Snap channel overview
Microk8s is a snap deploying Kubernetes. The MicroK8s snap closely follows upstream Kubernetes, so understanding a bit about the Kubernetes release cycle is helpful for more insight into MicroK8s releases.
Upstream Kubernetes ships a new release series (e.g. 1.17.x) approximately every three months. Prior release series may get periodic bugfix releases: for example, the latest 1.15 release is 1.15.5.
It is important to remember that upstream Kubernetes is committed to maintain
backwards compatibility only within a release series. That means that your
Kubernetes should not break when you upgrade from
there is no such guarantee when upgrading from
Choosing the right channel
When installing MicroK8s you can select your desired upstream Kubernetes series by choosing the corresponding snap channel.
All the currently available channels are shown if you run
snap info microk8s:
channels: stable: v1.17.2 2020-01-26 (1173) 179MB classic candidate: v1.17.2 2020-01-25 (1173) 179MB classic beta: v1.17.2 2020-01-25 (1173) 179MB classic edge: v1.17.2 2020-01-24 (1173) 179MB classic dqlite/stable: – dqlite/candidate: – dqlite/beta: – dqlite/edge: v1.16.2 2019-11-07 (1038) 189MB classic 1.18/stable: – 1.18/candidate: – 1.18/beta: – 1.18/edge: v1.18.0-alpha.2 2020-01-22 (1172) 179MB classic 1.17/stable: v1.17.0 2019-12-10 (1109) 179MB classic 1.17/candidate: v1.17.2 2020-01-26 (1176) 179MB classic 1.17/beta: v1.17.2 2020-01-26 (1176) 179MB classic 1.17/edge: v1.17.2 2020-01-25 (1176) 179MB classic 1.16/stable: v1.16.4 2020-01-13 (1117) 188MB classic 1.16/candidate: v1.16.6 2020-01-24 (1163) 179MB classic 1.16/beta: v1.16.6 2020-01-24 (1163) 179MB classic 1.16/edge: v1.16.6 2020-01-25 (1175) 179MB classic 1.15/stable: v1.15.7 2020-01-06 (1114) 171MB classic 1.15/candidate: v1.15.9 2020-01-23 (1165) 171MB classic 1.15/beta: v1.15.9 2020-01-23 (1165) 171MB classic 1.15/edge: v1.15.9 2020-01-25 (1178) 171MB classic 1.14/stable: v1.14.10 2020-01-06 (1120) 217MB classic 1.14/candidate: v1.14.10 2019-12-14 (1120) 217MB classic 1.14/beta: v1.14.10 2019-12-14 (1120) 217MB classic 1.14/edge: v1.14.10 2020-01-26 (1181) 217MB classic 1.13/stable: v1.13.6 2019-06-06 (581) 237MB classic 1.13/candidate: v1.13.6 2019-05-09 (581) 237MB classic 1.13/beta: v1.13.6 2019-05-09 (581) 237MB classic 1.13/edge: v1.13.7 2019-06-06 (625) 244MB classic 1.12/stable: v1.12.9 2019-06-06 (612) 259MB classic 1.12/candidate: v1.12.9 2019-06-04 (612) 259MB classic 1.12/beta: v1.12.9 2019-06-04 (612) 259MB classic 1.12/edge: v1.12.9 2019-05-28 (612) 259MB classic 1.11/stable: v1.11.10 2019-05-10 (557) 258MB classic 1.11/candidate: v1.11.10 2019-05-02 (557) 258MB classic 1.11/beta: v1.11.10 2019-05-02 (557) 258MB classic 1.11/edge: v1.11.10 2019-05-01 (557) 258MB classic 1.10/stable: v1.10.13 2019-04-22 (546) 222MB classic 1.10/candidate: v1.10.13 2019-04-22 (546) 222MB classic 1.10/beta: v1.10.13 2019-04-22 (546) 222MB classic 1.10/edge: v1.10.13 2019-04-22 (546) 222MB classic installed: v1.17.2 (1173) 179MB classic
To install the latest stable version, simply run:
snap install microk8s --classic
In this case you will get periodic snap updates to the latest stable release. Bear in mind that this could include a new Kubernetes series, and therefore is not guaranteed to continue running. For anything more than an ephemeral Kubernetes install, you are strongly advised to select a series.
For example, to install MicroK8s and let it follow the
v1.17 stable release
series you can run:
snap install microk8s --classic --channel=1.17/stable
In this case you will only receive updates for the 1.17 release of Kubernetes, and MicroK8s will never upgrade to 1.18, unless you explicitly refresh the snap
Stable, candidate, beta and edge releases
*/stable channels serve the latest stable upstream Kubernetes release of
the respective release series. Upstream releases are propagated to the MicroK8s
snap in about a week. This means your MicroK8s will upgrade to the latest
upstream release in your selected channel roughly one week after the upstream
*/beta channels get updated within hours of an upstream
release. Getting a MicroK8s deployment pointing to
1.17/beta is as simple as:
snap install microk8s --classic --channel=1.17/beta
*/edge channels get updated on each MicroK8s patch or upstream
Kubernetes patch release.
Keep in mind that edge and beta are snap constructs and do not relate to specific Kubernetes release names.
Tracks with pre-stable releases
On tracks where no stable Kubernetes release is available, MicroK8s ships pre-release versions under the following scheme:
1.17/edge) holds the alpha upstream releases.
1.17/beta) holds the beta upstream releases.
1.17/candidate) holds the release candidate of upstream releases.
Pre-release versions will be available the same day they are released upstream.
For example, to test your work against the alpha
v1.18 release simply run:
sudo snap install microk8s --classic --channel=1.18/edge
However, be aware that pre-release versions may require you to configure the Kubernetes services on your own.
I am confused. Which channel is right for me?
The single question you need to focus on is what channel should be used below:
sudo snap install microk8s --classic --channel=<which_channel?>
Here are some suggestions for the channel to use based on your needs:
I want to always be on the latest stable Kubernetes.
I want to always be on the latest release in a specific upstream K8s release.
I want to test-drive a pre-stable release.
--channel=<next_release>/edgefor alpha releases.
--channel=<next_release>/betafor beta releases.
--channel=<next_release>/candidatefor candidate releases.
I am waiting for a bug fix on MicroK8s:
I am waiting for a bug fix on upstream Kubernetes:
It is possible to change the snap channel using the refresh command. E.g. to transition from 1.17 stable to the latest alpha:
sudo snap refresh microk8s --channel=1.17/edge
Caution: Changing the channel to a different series will almost certainly cause problems, as the configuration from the current version will be retained. If at all possible, it is recommended to re-install MicroK8s rather than refresh to a different channel, as it is not guaranteed to work.
Changing the refresh schedule
By default, snaps are set to check for updates and automatically refresh to the latest version (for your selected channel) four times per day. There are some scenarios however where it may be inconvenient or difficult to refresh the current snap so often.
There are some controls available to set the global refresh schedule for all snaps on the system. These are outlined in the Snap documentation.