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Package Management

Overview

kapp-controller provides a declarative way to install, manage, and upgrade packages on a Kubernetes cluster. It leverages the PackageRepository, PackageMetadata, Package, and PackageInstall CRDs to do so. Get started by installing the latest release of kapp-controller.

Concepts & CustomResourceDefinitions

Package

A package is a combination of configuration metadata and OCI images that informs the package manager what software it holds and how to install itself onto a Kubernetes cluster. For example, an nginx-ingress package would instruct the package manager where to download the nginx container image, how to configure the associated Deployment, and install it into a cluster.

A Package is represented in kapp-controller using a Package CR. The Package CR is created for every new version of a package and it carries information about how to fetch, template, and deploy the package. A Package CR is a namespaced resource by default. Learn more about how to share a Package CR across all namespaces within a cluster.

apiVersion: data.packaging.carvel.dev/v1alpha1
kind: Package
metadata:
  # Must be of the form '<spec.refName>.<spec.version>' (Note the period)
  name: fluent-bit.carvel.dev.1.5.3
  # The namespace this package is available in
  namespace: my-ns
spec:
  # The name of the PackageMetadata associated with this version
  # Must be a valid PackageMetadata name (see PackageMetadata CR for details)
  # Cannot be empty
  refName: fluent-bit.carvel.dev
  # Package version; Referenced by PackageInstall;
  # Must be valid semver (required)
  # Cannot be empty
  version: 1.5.3
  # Version release notes (optional; string)
  releaseNotes: "Fixed some bugs"
  # System requirements needed to install the package.
  # Note: these requirements will not be verified by kapp-controller on
  # installation. (optional; string)
  capacityRequirementsDescription: "RAM: 10GB"
  # Description of the licenses that apply to the package software
  # (optional; Array of strings)
  licenses:
  - "Apache 2.0"
  - "MIT"
  # Timestamp of release (iso8601 formatted string; optional)
  releasedAt: 2021-05-05T18:57:06Z
  # valuesSchema can be used to show template values that
  # can be configured by users when a Package is installed.
  # These values should be specified in an OpenAPI schema format. (optional)
  valuesSchema:
    # openAPIv3 key can be used to declare template values in OpenAPIv3
    # format. Read more on using ytt to generate this schema: 
    # https://carvel.dev/kapp-controller/docs/latest/packaging-tutorial/#creating-the-custom-resources
    openAPIv3:
      title: fluent-bit.carvel.dev.1.5.3 values schema
      examples:
      - namespace: fluent-bit
      properties:
        namespace:
          type: string
          description: Namespace where fluent-bit will be installed.
          default: fluent-bit
          examples:
          - fluent-bit
  # App template used to create the underlying App CR.
  # See 'App CR Spec' docs for more info
  template:
    spec:
      fetch:
      - imgpkgBundle:
          image: registry.tkg.vmware.run/tkg-fluent-bit@sha256:...
      template:
      - ytt:
          paths:
          - config/
      - kbld:
          paths:
          # - must be quoted when included with paths
          - "-"
          - .imgpkg/images.yml
      deploy:
      - kapp: {}

Package Metadata

Package Metadata are attributes of a single package that do not change frequently and that are shared across multiple versions of a single package. It contains information similar to a project’s README.md.

It is represented in kapp-controller by a PackageMetadata CR. A PackageMetadata CR is a namespaced resource by default. Learn more about how to share a PackageMetadata CR across all namespaces within a cluster.

apiVersion: data.packaging.carvel.dev/v1alpha1
kind: PackageMetadata
metadata:
  # Must consist of at least three segments separated by a '.'
  # Cannot have a trailing '.'
  name: fluent-bit.vmware.com
  # The namespace this package metadata is available in
  namespace: my-ns
spec:
  # Human friendly name of the package (optional; string)
  displayName: "Fluent Bit"
  # Long description of the package (optional; string)
  longDescription: "Fluent bit is an open source..."
  # Short desription of the package (optional; string)
  shortDescription: "Log processing and forwarding"
  # Base64 encoded icon (optional; string)
  iconSVGBase64: YXNmZGdlcmdlcg==
  # Name of the entity distributing the package (optional; string)
  providerName: VMware
  # List of maintainer info for the package.
  # Currently only supports the name key. (optional; array of maintner info)
  maintainers:
  - name: "Person 1"
  - name: "Person 2"
  # Classifiers of the package (optional; Array of strings)
  categories:
  - "logging"
  - "daemon-set"
  # Description of the support available for the package (optional; string)
  supportDescription: "..."

Package Repository

A package repository is a collection of packages and their metadata. Similar to a maven repository or a rpm repository, adding a package repository to a cluster gives users of that cluster the ability to install any of the packages from that repository.

