Error during expansion of "!!merge <<:" anchor tags

[daraghlowe]

This is a follow up issue to #3675 as we still see errors when using the kustomize version 4.4 that has the YAML anchor fix. We're also seeing a similar error ( unsupported type: map[interface {}]interface {} ) for some other YAML in knative that doesn't have a YAML anchor.

We use kustomize v3.8.10 which works fine with knative but we get errors when using the later versions that use kyaml.

$ ./bin/kustomize44 version
{Version:kustomize/v4.4.0 GitCommit:63ec6bdb3d737a7c66901828c5743656c49b60e1 BuildDate:2021-09-27T16:24:12Z GoOs:darwin GoArch:amd64}

kustomization.yaml

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

bases:
- https://github.com/knative/serving/releases/download/v0.23.1/serving-core.yaml
- https://github.com/knative-sandbox/net-istio/releases/download/v0.23.1/release.yaml
- https://github.com/knative/serving/releases/download/v0.23.1/serving-domainmapping.yaml

The YAML anchor in serving-domainmapping.yaml and serving-core.yaml looks like this:

          readinessProbe: &probe
            periodSeconds: 1
            httpGet:
              scheme: HTTPS
              port: 8443
              httpHeaders:
                - name: k-kubelet-probe
                  value: "webhook"
          livenessProbe:
            !!merge <<: *probe
            failureThreshold: 6
            initialDelaySeconds: 20

Error during build:

Error: map[string]interface {}{"apiVersion":"apps/v1", "kind":"Deployment", "metadata":map[string]interface {}{"labels":map[string]interface {}{"serving.knative.dev/release":"v0.23.1"}, "name":"domainmapping-webhook", "namespace":"knative-serving"}, "spec":map[string]interface {}{"selector":map[string]interface {}{"matchLabels":map[string]interface {}{"app":"domainmapping-webhook", "role":"domainmapping-webhook"}}, "template":map[string]interface {}{"metadata":map[string]interface {}{"annotations":map[string]interface {}{"cluster-autoscaler.kubernetes.io/safe-to-evict":"false"}, "labels":map[string]interface {}{"app":"domainmapping-webhook", "role":"domainmapping-webhook", "serving.knative.dev/release":"v0.23.1"}}, "spec":map[string]interface {}{"affinity":map[string]interface {}{"podAntiAffinity":map[string]interface {}{"preferredDuringSchedulingIgnoredDuringExecution":[]interface {}{map[string]interface {}{"podAffinityTerm":map[string]interface {}{"labelSelector":map[string]interface {}{"matchLabels":map[string]interface {}{"app":"domainmapping-webhook"}}, "topologyKey":"kubernetes.io/hostname"}, "weight":100}}}}, "containers":[]interface {}{map[string]interface {}{"env":[]interface {}{map[string]interface {}{"name":"POD_NAME", "valueFrom":map[string]interface {}{"fieldRef":map[string]interface {}{"fieldPath":"metadata.name"}}}, map[string]interface {}{"name":"SYSTEM_NAMESPACE", "valueFrom":map[string]interface {}{"fieldRef":map[string]interface {}{"fieldPath":"metadata.namespace"}}}, map[string]interface {}{"name":"CONFIG_LOGGING_NAME", "value":"config-logging"}, map[string]interface {}{"name":"CONFIG_OBSERVABILITY_NAME", "value":"config-observability"}, map[string]interface {}{"name":"WEBHOOK_PORT", "value":"8443"}, map[string]interface {}{"name":"METRICS_DOMAIN", "value":"knative.dev/serving"}}, "image":"gcr.io/knative-releases/knative.dev/serving/cmd/domain-mapping-webhook@sha256:34bc9025e3589241ddf4d57e42818069bcbf69b3ec9ab0220437d9bfa0853be7", "livenessProbe":map[interface {}]interface {}{"failureThreshold":6, "httpGet":map[string]interface {}{"httpHeaders":[]interface {}{map[string]interface {}{"name":"k-kubelet-probe", "value":"webhook"}}, "port":8443, "scheme":"HTTPS"}, "initialDelaySeconds":20, "periodSeconds":1}, "name":"domainmapping-webhook", "ports":[]interface {}{map[string]interface {}{"containerPort":9090, "name":"metrics"}, map[string]interface {}{"containerPort":8008, "name":"profiling"}, map[string]interface {}{"containerPort":8443, "name":"https-webhook"}}, "readinessProbe":map[string]interface {}{"httpGet":map[string]interface {}{"httpHeaders":[]interface {}{map[string]interface {}{"name":"k-kubelet-probe", "value":"webhook"}}, "port":8443, "scheme":"HTTPS"}, "periodSeconds":1}, "resources":map[string]interface {}{"limits":map[string]interface {}{"cpu":"500m", "memory":"500Mi"}, "requests":map[string]interface {}{"cpu":"100m", "memory":"100Mi"}}, "securityContext":map[string]interface {}{"allowPrivilegeEscalation":false, "capabilities":map[string]interface {}{"drop":[]interface {}{"all"}}, "readOnlyRootFilesystem":true, "runAsNonRoot":true}}}, "serviceAccountName":"controller", "terminationGracePeriodSeconds":300}}}}: json: unsupported type: map[interface {}]interface {}

