* File and container image downloads are now cached localy, so that repeated vagrant up/down runs do not trigger downloading of those files. This is especially useful on laptops with kubernetes runnig locally on vm's. The total size of the cache, after an ansible run, is currently around 800MB, so bandwidth (=time) savings can be quite significant.
* When download_run_once is false, the default is still not to cache, but setting download_force_cache will still enable caching.
* The local cache location can be set with download_cache_dir and defaults to /tmp/kubernetes_cache
* A local docker instance is no longer required to cache docker images; Images are cached to file. A local docker instance is still required, though, if you wish to download images on localhost.
* Fixed a FIXME, wher the argument was that delegate_to doesn't play nice with omit. That is a correct observation and the fix is to use default(inventory_host) instead of default(omit). See ansible/ansible#26009
* Removed "Register docker images info" task from download_container and set_docker_image_facts because it was faulty and unused.
* Removed redundant when:download.{container,enabled,run_once} conditions from {sync,download}_container.yml
* All features of commit d6fd0d2aca by Timoses <timosesu@gmail.com>, merged May 1st 2019, are included in this patch. Not all code was included verbatim, but each feature of that commit was checked to be working in this patch. One notable change: The actual downloading of the kubeadm images was moved to {download,sync)_container, to enable caching.
Note 1: I considered splitting this patch, but most changes that are not directly related to caching, are a pleasant by-product of implementing the caching code, so splitting would be impractical.
Note 2: I have my doubts about the usefulness of the upload, download and upgrade tags in the download role. Must they remain or can they be removed? If anybody knows, then please speak up.
* Make local volume provisioner dir mode a variable
I need to change this for Nagios monitoring. Others may
need to as well. Had to close previous commits, sorry for
the spam.
* Make local volume provisioner dir mode a variable
I need to change this for Nagios monitoring. Others may
need to as well. Had to close previous commits, sorry for
the spam.
Task "kube-roter | Set cni directory permissions"
sets ownership of /opt/cni/bin to "kube"
Task "kube-router | Copy cni plugins"
copies the binaries from the archive setting the ownership
back to "root"
Fix "kube-roter" typo
Signed-off-by: Alberto Murillo <albertomurillosilva@gmail.com>
* Add support for arm images for hyperkube, kubeadm and cni_binary
* Add dummy etcd checksum for arm
This commit adds dummy etcd checksum for arm to avoid "no attribute" error
during setup.
* Add etcd host assert check
* Add 1.13.4 checksums of kubeadm and hyperkube for arm
* Update checksums of kubeadm and hyperkube for arm
* Add dummy checksums for calicoctl_binary_checksums dict
* disable gather_facts because it causes tests to fail
* Remove architecture check for etcd, due to unable to run tests
* Added pod psp in Rancher Local Path Provisioner
Added pod security policy (psp) in Rancher Local Path Provisioner.
Signed-off-by: André R. de Miranda <andre@miranda.work>
* Apply psp for Rancher Local Path Provisioner only when local_path_provisioner_namespace is not kube-system and also reorganized the templates
Kubespray waits exit of every drain before run other one.
Running drain every after each other seems better than parallel, because we should check resources availability every time.
But, this way, we have one additional problem: possible restart pods on the nodes that are killed little bit later.
Fast cordon before heavy drain seems like an easy solution.
Error starting nginx because in requiredDropCapabilities is dropped all capabilities.
The nginx requires the following capabilities:
- CHOWN
- SETGID
- SETUID
Signed-off-by: André R. de Miranda <andre@miranda.work>
Without this, pulls are considered for all
hosts groups, even if not targetted by the downloads
`groups` list. Hence, a download/sync is triggered
even though the host does not require the image.
* Disable kube_api_anonymous_auth by default to secure the setup
* Disable metrics-server in addons. Health endpoint is slow and unstable
* Fix anonymous-auth missing in configuration
* Cleanup a bit
* Fix kube anon auth
* Download to delegate and sync files when download_run_once
* Fail on error after saving container image
* Do not set changed status when downloaded container was up to date
* Only sync containers when they are actually required
Previously, non-required images (pull_required=false as
image existed on target host) were synced to the target
hosts. This failed as the image was not downloaded to
the download_delegate and hence was not available for
syncing.
