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Kubernetes custom configuration support at Runtime (r8,dsR8)

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Story: 2009766
Task: 47829

Signed-off-by: Elisamara Aoki Goncalves <elisamaraaoki.goncalves@windriver.com>
Change-Id: I32b9086daeccc6b970c58207ee4b91340a955933
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Elisamara Aoki Goncalves 2023-04-13 15:50:16 -03:00
parent 35af206725
commit afe224ee6a
1 changed files with 283 additions and 57 deletions
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340
doc/source/system_configuration/kubernetes/kubernetes-custom-configuration-31c1fd41857d.rst
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@ -19,7 +19,7 @@ Custom configuration includes:
controllers,
- Configuring options on ``kube-controller-manager`` such as
- ``node-monitor-period`` and ``pod-eviction-timeout``,
``node-monitor-period`` and ``pod-eviction-timeout``,
- Configuring options on ``kube-scheduler`` such as feature gates,
@ -30,7 +30,7 @@ Custom configuration includes:
kube-apiserver configuration
----------------------------
The Kubernetes API server validates and configures data for the api objects
The Kubernetes API server validates and configures data for the API objects
which include pods, services, replicationcontrollers, and others. The API
Server services REST operations and provides the frontend to the cluster's
shared state through which all other components interact.
@ -48,18 +48,19 @@ Example usage:
.. code-block::
apiserver_extra_args:
admission-control-config-file: "/etc/kubernetes/admission-control-config-file.yml"
audit-policy-file: "/etc/kubernetes/audit-policy-file.yml"
default-not-ready-toleration-seconds: "35"
default-unreachable-toleration-seconds: "35"
enable-admission-plugins: "NodeRestriction,PodNodeSelector"
event-ttl: "20h"
admission-control-config-file: "/etc/kubernetes/admission-control-config-file.yml"
audit-policy-file: "/etc/kubernetes/audit-policy-file.yml"
default-not-ready-toleration-seconds: "35"
default-unreachable-toleration-seconds: "35"
feature-gates: "SCTPSupport=true,TTLAfterFinished=true,HugePageStorageMediumSize=true,RemoveSelfLink=false,MemoryManager=true"
enable-admission-plugins: "NodeRestriction,PodNodeSelector"
event-ttl: "20h"
**Runtime configuration**
To set, modify or delete a ``kube-apiserver`` parameter use the
service-parameter add, modify or delete |CLI| command.
``service-parameter add``, ``modify`` or ``delete`` |CLI| command.
Example usage:
@ -73,7 +74,7 @@ Example usage:
.. note::
Parameter must not exists on service parameters, otherwise use
Parameter must not exist on service parameters, otherwise use
:command:`modify` command.
- Modify existing parameter
@ -86,11 +87,15 @@ Example usage:
- Delete parameter
#. system service-parameter-list
.. code-block:: none
#. copy parameter uuid to be deleted
system service-parameter-list
#. system service-parameter-delete <uuid>
Copy parameter uuid to be deleted:
.. code-block:: none
system service-parameter-delete <uuid>
-------------------------------------
@ -111,24 +116,23 @@ For a list of all configurable options of kube-controller-manager, see
To set or override a ``kube-controller-manager`` option, add the desired
parameters to an ``controllermanager_extra_args`` section in the
``localhost.yml`` .
``localhost.yml``.
Example usage:
.. code-block::
controllermanager_extra_args:
node-monitor-period: "4s"
node-monitor-grace-period: "25s"
pod-eviction-timeout: '35s'
feature-gates: "TTLAfterFinished=true,MemoryManager=true"
controllermanager_extra_args:
node-monitor-period: "4s"
node-monitor-grace-period: "25s"
pod-eviction-timeout: '35s'
feature-gates: "TTLAfterFinished=true,MemoryManager=true"
**Runtime configuration**
To set, modify or delete a ``kube-controller-manager`` parameter use the
service-parameter add, modify or delete |CLI| command.
``service-parameter add``, ``modify`` or ``delete`` |CLI| command.
Example usage:
@ -142,7 +146,7 @@ Example usage:
.. note::
Parameter must not exists on service parameters, otherwise use
Parameter must not exist on service parameters, otherwise use
:command:`modify` command.
- Modify existing parameter
@ -155,11 +159,15 @@ Example usage:
- Delete parameter
#. system service-parameter-list
.. code-block:: none
#. copy parameter uuid to be deleted
system service-parameter-list
#. system service-parameter-delete <uuid>
Copy parameter uuid to be deleted:
.. code-block:: none
system service-parameter-delete <uuid>
----------------------------
@ -170,28 +178,28 @@ The Kubernetes scheduler is a control plane process which assigns Pods to
Nodes. The scheduler determines which Nodes are valid placements for each Pod
in the scheduling queue according to constraints and available resources. The
scheduler then ranks each valid Node and binds the Pod to a suitable Node.
Multiple different schedulers may be used within a cluster; kube-scheduler is
the reference implementation.