The non YAML anchor related error example is in release.yaml:

apiVersion: "security.istio.io/v1beta1"
kind: "PeerAuthentication"
metadata:
  name: "domainmapping-webhook"
  namespace: "knative-serving"
  labels:
    serving.knative.dev/release: "v0.23.1"
    networking.knative.dev/ingress-provider: istio
spec:
  selector:
    matchLabels:
      app: domainmapping-webhook
  portLevelMtls:
    8443:
      mode: PERMISSIVE

The error we get is here:

Error: map[string]interface {}{"apiVersion":"security.istio.io/v1beta1", "kind":"PeerAuthentication", "metadata":map[string]interface {}{"labels":map[string]interface {}{"networking.knative.dev/ingress-provider":"istio", "serving.knative.dev/release":"v0.23.1"}, "name":"domainmapping-webhook", "namespace":"knative-serving"}, "spec":map[string]interface {}{"portLevelMtls":map[interface {}]interface {}{8443:map[string]interface {}{"mode":"PERMISSIVE"}}, "selector":map[string]interface {}{"matchLabels":map[string]interface {}{"app":"domainmapping-webhook"}}}}: json: unsupported type: map[interface {}]interface {}

[KnVerey]

The second problem might be caused by the integer key. Can you please try quoting it? Ref issue #3446

@monopole can you please take a look at the issue of the anchors still not working in the provided sample?

[eddiezane]

Second issue is indeed #3446.

[monopole]

@ack

[KnVerey]

/retitle Error during expansion of "!!merge <<:" anchor tags

[daraghlowe]

Thanks @eddiezane @KnVerey, the integer key is the second issue, confirmed that it works fine when I put it in quotes.

[KnVerey]

/triage accepted

[apshoemaker]

I am currently still receiving errors on the below yaml snippet (from https://github.com/knative/eventing/releases/download/v0.26.0/eventing-core.yaml) :

# Copyright 2018 The Knative Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: pingsource-mt-adapter
  namespace: knative-eventing
  labels:
    eventing.knative.dev/release: "v0.26.0"
    app.kubernetes.io/name: pingsource-mt-adapter
    app.kubernetes.io/version: "0.26.0"
    app.kubernetes.io/part-of: knative-eventing
spec:
  # when set to 0 (and only 0) will be set to 1 when the first PingSource is created.
  replicas: 0
  selector:
    matchLabels: &labels
      eventing.knative.dev/source: ping-source-controller
      sources.knative.dev/role: adapter
  template:
    metadata:
      labels:
        !!merge <<: *labels
        eventing.knative.dev/release: "v0.26.0"
        app.kubernetes.io/name: pingsource-mt-adapter
        app.kubernetes.io/version: "0.26.0"
        app.kubernetes.io/part-of: knative-eventing
    spec:
      affinity:
        podAntiAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
            - podAffinityTerm:
                labelSelector:
                  matchLabels: *labels
                topologyKey: kubernetes.io/hostname
              weight: 100
      enableServiceLinks: false
      containers:
        - name: dispatcher
          image: gcr.io/knative-releases/knative.dev/eventing/cmd/mtping@sha256:f47e953dfeb7747579f200b43af75f7796a5ab0e6fb616199abff233f3d03b4f
          env:
            - name: SYSTEM_NAMESPACE
              value: ""
              valueFrom:
                fieldRef:
                  apiVersion: v1
                  fieldPath: metadata.namespace
            # DO NOT MODIFY: The values below are being filled by the ping source controller
            # See 500-controller.yaml
            - name: K_METRICS_CONFIG
              value: ""
            - name: K_LOGGING_CONFIG
              value: ""
            - name: K_LEADER_ELECTION_CONFIG
              value: ""
            - name: K_NO_SHUTDOWN_AFTER
              value: ""
            - name: K_SINK_TIMEOUT
              value: "-1"
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
          ports:
            - containerPort: 9090
              name: metrics
              protocol: TCP
          resources:
            requests:
              cpu: 125m
              memory: 64Mi
            limits:
              cpu: 1000m
              memory: 2048Mi
      serviceAccountName: pingsource-mt-adapter

