Fetch VPC ID from runtime using VPC tags provided via controller flags

[jeswinkoshyninan]

Issue

This PR will address the issue raised: #3644

Description

This PR introduces a new runtime argument, aws-vpc-tags which is used to identify VPCs from the list of tags from which we can infer the VPC ID. There is also an optional argument called aws-vpc-name-tag-key incase if the "Name" will not be key-name for the VPC name in tag.

This is useful for cases where access to AWS metadata is blocked and the VPC ID is not known at deploy time, options to infer the VPC ID are limited

Manual Tests Details

Dev Build

➜  ~ kubectl get deploy aws-load-balancer-controller  -n aws-lb-controller -o=jsonpath="{.spec.template.spec.containers[0].args}" 
["--cluster-name=j119106042","--ingress-class=alb","--aws-vpc-tags=Name=j119106042"]%                                                                                                                                                                ➜  ~ 

When I have added the log to display the vpc_id, it got properly fetched the VPC(hidden) based on the given flag --aws-vpc-tags=Name="". 

➜  ~ kubectl logs aws-load-balancer-controller-566f9f556b-dhlbr -n aws-lb-controller 
{"level":"info","ts":"2024-05-09T20:12:03Z","msg":"version","GitVersion":"","GitCommit":"","BuildDate":""}
VPC ID:  vpc-XXXXXXXXXXXX
{"level":"info","ts":"2024-05-09

Current Build

➜  ~ kubectl logs aws-load-balancer-controller-6776c547-7mfj4  -n aws-lb-controller 
{"level":"info","ts":"2024-05-14T10:29:47Z","msg":"version","GitVersion":"","GitCommit":"","BuildDate":""}
{"level":"info","ts":"2024-05-14T10:29:47Z","logger":"controller-runtime.metrics","msg":"Metrics server is starting to listen","addr":":8080"}
{"level":"info","ts":"2024-05-14T10:29:47Z","logger":"setup","msg":"adding health check for controller"}
{"level":"info","ts":"2024-05-14T10:29:47Z","logger":"setup","msg":"adding readiness check for webhook"}
{"level":"info","ts":"2024-05-14T10:29:47Z","logger":"controller-runtime.webhook","msg":"Registering webhook","path":"/mutate-v1-pod"}
{"level":"info","ts":"2024-05-14T10:29:47Z","logger":"controller-runtime.webhook","msg":"Registering webhook","path":"/mutate-v1-service"}
{"level":"info","ts":"2024-05-14T10:29:47Z","logger":"controller-runtime.webhook","msg":"Registering webhook","path":"/validate-elbv2-k8s-aws-v1beta1-ingressclassparams"}
{"level":"info","ts":"2024-05-14T10:29:47Z","logger":"controller-runtime.webhook","msg":"Registering webhook","path":"/mutate-elbv2-k8s-aws-v1beta1-targetgroupbinding"}
{"level":"info","ts":"2024-05-14T10:29:47Z","logger":"controller-runtime.webhook","msg":"Registering webhook","path":"/validate-elbv2-k8s-aws-v1beta1-targetgroupbinding"}
{"level":"info","ts":"2024-05-14T10:29:47Z","logger":"controller-runtime.webhook","msg":"Registering webhook","path":"/validate-networking-v1-ingress"}
{"level":"info","ts":"2024-05-14T10:29:47Z","logger":"setup","msg":"starting podInfo repo"}
{"level":"info","ts":"2024-05-14T10:29:49Z","logger":"controller-runtime.webhook.webhooks","msg":"Starting webhook server"}
{"level":"info","ts":"2024-05-14T10:29:49Z","msg":"Starting server","kind":"health probe","addr":"0.0.0.0:61779"}
{"level":"info","ts":"2024-05-14T10:29:49Z","msg":"Starting server","path":"/metrics","kind":"metrics","addr":"0.0.0.0:8080"}
{"level":"info","ts":"2024-05-14T10:29:49Z","logger":"controller-runtime.certwatcher","msg":"Updated current TLS certificate"}
{"level":"info","ts":"2024-05-14T10:29:49Z","logger":"controller-runtime.certwatcher","msg":"Starting certificate watcher"}
{"level":"info","ts":"2024-05-14T10:29:49Z","logger":"controller-runtime.webhook","msg":"Serving webhook server","host":"","port":9443}

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the docs directory)
• Manually tested
• Made sure the title of the PR is a good description that can go into the release notes

BONUS POINTS checklist: complete for good vibes and maybe prizes?! 🤯

• Backfilled missing tests for code in same general area 🎉
• Refactored something and made the world a better place 🌟

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: jeswinkoshyninan (9d19525, 3a0ebce, 663315e, 69a5d42, 22b2e6b, 7b3f80d, 443d102, 8a01478, e20e081, 8ae3e3c)

[k8s-ci-robot]

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[k8s-ci-robot]

Hi @jeswinkoshyninan. Thanks for your PR.

