Commit graph

19 commits

Author SHA1 Message Date
Matthew Mosesohn
5f12b7aedf Remove kubedns and dnsmasq. Move dns_late phase after apps (#4406)
Both kubedns and dnsmasq modes are long not maintained.
We should run dns_late steps at the end because sshd
makes DNS lookups during Ansible run and has 2s timeouts
for each failed lookup trying to connect to coredns before
it is ready.
2019-04-01 12:32:34 -07:00
WillPlatnick
72fee60c8f Update nodelocal to be in its own section (#3931) 2018-12-25 07:10:08 -08:00
Florent Monbillard
e50647d252 dns_mode defaults to coredns (#3882)
since bad886ca9b, dns_mode is set to coredns by default instead of kubedns
2018-12-12 01:45:00 -08:00
Thomas Nys
3e3ee0aeb1 Add support for running a nodelocal dns cache (#3861)
* Add support for running a nodelocal dns cache

After encountering dns issues in a cluster I was recently working on I
noticed Kubernetes 1.13 introduced support for running a nodelocal dns
cache.

I believe this can usefull for more people.

73b548db06
https://github.com/kubernetes/enhancements/blob/master/keps/sig-network/0030-nodelocal-dns-cache.md

* Add requested changes

* Add additional requested changes + documentation

* Add requested changes after review

* Replace incorrect variable
2018-12-10 17:28:03 -08:00
amaya
aacc89e4e6 Fix default value for dns_mode on the document 2018-06-28 17:08:27 +09:00
woopstar
e40368ae2b Add CoreDNS support with various fixes
Added CoreDNS to downloads

Updated with labels. Should now work without RBAC too

Fix DNS settings on hosts

Rename CoreDNS service from kube-dns to coredns

Add rotate based on http://edgeofsanity.net/rant/2017/12/20/systemd-resolved-is-broken.html

Updated docs with CoreDNS info

Added labels and fixed minor settings from official yaml file: https://github.com/kubernetes/kubernetes/blob/release-1.9/cluster/addons/dns/coredns.yaml.sed

Added a secondary deployment and secondary service ip. This is to mitigate dns timeouts and create high resitency for failures. See discussion at 'https://github.com/coreos/coreos-kubernetes/issues/641#issuecomment-281174806'

Set dns list correct. Thanks to @whereismyjetpack

Only download KubeDNS or CoreDNS if selected

Move dns cleanup to its own file and import tasks based on dns mode

Fix install of KubeDNS when dnsmask_kubedns mode is selected

Add new dns option coredns_dual for dual stack deployment. Added variable to configure replicas deployed. Updated docs for dual stack deployment. Removed rotate option in resolv.conf.

Run DNS manifests for CoreDNS and KubeDNS

Set skydns servers on dual stack deployment

Use only one template for CoreDNS dual deployment

Set correct cluster ip for the dns server
2018-03-16 21:51:37 +01:00
Matthew Mosesohn
bf1411060e Add optional manual dns_mode (#2178) 2018-01-23 14:28:42 +01:00
Spencer Smith
8203383c03 rename almost all mentions of kargo 2017-06-16 13:25:46 -04:00
Alexander Block
1d2a18b355 Introduce dns_mode and resolvconf_mode and implement docker_dns mode
Also update reset.yml to do more dns/network related cleanup.
2017-01-05 23:38:51 +01:00
Bogdan Dobrelya
bb0c3537cb Do not forward bogus domains for upstream resolvers
Also fix kube log level 4 to log dnsmasq queries.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
2016-12-23 11:53:14 +01:00
Bogdan Dobrelya
f10d1327d4 Revert "Do not forward private domains for upstream resolvers" 2016-12-21 15:24:17 +01:00
Bogdan Dobrelya
101864c050 Do not forward private domains for upstream resolvers
Also fix kube log level 4 to log dnsmasq queries.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Co-authored-by: Matthew Mosesohn <mmosesohn@mirantis.com>
2016-12-19 11:01:41 +01:00
Bogdan Dobrelya
0515814e0c Fix resolvconf
Do not repeat options and nameservers in the dhclient hooks.
Do not prepend nameservers for dhclient but supersede and fail back
to the upstream_dns_resolvers then default_resolver. Fixes order of
nameservers placement, which is cluster DNS ip goes always first.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
2016-12-13 15:48:53 +01:00
Bogdan Dobrelya
3117858dcd Rework DNS stack to meet hostnet pods needs
* For Debian/RedHat OS families (with NetworkManager/dhclient/resolvconf
  optionally enabled) prepend /etc/resolv.conf with required nameservers,
  options, and supersede domain and search domains via the dhclient/resolvconf
  hooks.

