Kubernetes: Difference between revisions

From Skytech
Jump to navigation Jump to search
← Older edit
No edit summary
No edit summary
 
(3 intermediate revisions by the same user not shown)
Line 4: Line 4:
* http://alesnosek.com/blog/2017/02/14/accessing-kubernetes-pods-from-outside-of-the-cluster/
* http://alesnosek.com/blog/2017/02/14/accessing-kubernetes-pods-from-outside-of-the-cluster/


= Petsets =
= Disable some RBD features (or k8s will fail to launch pod) =
* fast-diff
* object-map
* deep-flatten
 
must all be disabled
<pre>
<pre>
Skip to content
rbd feature disable ssd/elasticsearch-data-01 fast-diff object-map deep-flatten
Personal Open source Business Explore
</pre>
Sign upSign inPricingBlogSupport
 
This repository
= RBD inside kubernetes =
Search
* https://github.com/kubernetes/examples/tree/master/staging/volumes/rbd
Watch 1,512  Star 18,562  Fork 6,134 kubernetes/kubernetes
 
Code  Issues 4,613  Pull requests 678  Projects 7  Wiki  Pulse  Graphs
Spent some time toying around with it but couldn't get it to work - it is a must to add the secret as described here: https://github.com/kubernetes/examples/tree/master/staging/volumes/rbd#use-ceph-authentication-secret and also add that part to the manifest:
Branch: master Find file Copy pathkubernetes/test/e2e/testing-manifests/petset/redis/petset.yaml
<pre>
f2bab13  4 days ago
...
@janetkuo janetkuo Remove 0 terminationGracePeriodSeconds from statefulset manifests
            user: admin
2 contributors @janetkuo @bprashanth
            keyring: /etc/ceph/ceph.client.admin.keyring
RawBlameHistory   
            secretRef:
98 lines (97 sloc)  2.66 KB
              name: ceph-secret
apiVersion: apps/v1beta1
...
kind: StatefulSet
</pre>
Link to example rbd manifest: https://github.com/kubernetes/examples/blob/master/staging/volumes/rbd/rbd.yaml
 
 
= Kube-dns - stub local DNS-servers with ip and zones =
<pre>
apiVersion: v1
kind: ConfigMap
metadata:
metadata:
  name: rd
    name: kube-dns
spec:
    namespace: kube-system
  serviceName: "redis"
data:
  replicas: 3
     stubDomains: |
  template:
         {"hq.skytech.dk": ["192.168.0.24", "10.0.0.24"]}
     metadata:
 
      labels:
         app: redis
      annotations:
        pod.alpha.kubernetes.io/initialized: "true"
        pod.alpha.kubernetes.io/init-containers: '[
            {
                "name": "install",
                "image": "gcr.io/google_containers/redis-install-3.2.0:e2e",
                "imagePullPolicy": "Always",
                "args": ["--install-into=/opt", "--work-dir=/work-dir"],
                "volumeMounts": [
                    {
                        "name": "opt",
                        "mountPath": "/opt"
                    },
                    {
                        "name": "workdir",
                        "mountPath": "/work-dir"
                    }
                ]
            },
            {
                "name": "bootstrap",
                "image": "debian:jessie",
                "command": ["/work-dir/peer-finder"],
                "args": ["-on-start=\"/work-dir/on-start.sh\"", "-service=redis"],
                "env": [
                  {
                      "name": "POD_NAMESPACE",
                      "valueFrom": {
                          "fieldRef": {
                              "apiVersion": "v1",
                              "fieldPath": "metadata.namespace"
                          }
                      }
                  }
                ],
                "volumeMounts": [
                    {
                        "name": "opt",
                        "mountPath": "/opt"
                    },
                    {
                        "name": "workdir",
                        "mountPath": "/work-dir"
                    }
                ]
            }
        ]'
    spec:
      containers:
      - name: redis
        image: debian:jessie
        ports:
        - containerPort: 6379
          name: peer
        command:
        - /opt/redis/redis-server
        args:
        - /opt/redis/redis.conf
        readinessProbe:
          exec:
            command:
            - sh
            - -c
            - "/opt/redis/redis-cli -h $(hostname) ping"
          initialDelaySeconds: 15
          timeoutSeconds: 5
        volumeMounts:
        - name: datadir
          mountPath: /data
        - name: opt
          mountPath: /opt
      volumes:
      - name: opt
        emptyDir: {}
      - name: workdir
        emptyDir: {}
  volumeClaimTemplates:
  - metadata:
      name: datadir
      annotations:
        volume.alpha.kubernetes.io/storage-class: anything
    spec:
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 1Gi
</pre>
</pre>

Latest revision as of 09:17, 13 August 2019


How to access Pods externally

Disable some RBD features (or k8s will fail to launch pod)

  • fast-diff
  • object-map
  • deep-flatten

must all be disabled 

rbd feature disable ssd/elasticsearch-data-01 fast-diff object-map deep-flatten

RBD inside kubernetes

Spent some time toying around with it but couldn't get it to work - it is a must to add the secret as described here: https://github.com/kubernetes/examples/tree/master/staging/volumes/rbd#use-ceph-authentication-secret and also add that part to the manifest: 

...
            user: admin
            keyring: /etc/ceph/ceph.client.admin.keyring
            secretRef:
              name: ceph-secret
...

Link to example rbd manifest: https://github.com/kubernetes/examples/blob/master/staging/volumes/rbd/rbd.yaml


Kube-dns - stub local DNS-servers with ip and zones

apiVersion: v1
kind: ConfigMap
metadata:
    name: kube-dns
    namespace: kube-system
data:
    stubDomains: |
        {"hq.skytech.dk": ["192.168.0.24", "10.0.0.24"]}
Retrieved from "https://wiki.skytech.dk/index.php?title=Kubernetes&oldid=2386"