[Issue-7956] - [Digital Ocean] Minor fix to have proper indexing for digital ocean regions

[srikiz]

Found an issue where regions ending with characters other than "1" like sfo2 had problems with etcdmanager.
The index was set to 2 instead of 1 because of the way we are currently trimming in https://github.com/kubernetes/kops/blob/master/cmd/kops/create_cluster.go#L802
Since this is a common code, I added special check for DO to use the logic differently that suits DO.
You now see the instanceGroup as below and the name is properly set to "1" instead of "2".

` configBase: do://sri-kops-space/dev5.techthreads.co.in
etcdClusters:

• cpuRequest: 200m
  etcdMembers:
  • instanceGroup: master-sfo2-1
    name: "1"
    memoryRequest: 100Mi
    name: main
• cpuRequest: 100m
  etcdMembers:
  • instanceGroup: master-sfo2-1
    name: "1"
    memoryRequest: 100Mi
    name: events
    `

[k8s-ci-robot]

Hi @srikiz. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[srikiz]

FYI - @timoreimann @prksu - please have a look when you get a chance. Thanks !

[prksu]

@srikiz i have a similar approach with you.
but i curious why we only give number prefix when masterCount grather than masterZones 🤔

/ok-to-test

[srikiz]

@srikiz i have a similar approach with you.

but i curious why we use a trimmed name that leaves one character from the end of the actual name for etcd-member. i think using the name of the instance group without the master- prefix is quite short.

Yeah - But it looks like the trimCommonPrefix removes the common prefix in comparing with the specific array. Since we had only one element in the masterCount, it just removes everything except the last character.
Ex input and output from https://github.com/kubernetes/kops/blob/master/cmd/kops/createcluster_test.go below :

Input:  []string{"us-test-1a-1", "us-test-1b-1", "us-test-1a-2", "us-test-1b-2", "us-test-1a-3"},
Output: []string{"a-1", "b-1", "a-2", "b-2", "a-3"},

I think from DO perspective, what we have is Ok, since we are actually using the name as the etcd-index for the master.

[srikiz]

@srikiz i have a similar approach with you.
but i curious why we only give number prefix when masterCount grather than masterZones 🤔

/ok-to-test

We are currently doing this if we have multiple masters in a given region.
This is one of the new additions to DO (I haven't added as part of the read me guide yet about the multiple master support - Though it works well, we need to manually add the load balancer currently. I'll be updating to include a DO load balancer via KOPS create command sooner).
Creation of a multi-master cluster in DO would look something like this. This would create 3 masters in the same zone - sfo2 as below

./kops create cluster --cloud=digitalocean --name=dev3.k8s.local --master-count=3 --networking=cilium --zones=sfo2 --ssh-public-key=~/.ssh/id_rsa.pub -v 10 --yes

  etcdClusters:
  - cpuRequest: 200m
    etcdMembers:
    - instanceGroup: master-sfo2-1
      name: "1"
    - instanceGroup: master-sfo2-2
      name: "2"
    - instanceGroup: master-sfo2-3
      name: "3"
    memoryRequest: 100Mi
    name: main
  - cpuRequest: 100m
    etcdMembers:
    - instanceGroup: master-sfo2-1
      name: "1"
    - instanceGroup: master-sfo2-2
      name: "2"
    - instanceGroup: master-sfo2-3
      name: "3"
    memoryRequest: 

[prksu]

fixes #7956
/lgtm

[zetaab]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: srikiz, zetaab

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [zetaab]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment