Yep I'm still working on a helm chart. Currently, each service is deployed with the bjw-s app-template helm chart, but I'd like to combine it all into a single chart.

The hardest part was getting ingress-nginx to pass ActivityPub requests to the backend, but we settled on a hack that seems to work well. We had to add the following configuration snippet to the frontend's ingress annotations:

nginx.ingress.kubernetes.io/configuration-snippet: |
  if ($http_accept = "application/activity+json") {
    set $proxy_upstream_name "lemmy-lemmy-8536";
  }
  if ($http_accept = "application/ld+json; profile=\"https://www.w3.org/ns/activitystreams\"") {
    set $proxy_upstream_name "lemmy-lemmy-8536";
  }
  if ($request_method = POST) {
    set $proxy_upstream_name "lemmy-lemmy-8536";
  }

The value of the variable is $NAMESPACE-$SERVICE-$PORT.
I tested this pretty thoroughly and haven't been able to break it so far, but please let me know if anybody has a better solution!