* Drop (z)nodnsupdate dhclient hook and re-implement it to complement the
  resolvconf -u command, which is distro/cloud provider specific.
  Update docs as well.

* Enable network restart to apply and persist changes and simplify handlers
  to rely on network restart only. This fixes DNS resolve for hostnet K8s
  pods for Red Hat OS family. Skip network restart for canal/calico plugins,
  unless https://github.com/projectcalico/felix/issues/1185 fixed.

* Replace linefiles line plus with_items to block mode as it's faster.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Co-authored-by: Matthew Mosesohn <mmosesohn@mirantis.com>
2016-12-12 17:43:47 +01:00
Bogdan Dobrelya
a15d626771 Preconfigure DNS stack and docker early
In order to enable offline/intranet installation cases:
* Move DNS/resolvconf configuration to preinstall role. Remove
  skip_dnsmasq_k8s var as not needed anymore.

* Preconfigure DNS stack early, which may be the case when downloading
  artifacts from intranet repositories. Do not configure
  K8s DNS resolvers for hosts /etc/resolv.conf yet early (as they may be
  not existing).

* Reconfigure K8s DNS resolvers for hosts only after kubedns/dnsmasq
  was set up and before K8s apps to be created.

* Move docker install task to early stage as well and unbind it from the
  etcd role's specific install path. Fix external flannel dependency on
  docker role handlers. Also fix the docker restart handlers' steps
  ordering to match the expected sequence (the socket then the service).

* Add default resolver fact, which is
  the cloud provider specific and remove hardcoded GCE resolver.

* Reduce default ndots for hosts /etc/resolv.conf to 2. Multiple search
  domains combined with high ndots values lead to poor performance of
  DNS stack and make ansible workers to fail very often with the
  "Timeout (12s) waiting for privilege escalation prompt:" error.

* Update docs.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
2016-12-09 17:30:55 +01:00
Bogdan Dobrelya
5fd43b7cf0 Allow subdomains of dns_domain and fix kubelet restarts
* Add a var for ndots (default 5) and put it hosts' /etc/resolv.conf.
* Poke kube dns container image to v1.7
* In order to apply changes to kubelet, notify it to
be restarted on changes made to /etc/resolv.conf. Ignore errors as the kubelet
may yet to be present up to the moment of the notification being processed.
* Remove unnecessary kubelet restart for master role as the node role ensures
it is up and running. Notify master static pods waiters for apiserver,
scheduler, controller-manager instead.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
2016-09-27 14:32:49 +02:00
Bogdan Dobrelya
7dde23e60b Add more DNS docs
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
2016-09-26 13:47:34 +02:00
Bogdan Dobrelya
dfb9063b3f Fix docs and dns servers placement order
- Update docs and a drawing to clarify DNS setup.
- Change order of nameservers placement to match
  changes in https://github.com/kubespray/kargo/pull/501

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
2016-09-23 16:16:00 +02:00
Bogdan Dobrelya
82ee60fe8b Make dnsmasq daemon set optional
Change additional dnsmasq opts:
- Adjust caching size and TTL
- Disable resolve conf to not create loops
- Change dnsPolicy to default (similarly to kubedns's dnsmasq). The
  ClusterFirst should not be used to not create loops
- Disable negative NXDOMAIN replies to be cached
- Make its very installation as optional step (enabled by default).
  If you don't want more than 3 DNS servers, including 1 for K8s, disable
  it.
- Add docs and a drawing to clarify DNS setup.
- Fix stdout logs for dnsmasq/kubedns app configs
- Add missed notifies to resolvconf -u handler
- Fix idempotency of resolvconf head file changes

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
2016-09-23 12:59:06 +02:00