Multiple different schedulers may be used within a cluster; ``kube-scheduler``
is the reference implementation.
For a list of all configurable options of ``kube-scheduler``, see `kube-scheduler
<https://kubernetes.io/docs/reference/command-line-tools-reference/kube-scheduler/>`__.
**Bootstrap configuration**
To set or override a ``kube-scheduler`` option, add the desired parameters to an
``scheduler_extra_args`` section in the ``localhost.yml`` .
To set or override a ``kube-scheduler`` option, add the desired parameters to
an ``scheduler_extra_args`` section in the ``localhost.yml``.
Example usage:
.. code-block::
scheduler_extra_args:
feature-gates: "TTLAfterFinished=false"
scheduler_extra_args:
feature-gates: "TTLAfterFinished=false"
**Runtime configuration**
To set, modify or delete a ``kube-controller-manager`` parameter use the
service-parameter add, modify or delete |CLI| command.
``service-parameter add``, ``modify`` or ``delete`` |CLI| command.
Example usage:
@ -205,7 +213,7 @@ Example usage:
.. note::
Parameter must not exists on service parameters, otherwise use
Parameter must not exist on service parameters, otherwise use
:command:`modify` command.
- Modify existing parameter
@ -218,11 +226,15 @@ Example usage:
- Delete parameter
#. system service-parameter-list
.. code-block:: none
#. copy parameter uuid to be deleted
system service-parameter-list
#. system service-parameter-delete <uuid>
Copy parameter uuid to be deleted:
.. code-block:: none
system service-parameter-delete <uuid>
----------------------
@ -234,14 +246,11 @@ The kubelet is the primary "node agent" that runs on each node.
For a list of all configurable options, see `Kubelet Configuration (v1beta1)
<https://kubernetes.io/docs/reference/config-api/kubelet-config.v1beta1/>`__.
To set or override a kubelet option, add the desired parameters to an
``kubelet_configurations`` section in the ``localhost.yml`` .
**Bootstrap configuration**
To set or override a kubelet option, add the desired parameters to a
``kubelet_configurations`` section in the ``localhost.yml``.
.. important::
Custom Kubelet configuration is not supported during runtime. This feature
will be supported in the next release.
Example usage:
@ -252,24 +261,88 @@ Example usage:
MemoryManager: true
HugePageStorageMediumSize: true
---------------------------------------------------------------------------------
apiserver_extra_volumes, controllermanager_extra_volumes, scheduler_extra_volumes
---------------------------------------------------------------------------------
**Runtime configuration**
To set, modify or delete a kubelet parameter use the ``service-parameter add``,
``modify`` or ``delete`` |CLI| command.
The expected structure for existing field types are:
- String, bool, meta/v1.Duration:
- No structure defined, quotes may or may not be used.
- Ex.: ``cgroupDriver=cgroupfs`` or ``cgroupDriver="cgroupfs"``
- int32,int64:
- No structure defined, quotes may or may not be used.
- Ex.: ``imageGCLowThresholdPercent=70`` or ``imageGCLowThresholdPercent="70"``
- Array of strings (``[]string``):
- JSON-like format: ``'["string1","string2","stringN"]'``
- Ex.: ``clusterDNS='["10.96.0.10"]'``
- ``map[string]string``: json format.
- JSON-like format: ``'{"key_string1":"string1","key_string2":"string2","key_stringN":"stringN"}'``
- Ex: ``evictionHard='{"memory.available":"100Mi", "nodefs.available": "10%","nodefs.inodesFree": "6%", "imagefs.available": "2Gi"}'``
Example usage:
- Add new parameter
.. code-block:: none
system service-parameter-add kubernetes kubelet clusterDNS='["10.96.0.10"]'
system service-parameter-apply kubernetes
.. note::
Parameter must not exist on service parameters, otherwise use
:command:`modify`` command.
- Modify existent parameter
.. code-block:: none
system service-parameter-modify kubernetes kubelet nodeStatusUpdateFrequency="5s"
system service-parameter-apply kubernetes
- Delete parameter
.. code-block:: none
system service-parameter-list
Copy parameter uuid to be deleted:
.. code-block:: none
system service-parameter-delete <uuid>
--------------------------------------------------------------------------------------
kube-apiserver, kube-controller-manager and kube-scheduler extra-volumes configuration
--------------------------------------------------------------------------------------
Some options/parameters specified in ``apiserver_extra_args``,
``controllermanager_extra_args`` and ``scheduler_extra_volumes`` refer to a
configuration file. The contents of these files are configured in the bootstrap
overrides (``localhost.yml``) with the ``apiserver_extra_volumes``,
``controllermanager_extra_volumes`` and ``scheduler_extra_volumes``
definitions.
``controller-manager_extra_args`` and ``scheduler extra-args`` refer to
configuration files or directories. Those referenced files or directories must
be mounted as volumes on the corresponding control plane pod using the
``extra-volume`` parameters.
