[BUG] Autogenerated resource names not properly formatted

[tabern]

Auto-generated resource names follow the format this.object.uniqueid. This results in output that does not conform with K8s naming validation.

Input TS

new Deployment(this, 'deployment', {
      spec: {
        replicas: 1,
        selector: {
          matchLabels: label
        },
        template: {
          metadata: { labels: label },
          spec: {
            containers: [
              {
                name: this.node.uniqueId,
                image: options.image,
                ports: [ { containerPort } ]
              }
            ]
          }
        }
      }
    });

Output YAML

spec:
  replicas: 1
  selector:
    matchLabels:
      app: myappnginx37F28063
  template:
    metadata:
      labels:
        app: myappnginx37F28063
    spec:
      containers:
        - name: myappnginx37F28063
          image: nginx
          ports:
            - containerPort: 8080
kind: Deployment
apiVersion: apps/v1
metadata:
  name: myapp.nginx.deployment.f97e0de6

Error

Error from server (Invalid): error when creating "myapp.k8s.yaml": Deployment.apps "myapp.nginx.deployment.f97e0de6" is invalid: spec.template.spec.containers[0].name: Invalid value: "myappnginx37F28063": a DNS-1123 label must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character (e.g. 'my-name',  or '123-abc', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?')

[eladb]

No problem. For some reason I was certain I read somewhere that dots are allowed but that’s a very easy fix.

[eladb]

@tabern the auto-generated resource names (like the one auto-generated for the Deployment object myapp.nginx.deployment.f97e0de6) are actually ok and comply with the k8s spec.

The problem here is that you used this.node.uniqueId for the container name (which is not a resource), which resulted in a unique ID that is not compatible with DNS -1123.

What was the motivation of using this.node.uniqueId instead of just supplying a concrete name? Was this in some example that you took?

[eladb]

Okay, got it. It's in the README.

Sadly we can't change this.node.uniqueid because it would be a huge breaking change for the AWS CDK (this is coming from @aws-cdk/core).

Let me update our README to actually work, and we'll think about this a bit more.

[eladb]

Well... More testing yielded the following error:

Error from server (Invalid): error when creating "webserviceexample.k8s.yaml": Service "web-service-example.hello.service.0556b74d" is invalid: metadata.name: Invalid value: "web-service-example.hello.service.0556b74d": a DNS-1035 label must consist of lower case alphanumeric characters or '-', start with an alphabetic character, and end with an alphanumeric character (e.g. 'my-name',  or 'abc-123', regex used for validation is '[a-z]([-a-z0-9]*[a-z0-9])?')

So, for Deployment, it's okay to have . in the name and for Service it's not okay?? Oh my...

[eladb]

Reverting the original bug name and continuing to investigate.

[eladb]

OK, so apparently, names have different constraints based on the resource type (aaaah!). The common denominator seems to be DNS_LABEL which is limited to 63 characters and can only use lowercase alphanumeric and - and must have an alphanumeric character at the beginning and the end.