mirror of
https://github.com/k3s-io/kubernetes.git
synced 2025-07-31 23:37:01 +00:00
new snapd_refresh config to control snapd refresh frequency (#141)
* add snapd_refresh config and handlers to k8s-master and -worker * lint readmes * add snapd_refresh doc to the readme; make "max" less specific * adjust wording to note snapd_refresh only affects store snaps
This commit is contained in:
Kevin W Monroe
cdkbot
parent
1b6268b616
commit
800d016dd4
@ -1,19 +1,19 @@
|
||||
# Kubernetes-master
|
||||
|
||||
[Kubernetes](http://kubernetes.io/) is an open source system for managing
|
||||
[Kubernetes](http://kubernetes.io/) is an open source system for managing
|
||||
application containers across a cluster of hosts. The Kubernetes project was
|
||||
started by Google in 2014, combining the experience of running production
|
||||
started by Google in 2014, combining the experience of running production
|
||||
workloads combined with best practices from the community.
|
||||
|
||||
The Kubernetes project defines some new terms that may be unfamiliar to users
|
||||
or operators. For more information please refer to the concept guide in the
|
||||
or operators. For more information please refer to the concept guide in the
|
||||
[getting started guide](https://kubernetes.io/docs/home/).
|
||||
|
||||
This charm is an encapsulation of the Kubernetes master processes and the
|
||||
This charm is an encapsulation of the Kubernetes master processes and the
|
||||
operations to run on any cloud for the entire lifecycle of the cluster.
|
||||
|
||||
This charm is built from other charm layers using the Juju reactive framework.
|
||||
The other layers focus on specific subset of operations making this layer
|
||||
The other layers focus on specific subset of operations making this layer
|
||||
specific to operations of Kubernetes master processes.
|
||||
|
||||
# Deployment
|
||||
@ -23,15 +23,15 @@ charms to model a complete Kubernetes cluster. A Kubernetes cluster needs a
|
||||
distributed key value store such as [Etcd](https://coreos.com/etcd/) and the
|
||||
kubernetes-worker charm which delivers the Kubernetes node services. A cluster
|
||||
requires a Software Defined Network (SDN) and Transport Layer Security (TLS) so
|
||||
the components in a cluster communicate securely.
|
||||
the components in a cluster communicate securely.
|
||||
|
||||
Please take a look at the [Canonical Distribution of Kubernetes](https://jujucharms.com/canonical-kubernetes/)
|
||||
or the [Kubernetes core](https://jujucharms.com/kubernetes-core/) bundles for
|
||||
Please take a look at the [Canonical Distribution of Kubernetes](https://jujucharms.com/canonical-kubernetes/)
|
||||
or the [Kubernetes core](https://jujucharms.com/kubernetes-core/) bundles for
|
||||
examples of complete models of Kubernetes clusters.
|
||||
|
||||
# Resources
|
||||
|
||||
The kubernetes-master charm takes advantage of the [Juju Resources](https://jujucharms.com/docs/2.0/developer-resources)
|
||||
The kubernetes-master charm takes advantage of the [Juju Resources](https://jujucharms.com/docs/2.0/developer-resources)
|
||||
feature to deliver the Kubernetes software.
|
||||
|
||||
In deployments on public clouds the Charm Store provides the resource to the
|
||||
@ -40,9 +40,41 @@ firewall rules may not be able to contact the Charm Store. In these network
|
||||
restricted environments the resource can be uploaded to the model by the Juju
|
||||
operator.
|
||||
|
||||
#### Snap Refresh
|
||||
|
||||
The kubernetes resources used by this charm are snap packages. When not
|
||||
specified during deployment, these resources come from the public store. By
|
||||
default, the `snapd` daemon will refresh all snaps installed from the store
|
||||
four (4) times per day. A charm configuration option is provided for operators
|
||||
to control this refresh frequency.
|
||||
|
||||
>NOTE: this is a global configuration option and will affect the refresh
|
||||
time for all snaps installed on a system.
|
||||
|
||||
Examples:
|
||||
|
||||
```sh
|
||||
## refresh kubernetes-master snaps every tuesday
|
||||
juju config kubernetes-master snapd_refresh="tue"
|
||||
|
||||
## refresh snaps at 11pm on the last (5th) friday of the month
|
||||
juju config kubernetes-master snapd_refresh="fri5,23:00"
|
||||
|
||||
## delay the refresh as long as possible
|
||||
juju config kubernetes-master snapd_refresh="max"
|
||||
|
||||
## use the system default refresh timer
|
||||
juju config kubernetes-master snapd_refresh=""
|
||||
```
|
||||
|
||||
For more information on the possible values for `snapd_refresh`, see the
|
||||
*refresh.timer* section in the [system options][] documentation.
|
||||
|
||||
[system options]: https://forum.snapcraft.io/t/system-options/87
|
||||
|
||||
# Configuration
|
||||
|
||||
This charm supports some configuration options to set up a Kubernetes cluster
|
||||
This charm supports some configuration options to set up a Kubernetes cluster
|
||||
that works in your environment:
|
||||
|
||||
#### dns_domain
|
||||
@ -61,14 +93,14 @@ Enable RBAC and Node authorisation.