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[jeswinkoshyninan]

@oliviassss @johngmyers can you please take look into this same ?

[shraddhabang]

/ok-to-test

[jeswinkoshyninan]

Thank you @shraddhabang , seems like test looks good to us. Can we merge this change?

[jeswinkoshyninan]

@shraddhabang @johngmyers @oliviassss tagging again incase if we lost the track of this PR, seems like the tests looks good and okay to merge ?

[oliviassss]

@jeswinkoshyninan thanks for the contribution, this change looks good to me overall, just a few questions:

1. iiuc, we are supporting filtering the vpc by tags, it does not have to be "Name". So can we change the flag aws-vpc-name-tag-key to aws-vpc-tag-key to make it more general, and by default it's Name.
2. I think maybe we need a validation that, if users use both flag --aws-vpc-id and --aws-vpc-tags, the controller should error out. since it should be either specify a vpc-id, or filter by vpc tag.

[jeswinkoshyninan]

@oliviassss thank you for the comments
Regarding your first point, I have made the changes and the second point, currently if VPCID is set, then that will be returned instead of fetching VPCID using tags. In this case, is this required to add a condition since this will not cause any problems. Please let me know your thoughts ?

[oliviassss]

yeah it's not causing any problem, since it's just return the vpc id if specified. But I think we should call out for this behavior:

1. in docs/deploy/configurations.md, add a call out that --aws-vpc-id will take precedence if both --aws-vpc-id and --aws-vpc-tag are specified.
2. maybe add a debug log line in the func getVpcID(), if cfg.VpcID != nil, we can log out that vpc-id is specified, and the controller just used it. It should be V(1) log, so only visible when users enable debug log level.

[jeswinkoshyninan]

@oliviassss make sense, have pushed the changes, please take a look.

[oliviassss]

Maybe also add a callout here:

Note that if both flags --aws-vpc-id and --aws-vpc-tags are specified, the controller uses the value in --aws-vpc-id to fetch the VPC info and ignores the other flag.

[oliviassss]

Another question, does it accept multiple key:value pairs for the tags filter?

[jeswinkoshyninan]

yes, it is a string Map. It will accept multiple values.

[jeswinkoshyninan]

Added the details here as well.

[oliviassss]

nit: reword a bit

Note that if both flags --aws-vpc-id and --aws-vpc-tags are specified, the controller uses the value in --aws-vpc-id to fetch the VPC info and ignores the other flag.

[jeswinkoshyninan]

refactor the sentence. thanks

[oliviassss]

/ok-to-test
can you also add the manual testing you've done in the PR description? thanks

[jeswinkoshyninan]

@oliviassss PR desc updated with the manual test details.

[oliviassss]

/lgtm
/assign @M00nF1sh

[jeswinkoshyninan]

@oliviassss just for transparency, seems like when enabling debug logs, the logs which we set to message user "vpcid is specified" is not working when I am testing. This will not affect the functionality. But just letting you know that I am checking.

[jeswinkoshyninan]

@oliviassss identified the problem with logger and fixed. I can see the logs what we set.

➜  .kube kubectl logs aws-load-balancer-controller-796b7c7f76-wrvdx -n aws-lb-controller -f
{"level":"info","ts":"2024-05-14T21:41:20Z","msg":"version","GitVersion":"","GitCommit":"","BuildDate":""}
{"level":"debug","ts":"2024-05-14T21:41:20Z","msg":"vpcid is specified using flag --aws-vpc-id, controller will use the value","vpc: ":"vpc-XXXXXXXXX"}

[oliviassss]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: jeswinkoshyninan, oliviassss

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[oliviassss]

@jeswinkoshyninan, discussed internally that we will ship this commit in next minor release, which should be v2.9.0, for a feature like this. Thanks for your patience.

[jeswinkoshyninan]

@oliviassss thank you for the updates, please let me know once we confirm the release v2.9.0.

[alfredkrohmer]

@jeswinkoshyninan I don't really get this part: why does this allow to pass a map with an arbitrary number of items for --aws-vpc-tags if we only ever pass a single key-value pair (the one with the key specified in aws-vpc-tag-key) as the tag filter? Shouldn't it rather just convert the map from --aws-vpc-tags into a list of tag filters, one for each item?

[pinkavaj]

Related to #3889