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Lab_8

sashko
sashko Posts: 8
in LFS258 Class Forum

Hello Team,
1- Working on LFS258 Lab_8.2 it says in previous exercise we deployed a LoadBalancer. However reviewing my deployment from the Lab_8.1 it shows - nginx-one ClusterIP; I used example yaml file at the beginning of the lab_8.1. Please help me to find out what I missed in this Lab setup :-)
2- Regarding the same Lab_8.1, curl to the service IP or ep IP works on the port 80 from worker node, where svc is deployed, however it's not reachable from the master node. It seems it should be accessible with this yaml deployment from both master and worker nodes. Any tips on how to troubleshoot this would be greatly appreciated.

Thank you,

Comments

  • sashko
    sashko Posts: 8

    Hello and Thank you for a quick reply.
    1- I completely understand that it's impossible to troubleshoot like that :-) . I have not hit any error with the deployment. I have run the deployment following steps in Lab_8.1.pdf, those are major commands:
    kubectl create -f nginx-one.yaml -> kubectl create ns accounting -> kubectl label nodes lfs258-worker system=secondOne -> kubectl -n accounting expose deployment nginx-one
    My confusion is that this expected to be a LoadBalancer one. It seems I have explicitly specify the type=LoadBalancer, in the yaml or expose command, otherwise default would be ClusterIP.

    2- I'm deploying in AKS. I made sure that no firewall restrictions, everything is wide open. Apparently is not, i'm going to double check that. The error from master I'm getting while connecting to service that runs on worker is timeout:
    curl: (7) Failed to connect to 10.110.243.210 port 80: Connection timed out

    Thank you,

  • sashko
    sashko Posts: 8

    Thank you for quick reply.
    To be more accurate i'm using just vm's on Azure, it's not AKS, my bad. I installed k8s following Lab assignment from this training on regular ubuntu vm's.
    Declaring the resource it make sense, I'm going to test that. In this case Lab_8.1 should be updated I guess to explicitly point out to expose service as LB, or maybe example yaml should have this type.
    Thanks again, I'll continue looking from the vm networking side of things then.

  • sashko
    sashko Posts: 8

    Thank you for the quick reply. The network portion is clear.
    Regarding the type LoadBalancer in Lab_8.1. Is the step specifying exact type is missing in the lab pdf or I have to revisit the setup?

    Regards,

  • sashko
    sashko Posts: 8

    Thanks again. I'll go back reviewing previous labs configurations one more time.
    Regards.

  • sashko
    sashko Posts: 8

    Hello,
    Could you please provide more details on how correctly enable kubectl commands running on the worker node? Should we just copy over .kube/config from the master to worker node?
    Thank you.

  • chrispokorni
    chrispokorni Posts: 2,606

    Hi @sashko,
    The .kube/config file is for the control plane only, so in this case only for the master node. Kubectl should be issued from the master node, and has effect over the entire cluster - master and worker(s).
    If you are using the Calico network plugin for pod networking, there have been issues reported earlier on running a Kubernetes cluster on Azure VMs, with the Calico network plugin.
    You can find out more details on the Calico documentation page.
    Regards,
    -Chris

  • nkristianto
    nkristianto Posts: 13

    hi @chrispokorni , @serewicz
    i'm facing this issue
    on the lab 8.1, i can't do curl to local ip (192.xxx) from the master, but that's accessible from the worker
    kindly give some advice

  • nkristianto
    nkristianto Posts: 13

    another thing, i cannot access nginx using node public IP, i can access using worker public IP
    is anything wrong ?

  • chrispokorni
    chrispokorni Posts: 2,606

    Hi @nkristianto,
    Similar issues have been discussed and resolved in earlier posts.
    It seems that the networking between your nodes is not properly setup, and traffic to some ports may be blocked.
    There are a few reasons why this happens. There may be a firewall running on your Ubuntu instances: ufw, apparmor, ... Or there may be a firewall between the nodes at your infrastructure level. The fixes are to disable any local firewall on the Ubuntu instances, and to create a custom VPC network with a custom firewall rule open to all traffic: all ports, all protocols, all sources/destinations and add your VM instances to that VPC.
    Regards,
    -Chris

  • nkristianto
    nkristianto Posts: 13

    hi @chrispokorni
    thanks for the response
    for this, i'm using GCP,

    will try your suggestions for open to all traffic: all ports, all protocols, all sources/destinations and add your VM instances to that VPC. i'll get back for the result
    Regards
    nkristianto

  • nkristianto
    nkristianto Posts: 13

    hi @chrispokorni

    implement all firewall rules to allow all traffic for all port, disable firewall on local ubuntu instance, but still cannot do CURL from master
    do you have any suggestion ?

    thanks
    regards
    nkristianto

  • nkristianto
    nkristianto Posts: 13

    nvm Cris,
    i made a mistake.
    all is working fine now after allow all ip range with all port and all protocol
    thanks...

    regards
    nkristianto

  • sashko
    sashko Posts: 8

    Hello @chrispokorni,
    I'm not sure I fully understand your reply to my question regarding running kubectl commands on worker nodes. My question is basically what needs to be done in order to be able to run kubectl commands from worker node or for instance from just a regular pc, interacting with the cluster?
    Thank you,

  • chrispokorni
    chrispokorni Posts: 2,606

    Hi @sashko, in order to run kubectl from a remote workstation to manage your cluster install kubect on the remote workstation and copy the .kube/config file to the remote workstation. If kubectl does not work after these 2 steps, then you may need to edit the remote .kube/config file to include the master node's private or public IP and you may also need to re-set the certs from your remote .kube/config file - these last 2 steps may have to be performed depending on your current setup.
    Regards,
    -Chris

  • sashko
    sashko Posts: 8

    Thank you Chris! Really appreciate your help with this.

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