|
||||
# DNS for the cluster
|
||||
|
||||
The DNS add-on allows the pods to have a DNS names in addition to IP addresses.
|
||||
The Kubernetes cluster DNS server (based off the SkyDNS library) supports
|
||||
forward lookups (A records), service lookups (SRV records) and reverse IP
|
||||
The Kubernetes cluster DNS server (based off the SkyDNS library) supports
|
||||
forward lookups (A records), service lookups (SRV records) and reverse IP
|
||||
address lookups (PTR records). More information about the DNS can be obtained
|
||||
from the [Kubernetes DNS admin guide](http://kubernetes.io/docs/admin/dns/).
|
||||
|
||||
# Actions
|
||||
|
||||
The kubernetes-master charm models a few one time operations called
|
||||
The kubernetes-master charm models a few one time operations called
|
||||
[Juju actions](https://jujucharms.com/docs/stable/actions) that can be run by
|
||||
Juju users.
|
||||
|
||||
@ -80,7 +112,7 @@ requires a relation to the ceph-mon charm before it can create the volume.
|
||||
|
||||
#### restart
|
||||
|
||||
This action restarts the master processes `kube-apiserver`,
|
||||
This action restarts the master processes `kube-apiserver`,
|
||||
`kube-controller-manager`, and `kube-scheduler` when the user needs a restart.
|
||||
|
||||
# More information
|
||||
@ -93,7 +125,7 @@ This action restarts the master processes `kube-apiserver`,
|
||||
# Contact
|
||||
|
||||
The kubernetes-master charm is free and open source operations created
|
||||
by the containers team at Canonical.
|
||||
by the containers team at Canonical.
|
||||
|
||||
Canonical also offers enterprise support and customization services. Please
|
||||
refer to the [Kubernetes product page](https://www.ubuntu.com/cloud/kubernetes)
|
||||
|
||||
@ -147,6 +147,15 @@ options:
|
||||
default: true
|
||||
description: |
|
||||
If true the metrics server for Kubernetes will be deployed onto the cluster.
|
||||
snapd_refresh:
|
||||
default: "max"
|
||||
type: string
|
||||
description: |
|
||||
How often snapd handles updates for installed snaps. Setting an empty
|
||||
string will check 4x per day. Set to "max" to delay the refresh as long
|
||||
as possible. You may also set a custom string as described in the
|
||||
'refresh.timer' section here:
|
||||
https://forum.snapcraft.io/t/system-options/87
|
||||
default-storage:
|
||||
type: string
|
||||
default: "auto"
|
||||
|
||||
@ -427,6 +427,38 @@ def set_app_version():
|
||||
hookenv.application_version_set(version.split(b' v')[-1].rstrip())
|
||||
|
||||
|
||||
@when('kubernetes-master.snaps.installed')
|
||||
@when('snap.refresh.set')
|
||||
@when('leadership.is_leader')
|
||||
def process_snapd_timer():
|
||||
''' Set the snapd refresh timer on the leader so all cluster members
|
||||
(present and future) will refresh near the same time. '''
|
||||
# Get the current snapd refresh timer; we know layer-snap has set this
|
||||
# when the 'snap.refresh.set' flag is present.
|
||||
timer = snap.get(snapname='core', key='refresh.timer').decode('utf-8')
|
||||
|
||||
# The first time through, data_changed will be true. Subsequent calls
|
||||
# should only update leader data if something changed.
|
||||
if data_changed('master_snapd_refresh', timer):
|
||||
hookenv.log('setting snapd_refresh timer to: {}'.format(timer))
|
||||
leader_set({'snapd_refresh': timer})
|
||||
|
||||
|
||||
@when('kubernetes-master.snaps.installed')
|
||||
@when('snap.refresh.set')
|
||||
@when('leadership.changed.snapd_refresh')
|
||||
@when_not('leadership.is_leader')
|
||||
def set_snapd_timer():
|
||||
''' Set the snapd refresh.timer on non-leader cluster members. '''
|
||||
# NB: This method should only be run when 'snap.refresh.set' is present.
|
||||
# Layer-snap will always set a core refresh.timer, which may not be the
|
||||
# same as our leader. Gating with 'snap.refresh.set' ensures layer-snap
|
||||
# has finished and we are free to set our config to the leader's timer.
|
||||
timer = leader_get('snapd_refresh')
|
||||
hookenv.log('setting snapd_refresh timer to: {}'.format(timer))
|
||||
snap.set_refresh_timer(timer)
|
||||
|
||||
|
||||
@hookenv.atexit
|
||||
def set_final_status():
|
||||
''' Set the final status of the charm as we leave hook execution '''
|
||||
|
||||
@ -27,6 +27,38 @@ To add additional compute capacity to your Kubernetes workers, you may
|
||||
join any related kubernetes-master, and enlist themselves as ready once the
|
||||
deployment is complete.
