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Package transformations guide

Package Transformations Work in Nephio Sandbox Installation

Table of Contents

Vanilla kpt for the Management cluster

Before reading this, please read the kpt book.

kpt pkg get

The kpt pkg get --for-deployment https://<repo-path>/<repo-pkg-name>@<repo-pkg-name>/<pkg-version> <local-pkg-name> command downloads a kpt package from a repository.

The fields in the command above are as follows:

Field Description
repo-path The path in the repository to the kpt package
repo-pkg-name The name of the kpt package in the repository
pkg-version The version of the kpt package
local-pkg-name The local name of the kpt package in the repository, defaults to repo-pkg-name

kpt pkg get make the following transformations:

  1. The metadata.name field in the root Kptfile in the package is changed from whatever value it has to local-pkg-name
  2. The metadata.namespace field in the root Kptfile in the package is removed
  3. upstream and upstreamlock root fields are added to the root Kptfile as follows:
upstream:
  type: git
  git:
    repo: https://<repo-path>/<repo-pkg-name>
    directory: /<local-pkg-name>
    ref: <pkg-version>
  updateStrategy: resource-merge
upstreamLock:
  type: git
  git:
    repo: https://<repo-path>/<repo-pkg-name>
    directory: /<local-pkg-name>
    ref: <pkg-version>
    commit: 0123456789abcdef0123456789abcdef01234567
  1. The data.name field in the root package-context.yaml files is changed to be local-pkg-name
  2. The package-context.yaml file is added if it does not exist with the following content:
apiVersion: v1
kind: ConfigMap
metadata:
  name: kptfile.kpt.dev
  annotations:
    config.kubernetes.io/local-config: "true"
data:
  name: <local-pkg-name|sub-pkg-name>
  1. The data.name field in package-context.yaml files in the sub kpt packages is changed to be the name of the sub package
  2. All other sub-fields under the data: field are deleted
  3. The comment metadata: # kpt-merge: <namespace>/<name> is added to root metadata fields on all YAML documents in the kpt package and enclosed sub-packages that have a root apiVersion and kind field if such a comment does not already exist. The namespace and name values used are the values of those fields in the metadata field. Note that a YAML file can contain multiple YAML documents and each root metadata field is commented. For example:
metadata: # kpt-merge: cert-manager/cert-manager-cainjector
  name: cert-manager-cainjector
  namespace: cert-manager
  1. The annotation internal.kpt.dev/upstream-identifier: '<apiVersion>|<kind>|<namespace>|<name>' is added to root metadata.annotations: fields on all YAML documents in the kpt package and enclosed sub-packages that have a root apiVersion: and kind: field if such an annotation does not already exist. The namespace and name values used are the values of those fields in the metadata field. Note that a YAML file can contain multiple YAML documents and each root metadata field is commented. For example:
metadata: # kpt-merge: cert-manager/cert-manager-cainjector
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata: # kpt-merge: capi-kubeadm/leader-election-rolebinding
  name: leader-election-rolebinding
  namespace: capi-kubeadm
  annotations:
    internal.kpt.dev/upstream-identifier: 'rbac.authorization.k8s.io|RoleBinding|capi-kubeadm|leader-election-rolebinding'

kpt fn render

The kpt fn render <local-pkg-name> runs kpt functions on a local package, thus applying local changes to the package.

In the Nephio sandbox installation, kpt fn render only acts on the repository and rootsync kpt packages from nephio-example-packages.

repository package

The repository package has a kpt function written in starlark, which is invoked by a pipeline specified in the kptfile.

pipeline:
  mutators:
  - image: gcr.io/kpt-fn/starlark:v0.4.3
    configPath: set-values.yaml

The starlark function is specified in the set-values.yaml file. It makes the following transformations on the repositories:

  1. In the file repo-gitea.yaml
  • the metadata.name field gets the value of <local-pkg-name>
  • the spec.description field gets the value of <local-pkg-name> repository
  1. In the file repo-porch.yaml
  • the metadata.name field gets the value of <local-pkg-name>
  • the spec.git.repo field gets the value of "http://172.18.0.200:3000/nephio/<local-pkg-name>.git
  • the spec.git.secretRef.name field gets the value of <local-pkg-name>-access-token-porch
  • if the <local-pkg-name> is called mgmt-staging, then the following extra changes are made:
    • the spec.deployment field is set to false (it defaults to true)
    • the annotation metadata.annotations.nephio.org/staging: "true" is added
  1. In the file token-configsync.yaml
  • the metadata.name field gets the value of <local-pkg-name>-access-token-configsync
  • the metadata.namespace field gets the value of config-management-system
  1. In the file token-porch.yaml
  • the metadata.name field gets the value of <local-pkg-name>-access-token-porch

rootsync Package

The rootsync package also has a kpt function written in starlark specified in the set-values.yaml file. It makes the following transformations on repositories:

