj.
When a new instance is created, OpenStackManager automatically makes an entry for the instance, like this:
# i-000007b7.eqiad.wmflabs, hosts, wikimedia.org dn: dc=i-000007b7.eqiad.wmflabs,ou=hosts,dc=wikimedia,dc=org objectClass: domainrelatedobject objectClass: dnsdomain objectClass: puppetclient objectClass: domain objectClass: dcobject objectClass: top puppetVar: realm=labs puppetVar: instanceproject=openstack puppetVar: instancename=labs-bootstrapvz-jessie puppetClass: base puppetClass: role::labs::instance puppetClass: labs_bootstrapvz l: eqiad associatedDomain: i-000007b7.eqiad.wmflabs associatedDomain: labs-bootstrapvz-jessie.eqiad.wmflabs dc: i-000007b7.eqiad.wmflabs aRecord: 10.68.16.107
Note that the private DNS record in ldap is generally unused, the result of an aborted earlier attempt to move away from dnsmasq.
When floating IPs are allocated and assigned, OpenStackManager creates something like this:
# 220.127.116.11, hosts, wikimedia.org dn: dc=18.104.22.168,ou=hosts,dc=wikimedia,dc=org objectClass: domainrelatedobject objectClass: dnsdomain objectClass: domain objectClass: dcobject objectClass: top associatedDomain: bastion-eqiad.wmflabs.org associatedDomain: bastion1-eqiad.wmflabs.org associatedDomain: bastion.wmflabs.org associatedDomain: bastion1.wmflabs.org dc: 22.214.171.124 aRecord: 126.96.36.199
PowerDNS copes very poorly with interruptions in ldap service. Anytime opendj restarts, pdns needs to be restarted as well. So, to refresh either service (ldap or dns):
$ sudo service opendj restart (on nembus and/or neptunium) $ sudo service pdns restart (on virt1000 and labcontrol2001)
DHCP and internal DNS
Hostnames (such as deployment-mediawiki04.deployment-prep.eqiad.wmflabs) are resolved by dnsmasq, which also assigns them IP addresses (via DHCP). This is managed completely by nova network on labnet1001. To make any changes to the dnsmasq setup take effect,
- Kill dnsmasq manually on labnet1001 (there's no upstart script since nova-network doesn't apparently like dnsmasq's upstart being called. Sounds very possessive).
- Restart nova-network (service nova-network restart)