|
||||
|
||||
## Snap Configuration
|
||||
|
||||
The kubernetes resources used by this charm are snap packages. When not
|
||||
specified during deployment, these resources come from the public store. By
|
||||
default, the `snapd` daemon will refresh all snaps installed from the store
|
||||
four (4) times per day. A charm configuration option is provided for operators
|
||||
to control this refresh frequency.
|
||||
|
||||
>NOTE: this is a global configuration option and will affect the refresh
|
||||
time for all snaps installed on a system.
|
||||
|
||||
Examples:
|
||||
|
||||
```sh
|
||||
## refresh kubernetes-worker snaps every tuesday
|
||||
juju config kubernetes-worker snapd_refresh="tue"
|
||||
|
||||
## refresh snaps at 11pm on the last (5th) friday of the month
|
||||
juju config kubernetes-worker snapd_refresh="fri5,23:00"
|
||||
|
||||
## delay the refresh as long as possible
|
||||
juju config kubernetes-worker snapd_refresh="max"
|
||||
|
||||
## use the system default refresh timer
|
||||
juju config kubernetes-worker snapd_refresh=""
|
||||
```
|
||||
|
||||
For more information on the possible values for `snapd_refresh`, see the
|
||||
*refresh.timer* section in the [system options][] documentation.
|
||||
|
||||
[system options]: https://forum.snapcraft.io/t/system-options/87
|
||||
|
||||
## Operational actions
|
||||
|
||||
The kubernetes-worker charm supports the following Operational Actions:
|
||||
@ -89,7 +121,7 @@ service is not reachable.
|
||||
Note: When debugging connection issues with NodePort services, its important
|
||||
to first check the kube-proxy service on the worker units. If kube-proxy is not
|
||||
running, the associated port-mapping will not be configured in the iptables
|
||||
rulechains.
|
||||
rulechains.
|
||||
|
||||
If you need to close the NodePort once a workload has been terminated, you can
|
||||
follow the same steps inversely.
|
||||
@ -97,4 +129,3 @@ follow the same steps inversely.
|
||||
```
|
||||
juju run --application kubernetes-worker close-port 30510
|
||||
```
|
||||
|
||||
|
||||
@ -80,3 +80,12 @@ options:
|
||||
description: |
|
||||
Docker image to use for the default backend. Auto will select an image
|
||||
based on architecture.
|
||||
snapd_refresh:
|
||||
default: "max"
|
||||
type: string
|
||||
description: |
|
||||
How often snapd handles updates for installed snaps. Setting an empty
|
||||
string will check 4x per day. Set to "max" to delay the refresh as long
|
||||
as possible. You may also set a custom string as described in the
|
||||
'refresh.timer' section here:
|
||||
https://forum.snapcraft.io/t/system-options/87
|
||||
|
||||
@ -22,6 +22,8 @@ import shutil
|
||||
import subprocess
|
||||
import time
|
||||
|
||||
from charms.leadership import leader_get, leader_set
|
||||
|
||||
from pathlib import Path
|
||||
from shlex import split
|
||||
from subprocess import check_call, check_output
|
||||
@ -289,6 +291,38 @@ def set_app_version():
|
||||
hookenv.application_version_set(version.split(b' v')[-1].rstrip())
|
||||
|
||||
|
||||
@when('kubernetes-worker.snaps.installed')
|
||||
@when('snap.refresh.set')
|
||||
@when('leadership.is_leader')
|
||||
def process_snapd_timer():
|
||||
''' Set the snapd refresh timer on the leader so all cluster members
|
||||
(present and future) will refresh near the same time. '''
|
||||
# Get the current snapd refresh timer; we know layer-snap has set this
|
||||
# when the 'snap.refresh.set' flag is present.
|
||||
timer = snap.get(snapname='core', key='refresh.timer').decode('utf-8')
|
||||
|
||||
# The first time through, data_changed will be true. Subsequent calls
|
||||
# should only update leader data if something changed.
|
||||
if data_changed('worker_snapd_refresh', timer):
|
||||
hookenv.log('setting snapd_refresh timer to: {}'.format(timer))
|
||||
leader_set({'snapd_refresh': timer})
|
||||
|
||||
|
||||
@when('kubernetes-worker.snaps.installed')
|
||||
@when('snap.refresh.set')
|
||||
@when('leadership.changed.snapd_refresh')
|
||||
@when_not('leadership.is_leader')
|
||||
def set_snapd_timer():
|
||||
''' Set the snapd refresh.timer on non-leader cluster members. '''
|
||||
# NB: This method should only be run when 'snap.refresh.set' is present.
|
||||
# Layer-snap will always set a core refresh.timer, which may not be the
|
||||
# same as our leader. Gating with 'snap.refresh.set' ensures layer-snap
|
||||
# has finished and we are free to set our config to the leader's timer.
|
||||
timer = leader_get('snapd_refresh')
|
||||
hookenv.log('setting snapd_refresh timer to: {}'.format(timer))
|
||||
snap.set_refresh_timer(timer)
|
||||
|
||||
|
||||
@when('kubernetes-worker.snaps.installed')
|
||||
@when_not('kube-control.dns.available')
|
||||
def notify_user_transient_status():
|
||||
|
||||
Loading…
Reference in New Issue
Block a user