* Sync containers when only missing on some hosts
* Consider images with multiple repo tags
* Enable kubeadm images pull/syncing with download_delegate
* Use kubeadm images list to pull/sync
'kubeadm config images pull' is replaced by collecting the images
list with 'kubeadm config images list' and using the commonly
used method of pull/syncing the images.
* Ensure containers are downloaded and synced for all hosts
* Fix download/syncing when download_delegate is a kubernetes host
When docker_container_storage_setup is false,
docker service should not depend on docker-storage-setup service,
because it's not installed.
For example, when using overlay2 on recent RHEL 7/Centos 7 kernels,
you most likely don't need it.
* Fix nodeselectors for contiv and nginx-ingress
Change-Id: Ib3eb6bd87193c69a90ee944c9164a0b6792c79ba
* Set kube proxy mode to iptables for addons task
Change-Id: Iff71a71f672405c74b4708c71db15ddc4391a53a
add the support of the folling property in azure-credential-check.yml
- azure_loadbalancer_sku: Sku of Load Balancer and Public IP. Candidate values are: basic and standard.
- azure_exclude_master_from_standard_lb: excludes master nodes from standard load balancer.
- azure_disable_outbound_snat: disables the outbound SNAT for public load balancer rules
- useInstanceMetadata: Use instance metadata service where possible
- azure_primary_availability_set: (Optional) The name of the availability set that should be used as the load balancer backend
We don't need to support upgrades from 2 year old installs,
just from the last major version.
Also changed most retried tasks to 1s delay instead of longer.
* Add README to bootstrap-os role
* Rework bootstrap-os once more
* Document workarounds for bugs/deficiencies in Ansible modules
* Unify and document role variables
* Remove installation of additional packages and repositories
* Merge Ubuntu and Debian tasks
* Remove pipelining setting from default playbooks
* Fix OpenSUSE not running its required tasks
The docker service provided by the containers-basic bundle is masked
in ClearLinux distribution. This is causing errors in the following
steps. This commit ensures that the unit is not masked.
* Use K8s 1.14 and add kubeadm experimental control plane mode
This reverts commit d39c273d96.
* Cleanup kubeadm setup run on first master
* pin kubeadm_certificate_key in test
* Remove kubelet autolabel of kube-node, add symlink for pki dir
Change-Id: Id5e74dd667c60675dbfe4193b0bc9fb44380e1ca
The BINDIR variable defined on the runc's Makefile[1] defines
installation path is on $(PREFIX)/sbin which used for most of the
Linux distributions. This change fixes the absolute path used for
non-ClearLinux distributions (CentOS, Ubuntu).
[1] https://github.com/opencontainers/runc/blob/master/Makefile#L10
The Stateless ClearLinux feature[1] requires the creation of folders
in /etc folder. This change ensure the existence of the
/etc/bash_completion.d/ folder for ClearLinux Distribution.
[1] https://clearlinux.org/features/stateless
* Enable nodelocaldns by default
* Enable nodelocaldns by default
* nodelocaldns is now default
* Disable enable_nodelocaldns for the addons CI jobs
Disable enable_nodelocaldns for the addons CI jobs to make sure things still work without nodelocaldns
* Add ansible-lint as gitlab-ci step
* Fix jinja2 syntax in include_tasks that breaks ansible-lint
* Use a block scalar to get around gitlab quoting/escaping rules
* Run ansible-lint in verbose mode in CI
This will fix error: error converting YAML to JSON: yaml: line 36: mapping values are not allowed in this context
Signed-off-by: Abdulaziz AlMalki <almalki.a@gmail.com>
* Vagrantfile: Bump openSUSE to Leap 15.0
* roles: container-engine: Add 'containerd' package for openSUSE
The 'containerd' package contains the docker-containerd and
docker-containerd-shim binaries. We also need to ensure that the latest
version is installed since an older version may already be present (eg GCE
images)
* Remove docker log-opts for opensuse
* roles: bootstrap-os: Use lowercase 'o' for openSUSE
OpenSUSE is not a valid family name. The correct one is openSUSE
* roles: bootstrap-os: Update zypper cache before first installation
The zypper cache may be outdated so ensure that it's fully updated
before we try and install the bootstrap packages.
