281 lines
14 KiB
Markdown
281 lines
14 KiB
Markdown
# Ansible variables
|
|
|
|
## Inventory
|
|
|
|
The inventory is composed of 3 groups:
|
|
|
|
* **kube_node** : list of kubernetes nodes where the pods will run.
|
|
* **kube_control_plane** : list of servers where kubernetes control plane components (apiserver, scheduler, controller) will run.
|
|
* **etcd**: list of servers to compose the etcd server. You should have at least 3 servers for failover purpose.
|
|
|
|
Note: do not modify the children of _k8s_cluster_, like putting
|
|
the _etcd_ group into the _k8s_cluster_, unless you are certain
|
|
to do that and you have it fully contained in the latter:
|
|
|
|
```ShellSession
|
|
k8s_cluster ⊂ etcd => kube_node ∩ etcd = etcd
|
|
```
|
|
|
|
When _kube_node_ contains _etcd_, you define your etcd cluster to be as well schedulable for Kubernetes workloads.
|
|
If you want it a standalone, make sure those groups do not intersect.
|
|
If you want the server to act both as control-plane and node, the server must be defined
|
|
on both groups _kube_control_plane_ and _kube_node_. If you want a standalone and
|
|
unschedulable control plane, the server must be defined only in the _kube_control_plane_ and
|
|
not _kube_node_.
|
|
|
|
There are also two special groups:
|
|
|
|
* **calico_rr** : explained for [advanced Calico networking cases](/docs/calico.md)
|
|
* **bastion** : configure a bastion host if your nodes are not directly reachable
|
|
|
|
Below is a complete inventory example:
|
|
|
|
```ini
|
|
## Configure 'ip' variable to bind kubernetes services on a
|
|
## different ip than the default iface
|
|
node1 ansible_host=95.54.0.12 ip=10.3.0.1
|
|
node2 ansible_host=95.54.0.13 ip=10.3.0.2
|
|
node3 ansible_host=95.54.0.14 ip=10.3.0.3
|
|
node4 ansible_host=95.54.0.15 ip=10.3.0.4
|
|
node5 ansible_host=95.54.0.16 ip=10.3.0.5
|
|
node6 ansible_host=95.54.0.17 ip=10.3.0.6
|
|
|
|
[kube_control_plane]
|
|
node1
|
|
node2
|
|
|
|
[etcd]
|
|
node1
|
|
node2
|
|
node3
|
|
|
|
[kube_node]
|
|
node2
|
|
node3
|
|
node4
|
|
node5
|
|
node6
|
|
|
|
[k8s_cluster:children]
|
|
kube_node
|
|
kube_control_plane
|
|
```
|
|
|
|
## Group vars and overriding variables precedence
|
|
|
|
The group variables to control main deployment options are located in the directory ``inventory/sample/group_vars``.
|
|
Optional variables are located in the `inventory/sample/group_vars/all.yml`.
|
|
Mandatory variables that are common for at least one role (or a node group) can be found in the
|
|
`inventory/sample/group_vars/k8s_cluster.yml`.
|
|
There are also role vars for docker, kubernetes preinstall and control plane roles.
|
|
According to the [ansible docs](https://docs.ansible.com/ansible/latest/playbooks_variables.html#variable-precedence-where-should-i-put-a-variable),
|
|
those cannot be overridden from the group vars. In order to override, one should use
|
|
the `-e` runtime flags (most simple way) or other layers described in the docs.
|
|
|
|
Kubespray uses only a few layers to override things (or expect them to
|
|
be overridden for roles):
|
|
|
|
Layer | Comment
|
|
------|--------
|
|
**role defaults** | provides best UX to override things for Kubespray deployments
|
|
inventory vars | Unused
|
|
**inventory group_vars** | Expects users to use ``all.yml``,``k8s_cluster.yml`` etc. to override things
|
|
inventory host_vars | Unused
|
|
playbook group_vars | Unused
|
|
playbook host_vars | Unused
|
|
**host facts** | Kubespray overrides for internal roles' logic, like state flags
|
|
play vars | Unused
|
|
play vars_prompt | Unused
|
|
play vars_files | Unused
|
|
registered vars | Unused
|
|
set_facts | Kubespray overrides those, for some places
|
|
**role and include vars** | Provides bad UX to override things! Use extra vars to enforce
|
|
block vars (only for tasks in block) | Kubespray overrides for internal roles' logic
|
|
task vars (only for the task) | Unused for roles, but only for helper scripts
|
|
**extra vars** (always win precedence) | override with ``ansible-playbook -e @foo.yml``
|
|
|
|
## Ansible tags
|
|
|
|
The following tags are defined in playbooks:
|
|
|
|
| Tag name | Used for
|
|
|--------------------------------|---------
|
|
| ambassador | Ambassador Ingress Controller
|
|
| annotate | Create kube-router annotation
|
|
| apps | K8s apps definitions
|
|
| asserts | Check tasks for download role
|
|
| aws-ebs-csi-driver | Configuring csi driver: aws-ebs
|
|
| azure-csi-driver | Configuring csi driver: azure
|
|
| bastion | Setup ssh config for bastion
|
|
| bootstrap-os | Anything related to host OS configuration
|
|
| calico | Network plugin Calico
|
|
| calico_rr | Configuring Calico route reflector
|
|
| canal | Network plugin Canal
|
|
| cephfs-provisioner | Configuring CephFS
|
|
| cert-manager | Configuring certificate manager for K8s
|
|
| cilium | Network plugin Cilium
|
|
| cinder-csi-driver | Configuring csi driver: cinder
|
|
| client | Kubernetes clients role
|
|
| cloud-provider | Cloud-provider related tasks
|
|
| cluster-roles | Configuring cluster wide application (psp ...)
