Container logs doesn't follow properly for multi-line logs

[eva-vashkevich]

Setup

• Rancher version: 2.10
• Rancher UI Extensions: N/A
• Browser type & version: Chrome

Describe the bug

Logs container stops following logs for multi-line logs

To Reproduce

1. Create a new deployment with the following yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    workload.user.cattle.io/workloadselector: apps.deployment-default-test-logs
  name: test-logs
  namespace: default
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      workload.user.cattle.io/workloadselector: apps.deployment-default-test-logs
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        workload.user.cattle.io/workloadselector: apps.deployment-default-test-logs
    spec:
      affinity: {}
      containers:
      - args:
        - 'i=0; while true; do echo "$i: $(date) Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"; i=$((i+1)); sleep .001; done'
        command:
        - /bin/sh
        - -c
        image: busybox
        imagePullPolicy: Always
        name: fast
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      - args:
        - 'i=0; while true; do echo "$i: $(date) Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"; i=$((i+1)); sleep 1; done'
        command:
        - /bin/sh
        - -c
        image: busybox
        imagePullPolicy: Always
        name: slower
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      - args:
        - 'i=0; while true; do echo "$i: $(date) Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"; i=$((i+1)); sleep 10; done'
        command:
        - /bin/sh
        - -c
        image: busybox
        imagePullPolicy: Always
        name: sloooow
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30

2. Go to pods -> test-logs
3. Let it run for a few minutes

Result
"Follow" button becomes available again and logs are no longer at the bottom of the page

Expected Result

"Follow" button should remain disabled and logs should show last available log record

Screenshots

Screen.Recording.2024-08-29.at.2.09.34.PM.mov

Additional context