OCI Repositories

The GitOps Toolkit Custom Resource Definitions documentation.

The OCIRepository API defines a Source to produce an Artifact for an OCI repository.

Example

The following is an example of an OCIRepository. It creates a tarball (.tar.gz) Artifact with the fetched data from an OCI repository for the resolved digest.

---
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: podinfo
  namespace: default
spec:
  interval: 5m0s
  url: oci://ghcr.io/stefanprodan/manifests/podinfo
  ref:
    tag: latest

In the above example:

  • An OCIRepository named podinfo is created, indicated by the .metadata.name field.
  • The source-controller checks the OCI repository every five minutes, indicated by the .spec.interval field.
  • It pulls the latest tag of the ghcr.io/stefanprodan/manifests/podinfo repository, indicated by the .spec.ref.tag and .spec.url fields.
  • The resolved tag and SHA256 digest is used as the Artifact revision, reported in-cluster in the .status.artifact.revision field.
  • When the current OCIRepository digest differs from the latest fetched digest, a new Artifact is archived.
  • The new Artifact is reported in the .status.artifact field.

You can run this example by saving the manifest into ocirepository.yaml.

  1. Apply the resource on the cluster:

    kubectl apply -f ocirepository.yaml
    
  2. Run kubectl get ocirepository to see the OCIRepository:

    NAME      URL                                            AGE   READY   STATUS                                                                        
    podinfo   oci://ghcr.io/stefanprodan/manifests/podinfo   5s    True    stored artifact with revision 'latest@sha256:3b6cdcc7adcc9a84d3214ee1c029543789d90b5ae69debe9efa3f66e982875de'
    
  3. Run kubectl describe ocirepository podinfo to see the Artifact and Conditions in the OCIRepository’s Status:

    ...
    Status:
      Artifact:
        Digest:            sha256:d7e924b4882e55b97627355c7b3d2e711e9b54303afa2f50c25377f4df66a83b
        Last Update Time:  2022-06-14T11:23:36Z
        Path:              ocirepository/default/podinfo/3b6cdcc7adcc9a84d3214ee1c029543789d90b5ae69debe9efa3f66e982875de.tar.gz
        Revision:          latest@sha256:3b6cdcc7adcc9a84d3214ee1c029543789d90b5ae69debe9efa3f66e982875de
        Size:              1105
        URL:               http://source-controller.flux-system.svc.cluster.local./ocirepository/oci/podinfo/3b6cdcc7adcc9a84d3214ee1c029543789d90b5ae69debe9efa3f66e982875de.tar.gz
      Conditions:
        Last Transition Time:  2022-06-14T11:23:36Z
        Message:               stored artifact for revision 'latest@sha256:3b6cdcc7adcc9a84d3214ee1c029543789d90b5ae69debe9efa3f66e982875de'
        Observed Generation:   1
        Reason:                Succeeded
        Status:                True
        Type:                  Ready
        Last Transition Time:  2022-06-14T11:23:36Z
        Message:               stored artifact for revision 'latest@sha256:3b6cdcc7adcc9a84d3214ee1c029543789d90b5ae69debe9efa3f66e982875de'
        Observed Generation:   1
        Reason:                Succeeded
        Status:                True
        Type:                  ArtifactInStorage
      Observed Generation:     1
      URL:                     http://source-controller.source-system.svc.cluster.local./gitrepository/default/podinfo/latest.tar.gz
    Events:
      Type    Reason               Age   From               Message
      ----    ------               ----  ----               -------
      Normal  NewArtifact          62s   source-controller  stored artifact with revision 'latest/3b6cdcc7adcc9a84d3214ee1c029543789d90b5ae69debe9efa3f66e982875de' from 'oci://ghcr.io/stefanprodan/manifests/podinfo'
    

Writing an OCIRepository spec

As with all other Kubernetes config, an OCIRepository needs apiVersion, kind, and metadata fields. The name of an OCIRepository object must be a valid DNS subdomain name.

An OCIRepository also needs a .spec section.

URL

.spec.url is a required field that specifies the address of the container image repository in the format oci://<host>:<port>/<org-name>/<repo-name>.

Note: that specifying a tag or digest is not acceptable for this field.

Provider

.spec.provider is an optional field that allows specifying an OIDC provider used for authentication purposes.

