A way to load resources directly from file yaml manifest

[wizard580]

Hi,

Is there a way to load resources directly from file yaml manifest? Let's say I have manifest stored in git and I want to apply it to the cluster.

I think it's possible to do so by creating new resource (in my case - deployment) and then apply this new resource, but it would be really nice to have out-of-the-box method for this, and maybe this method will take care of resource API version.

[ericchiang]

I'd recommend shelling out to kubectl or using client-go for now. Supporting YAML and JSON serialization for known manifests isn't easy (https://github.com/ericchiang/k8s/issues/8).

I've had the thought of adding a RawResouce, where you could stick a payload then the client would POST whatever's in the body:

type RawResource struct {
    APIVersion string
    Kind       string
    Metadata   v1.ObjectMeta

    ContentType string
    Bytes       []byte
}

but for now, it sounds like you'd probably just want to use kubectl apply -f

[wizard580]

the issue: app should support two different clusters, as example 1.7 and 1.11+ yes, I know that we can use kubectl for each version... but it's not nice.

[ericchiang]

the issue: app should support two different clusters, as example 1.7 and 1.11+

You probably want two different manifest then anyway, right?

yes, I know that we can use kubectl for each version... but it's not nice.

A couple lines of bash sounds nicer to me than messing with untyped YAML and JSON in Go :)

[KaelBaldwin]

@wizard580

This might not help you, and it's certainly not ideal, but at least to share what worked for my use case:

While using a manifest file that would work with kubernetes doesn't work as is, you could adjust the yaml so that the fields line up with what the unmarshaller is expecting. I used https://github.com/ghodss/yaml for yaml since it transitions through json allowing you to take advantage of the json related tags. (this might not be necessary any more, I see yaml tags have been merged in)

You could also get an existing resource via the library and then marshall it to to yaml and dump it out to a file to get an example of what it needs to look like, I think that would work.

for example a readinessProbe might become:

readinessProbe:
  handler:
    httpGet:
      path: /
      port:
        type: 1
        strval: http
  timeoutSeconds: 1

Once you get used to the differences they are pretty easy to write, they are just a little more verbose, and unfortunately it does require separate manifests for whatever you are using this library for.

[cplee]

I love the simplicity of this kubernetes client, but I too am running into this same challenge. Any thoughts on replacing the apis package in this project with kubernetes/api? The resources in that projects support not only protobuf but also YAML and JSON marshalling/unmarshalling

[ericchiang]

I love the simplicity of this kubernetes client, but I too am running into this same challenge. Any thoughts on replacing the apis package in this project with kubernetes/api? The resources in that projects support not only protobuf but also YAML and JSON marshalling/unmarshalling

If you need those packages I'd recommend using client-go. There's no way to import kubernetes/api without getting most of the client-go package anyway.

I still think my earlier comment about a RawResource would be the way to handle this use case.