Update openfaas chart to support JetStream

[welteki]

Description

Update the openfaas chart to support JetStream.

Motivation and Context

Part of the migration to JetStream for the OpenFaaS async system.

How Has This Been Tested?

1. Deploy OpenFaaS with the updated chart

git clone https://github.com/welteki/faas-netes \
  --depth=1 \
  --branch jetstream
  
cd faas-netes

kubectl apply -f namespaces.yml

kubectl create secret generic \
    -n openfaas \
    openfaas-license \
    --from-file license=$HOME/.openfaas/LICENSE
    
helm upgrade openfaas --install chart/openfaas \
  --namespace openfaas \
  --set functionNamespace=openfaas-fn  \
  --set generateBasicAuth=true  \
  --set openfaasPro=true \
  --set nats.queueMode=jetstream

2. Verify NATS JetStream is running and that the queue-worker created the default stream.

kubectl port-forward -n openfaas svc/nats 4222:4222
nats stream info faas-request

Information for Stream faas-request created 2022-07-22T19:52:35+02:00

Configuration:

             Subjects: faas-request
     Acknowledgements: true
            Retention: File - Limits
             Replicas: 1
       Discard Policy: Old
     Duplicate Window: 2m0s
    Allows Msg Delete: true
         Allows Purge: true
       Allows Rollups: false
     Maximum Messages: unlimited
        Maximum Bytes: unlimited
          Maximum Age: unlimited
 Maximum Message Size: unlimited
    Maximum Consumers: unlimited


State:

             Messages: 200
                Bytes: 108 KiB
             FirstSeq: 1 @ 2022-07-22T17:52:43 UTC
              LastSeq: 200 @ 2022-07-22T17:52:43 UTC
     Active Consumers: 1

3. Deployed some functions and successfully invoked them asynchronously.

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I've read the CONTRIBUTION guide
• [x] I have signed-off my commits with git commit -s
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.

[derek[bot]]

Thank you for your contribution. unfortunately, one or more of your commits are missing the required "Signed-off-by:" statement. Signing off is part of the Developer Certificate of Origin (DCO) which is used by this project.

Read the DCO and project contributing guide carefully, and amend your commits using the git CLI. Note that this does not require any cryptography, keys or special steps to be taken.

:bulb: Shall we fix this?

This will only take a few moments.

First, clone your fork and checkout this branch using the git CLI.

Next, set up your real name and email address:

git config --global user.name "Your Full Name" git config --global user.email "[email protected]"

Finally, run one of these commands to add the "Signed-off-by" line to your commits.

If you only have one commit so far then run: git commit --amend --signoff and then git push --force. If you have multiple commits, watch this video.

Check that the message has been added properly by running "git log".

[alexellis]

Impact to existing users:

If you are running OF CE and upgrade, the template will just use the stan field.

If you are running OF Pro and upgrade, the template will just use the stan field.

If you are running OF Pro and enable JetStream, it will use the nats field

If you're running OF with a pinned value in .Values.nats, then upgrade, it will deploy the wrong version. Assuming you're not using an external NATS server