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Load balancer config

 published on

Default haproxy config

  • Inter 1s (The “inter” parameter sets the interval between two consecutive health checks to milliseconds.)

  • Fall 2 (The “fall” parameter states that a server will be considered as dead after consecutive unsuccessful health checks.)

  • Rise 3 (The “rise” parameter states that a server will be considered as operational after consecutive successful health checks.)

  • HttpCheck GET /readyz HTTP/1.0

global
  stats socket /var/lib/haproxy/run/haproxy.sock  mode 600 level admin expose-fd listeners
defaults
  maxconn 20000
  mode    tcp
  log     /var/run/haproxy/haproxy-log.sock local0
  option  dontlognull
  retries 3
  timeout http-request 30s
  timeout queue        1m
  timeout connect      10s
  timeout client       86400s
  timeout server       86400s
  timeout tunnel       86400s
frontend  main
  bind :::9445 v4v6
  default_backend masters
listen health_check_http_url
  bind :::9444 v4v6
  mode http
  monitor-uri /haproxy_ready
  option dontlognull
listen stats
  bind localhost:29445
  mode http
  stats enable
  stats hide-version
  stats uri /haproxy_stats
  stats refresh 30s
  stats auth Username:Password
backend masters
   option  httpchk GET /readyz HTTP/1.0
   option  log-health-checks
   balance roundrobin
   server master-0 10.10.0.209:6443 weight 1 verify none check check-ssl inter 1s fall 2 rise 3
   server master-2 10.10.0.228:6443 weight 1 verify none check check-ssl inter 1s fall 2 rise 3
   server master-1 10.10.0.250:6443 weight 1 verify none check check-ssl inter 1s fall 2 rise 3
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NFS defaults

 published on  included in Openshift

Default versions

Kernel versions 4.18 and above default to nfs 4.2. The client will try in order 4.2 then 4.1 then 4.0.
https://access.redhat.com/articles/6907891
https://access.redhat.com/articles/3626571

Default mount options

rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,local_lock=none,addr=<nfs_server>

Customize mount options

https://access.redhat.com/solutions/6065961

apiVersion: v1
kind: PersistentVolume
spec:
[...]
  mountOptions:
    - nfsvers=4.1
[...]

You can make a RPC call to the NFS server to get supported versions :

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 Openshift

Pod Security Admission

 published on  included in Openshift

Pod Security Policies are deprecated in K8S 1.21

https://kubernetes.io/docs/concepts/security/pod-security-standards/

https://cloud.redhat.com/blog/pod-security-admission-in-openshift-4.11

New labels added in each namespace

pod-security.kubernetes.io/enforce=privileged
pod-security.kubernetes.io/audit=restricted
pod-security.kubernetes.io/warn=restricted

security.openshift.io/scc.podSecurityLabelSync=true #Default

Specs needed for restricted profile

securityContext:
  runAsNonRoot: true
  seccompProfile:
    type: RuntimeDefault
containers:
- name: my-cronjob-container
  securityContext:
    allowPrivilegeEscalation: false
    capabilities:
      drop: ['ALL']

Dry run apply enforce

$ oc label --dry-run=server --overwrite ns --all pod-security.kubernetes.io/enforce=restricted

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