Supported options are:

  • generic
  • aws
  • azure
  • gcp

The generic provider can be used for public repositories or when static credentials are used for authentication, either with spec.secretRef or spec.serviceAccountName. If you do not specify .spec.provider, it defaults to generic.

AWS

The aws provider can be used to authenticate automatically using the EKS worker node IAM role or IAM Role for Service Accounts (IRSA), and by extension gain access to ECR.

When the worker node IAM role has access to ECR, source-controller running on it will also have access to ECR.

When using IRSA to enable access to ECR, add the following patch to your bootstrap repository, in the flux-system/kustomization.yaml file:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - gotk-components.yaml
  - gotk-sync.yaml
patches:
  - patch: |
      apiVersion: v1
      kind: ServiceAccount
      metadata:
        name: source-controller
        annotations:
          eks.amazonaws.com/role-arn: <role arn>      
    target:
      kind: ServiceAccount
      name: source-controller

Note that you can attach the AWS managed policy arn:aws:iam::aws:policy/AmazonEC2ContainerRegistryReadOnly to the IAM role when using IRSA.

Azure

The azure provider can be used to authenticate automatically using Workload Identity and Kubelet Managed Identity to gain access to ACR.

Kubelet Managed Identity

When the kubelet managed identity has access to ACR, source-controller running on it will also have access to ACR.

Note: If you have more than one identity configured on the cluster, you have to specify which one to use by setting the AZURE_CLIENT_ID environment variable in the source-controller deployment.

If you are running into further issues, please look at the troubleshooting guide.

Workload Identity

When using Workload Identity to enable access to ACR, add the following patch to your bootstrap repository, in the flux-system/kustomization.yaml file:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - gotk-components.yaml
  - gotk-sync.yaml
patches:
  - patch: |-
      apiVersion: v1
      kind: ServiceAccount
      metadata:
        name: source-controller
        namespace: flux-system
        annotations:
          azure.workload.identity/client-id: <AZURE_CLIENT_ID>
        labels:
          azure.workload.identity/use: "true"      
  - patch: |-
      apiVersion: apps/v1
      kind: Deployment
      metadata:
        name: source-controller
        namespace: flux-system
        labels:
          azure.workload.identity/use: "true"
      spec:
        template:
          metadata:
            labels:
              azure.workload.identity/use: "true"      

Ensure Workload Identity is properly set up on your cluster and the mutating webhook is installed. Create an identity that has access to ACR. Next, establish a federated identity between the source-controller ServiceAccount and the identity. Patch the source-controller Deployment and ServiceAccount as shown in the patch above. Please take a look at this guide.

GCP

The gcp provider can be used to authenticate automatically using OAuth scopes or Workload Identity, and by extension gain access to GCR or Artifact Registry.

When the GKE nodes have the appropriate OAuth scope for accessing GCR and Artifact Registry, source-controller running on it will also have access to them.

When using Workload Identity to enable access to GCR or Artifact Registry, add the following patch to your bootstrap repository, in the flux-system/kustomization.yaml file:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - gotk-components.yaml
  - gotk-sync.yaml
patches:
  - patch: |
      apiVersion: v1
      kind: ServiceAccount
      metadata:
        name: source-controller
        annotations:
          iam.gke.io/gcp-service-account: <identity-name>      
    target:
      kind: ServiceAccount
      name: source-controller

The Artifact Registry service uses the permission artifactregistry.repositories.downloadArtifacts that is located under the Artifact Registry Reader role. If you are using Google Container Registry service, the needed permission is instead storage.objects.list which can be bound as part of the Container Registry Service Agent role. Take a look at this guide for more information about setting up GKE Workload Identity.

Secret reference

.spec.secretRef.name is an optional field to specify a name reference to a Secret in the same namespace as the OCIRepository, containing authentication credentials for the OCI repository.

This secret is expected to be in the same format as imagePullSecrets. The usual way to create such a secret is with:

kubectl create secret docker-registry ...

Service Account reference

.spec.serviceAccountName is an optional field to specify a name reference to a Service Account in the same namespace as the OCIRepository. The controller will fetch the image pull secrets attached to the service account and use them for authentication.

Note: that for a publicly accessible image repository, you don’t need to provide a secretRef nor serviceAccountName.

Cert secret reference

.spec.certSecretRef.name is an optional field to specify a secret containing TLS certificate data. The secret can contain the following keys:

  • tls.crt and tls.key, to specify the client certificate and private key used for TLS client authentication. These must be used in conjunction, i.e. specifying one without the other will lead to an error.
  • ca.crt, to specify the CA certificate used to verify the server, which is required if the server is using a self-signed certificate.

