kunalkushwaha

Overview.

• If stateful app(/Assuing Storage NAS) running on one node.

  • In case of network failure with Node, Pod will process the data. But K8s will rechedule the pod to new instance.
  • In such cases data corrucption can happens!.

  In case of failure on Node.

  • Notice that we can’t unmount the volume from the failed node

• Use the Storage api to force detach the volume

kunalkushwaha

Create container:

$ docker run -d --hostname my-rabbit --name some-rabbit -p 15672:15672 -p 5672:5672 rabbitmq:3-management

Here the default settings include user: user pass: user rabbitmq access port : 5672

kunalkushwaha

module github.com/kunalkushwaha/kubevirtmon

go 1.12

require (
	github.com/cjbassi/gotop v0.0.0-20190715230637-2cd92e147e6b
	github.com/gizak/termui/v3 v3.1.0
	github.com/spf13/pflag v1.0.3
	k8s.io/apimachinery v0.0.0-20190719140911-bfcf53abc9f8
	kubevirt.io/client-go v0.24.0

kunalkushwaha

$ make cluster-sync                                                                                                                                                                            
PUSH_LOG_FILE= ./hack/cluster-build.sh                                                                                                                                                         
Building ...                                                                                                                                                                                   
[+] Building 0.2s (9/9) FINISHED                                                                                                                                                               
 => [internal] load .dockerignore                                                                                                                                                         0.0s 
 => => transferring context: 2B                                 

kunalkushwaha

• We need mechnism to have static IP for Service in different network segment.
  • Lot of legacy systems are designed like that
  • Service should be the point of contact for VMs too, not ip of VM. kubevirt/kubevirt#861

kunalkushwaha

Problem: As we discussed yesterday, we'd like to prepare for some specific technical discussion for the next interview. As I explained during our conversation yesterday, it's not unusual for engineers here to need to come up to speed on unfamiliar code bases as an integral part of investigating a customer issue.

With that in mind, as the role you're applying for has a heavy OpenStack component, we will ask you to please prepare to discuss aspects of the neutron openvswitch agent.

We would like you to study and be able to describe the code path in the OVSNeutronAgent.rpc_loop method in neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py.

We will discuss the overall flow of the code path executed. For this exercise, you can assume that the version of the Neutron code is the Rocky release of OpenStack, available through:

kunalkushwaha

package main

import (
	"context"
	"fmt"

	"github.com/moby/buildkit/client"
	"github.com/moby/buildkit/client/llb"
	"github.com/moby/buildkit/util/entitlements"
)

kunalkushwaha

// https://blogs.oracle.com/janp/entry/how_the_scp_protocol_works
package main

import (
	"fmt"

	"golang.org/x/crypto/ssh"
)

const privateKey = `content of id_rsa`

kunalkushwaha

$ virtctl expose virtualmachineinstance vmi-trac --name trac --type NodePort  --target-port 22
Service trac successfully exposed for virtualmachineinstance vmi-trac

$ kubectl get service 
NAME         TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)                     AGE
kubernetes   ClusterIP   10.96.0.1      <none>        443/TCP                     3d2h
trac         NodePort    10.108.30.13   <none>        80:30322/TCP,22:31358/TCP   2s

kunalkushwaha

$ kubectl apply -f postrgess-vmi.yaml                                                                                                                                                          
virtualmachineinstance.kubevirt.io/vmi-trac created                                                                                                                                    
                                                                                                                                                                                               
                                                                                                                                                                  
$ kubectl get vmi                                                                                                                                                                              
NAME               AGE   PHASE        IP    NODENAME