[tracking] Support Jupyter-free images (2.0)

[sgaist]

This ticket tracks the Amalthea specific work to be done to implement the support of user session without Jupyter.

Tasks

• [x] https://github.com/SwissDataScienceCenter/amalthea/pull/585
• [x] #598
• [x] #608
• [x] #602
• [x] #603
• [x] #606
• [x] #616
• [x] #607
• [x] Session mutation (I think this is pretty much done)
• [x] #619
• [x] #617
• [ ] #630 ----------------------------------------------- REQUIRED FOR USE IN RENKU V2 ^^^
• [ ] Helm chart resource requirements and stress testing of the new operator
• [x] Support ephemeral storage (already possible with extra volumes and extra mounts options).
• [x] #632
• [ ] Add status conditions
• [ ] #612
• [ ] #614
• [ ] #637
• [ ] #638
• [ ] #622
• [ ] #635
• [ ] export prometheus metrics

Part of: https://github.com/SwissDataScienceCenter/renku/issues/3679

[olevski]

Btw I created an issue for Storage object handling above by mistake. I am not working on this rn.

[olevski]

For adjusting /dev/shm this is how we patch it in the old sessions:

            {
                "type": "application/json-patch+json",
                "patch": [
                    {
                        "op": "add",
                        "path": "/statefulset/spec/template/spec/volumes/-",
                        "value": {
                            "name": "shm",
                            "emptyDir": {
                                "medium": "Memory",
                                # NOTE: We are giving /dev/shm up to half of the memory request
                                "sizeLimit": int(server.server_options.storage / 2),
                            },
                        },
                    },
                    {
                        "op": "add",
                        "path": "/statefulset/spec/template/spec/containers/1/volumeMounts/-",
                        "value": {
                            "mountPath": "/dev/shm",
                            "name": "shm",
                        },
                    },
                ],
            }

So it is a memory backed volume mounted at /dev/shm. And its size is half the memory request for the session. Here we can make it part of the CRD with a default value of 1Gi or something like that.

[sgaist]

@olevski works for me but shouldn't it be 500Mi ? The default storage size is currently 1Gi

[sgaist]

@olevski On the subject of ephemeral storage, what was it about ?

Any "non-conventional" storage can already be added to the CRD using the ExtraVolumes and ExtraVolumeMounts fields

[olevski]

@olevski On the subject of ephemeral storage, what was it about ?

Any "non-conventional" storage can already be added to the CRD using the ExtraVolumes and ExtraVolumeMounts fields

@sgaist yes you are right, I did not think of this. We did not have the extra volumes and mounts option in the old amalthea. So there we had to add this. But you are correct that someone can very easily use these two options on the CRD and in combination with the working directory have everything working. So I will just completely remove this from the list.