Both the `yum` and `apt` modules support a list as input, this allows us avoid the slower `with_items` approach, which can take a long time with a large count of cluster nodes.
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.
values from inventory in roles/kubespray-defaults/defaults/main.yml
hardcoded values in roles/container-engine/defaults/main.yml
dns_servers set empty in roles/container-engine/defaults/main.yml and skydns_server not set in docker_dns_servers variables
also set default value for manual_dns_serve
another variables in roles/container-engine/defaults not need to set
* feat(external-provisioner/local-path-provisioner): adds support for local path provisioner
Helpful for local development but also in production workloads (once the
permission model is worked out) where you have redundancy built into the
software uses the PVCs (e.g. database cluster with synchronous
replication)
* feat(local-path-provisioner): adds debug flag, image tag group var
* fix(local-path-provisioner): moves image repo/tag to download role
* test(gce_centos7-flannel): enables local-path-provisioner in test case
* fix(addons): add image repo/tag to commented default values
* fix(local-path-provisioner): typo in jinja template for local path provisioner
* style(local-path-provisioner): debug flag condition re-formatted
* fix(local-path-provisioner): adds missing default value for debug flag
* fix(local-path-provisioner): syntax fix for debug if condition end
* fix(local-path-provisioner): jinja template syntax: if condition white space
This was already approved in #4106 but there are CI issues
with that PR due to references to kubernetes incubator.
After upgrading to Kubespray 2.8.1 with Kubeadm enabled Rook
Ceph volume provision failed due to the flexvolume plugin dir not
being correct. Adding the var fixed the issue
* Adding ability to maintain existing Encryption Secrets at Rest.
If secrets_encryption.yaml is present it will not be overriten with a new kube_encrypt_token.
This should allow for it to be set ahead of a playbook running or maintain it if cluster.yml is ran on the same cluster and the ansible host does not have access to the secrets.
* Setting existing kube_encrypt_token across all master nodes in case it was missing in one or more nodes.
This fixes an issue where the `nodename` in calico's cni config json can fall out of sync with the k8s node name used by the calico pod if `kube_override_hostname` is set
Currently, the task `container_download | download images for kubeadm config images` fetches etcd image even though it's not required (etcd is bootstrapped by kubespray, not kubeadm).
`kubeadm-images.yaml` is only a subset of `kubeadm-config.yaml`, therefore ``kubeadm config images pull` will try to get all this list (including etcd)
```
# kubeadm config images list --config /etc/kubernetes/kubeadm-images.yaml
k8s.gcr.io/kube-apiserver:v1.13.2
k8s.gcr.io/kube-controller-manager:v1.13.2
k8s.gcr.io/kube-scheduler:v1.13.2
k8s.gcr.io/kube-proxy:v1.13.2
k8s.gcr.io/pause:3.1
k8s.gcr.io/etcd:3.2.24
k8s.gcr.io/coredns:1.2.6
```
When using the `kubeadm-config.yaml` though, it doesn't list etcd image:
```
# kubeadm config images list --config /etc/kubernetes/kubeadm-config.yaml
k8s.gcr.io/kube-apiserver:v1.13.2
k8s.gcr.io/kube-controller-manager:v1.13.2
k8s.gcr.io/kube-scheduler:v1.13.2
k8s.gcr.io/kube-proxy:v1.13.2
k8s.gcr.io/pause:3.1
k8s.gcr.io/coredns:1.2.6
```
This change just adds the etcd endpoints in the `kubeadm-images.yaml` to give a hint to kubeadm it doesn't need etcd image for its boostrapping as etcd is "external".
I confess it is a ugly hack, a better way would be to use a single `kubeadm-config.yaml` for both tasks, but they are triggered by different roles (`kubeadm-images.yaml` is used by download, `kubeadm-config.yaml` by kubernetes/master) at different steps and I didn't want to refactor too many things to prevent breakage.