|
|
| cni | CNI plugins for Network Plugins
|
|
| containerd | Configuring containerd engine runtime for hosts
|
|
| container_engine_accelerator | Enable nvidia accelerator for runtimes
|
|
| container-engine | Configuring container engines
|
|
| container-runtimes | Configuring container runtimes
|
|
| coredns | Configuring coredns deployment
|
|
| crio | Configuring crio container engine for hosts
|
|
| crun | Configuring crun runtime
|
|
| csi-driver | Configuring csi driver
|
|
| dashboard | Installing and configuring the Kubernetes Dashboard
|
|
| dns | Remove dns entries when resetting
|
|
| docker | Configuring docker engine runtime for hosts
|
|
| download | Fetching container images to a delegate host
|
|
| etcd | Configuring etcd cluster
|
|
| etcd-secrets | Configuring etcd certs/keys
|
|
| etchosts | Configuring /etc/hosts entries for hosts
|
|
| external-cloud-controller | Configure cloud controllers
|
|
| external-openstack | Cloud controller : openstack
|
|
| external-provisioner | Configure external provisioners
|
|
| external-vsphere | Cloud controller : vsphere
|
|
| facts | Gathering facts and misc check results
|
|
| files | Remove files when resetting
|
|
| flannel | Network plugin flannel
|
|
| gce | Cloud-provider GCP
|
|
| gcp-pd-csi-driver | Configuring csi driver: gcp-pd
|
|
| gvisor | Configuring gvisor runtime
|
|
| helm | Installing and configuring Helm
|
|
| ingress-controller | Configure ingress controllers
|
|
| ingress_alb | AWS ALB Ingress Controller
|
|
| init | Windows kubernetes init nodes
|
|
| iptables | Flush and clear iptable when resetting
|
|
| k8s-pre-upgrade | Upgrading K8s cluster
|
|
| k8s-secrets | Configuring K8s certs/keys
|
|
| k8s-gen-tokens | Configuring K8s tokens
|
|
| kata-containers | Configuring kata-containers runtime
|
|
| krew | Install and manage krew
|
|
| kubeadm | Roles linked to kubeadm tasks
|
|
| kube-apiserver | Configuring static pod kube-apiserver
|
|
| kube-controller-manager | Configuring static pod kube-controller-manager
|
|
| kubectl | Installing kubectl and bash completion
|
|
| kubelet | Configuring kubelet service
|
|
| kube-ovn | Network plugin kube-ovn
|
|
| kube-router | Network plugin kube-router
|
|
| kube-proxy | Configuring static pod kube-proxy
|
|
| localhost | Special steps for the localhost (ansible runner)
|
|
| local-path-provisioner | Configure External provisioner: local-path
|
|
| local-volume-provisioner | Configure External provisioner: local-volume
|
|
| macvlan | Network plugin macvlan
|
|
| master | Configuring K8s master node role
|
|
| metallb | Installing and configuring metallb
|
|
| metrics_server | Configuring metrics_server
|
|
| netchecker | Installing netchecker K8s app
|
|
| network | Configuring networking plugins for K8s
|
|
| mounts | Umount kubelet dirs when reseting
|
|
| multus | Network plugin multus
|
|
| nginx | Configuring LB for kube-apiserver instances
|
|
| node | Configuring K8s minion (compute) node role
|
|
| nodelocaldns | Configuring nodelocaldns daemonset
|
|
| node-label | Tasks linked to labeling of nodes
|
|
| node-webhook | Tasks linked to webhook (grating access to resources)
|
|
| nvidia_gpu | Enable nvidia accelerator for runtimes
|
|
| oci | Cloud provider: oci
|
|
| ovn4nfv | Network plugin ovn4nfv
|
|
| persistent_volumes | Configure csi volumes
|
|
| persistent_volumes_aws_ebs_csi | Configuring csi driver: aws-ebs
|
|
| persistent_volumes_cinder_csi | Configuring csi driver: cinder
|
|
| persistent_volumes_gcp_pd_csi | Configuring csi driver: gcp-pd
|
|
| persistent_volumes_openstack | Configuring csi driver: openstack
|
|
| policy-controller | Configuring Calico policy controller
|
|
| post-remove | Tasks running post-remove operation
|
|
| post-upgrade | Tasks running post-upgrade operation
|
|
| pre-remove | Tasks running pre-remove operation
|
|
| pre-upgrade | Tasks running pre-upgrade operation
|
|