  1. In the file rootsync.yaml
  • the metadata.name field gets the value of <local-pkg-name>
  • the spec.git.repo field gets the value of "http://172.18.0.200:3000/nephio/<local-pkg-name>.git
  • the spec.git.secretRef.name field gets the value of <local-pkg-name>-access-token-configsync

kpt live init

The kpt live init <local-pkg-name> initializes a local package, making it ready for application to a cluster. This command creates a resourcegroup.yaml in the kpt package with content similar to:

apiVersion: kpt.dev/v1alpha1
kind: ResourceGroup
metadata:
  name: inventory-12345678
  namespace: default
  labels:
    cli-utils.sigs.k8s.io/inventory-id: 0123456789abcdef0123456789abcdef01234567-0123456789abcdef012

kpt alpha rpkg for Workload clusters

The kpt alpha rpkg suite of commands that act on Repository resources on the kubernetes cluster in scope. The packages in the Repository resources are remote packages (rpkg).

To see which repositories are in scope:

NAME                      TYPE   CONTENT   DEPLOYMENT   READY   ADDRESS
free5gc-packages          git    Package   false        True    https://github.com/nephio-project/free5gc-packages.git
mgmt                      git    Package   true         True    http://172.18.0.200:3000/nephio/mgmt.git
mgmt-staging              git    Package   false        True    http://172.18.0.200:3000/nephio/mgmt-staging.git
nephio-example-packages   git    Package   false        True    https://github.com/nephio-project/nephio-example-packages.git

To see all the remote packages that are available:

$ kpt alpha rpkg get 
NAME                                                               PACKAGE                              WORKSPACENAME   REVISION   LATEST   LIFECYCLE   REPOSITORY
free5gc-packages-daba5a241a23af3ce777b256c39dcedc3c5e3917          free5gc-cp                           v1              v1         true     Published   free5gc-packages
free5gc-packages-ab9c21f547bdf11832d683a01dde851305ab151e          free5gc-operator                     v3              v3         true     Published   free5gc-packages
free5gc-packages-bc41f4d0a9f984b7a7aa8ef6623a615e2aa75993          free5gc-upf                          v1              v1         true     Published   free5gc-packages
free5gc-packages-4c66951196b8727569070db9f0d19f83bdb21adf          pkg-example-amf-bp                   v3              v3         true     Published   free5gc-packages
free5gc-packages-0292da186776c49eb0f72489a33d67cb6f0f1da2          pkg-example-smf-bp                   v3              v3         true     Published   free5gc-packages
free5gc-packages-a845d4297634409d813c882a307f033999b05d03          pkg-example-upf-bp                   v3              v3         true     Published   free5gc-packages
nephio-example-packages-ae679b5ac4fbb7719e7302fe6726e26005b004e0   5g-core-topology                     v2              v2         true     Published   nephio-example-packages
nephio-example-packages-5d6969cb98e4d6494ff6eadd6c52e94368f8261c   cert-manager                         v2              v2         true     Published   nephio-example-packages
nephio-example-packages-2144369250410c527ac4716b50fce8c88656f231   cluster-capi                         v4              v4         true     Published   nephio-example-packages
nephio-example-packages-6be85e6942a3f9a2e2e4d6e6b9a4c95172142c8e   cluster-capi-infrastructure-docker   v1              v1         true     Published   nephio-example-packages
nephio-example-packages-0bb045b3458818144b6596c1239e8cf307ed10d0   cluster-capi-kind                    v5              v5         true     Published   nephio-example-packages
nephio-example-packages-4204d1ed31d71ac2147a4bd7dad614bf3ab0dd50   cluster-capi-kind-docker-templates   v1              v1         true     Published   nephio-example-packages
nephio-example-packages-73a2b11f81e580686fc01773809b4050958177e3   configsync                           v1              v1         true     Published   nephio-example-packages
nephio-example-packages-12b4164a8aed5ffc6e197b8af97edb34b31a11bf   free5gc-smf-org-example              v2              v2         true     Published   nephio-example-packages
nephio-example-packages-e3f5dce5fc98f9c06c32fa0342f9b0ae78eca562   gitea                                v3              v3         true     Published   nephio-example-packages
nephio-example-packages-073f3256d9ba4c32a3cf491c1cb9ee683b14b5c0   kindnet                              v1              v1         true     Published   nephio-example-packages
nephio-example-packages-7f4c57efd2a8707ef17f3ff1565da41b39ef6412   local-path-provisioner               v1              v1         true     Published   nephio-example-packages
nephio-example-packages-14dcd072fa92334197a1f23af02d9a4b55e8bae5   metallb                              v1              v1         true     Published   nephio-example-packages
nephio-example-packages-a48da09e5a4d99fae4ad5f54261e53ef1ee98b25   metallb-sandbox-config               v1              v1         true     Published   nephio-example-packages
nephio-example-packages-a226e2e41725db980f780812d9ab42f653a1a049   multus                               v1              v1         true     Published   nephio-example-packages
nephio-example-packages-943d66ad8063c09731550ab456bd93e099a55a8d   nephio-controllers                   v5              v5         true     Published   nephio-example-packages
nephio-example-packages-aa903df4b3652fdb5fdec2fd599b5b6275397b28   nephio-stock-repos                   v1              v1         true     Published   nephio-example-packages
nephio-example-packages-7895e28d847c0296a204007ed577cd2a4222d1ea   nephio-workload-cluster              v8              v8         true     Published   nephio-example-packages
nephio-example-packages-0e363ac47ac4612c2d41d37e976a783abe849067   network                              v1              v1         true     Published   nephio-example-packages
nephio-example-packages-7264e782c747fe720fb41b2b55a3234ffcd053f0   porch-dev                            v2              v2         true     Published   nephio-example-packages
nephio-example-packages-bb0001a2735f809281be792895a6a410abbe60fd   repository                           v3              v3         true     Published   nephio-example-packages
nephio-example-packages-6bf353f2bfe4b09bfd69d62ca169f30a35404d33   resource-backend                     v2              v2         true     Published   nephio-example-packages
nephio-example-packages-b0e4d5eb9e14d3a49d1e3a386b58e4eb9450243c   rootsync                             v3              v3         true     Published   nephio-example-packages
nephio-example-packages-fb6e4adecc13c50da838953ece623cf04de21884   ueransim                             v1              v1         true     Published   nephio-example-packages
nephio-example-packages-dc0b55fb7a17d107e834417a2c9d8fb37f36d7cb   vlanindex                            v1              v1         true     Published   nephio-example-packages
To see the versions of a particular package: 
$ kpt alpha rpkg get --name nephio-workload-cluster
NAME                                                               PACKAGE                   WORKSPACENAME   REVISION   LATEST   LIFECYCLE   REPOSITORY
nephio-example-packages-05707c7acfb59988daaefd85e3f5c299504c2da1   nephio-workload-cluster   main            main       false    Published   nephio-example-packages
nephio-example-packages-781e1c17d63eed5634db7b93307e1dad75a92bce   nephio-workload-cluster   v1              v1         false    Published   nephio-example-packages
nephio-example-packages-5929727104f2c62a2cb7ad805dabd95d92bf727e   nephio-workload-cluster   v2              v2         false    Published   nephio-example-packages
nephio-example-packages-cdc6d453ae3e1bd0b64234d51d575e4a30980a77   nephio-workload-cluster   v3              v3         false    Published   nephio-example-packages
nephio-example-packages-c78ecc6bedc8bf68185f28a998718eed8432dc3b   nephio-workload-cluster   v4              v4         false    Published   nephio-example-packages
nephio-example-packages-46b923a6bbd09c2ab7aa86c9853a96cbd38d1ed7   nephio-workload-cluster   v5              v5         false    Published   nephio-example-packages
nephio-example-packages-17bffe318ac068f5f9ef22d44f08053e948a3683   nephio-workload-cluster   v6              v6         false    Published   nephio-example-packages
nephio-example-packages-0fbaccf6c5e75a3eff7976a523bb4f42bb0118ce   nephio-workload-cluster   v7              v7         false    Published   nephio-example-packages
nephio-example-packages-7895e28d847c0296a204007ed577cd2a4222d1ea   nephio-workload-cluster   v8              v8         true     Published   nephio-example-packages

Create the Workload cluster package

The Workload cluster package contains PackageVariant files for configuring the new cluster.