This is specially useful for offline installation where a whitelist of container images is mirrored on a local private container registry. `k8s.gcr.io/etcd` and `quay.io/coreos/etcd` are two different repositories hosting the same images but using *different tags*!
* coreos/etcd:v3.2.24
* k8s.gcr.io/etcd:3.2.24 (note the missing 'v' in the tag name)
Fix issue where `kubeadm join` could wait forever for joining.
Fix issue where `kubeadm join` were not reaching the user, making
impossible to find the cause of the failure.
New behaviour is to first attempt to join without bypassing the
verifications checks and to display them if needed.
If this fails it still attempts to join by ignoring the check in
order to make previous behavior.
A timeout of 60 seconds is allocated for a joining.
Related-bug: #3973
* bootstrap: rework role
* support being called from a non-root user
* run some commands in check mode
* unify spelling/task names
* bootstrap: fix wording of comments for check_mode: false
* bootstrap: remove setup-pipelining task
* OCI subnet AD 2 is not required for CCM >= 0.7.0
Reorganize OCI provider to generate configuration, rather than pull
Add pull secret option to OCI cloud provider
* Updated oci example to document new parameters
This PR ensures that the e2fsprogs and xfsprogs packages are
installed on all Kubernetes nodes and that the packages are
the latest versions. It also ensures that the nodes can
create XFS filesystems when necessary, since not all distros
install xfsprogs by default.
e2fsprogs - ext2/ext3/ext4 file system utilities
xfsprogs - Utilities for managing the XFS filesystem
* Calico: Ability to define the default IPPool CIDR (instead of kube_pods_subnet)
* Documentation for calico_pool_cidr (and calico_advertise_cluster_ips which has been forgotten...)
* Set cluster DNS correctly in case of nodelocal dns cache
* Pass in cluster_ip based on dns mode
* Disable nodelocaldns by default
* Fix syntax error
* Fix syntax issue
* Add nodelocadns ip to vars of node installation
* Change location of nodelocaldns_ip
* Try to remove newlines from jinja template
* Add debug for config file
* Move parameter logic outside of template
* Adapt templates after feedback
* Remove debugging
Addressing the discussion started in #4064, this PR moves kubeadm and
hyperkube binaries to /usr/local/bin before running them on the master
nodes.
It is to address the case where local_release_dir points to /tmp
(kubespray default) and /tmp is mounted with noexec mode, preventing
any binaries to be run in that partition.
In role "node", we still move kubeadm to bin_dir only on the worker
nodes.
I know this is a bit hack.
If you use cloud LB, you can use kubeadm's controlPlaneEndpoint to configure kube-proxy's server field.
But for nginx-proxy, it didn't start when kubeadm init.
Looks like `epel_enabled` was not configured for the epel install in `bootstrap-centos.yml`. Also, there were no conditionals that would trigger bootstrap for RHEL.
* Use external LB IP for external api endpoint
Use loadbalancer_apiserver.address instead of apiserver_loadbalancer_domain_name for kudadm init --apiserver-advertise-address argument
https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm-init/#options states apiserver-advertise-address needs to be a IPv4 or IPv6 address
* only use loadbalancer IP if it is defined
I found a potential use case where `writable` could be null and therfore
not treated like a boolean, so this adds an extra default statement to
avoid negating a non-boolean as boolean which would lead to undefined. refs #4020
Looks like the template is removing the trailing space between storage
class entries, and since CI only has one storage class we never hit this
issue. This change will prevent the yaml from printing on a single line
when multiple storage classes are defined.
In v1beta1 of `ClusterConfiguration` the extraVolumes `writable` field was changed to `readOnly` and its boolean value must be negated.
Also, the json field for `useHyperKubeImage` was incorrectly capitalized.
Right now we're consistently getting warnings about kubelet not found in
path during `kubeadm init`. We fixed this for `kubeadm join` in #3342, and this brings the change to init
as well.
