Commit graph

30 commits

Author SHA1 Message Date
Alexander Block
89e570493a Also add the system nameservers to upstream servers in dnsmasq
Also make no-resolv unconditional again. Otherwise, we may end up in
a resolver loop. The resolver loop was the cause for the piling up
parallel queries.
2017-02-08 14:38:55 +01:00
Matthew Mosesohn
fd30131dc2 Revert "Drop linux capabilities and rework users/groups" 2017-02-06 15:58:54 +03:00
Bogdan Dobrelya
cae2982d81 Merge pull request #911 from bogdando/DROP_CAPS
Drop linux capabilities and rework users/groups
2017-02-06 12:05:51 +01:00
Artem Panchenko
1418fb394b Explicitly set config path for DNSMasq
When DNSMasq is configured to read its settings
from a folder ('-7' or '--conf-dir' option) it only
checks that the directory exists and doesn't fail if
it's empty. It could lead to a situation when DNSMasq
is running and handles requests, but not properly
configured, so some of queries can't be resolved.
2017-01-31 12:14:57 +02:00
Bogdan Dobrelya
cb2e5ac776 Drop linux capabilities and rework users/groups
* Drop linux capabilities for unprivileged containerized
  worlkoads Kargo configures for deployments.
* Configure required securityContext/user/group/groups for kube
  components' static manifests, etcd, calico-rr and k8s apps,
  like dnsmasq daemonset.
* Rework cloud-init (etcd) users creation for CoreOS.
* Fix nologin paths, adjust defaults for addusers role and ensure
  supplementary groups membership added for users.
* Add netplug user for network plugins (yet unused by privileged
  networking containers though).
* Grant the kube and netplug users read access for etcd certs via
  the etcd certs group.
* Grant group read access to kube certs via the kube cert group.
* Remove priveleged mode for calico-rr and run it under its uid/gid
  and supplementary etcd_cert group.
* Adjust docs.
* Align cpu/memory limits and dropped caps with added rkt support
  for control plane.

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>
2017-01-20 08:50:42 +01:00
Sergii Golovatiuk
61d05dea58 Allow to specify number of concurrent DNS queries
ndots creates overhead as every pod creates 5 concurrent connections
that are forwarded to sky dns. Under some circumstances dnsmasq may
prevent forwarding traffic with "Maximum number of concurrent DNS
queries reached" in the logs.

This patch allows to configure the number of concurrent forwarded DNS
queries "dns-forward-max" as well as "cache-size" leaving the default
values as they were before.

Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>
2017-01-19 11:47:37 +01:00
Alexander Block
a8b5b856d1 Only use default resolver in dnsmasq when we are using host_resolvconf mode 2017-01-06 10:21:07 +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
c75f394707 Address standalone kubelet config case
Also place in global vars and do not repeat the kube_*_config_dir
and kube_namespace vars for better code maintainability and UX.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
2016-12-13 16:35:53 +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
2d18e19263 Tune dnsmasq/kubedns limits, replicas, logging
* Add dns_replicas, dns_memory/cpu_limit/requests vars for
dns related apps.
* When kube_log_level=4, log dnsmasq queries as well.
* Add log level control for skydns (part of kubedns app).
* Add limits/requests vars for dnsmasq (part of kubedns app) and
  dnsmasq daemon set.
* Drop string defaults for kube_log_level as it is int and
  is defined in the global vars as well.
* Add docs

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
2016-11-25 12:49:17 +01:00
Bogdan Dobrelya
d208896c46 Ensure /etc/resolv.conf content for CoreOS
Use cloud-init config to replace /etc/resolv.conf with the
content for kubelet to properly configure hostnet pods.

Do not use systemd-resolved yet, see
https://coreos.com/os/docs/latest/configuring-dns.html
"Only nss-aware applications can take advantage of the
systemd-resolved cache. Notably, this means that statically
linked Go programs and programs running within Docker/rkt
will use /etc/resolv.conf only, and will not use the
systemd-resolve cache."

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
2016-11-23 16:51:49 +01:00
Bogdan Dobrelya
dff78f616e Allow pre-downloaded images to be used effectively
According to http://kubernetes.io/docs/user-guide/images/ :
By default, the kubelet will try to pull each image from the
specified registry. However, if the imagePullPolicy property
of the container is set to IfNotPresent or Never, then a local\
image is used (preferentially or exclusively, respectively).

Use IfNotPresent value to allow images prepared by the download
role dependencies to be effectively used by kubelet without pull
errors resulting apps to stay blocked in PullBackOff/Error state
even when there are images on the localhost exist.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
2016-11-22 16:16:04 +01:00
Matthew Mosesohn
4b7347f1cd fix dnsmasq template cloud_provider lookup 2016-10-21 13:00:40 +03:00
Chad Swenson
c402feffbd Parameterize several dependency endpoints so that they can be overridden with internal mirrors.
Signed-off-by: Chad Swenson <chadswen@gmail.com>
2016-10-15 12:26:52 -05:00
Smana
056f4b6c00 upgrade to kubernetes version 1.4.0
test to change the machine type

Revert "test to change the machine type"

This reverts commit 7a91f1b5405a39bee6cb91940b09a0b0f9d3aee1.

use google dns server when no upstream dns are defined

comment upstream_dns_servers

update documentation

remove deprecated kubelet flags

Revert "remove deprecated kubelet flags"

This reverts commit 21e3b893c896d0291c36a07d0414f4cb88b8d8ac.
2016-10-10 22:44:47 +02:00
Matthew Mosesohn
5579cddbdb Disable reverse lookups again
Initially this was removed, but it turns out that services that
perform reverse lookups (such as MariaDB) will encounter severe
performance degredation with this disabled.
2016-09-29 10:49:55 +04:00
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
Özgür Caner
123532d2a4 Changed ImagePullPolicy from Always to IfNotPresent to avoid download issue when DNS is not working 2016-09-20 10:34:44 +02:00
Ivan Shvedunov
13874f4610 Fix reverse DNS lookups of service IPs.
This fixes "DNS should provide DNS for services [Conformance]"
e2e test in k8s.
2016-09-19 09:12:10 +03:00
ant31
6297e5ea93 Use dnsmasq inside pods 2016-03-19 23:41:27 +01:00
Smaine Kahlouch
4c5735cef8 configure dnsmasq to listen on localhost only 2016-01-19 13:34:30 +01:00
Smaine Kahlouch
f58b4d3dd6 dnsmasq listens on localhost 2016-01-19 10:29:33 +01:00
ant31
9c461e1018 Use inline update for resolv.conf 2016-01-05 12:31:49 +01:00
ant31
2df70d6a3d Docker dnsmasq 2015-12-30 14:02:22 +01:00
Smaine Kahlouch
b23b8aa3de dnsmasq with multi master arch 2015-12-12 19:37:08 +01:00
Smaine Kahlouch
6183a4d3b1 dns vars for skydns submodule 2015-10-13 17:12:59 +02:00
Smaine Kahlouch
00c562828f Initial commit 2015-10-03 22:19:50 +02:00