Clone the nephio-workload-cluster package into the mgmt repository. This creates the blueprint package for the workload cluster in the management repository.

kpt alpha rpkg clone -n default nephio-example-packages-7895e28d847c0296a204007ed577cd2a4222d1ea --repository mgmt regional

During the clone operation, the command above performs the following operations:

  1. It creates a drafts/regional/v1 branch on the mgmt repository

  2. It does the equivalent of a kpt pkg get on the nephio-workload-cluster package into a directory called regional on that branch, with the same transformations on package files carried out as the kpt pkg get command above, this content is checked into the new branch in the initial commit

  3. The pipeline specified in the Kptfileof the nephio-workload-cluster package specifies an apply-replacements specified in the apply-replacements.yaml file in the package and uses the value of the package-context.yaml:data.name field set in 2. above (which is the workload cluster name) as follows:

    • In all PackageVariant files, the metadata.name and spec.downstream.package field before the ‘-’ is replaced with that field value. In this way, the downstream package names for all the packages to be pulled from the mgmt-staging repository for the workload cluster are specified.
    • In all PackageVariant files, the spec.injectors.WorkloadCluster.name field is replaced with the workload cluster name. This gives us the handle for packageVariant injection for the workload cluster in question.
    • In all PackageVariant files, the spec.pipeline.mutators.[image=gcr.io/kpt-fn/set-annotations:v0.1.4].configMap.[nephio.org/cluster-name] field is replaced with the workload cluster name.
    • In all WorkloadCluster files, the metadata.name and spec.clusterName fields are replaced with the workload cluster name.

We now have a draft blueprint package for our workload cluster ready for further configuration.

Configure the Package

We follow the instructions in the installation README file.

  1. Get the name of the package:
kpt alpha rpkg get | egrep '(NAME|regional)'
NAME                                           PACKAGE  WORKSPACENAME REVISION LATEST LIFECYCLE REPOSITORY
mgmt-08c26219f9879acdefed3469f8c3cf89d5db3868  regional v1                     false  Draft     mgmt
  1. Pull the package to get a local copy of it
kpt alpha rpkg pull -n default mgmt-08c26219f9879acdefed3469f8c3cf89d5db3868 regional
  1. Set the Nephio labels on the package
kpt fn eval --image gcr.io/kpt-fn/set-labels:v0.2.0 regional -- "nephio.org/site-type=regional" "nephio.org/region=us-west1"
  1. Check that the labels have been set. In all PackageVariant and WorkloadCluster files, the following metadata.labels fields have been added:
labels:
  nephio.org/region: us-west1
  nephio.org/site-type: regional
  1. Push the updated package back to the draft branch on the repository:
kpt alpha rpkg push -n default mgmt-08c26219f9879acdefed3469f8c3cf89d5db3868 regional
[RUNNING] "gcr.io/kpt-fn/apply-replacements:v0.1.1"
[PASS] "gcr.io/kpt-fn/apply-replacements:v0.1.1"

Propose the Package

Propose the package:

kpt alpha rpkg propose -n default mgmt-08c26219f9879acdefed3469f8c3cf89d5db3868
mgmt-08c26219f9879acdefed3469f8c3cf89d5db3868 proposed

Proposing the package changes the name of the drafts/regional/v1 to proposed/regional/v1. There are no changes to the content of the branch.

Approve the Package and Trigger Configsync

Approving the package triggers configsync, which triggers creation of the new workload cluster using all the PackageVariant components specified in the nephio-workload-cluster kpt package.

kpt alpha rpkg approve -n default mgmt-08c26219f9879acdefed3469f8c3cf89d5db3868
mgmt-08c26219f9879acdefed3469f8c3cf89d5db3868 approved

The new cluster comes up after a number of minutes.

Transformations in the Workload cluster creation

Approving the regional Workload cluster package in the mgmt repository triggered configsync to apply the PackageVariant configurations in the mgmt/regional package. Let’s examine those PackageVariant configurations one by one.