The error received is:

Error: map[string]interface {}{"apiVersion":"apps/v1", "kind":"Deployment", "metadata":map[string]interface {}{"labels":map[string]interface {}{"app.kubernetes.io/name":"pingsource-mt-adapter", "app.kubernetes.io/part-of":"knative-eventing", "app.kubernetes.io/version":"0.26.0", "eventing.knative.dev/release":"v0.26.0"}, "name":"pingsource-mt-adapter", "namespace":"knative-eventing"}, "spec":map[string]interface {}{"replicas":0, "selector":map[string]interface {}{"matchLabels":map[string]interface {}{"eventing.knative.dev/source":"ping-source-controller", "sources.knative.dev/role":"adapter"}}, "template":map[string]interface {}{"metadata":map[string]interface {}{"labels":map[interface {}]interface {}{"app.kubernetes.io/name":"pingsource-mt-adapter", "app.kubernetes.io/part-of":"knative-eventing", "app.kubernetes.io/version":"0.26.0", "eventing.knative.dev/release":"v0.26.0", "eventing.knative.dev/source":"ping-source-controller", "sources.knative.dev/role":"adapter"}}, "spec":map[string]interface {}{"affinity":map[string]interface {}{"podAntiAffinity":map[string]interface {}{"preferredDuringSchedulingIgnoredDuringExecution":[]interface {}{map[string]interface {}{"podAffinityTerm":map[string]interface {}{"labelSelector":map[string]interface {}{"matchLabels":map[string]interface {}{"eventing.knative.dev/source":"ping-source-controller", "sources.knative.dev/role":"adapter"}}, "topologyKey":"kubernetes.io/hostname"}, "weight":100}}}}, "containers":[]interface {}{map[string]interface {}{"env":[]interface {}{map[string]interface {}{"name":"SYSTEM_NAMESPACE", "value":"", "valueFrom":map[string]interface {}{"fieldRef":map[string]interface {}{"apiVersion":"v1", "fieldPath":"metadata.namespace"}}}, map[string]interface {}{"name":"K_METRICS_CONFIG", "value":""}, map[string]interface {}{"name":"K_LOGGING_CONFIG", "value":""}, map[string]interface {}{"name":"K_LEADER_ELECTION_CONFIG", "value":""}, map[string]interface {}{"name":"K_NO_SHUTDOWN_AFTER", "value":""}, map[string]interface {}{"name":"K_SINK_TIMEOUT", "value":"-1"}, map[string]interface {}{"name":"POD_NAME", "valueFrom":map[string]interface {}{"fieldRef":map[string]interface {}{"fieldPath":"metadata.name"}}}}, "image":"gcr.io/knative-releases/knative.dev/eventing/cmd/mtping@sha256:f47e953dfeb7747579f200b43af75f7796a5ab0e6fb616199abff233f3d03b4f", "name":"dispatcher", "ports":[]interface {}{map[string]interface {}{"containerPort":9090, "name":"metrics", "protocol":"TCP"}}, "resources":map[string]interface {}{"limits":map[string]interface {}{"cpu":"1000m", "memory":"2048Mi"}, "requests":map[string]interface {}{"cpu":"125m", "memory":"64Mi"}}}}, "enableServiceLinks":false, "serviceAccountName":"pingsource-mt-adapter"}}}}: json: unsupported type: map[interface {}]interface {}

➜ ~/Downloads kustomize version                                             
{Version:kustomize/v4.4.0 GitCommit:63ec6bdb3d737a7c66901828c5743656c49b60e1 BuildDate:2021-09-27T16:24:12Z GoOs:linux GoArch:amd64}

Please advise - thanks!

[RafaeLeal]

I'm having this same issue, I tried to understand more deeply the issue and come up with a solution...

I'm still reading the Contribution Guidelines, and I was not sure if I could do it because I'm not familiar with the codebase.

I opened a PR on my fork, and I'm still dealing with some corner cases related to comments and JSON serialization... https://github.com/RafaeLeal/kustomize/pull/1/files

After signing the CLA I can open this PR if there's nothing terribly wrong with it 😅

[natasha41575]

@RafaeLeal I took a very quick glance at your PR, and nothing about it seems terribly outlandish, it would be great if you could open the PR here and we can do a more thorough review.

[RafaeLeal]

@natasha41575 Created, thanks! :)

[KnVerey]

Closed by https://github.com/kubernetes-sigs/kustomize/pull/4383