Skip to content

Update multicluster-using-statefulsets #1945

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kflynn merged 4 commits into from
Apr 22, 2025
Merged

Update multicluster-using-statefulsets #1945

Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
fcffb4b
Update multicluster-using-statefulsets
alpeb Mar 28, 2025
03f3030
Merge branch 'main' into alpeb/mc-statefulsets-2.18
kflynn Apr 11, 2025
a10e0f7
Update linkerd.io/content/2-edge/tasks/multicluster-using-statefulset…
alpeb Apr 11, 2025
20b755b
Merge branch 'main' into alpeb/mc-statefulsets-2.18
kflynn Apr 22, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
19 changes: 9 additions & 10 deletions linkerd.io/content/2-edge/tasks/multicluster-using-statefulsets.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,7 @@ on how multi-cluster support for headless services work, check out
- [`smallstep/CLI`](https://github.com/smallstep/cli/releases) to generate
certificates for Linkerd installation.
- [`A recent linkerd release`](https://github.com/linkerd/linkerd2/releases)
(2.11 or older).
(2.18 or newer).

To help with cluster creation and installation, there is a demo repository
available. Throughout the guide, we will be using the scripts from the
Expand All @@ -48,7 +48,7 @@ repository on your local machine.

```sh
# clone example repository
$ git clone git@github.com:mateiidavid/l2d-k3d-statefulset.git
$ git clone git@github.com:linkerd/l2d-k3d-statefulset.git
$ cd l2d-k3d-statefulset
```

Expand All @@ -71,10 +71,9 @@ west 1/1 0/0 true

Once our clusters are created, we will install Linkerd and the multi-cluster
extension. Finally, once both are installed, we need to link the two clusters
together so their services may be mirrored. To enable support for headless
services, we will pass an additional `--set "enableHeadlessServices=true` flag
Copy link
Member

@wmorgan wmorgan Apr 5, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

For my understanding, is this flag no longer required?

Copy link
Member Author

@alpeb alpeb Apr 7, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

That setting is a controller setting, so it has been moved to the controllers section in the multicluster extension values.yaml:

E.g. for east, https://github.com/linkerd/l2d-k3d-statefulset/blob/main/east/mc-values.yml :

controllers:
- link:
    ref:
      name: k3d-west
  logLevel: debug
  enableHeadlessServices: true

to `linkerd multicluster link`. As before, these steps are automated through
the provided scripts, but feel free to have a look!
together so their services may be mirrored. As before, these steps are automated
through the provided scripts; please give them a look and see how the
controllers and links are generated for both clusters.

```sh
# Install Linkerd and multicluster, output to check should be a success
Expand Down Expand Up @@ -178,7 +177,7 @@ nginx-set-1 2/2 Running 0 4m58s
nginx-set-2 2/2 Running 0 4m51s
curl-56dc7d945d-s4n8j 0/2 PodInitializing 0 4s

$ kubectl --context=k3d-west exec -it curl-56dc7d945d-s4n8j -c curl -- bin/sh
$ kubectl --context=k3d-west exec -it curl-56dc7d945d-s4n8j -c curl -- sh
/$ # prompt for curl pod
```

Expand Down Expand Up @@ -235,7 +234,7 @@ endpoints for `nginx-svc-west` will have the same hostnames, but each hostname
will point to one of the services we see above:

```sh
$ kubectl --context=k3d-east get endpoints nginx-svc-west -o yaml
$ kubectl --context=k3d-east get endpoints nginx-svc-k3d-west -o yaml
subsets:
- addresses:
- hostname: nginx-set-0
Expand All @@ -256,12 +255,12 @@ NAME READY STATUS RESTARTS AGE
curl-56dc7d945d-96r6p 2/2 Running 0 23m

# exec and curl
$ kubectl --context=k3d-east exec pod curl-56dc7d945d-96r6p -it -c curl -- bin/sh
$ kubectl --context=k3d-east exec curl-56dc7d945d-96r6p -it -c curl -- sh
# we want to curl the same hostname we see in the endpoints object above.
# however, the service and cluster domain will now be different, since we
# are in a different cluster.
#
/ $ curl nginx-set-0.nginx-svc-west.default.svc.east.cluster.local
/ $ curl nginx-set-0.nginx-svc-k3d-west.default.svc.east.cluster.local
<!DOCTYPE html>
<html>
<head>
Expand Down