**Bootstrap configuration**
.. important::
Kubernetes custom configuration of extra-volumes for ``kube-apiserver``,
``kube-controller-manager`` and ``kube-scheduler`` are not supported during
runtime. This feature will be supported in the next release.
To set or override an ``extra-volumes`` option, add the desired parameters to
the corresponding ``extra-args`` section in the ``localhost.yml``, add the
desired ``extra-volume`` including the volume details and file contents (if
corresponds).
For instance, if admission plugins are configured and need additional
configuration, that configuration should be set in a specific file referenced
@ -335,7 +408,7 @@ Example usage:
namespace2: name-of-node-selector
The example below enables kubernetes auditing which requires an
audit-policy-file.yaml file to specify the details of what events should be
``audit-policy-file.yaml`` file to specify the details of what events should be
audited.
Example usage:
@ -362,6 +435,159 @@ Example usage:
readOnly: false
pathType: "DirectoryOrCreate"
**Runtime configuration**
To set, modify or delete an extra-volume parameter use the ``service-parameter
add``, ``modify`` or ``delete`` |CLI| command.
Valid extra-volume sections:
- ``kube_apiserver_volumes``
- ``kube_controller_manager_volumes``
- ``kube_scheduler_volumes``
Valid extra-volume parameter fields:
- ``name``:
- Volume name.
- ``hostPath``:
- Absolute path in node file system where the file or directory to mount is located.
- ``mounthPath (opc)``:
- Absolute path in pod file system used to mount the file or directory.
- Default value: same as hostPath.
- ``pathType (opc)``:
- The supported values are:
- DirectoryOrCreate: If nothing exists at the given path, an empty
directory will be created there as needed with permission set to 0755,
having the same group and ownership with Kubelet.
- File: A file must exist at the given path.
- Default value: File.
- ``readOnly (opc)``:
- The supported values are: true or false.
- Default value: true.
Valid input formats:
- Pairs of strings separated by commas:
- Ex.: ``audit-log-dir=hostPath:/var/log/kubernetes/audit,readOnly:false,pathType:DirectoryOrCreate``
- JSON format:
- Ex.: ``encryption-config='{"name": "encryption-config", "hostPath": "/etc/kubernetes/encryption-provider.yaml", "mountPath": "/etc/kubernetes/encryption-provider.yaml", "readOnly": true, "pathType":"File"}'``
Example usage with two linked configuration files:
An admission controller could be added to mitigates the problem when the API
server gets flooded by requests to store new Events. The cluster admin can
specify event rate limits by enabling the EventRateLimit admission controller
and referencing an EventRateLimit configuration file.
- Add new extra-args parameters
.. code-block:: none
system service-parameter-add kubernetes kube_apiserver admission-control-config-file=/etc/kubernetes/admission-control-config-file.yaml
system service-parameter-add kubernetes kube_apiserver enable-admission-plugins=EventRateLimit
.. note::
Parameter must not exist on service parameters, otherwise use
:command:`modify` command.
- Add new extra-volume parameters
.. code-block:: none
system service-parameter-add kubernetes kube_apiserver_volumes admission-control-config-file=hostPath:/etc/kubernetes/admission-control-config-file.yaml
system service-parameter-add kubernetes kube_apiserver_volumes eventconfig=hostPath:/etc/kubernetes/eventconfig.yaml
system service-parameter-apply kubernetes
.. note::
Parameter must not exist on service parameters, otherwise use
:command:`modify` command.
- Modify existent parameter
The configuration file name, for example, can be changed. During this
operation, the preloaded configuration file will be replaced.
.. code-block:: none
system service-parameter-modify kubernetes kube_apiserver_volumes admission-control-config-file=hostPath:/etc/kubernetes/new-admission-control-config-file.yaml
system service-parameter-apply kubernetes
- Delete parameters
.. code-block:: none
system service-parameter-list
Copy parameter uuid to be deleted:
.. code-block:: none
system service-parameter-delete <uuid>
In the current example, if EventRateLimit is no longer needed, it should be
removed from the ``kube_apiserver enable-admission-plugins`` parameter,
either by changing its value or by removing the parameter. Then the
extra-volume ``kube_apiserver_volumes eventconfig`` parameter can be deleted.
If the configuration file is no longer needed, the ``kube_apserver
admission-control-config-file`` parameter can also be removed. Then the-extra
volume ``kube_apiserver_volumes connections-control-config-file`` can be
deleted.
- Configuration Files Examples:
- ``admission-control-config-file.yaml``
.. code-block:: none
apiVersion: apiserver.config.k8s.io/v1
kind: AdmissionConfiguration
plugins:
- name: EventRateLimit
path: /etc/kubernetes/eventconfig.yaml
- ``eventconfig.yaml``
.. code-block:: none
apiVersion: eventratelimit.admission.k8s.io/v1alpha1
kind: Configuration
limits:
- type: Namespace
qps: 50
burst: 100
cacheSize: 2000
- type: User
qps: 10
burst: 50
-----------------------------
Complex Example configuration
-----------------------------