It is represented in kapp-controller by a PackageRepository CR. A PackageRepository CR is a namespaced resource by default. Learn more about how to share a PackageRepository CR across all namespaces within a cluster.

apiVersion: packaging.carvel.dev/v1alpha1
kind: PackageRepository
metadata:
  # Any user-chosen name that describes package repository
  name: basic.carvel.dev
  # The namespace to make packages available to
  namespace: my-ns
spec:
  # pauses _future_ reconcilation; does _not_ affect
  # currently running reconciliation (optional; default=false)
  paused: true
  # specifies the length of time to wait, in time + unit
  # format, before reconciling.(optional; default=10m)
  syncPeriod: 1m
  # Must have only one directive.
  fetch:
    # pulls imgpkg bundle from Docker/OCI registry
    imgpkgBundle:
      # Docker image url; unqualified, tagged, or
      # digest references supported (required)
      image: host.com/username/image:v0.1.0
      # specifies a strategy to choose a tag (optional; v0.24.0+)
      # if specified, do not include a tag in url key
      tagSelection:
        semver:
          # list of semver constraints (see https://carvel.dev/vendir/docs/latest/versions/ for details) (required)
          constraints: ">1.0.0 <3.0.0"
          # by default prerelease versions are not included (optional; v0.24.0+)
          prereleases:
            # select prerelease versions that include given identifiers (optional; v0.24.0+)
            identifiers: [beta, rc]
    # pulls image containing packages from Docker/OCI registry
    image:
      # Image url; unqualified, tagged, or
      # digest references supported (required)
      url: host.com/username/image:v0.1.0
      # grab only portion of image (optional)
      subPath: inside-dir/dir2
      # specifies a strategy to choose a tag (optional; v0.24.0+)
      # if specified, do not include a tag in url key
      tagSelection:
        semver:
          # list of semver constraints (see https://carvel.dev/vendir/docs/latest/versions/ for details) (required)
          constraints: ">1.0.0 <3.0.0"
          # by default prerelease versions are not included (optional; v0.24.0+)
          prereleases:
            # select prerelease versions that include given identifiers (optional; v0.24.0+)
            identifiers: [beta, rc]
    # uses http library to fetch file containing packages
    http:
      # http and https url are supported;
      # plain file, tgz and tar types are supported (required)
      url: https://host.com/archive.tgz
      # checksum to verify after download (optional)
      sha256: 0a12cdef83...
      # grab only portion of download (optional)
      subPath: inside-dir/dir2
    # uses git to clone repository containing package list
    git:
      # http or ssh urls are supported (required)
      url: https://github.com/k14s/k8s-simple-app-example
      # branch, tag, commit; origin is the name of the remote (required)
      ref: origin/develop
      # grab only portion of repository (optional)
      subPath: config-step-2-template
      # skip lfs download (optional)
      lfsSkipSmudge: true
      # specifies a strategy to resolve to an explicit ref (optional; v0.24.0+)
      refSelection:
        semver:
          # list of semver constraints (see https://carvel.dev/vendir/docs/latest/versions/ for details) (required)
          constraints: ">0.4.0"
          # by default prerelease versions are not included (optional; v0.24.0+)
          prereleases:
            # select prerelease versions that include given identifiers (optional; v0.24.0+)
            identifiers: [beta, rc]

Package Install

A Package Install is an actual installation of a package and its underlying resources on a Kubernetes cluster. It is represented in kapp-controller by a PackageInstall CR. A PackageInstall CR must reference a Package CR.

apiVersion: packaging.carvel.dev/v1alpha1
kind: PackageInstall
metadata:
  name: fluent-bit
  # The namespace to install the package in to
  namespace: my-ns
spec:
  # pauses _future_ reconcilation; does _not_ affect
  # currently running reconciliation (optional; default=false)
  paused: true
  # cancels current and future reconciliations (optional; default=false)
  canceled: true
  # Deletion requests for the PackageInstall/App will result in 
  # the PackageInstall/App CR being deleted, but its associated 
  # resources will not be deleted (optional; default=false)
  noopDelete: true
  # specifies the length of time to wait, in time + unit
  # format, before reconciling. Always >= 30s. If value below
  # 30s is specified, 30s will be used. (optional; default=30s)
  syncPeriod: 1m
  # specifies that Package should be deployed to destination cluster;
  # by default, cluster is same as where this resource resides (optional)
  cluster:
    # specifies namespace in destination cluster (optional)
    namespace: ns2
    # specifies secret containing kubeconfig (required)
    kubeconfigSecretRef:
      # specifies secret name within app's namespace (required)
      name: cluster1
      # specifies key that contains kubeconfig (optional)
      key: value
  # specifies service account that will be used to install underlying package contents
  serviceAccountName: fluent-bit-sa
  packageRef:
    # Specifies the name of the package to install (required)
    refName: fluent-bit.vmware.com
    # Selects version of a package based on constraints provided (optional)
    # Either version or versionSelection is required.
    versionSelection:
      # Constraint to limit acceptable versions of a package;
      # Latest version satisfying the constraint is chosen;
      # Newly available, acceptable later versions are picked up and installed automatically. (optional)
      constraints: ">v1.5.3"
      # Include prereleases when selecting version. (optional)
      prereleases: {}
  # Values to be included in package's templating step
  # (currently only included in the first templating step) (optional)
  values:
  - secretRef:
      name: fluent-bit-values
# Populated by the controller
status:
  packageRef:
    # Kubernetes resource name of the package chosen against the constraints
    name: fluent-bit.tkg.vmware.com.v1.5.3
  # Derived from the underlying App's Status
  conditions:
  - type: ValuesSchemaCheckFailed
  - type: ReconcileSucceeded
  - type: ReconcileFailed
  - type: Reconciling

Note: Values will only be included in the first templating step of the package, though we intend to improve this experience in later releases.