If the server is using a self-signed certificate and has TLS client authentication enabled, all three values are required.

The Secret should be of type Opaque or kubernetes.io/tls. All the files in the Secret are expected to be PEM-encoded. Assuming you have three files; client.key, client.crt and ca.crt for the client private key, client certificate and the CA certificate respectively, you can generate the required Secret using the flux create secret tls command:

flux create secret tls --tls-key-file=client.key --tls-crt-file=client.crt --ca-crt-file=ca.crt

Example usage:

---
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: example
  namespace: default
spec:
  interval: 5m0s
  url: oci://example.com
  certSecretRef:
    name: example-tls
---
apiVersion: v1
kind: Secret
metadata:
  name: example-tls
  namespace: default
type: kubernetes.io/tls # or Opaque
data:
  tls.crt: <BASE64>
  tls.key: <BASE64>
  # NOTE: Can be supplied without the above values
  ca.crt: <BASE64>

Warning: Support for the caFile, certFile and keyFile keys have been deprecated. If you have any Secrets using these keys and specified in an OCIRepository, the controller will log a deprecation warning.

Proxy secret reference

.spec.proxySecretRef.name is an optional field used to specify the name of a Secret that contains the proxy settings for the object. These settings are used for all the remote operations related to the OCIRepository. The Secret can contain three keys:

  • address, to specify the address of the proxy server. This is a required key.
  • username, to specify the username to use if the proxy server is protected by basic authentication. This is an optional key.
  • password, to specify the password to use if the proxy server is protected by basic authentication. This is an optional key.

Example:

---
apiVersion: v1
kind: Secret
metadata:
  name: http-proxy
type: Opaque
stringData:
  address: http://proxy.com
  username: mandalorian
  password: grogu

Proxying can also be configured in the source-controller Deployment directly by using the standard environment variables such as HTTPS_PROXY, ALL_PROXY, etc.

.spec.proxySecretRef.name takes precedence over all environment variables.

Warning: Cosign keyless verification is not supported for this API. If you require cosign keyless verification to use a proxy you must use the standard environment variables mentioned above. If you specify a proxySecretRef the controller will simply send out the requests needed for keyless verification without the associated object-level proxy settings.

Insecure

.spec.insecure is an optional field to allow connecting to an insecure (HTTP) container registry server, if set to true. The default value is false, denying insecure (HTTP) connections.

Interval

.spec.interval is a required field that specifies the interval at which the OCI repository must be fetched.

After successfully reconciling the object, the source-controller requeues it for inspection after the specified interval. The value must be in a Go recognized duration string format, e.g. 10m0s to reconcile the object every 10 minutes.

If the .metadata.generation of a resource changes (due to e.g. a change to the spec), this is handled instantly outside the interval window.

Note: The controller can be configured to apply a jitter to the interval in order to distribute the load more evenly when multiple OCIRepository objects are set up with the same interval. For more information, please refer to the source-controller configuration options.

Timeout

.spec.timeout is an optional field to specify a timeout for OCI operations like pulling. The value must be in a Go recognized duration string format, e.g. 1m30s for a timeout of one minute and thirty seconds. The default value is 60s.

Reference

.spec.ref is an optional field to specify the OCI reference to resolve and watch for changes. References are specified in one or more subfields (.tag, .semver, .digest), with latter listed fields taking precedence over earlier ones. If not specified, it defaults to the latest tag.

Tag example

To pull a specific tag, use .spec.ref.tag:

---
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: <repository-name>
spec:
  ref:
    tag: "<tag-name>"

SemVer example

To pull a tag based on a SemVer range, use .spec.ref.semver:

---
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: <repository-name>
spec:
  ref:
    # SemVer range reference: https://github.com/Masterminds/semver#checking-version-constraints
    semver: "<semver-range>"

This field takes precedence over .tag.

SemverFilter example

.spec.ref.semverFilter is an optional field to specify a SemVer filter to apply when fetching tags from the OCI repository. The filter is a regular expression that is applied to the tags fetched from the repository. Only tags that match the filter are considered for the semver range resolution.

Note: The filter is only taken into account when the .spec.ref.semver field is set.

