* 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.
73b548db06https://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
* Upgrade kubernetes to v1.13.0
* Remove all precense of scheduler.alpha.kubernetes.io/critical-pod in templates
* Fix cert dir
* Use kubespray v2.8 as baseline for gitlab
* Remove variables defined in download role. Fixes#3799
* Cleanup some more variables
* Fix bad templating
* Minor fix
* Add dashboard to download role. Fixes#3736
* Enable AutoScaler for CoreDNS
* Only use one template for dns autoscaler
* Rename a few variables for replicas and minimum pods
* Rename a few variables for replicas and minimum pods
* Remove replicas to make autoscale work
* Cleanup kubedns-autoscaler as it has been renamed
* failed
* version_compare
* succeeded
* skipped
* success
* version_compare becomes version since ansible 2.5
* ansible minimal version updated in doc and spec
* last version_compare
* Fix DNS loop when resolvconf_mode is set to host_resolvconf
* Make sure upstream_dns_servers is defined when using resolvconf_mode == 'host_resolvconf'
* Only set upstream dns servers on KubeDNS and CoreDNS if they are defined
* Only set upstream dns servers on KubeDNS and CoreDNS if they are defined
* Changes to assign pod priority to kube components.
* Removed the boolean flag pod_priority_assignment
* Created new priorityclass k8s-cluster-critical
* Created new priorityclass k8s-cluster-critical
* Fixed the trailing spaces
* Fixed the trailing spaces
* Added kube version check while creating Priority Class k8s-cluster-critical
* Moved k8s-cluster-critical.yml
* Moved k8s-cluster-critical.yml to kube_config_dir
ensure there is pin priority for docker package to avoid upgrade of docker to incompatible version
remove empty when line
ensure there is pin priority for docker package to avoid upgrade of docker to incompatible version
force kubeadm upgrade due to failure without --force flag
ensure there is pin priority for docker package to avoid upgrade of docker to incompatible version
added nodeSelector to have compatibility with hybrid cluster with win nodes, also fix for download with missing container type
fixes in syntax and LF for newline in files
fix on yamllint check
ensure there is pin priority for docker package to avoid upgrade of docker to incompatible version
some cleanup for innecesary lines
remove conditions for nodeselector
* kubedns & kubedns-autoscaler: Stick to master nodes.
- Tolerate only master nodes and not any NoSchedule taint
- Pods are on different nodes
- Pods are required to be on a master node.
* kubedns: use soft nodeAffinity.
Prefer to be on a master node, don't require.
* coredns: Stick to (different) master nodes.
- Pods are on different nodes
- Pods are preferred to be on a master node.
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
* Use kubectl apply instead of create/replace
Disable checks for existing resources to speed up execution.
* Fix non-rbac deployment of resources as a list
* Fix autoscaler tolerations field
* set all kube resources to state=latest
* Update netchecker and weave
* Adding yaml linter to ci check
* Minor linting fixes from yamllint
* Changing CI to install python pkgs from requirements.txt
- adding in a secondary requirements.txt for tests
- moving yamllint to tests requirements
Pod opbject is not reschedulable by kubernetes. It means that if node
with netchecker-server goes down, netchecker-server won't be scheduled
somewhere. This commit changes the type of netchecker-server to
Deployment, so netchecker-server will be scheduled on other nodes in
case of failures.
In kubernetes 1.6 ClusterFirstWithHostNet was added as an option. In
accordance to it kubelet will generate resolv.conf based on own
resolv.conf. However, this doesn't create 'options', thus the proper
solution requires some investigation.
This patch sets the same resolv.conf for kubelet as host
Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>
By default Calico CNI does not create any network access policies
or profiles if 'policy' is enabled in CNI config. And without any
policies/profiles network access to/from PODs is blocked.
K8s related policies are created by calico-policy-controller in
such case. So we need to start it as soon as possible, before any
real workloads.
This patch also fixes kube-api port in calico-policy-controller
yaml template.
Closes#1132
By default kubedns and dnsmasq scale when installed.
Dnsmasq is no longer a daemonset. It is now a deployment.
Kubedns is no longer a replicationcluster. It is now a deployment.
Minimum replicas is two (to enable rolling updates).
Reduced memory erquirements for dnsmasq and kubedns
Operator can specify any port for kube-api (6443 default) This helps in
case where some pods such as Ingress require 443 exclusively.
Closes: 820
Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>
Netchecker is rewritten in Go lang with some new args instead of
env variables. Also netchecker-server no longer requires kubectl
container. Updating playbooks accordingly.
* 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>
* Add restart for weave service unit
* Reuse docker_bin_dir everythere
* Limit systemd managed docker containers by CPU/RAM. Do not configure native
systemd limits due to the lack of consensus in the kernel community
requires out-of-tree kernel patches.
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
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>
* Add an option to deploy K8s app to test e2e network connectivity
and cluster DNS resolve via Kubedns for nethost/simple pods
(defaults to false).
* Parametrize existing k8s apps templates with kube_namespace and
kube_config_dir instead of hardcode.
* For CoreOS, ensure nameservers from inventory to be put in the
first place to allow hostnet pods connectivity via short names
or FQDN and hostnet agents to pass as well, if netchecker
deployed.
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
* 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>
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>
Pre download all required container images as roles' deps.
Drop unused flannel-server-helper images pre download.
Improve pods creation post-install test pre downloaded busybox.
Improve logs collection script with kubectl describe, fix sudo/etcd/weave
commands.
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
'etcd_cert_dir' variable is missing from 'kubernetes-apps/ansible'
role which breaks Calico policy controller deployment.
Also fixing calico-policy-controller.yml.
The requirements for network policy feature are described here [1]. In
order to enable it, appropriate configuration must be provided to the CNI
plug in and Calico policy controller must be set up. Beside that
corresponding extensions needed to be enabled in k8s API.
Now to turn on the feature user can define `enable_network_policy`
customization variable for Ansible.
[1] http://kubernetes.io/docs/user-guide/networkpolicies/
* 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>
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>