- Fixed an issue where storage class host directories were looped
through excessive target hosts
- Fixes examples in the LVP `README.md` to use nested dicts instead of a
list of dicts
* Makes local volume provisioner more dynamic
* Correct variable name in local storage provisioner defaults
* Updates external-provisioner readme
* Updates variable naming to be more clear, more documentation, fixes sample inventory
* Variable refactor, untangled some jinja2 loops
* Corrects variable name
* No variable substitution in dict keys, replaced with anchor
* Fixes default storage_classes dict, inline docs
* Fixes spelling in inline docs
* Addresses comments in review
* Updates all the defaults
* Fix failing CI task
* Fixes external provisioner daemonset
* allows to override the bind addresses for controller-manager and scheduler
Useful for Prometheus metrics monitoring
* Add bind addr override support in kubeadm/v1beta1
Adds support for override of bind addresses for controller-manager
and scheduler in kubeadm/v1beta1
* Move location of bind address vars
* Remove double declaration of schedulerExtraArgs
The change implemented in #3908 remove line breaks for supplementary
addresses in kubeadm SANs, causing errors in the config file and
failure to bring cluster up. This commit reimplement line breaks in
between supplementary addresses.
- Creates and defaults an ansible variable for every configuration option in the `kubeproxy.config.k8s.io/v1alpha1` type spec
- Fixes vars that were orphaned by removing non-kubeadm
- Fixes previously harcoded kubeadm values
- Introduces a `main` directory for role default files per component (requires ansible 2.6.0+)
- Split out just `kube-proxy.yml` in this first effort
- Removes the kube-proxy server field patch task
We should continue to pull out other components from `main.yml` into their own defaults files as I did here for `defaults/main/kube-proxy.yml`. I hope for and will need others to join me in this refactoring across the project until each component config template has a matching role defaults file, with shared defaults in `kubespray-defaults` or `downloads`
The containerd service and socket files have been dropped from the
openSUSE docker package so we should not require them in the docker
service anymore. This makes the docker service file look similar to
the one shipped by the openSUSE package.
Signed-off-by: Markos Chandras <mchandras@suse.de>
* controlPlaneEndpoint set up through load balancer should be possible even in single master setups
Enable load balancer for single-master setups
Fixes an issue where single-master setups are not reachable using the usual admin.conf from outside the cluster.
controlPlaneEndpoint set up through load balancer should be possible even in single master setups
* add fix to other api versions
* remove obsolete check completely
* remove check, pass 2
* removes checks in client configuration
* delete 'and'
* 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
Setting host_architecture to allow etcd upgrade working through: ansible-playbook -b -i inventory/sample/hosts.ini cluster.yml --tags=etcd (on other case host_architecture is missing)
* 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 non-kubeadm deployment
* More cleanup
* More cleanup
* More cleanup
* More cleanup
* Fix gitlab
* Try stop gce first before absent to make the delete process work
* More cleanup
* Fix bug with checking if kubeadm has already run
* Fix bug with checking if kubeadm has already run
* More fixes
* Fix test
* fix
* Fix gitlab checkout untill kubespray 2.8 is on quay
* Fixed
* Add upgrade path from non-kubeadm to kubeadm. Revert ssl path
* Readd secret checking
* Do gitlab checks from v2.7.0 test upgrade path to 2.8.0
* fix typo
* Fix CI jobs to kubeadm again. Fix broken hyperkube path
* Fix gitlab
* Fix rotate tokens
* More fixes
* More fixes
* Fix tokens
* Remove variables defined in download role. Fixes#3799
* Cleanup some more variables
* Fix bad templating
* Minor fix
* Add dashboard to download role. Fixes#3736
* Set configure-cloud-routes=false as default if no network plugin is used
As configure-cloud-routes default value is `true`, so it need to be set to `false` when not required to avoid error messages like:
"Couldn't reconcile node routes: error listing routes: unable to find route table for AWS cluster"
on, for example, AWS installations that don't use cloud native routing.
* Update kube-controller-manager.manifest.j2
remove extra spaces
Introduced variable node_taints which can be set in inventory for
specific hosts or in group_vars, which generates --register-with-taints
command line argument for kubelet.
Introduced variable `ingress_nginx_tolerations` to set custom
tolerations for Ingress nginx daemonset, to be able to schedule
ingress-nginx on dedicated nodes with taints.