---
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: podinfo
  namespace: default
spec:
  interval: 5m0s
  url: oci://ghcr.io/stefanprodan/manifests/podinfo
  ref:
    # SemVer comparisons using constraints without a prerelease comparator will skip prerelease versions.
    # Adding a `-0` suffix to the semver range will include prerelease versions.
    semver: ">= 6.1.x-0"
    semverFilter: ".*-rc.*"

In the above example, the controller fetches tags from the ghcr.io/stefanprodan/manifests/podinfo repository and filters them using the regular expression .*-rc.*. Only tags that contain the -rc suffix are considered for the semver range resolution.

Digest example

To pull a specific digest, use .spec.ref.digest:

---
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: <repository-name>
spec:
  ref:
    digest: "sha256:<SHA-value>"

This field takes precedence over all other fields.

Layer selector

spec.layerSelector is an optional field to specify which layer should be extracted from the OCI Artifact. If not specified, the controller will extract the first layer found in the artifact.

To extract a layer matching a specific OCI media type:

---
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: <repository-name>
spec:
  layerSelector:
    mediaType: "application/deployment.content.v1.tar+gzip"
    operation: extract # can be 'extract' or 'copy', defaults to 'extract'

If the layer selector matches more than one layer, the first layer matching the specified media type will be used. Note that the selected OCI layer must be compressed in the tar+gzip format.

When .spec.layerSelector.operation is set to copy, instead of extracting the compressed layer, the controller copies the tarball as-is to storage, thus keeping the original content unaltered.

Ignore

.spec.ignore is an optional field to specify rules in the .gitignore pattern format. Paths matching the defined rules are excluded while archiving.

When specified, .spec.ignore overrides the default exclusion list, and may overrule the .sourceignore file exclusions. See excluding files for more information.

Verification

.spec.verify is an optional field to enable the verification of Cosign or Notation signatures. The field offers three subfields:

  • .provider, to specify the verification provider. The supported options are cosign and notation at present.
  • .secretRef.name, to specify a reference to a Secret in the same namespace as the OCIRepository, containing the Cosign public keys of trusted authors. For Notation this Secret should also include the trust policy in addition to the CA certificate.
  • .matchOIDCIdentity, to specify a list of OIDC identity matchers (only supported when using cosign as the verification provider). Please see Keyless verification for more details.

Cosign

The cosign provider can be used to verify the signature of an OCI artifact using either a known public key or via the Cosign Keyless procedure.

---
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: <repository-name>
spec:
  verify:
    provider: cosign
    secretRef:
      name: cosign-public-keys

When the verification succeeds, the controller adds a Condition with the following attributes to the OCIRepository’s .status.conditions:

  • type: SourceVerified
  • status: "True"
  • reason: Succeeded
Public keys verification

To verify the authenticity of an OCI artifact, create a Kubernetes secret with the Cosign public keys:

---
apiVersion: v1
kind: Secret
metadata:
  name: cosign-public-keys
type: Opaque
data:
  key1.pub: <BASE64>
  key2.pub: <BASE64>

Note that the keys must have the .pub extension for Flux to make use of them.

Flux will loop over the public keys and use them to verify an artifact’s signature. This allows for older artifacts to be valid as long as the right key is in the secret.

Keyless verification

For publicly available OCI artifacts, which are signed using the Cosign Keyless procedure, you can enable the verification by omitting the .verify.secretRef field.

To verify the identity’s subject and the OIDC issuer present in the Fulcio certificate, you can specify a list of OIDC identity matchers using .spec.verify.matchOIDCIdentity. The matcher provides two required fields:

  • .issuer, to specify a regexp that matches against the OIDC issuer.
  • .subject, to specify a regexp that matches against the subject identity in the certificate. Both values should follow the Go regular expression syntax.

The matchers are evaluated in an OR fashion, i.e. the identity is deemed to be verified if any one matcher successfully matches against the identity.

Example of verifying artifacts signed by the Cosign GitHub Action with GitHub OIDC Token:

apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: podinfo
spec:
  interval: 5m
  url: oci://ghcr.io/stefanprodan/manifests/podinfo
  verify:
    provider: cosign
    matchOIDCIdentity:
      - issuer: "^https://token.actions.githubusercontent.com$"
        subject: "^https://github.com/stefanprodan/podinfo.*$"

The controller verifies the signatures using the Fulcio root CA and the Rekor instance hosted at rekor.sigstore.dev.