In the text below, let’s assume we are creating a workload cluster called lambda.

pv-cluster.yaml: creates the Workload cluster

In the text below, let’s assume we are creating a workload cluster called lambda.

This package variant transformation results in a package variant of the cluster-capi-kind package called lambda-package. The lambda-package contains the definition of a pair custom resources that are created when the package is applied. The custom resource pair are instances of the CRDs below

Custom Resource Definition Controller Function
clusters.cluster.x-k8s.io capi-system.capi-controller-manager Trigger creation and start of the kind cluster
workloadclusters.infra.nephio.org nephio-system.nephio-controller Trigger addition of nephio-specific configuration to the kind cluster

The PackageVariant specified in pv-cluster.yaml is executed and:

  1. Produces a package variant of the cluster-capi-kind package called lambda-cluster in the gitea mgmt repository on your management cluster.
  2. Applies the lambda-cluster kpt package to create the kind cluster for the workload cluster

Package transformations

During creation of the package variant kpt package, the following transformations occur:

  1. It creates a drafts/lambda-cluster/v1 branch on the mgmt repository

  2. It does the equivalent of a kpt pkg get on the cluster-capi-kind package into a directory called lambda-cluster on that branch, with the same transformations on package files carried out as the kpt pkg get command above, this content is checked into the new branch in the initial commit

  3. The pipeline specified in the Kptfileof the cluster-capi-kind package specifies an apply-replacements specified in the apply-replacements.yaml file in the package and uses the value of the workload-cluster.yaml:spec.clusterName field set in 2. above (which is the workload cluster name). This has the value of example in the workload-cluster.yaml file. This means that in the cluster.yaml file the value of field metadata.name is changed from workload to example.

  4. The package variant spec.injectors changes specified in the pv-cluster.yaml file are applied.
    a. The relevant pv-cluster.yaml fields are: ``` spec: injectors:

    • kind: WorkloadCluster name: example pipeline: mutators:

      • image: gcr.io/kpt-fn/set-annotations:v0.1.4 configMap: nephio.org/cluster-name: example ```

    b. The following PackageVariant changes are made to the lambda-cluster package:

    1. The field info.readinessGates.conditionType is added to the Kptfile with the value config.injection.WorkloadCluster.workload-cluster.
    2. An extra pipeline.mutators entry is inserted in the Kptfile. This mutator is the mutator specified in the pv-cluster.yaml package variant specification, which specifies that the annotation nephio.org/cluster-name: lambda should be set on the resources in the package:
      pipeline:
    mutators:
    - name: PackageVariant.lambda-cluster..0
      image: gcr.io/kpt-fn/set-annotations:v0.1.4
      configMap:
        nephio.org/cluster-name: lambda
    1. The field status.conditions is added to the Kptfile with the values below. This condition means that the kpt package is not considered to be applied until the condition config.injection.WorkloadCluster.workload-cluster is True:
      status:
    conditions:
    - type: config.injection.WorkloadCluster.workload-cluster
      status: "True"
      message: injected resource "lambda" from cluster
      reason: ConfigInjected
    1. The spec in the WorkloadCluster file workload-cluster.yaml is set. This is the specification of the extra configuration that will be carried out on the workload cluster once kind has brought it up:
      clusterName: lambda
    cnis:
    - macvlan
    - ipvlan
    - sriov
    masterInterface: eth1

  5. The amended pipeline specified in the Kptfileof the lambda-cluster is now re-executed. It was previously executed in step 3 above but there is now an extra mutator added by the package variant. The following changes result:

    a. The new mutator added to the Kptfile by the package variant adds the annotation nephio.org/cluster-name: lambda is added to every resource in the package. b. The existing annotation in the Kptfile (coming from the Kptfile in the parent cluster-capi-kind package) sets the value lambda of the spec.clusterName field in workload-cluster.yaml as the value of the metadata.name field in the cluster.yaml file.

  6. The lambda-cluster package is now ready to go. It is proposed and approved and the process of cluster creation commences.

Cluster Creation

TBD.

pv-rootsync.yaml:

TBD.

pv-repo.yaml: create the workload cluster repository

TBD.

pv-configsync.yaml:

TBD.

pv-kindnet.yaml:

TBD.

pv-local-path-provisioner.yaml:

TBD.

pv-multus.yaml:

TBD.

pv-vlanindex.yaml:

TBD.