* Update defaults to match k8s 1.12 suggestions
* Test if Netchecker works with node ip instead of localhost
* Update defaults to ipvs and coredns
* Update defaults for kube_apiserver_insecure_port
* Update main.yaml
When `ansible_user` is not root, using `-b` option.
And with `download_run_once` and `download_localhost` set `true`.
Ansible will executes `container_download | upload container images to nodes` task.
It uses rsync to upload images to `/tmp/release/container/`, but the
`container` directory owned by `root`.
Now the `kubespray-aws-inventory.py` script always set a node_labels key
to ansible_host.
When AWS instance did not set property labels, it would be an empty
string.
The TASK `Write kubelet config file (kubeadm or non-kubeadm)` will
failed with a msg:
`AnsibleUndefinedVariable: 'unicode object' has no attribute 'items'`.
* Support Metrics Server as addon (#3560).
* Update metrics server v0.3.1.
* Add metrics server test.
* Replace metrics server manifests with kubernetes/cluster/addons's.
* Modify metrics server manifests for kubespray.
* Follow PR#3558 node label node-role.kubernetes.io/master change
* Fix metrics server parameters base_metrics_server_... to metrics_server_...
* Fix too hard corded metrics_server_memory_per_node
* Add configurable insecure tls for metrics-apiservice
* Downloadable addon-resizer and extract parameter as variables
* Remove metrics server version from deployment name
* Metrics Server work when all masters has node role
* Download metrics-server and add-resizer container only on master
* ServiceAccount and ConfigMap is separated and fix application name
* Remove old metrics server clusterrole template
* Fix addon-resizer image specify
* Make InternalIP default for metrics_server_kubelet_preferred_address_types
Make InternalIP default because multiple preferrred address types does not work.
comparison that happens during `TASK [kubernetes-apps/ansible : Kubernetes Apps | Lay Down CoreDNS Template]` where the `dns-autoscaler` template is deployed causes coredns to fail deployment. The error is caused by the variable `dns_prevent_single_point_failure` where an integer is being compared with a string. The resulting error:
```bash
'>' not supported between instances of 'int' and 'str'
```
prevents successful deployment of CoreDNS.
The change makes the comparison happen between integers and allows CoreDNS to succeed.
* 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
add prometheus annotations to calico-node if
calico_felix_prometheusmetricsenabled is enabled.
This will allow a kubernetes_sd to automaticly find the pods and start
scraping.
* Fix Failure talking to yum: Cannot find a valid baseurl for repo: base/7/x86_64 if Install packages in CentOS using proxy
* Add proxy to /etc/yum.conf if http_proxy is defined
* Added changes to clean up orphan containers and reload docker & kubelet directories.
* Added new files for cleaning up orphans and docker & kubelet directories
* Added new lines at the end of these files
* removed the trailing whitespaces from main.yml and clean-up.yml
* Updated as per the review comments
* Updated as per the review comments
* Removed service_facts and package_facts because they are not supported in ansible 2.4.0
* Corrected yaml syntax errors
* Removed the use of json_query filter and utilized selectattr
* Removed trailing spaces
* Changed the default value of docker_clean_up to false
* Added Changes to only include cleanup-docker-orphans.sh
* Reverted back changes done inside handler.
* Removed trailing spaces and made default value of docker_orphan_clean_up as true
* Reverted the default value of docker_orphan_clean_up as false
* Made the docker clean up as drop in
* Made the docker clean up as drop in
* Reverted the value of boolean docker_orphan_clean_up to false
* Converted ExecStop to ExecSTartPost. Removed the live restore check from the orphan script
* Adds support for Multus (multiple interfaces) CNI plugin
Multus is a latin word for "Multi". As the name suggests, it acts as a
Multi plugin in Kubernetes and provides multiple network interface
support in a pod. Multus uses the concept of invoking delegates by
grouping multiple plugins into delegates and invoking them in the
sequential order of the CNI configuration file provided in json format.
* Change CNI version (0.1.0->0.3.1) of Contiv to be compatible with Multus
When using resolvconf_mode host_resolvconf, there is an early DNS
config stage where Kubernetes cluster DNS is not injected for host
DNS intially. Later, the cluster DNS is enabled, but we do not
need to run every task from the kubernetes/preinstall role.