| preinstall | Preliminary configuration steps
|
|
| registry | Configuring local docker registry
|
|
| reset | Tasks running doing the node reset
|
|
| resolvconf | Configuring /etc/resolv.conf for hosts/apps
|
|
| rbd-provisioner | Configure External provisioner: rdb
|
|
| services | Remove services (etcd, kubelet etc...) when resetting
|
|
| snapshot | Enabling csi snapshot
|
|
| snapshot-controller | Configuring csi snapshot controller
|
|
| upgrade | Upgrading, f.e. container images/binaries
|
|
| upload | Distributing images/binaries across hosts
|
|
| vsphere-csi-driver | Configuring csi driver: vsphere
|
|
| weave | Network plugin Weave
|
|
| win_nodes | Running windows specific tasks
|
|
|
|
Note: Use the ``bash scripts/gen_tags.sh`` command to generate a list of all
|
|
tags found in the codebase. New tags will be listed with the empty "Used for"
|
|
field.
|
|
|
|
## Example commands
|
|
|
|
Example command to filter and apply only DNS configuration tasks and skip
|
|
everything else related to host OS configuration and downloading images of containers:
|
|
|
|
```ShellSession
|
|
ansible-playbook -i inventory/sample/hosts.ini cluster.yml --tags preinstall,facts --skip-tags=download,bootstrap-os
|
|
```
|
|
|
|
And this play only removes the K8s cluster DNS resolver IP from hosts' /etc/resolv.conf files:
|
|
|
|
```ShellSession
|
|
ansible-playbook -i inventory/sample/hosts.ini -e dns_mode='none' cluster.yml --tags resolvconf
|
|
```
|
|
|
|
And this prepares all container images locally (at the ansible runner node) without installing
|
|
or upgrading related stuff or trying to upload container to K8s cluster nodes:
|
|
|
|
```ShellSession
|
|
ansible-playbook -i inventory/sample/hosts.ini cluster.yml \
|
|
-e download_run_once=true -e download_localhost=true \
|
|
--tags download --skip-tags upload,upgrade
|
|
```
|
|
|
|
Note: use `--tags` and `--skip-tags` wise and only if you're 100% sure what you're doing.
|
|
|
|
## Bastion host
|
|
|
|
If you prefer to not make your nodes publicly accessible (nodes with private IPs only),
|
|
you can use a so called *bastion* host to connect to your nodes. To specify and use a bastion,
|
|
simply add a line to your inventory, where you have to replace x.x.x.x with the public IP of the
|
|
bastion host.
|
|
|
|
```ShellSession
|
|
[bastion]
|
|
bastion ansible_host=x.x.x.x
|
|
```
|
|
|
|
For more information about Ansible and bastion hosts, read
|
|
[Running Ansible Through an SSH Bastion Host](https://blog.scottlowe.org/2015/12/24/running-ansible-through-ssh-bastion-host/)
|
|
|
|
## Mitogen
|
|
|
|
You can use [mitogen](/docs/mitogen.md) to speed up kubespray.
|
|
|
|
## Beyond ansible 2.9
|
|
|
|
Ansible project has decided, in order to ease their maintenance burden, to split between
|
|
two projects which are now joined under the Ansible umbrella.
|
|
|
|
Ansible-base (2.10.x branch) will contain just the ansible language implementation while
|
|
ansible modules that were previously bundled into a single repository will be part of the
|
|
ansible 3.x package. Pleasee see [this blog post](https://blog.while-true-do.io/ansible-release-3-0-0/)
|
|
that explains in detail the need and the evolution plan.
|
|
|
|
**Note:** this change means that ansible virtual envs cannot be upgraded with `pip install -U`.
|
|
You first need to uninstall your old ansible (pre 2.10) version and install the new one.
|
|
|
|
```ShellSession
|
|
pip uninstall ansible
|
|
cd kubespray/
|
|
pip install -U .
|
|
```
|
|
|
|
**Note:** some changes needed to support ansible 2.10+ are not backwards compatible with 2.9
|
|
Kubespray needs to evolve and keep pace with upstream ansible and will be forced to eventually
|
|
drop 2.9 support. Kubespray CIs use only the ansible version specified in the `requirements.txt`
|
|
and while the `ansible_version.yml` may allow older versions to be used, these are not
|
|
exercised in the CI and compatibility is not guaranteed.
|