Note that keyless verification is an experimental feature, using custom root CAs or self-hosted Rekor instances are not currently supported.

Notation

The notation provider can be used to verify the signature of an OCI artifact using known trust policy and CA certificate.

---
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: <repository-name>
spec:
  verify:
    provider: notation
    secretRef:
      name: notation-config

When the verification succeeds, the controller adds a Condition with the following attributes to the OCIRepository’s .status.conditions:

  • type: SourceVerified
  • status: "True"
  • reason: Succeeded

To verify the authenticity of an OCI artifact, create a Kubernetes secret containing Certificate Authority (CA) root certificates and the a trust policy

---
apiVersion: v1
kind: Secret
metadata:
  name: notation-config
type: Opaque
data:
  certificate1.pem: <BASE64>
  certificate2.crt: <BASE64>
  trustpolicy.json: <BASE64>

Note that the CA certificates must have either .pem or .crt extension and your trust policy must be named trustpolicy.json for Flux to make use of them.

For more information on the signing and verification process see Signing and Verification Workflow.

Flux will loop over the certificates and use them to verify an artifact’s signature. This allows for older artifacts to be valid as long as the right certificate is in the secret.

Suspend

.spec.suspend is an optional field to suspend the reconciliation of a OCIRepository. When set to true, the controller will stop reconciling the OCIRepository, and changes to the resource or in the OCI repository will not result in a new Artifact. When the field is set to false or removed, it will resume.

Working with OCIRepositories

Excluding files

By default, files which match the default exclusion rules are excluded while archiving the OCI repository contents as an Artifact. It is possible to overwrite and/or overrule the default exclusions using the .spec.ignore field.

---
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: <repository-name>
spec:
  ignore: |
    # exclude all
    /*
    # include deploy dir
    !/deploy
    # exclude file extensions from deploy dir
    /deploy/**/*.md
    /deploy/**/*.txt    

.sourceignore file

Excluding files is possible by adding a .sourceignore file in the artifact. The .sourceignore file follows the .gitignore pattern format, and pattern entries may overrule default exclusions.

The controller recursively loads ignore files so a .sourceignore can be placed in the artifact root or in subdirectories.

Triggering a reconcile

To manually tell the source-controller to reconcile a OCIRepository outside the specified interval window, an OCIRepository can be annotated with reconcile.fluxcd.io/requestedAt: <arbitrary value>. Annotating the resource queues the OCIRepository for reconciliation if the <arbitrary-value> differs from the last value the controller acted on, as reported in .status.lastHandledReconcileAt.

Using kubectl:

kubectl annotate --field-manager=flux-client-side-apply --overwrite ocirepository/<repository-name> reconcile.fluxcd.io/requestedAt="$(date +%s)"

Using flux:

flux reconcile source oci <repository-name>

Waiting for Ready

When a change is applied, it is possible to wait for the OCIRepository to reach a ready state using kubectl:

kubectl wait gitrepository/<repository-name> --for=condition=ready --timeout=1m

Suspending and resuming

When you find yourself in a situation where you temporarily want to pause the reconciliation of an OCIRepository, you can suspend it using the .spec.suspend field.

Suspend an OCIRepository

In your YAML declaration:

---
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: <repository-name>
spec:
  suspend: true

Using kubectl:

kubectl patch ocirepository <repository-name> --field-manager=flux-client-side-apply -p '{\"spec\": {\"suspend\" : true }}'

Using flux:

flux suspend source oci <repository-name>

Note: When an OCIRepository has an Artifact and it is suspended, and this Artifact later disappears from the storage due to e.g. the source-controller Pod being evicted from a Node, this will not be reflected in the OCIRepository’s Status until it is resumed.

Resume an OCIRepository

In your YAML declaration, comment out (or remove) the field:

---
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: <repository-name>
spec:
  # suspend: true

Note: Setting the field value to false has the same effect as removing it, but does not allow for “hot patching” using e.g. kubectl while practicing GitOps; as the manually applied patch would be overwritten by the declared state in Git.

Using kubectl:

kubectl patch ocirepository <repository-name> --field-manager=flux-client-side-apply -p '{\"spec\" : {\"suspend\" : false }}'

Using flux:

flux resume source oci <repository-name>

Debugging an OCIRepository

There are several ways to gather information about a OCIRepository for debugging purposes.

Describe the OCIRepository

Describing an OCIRepository using kubectl describe ocirepository <repository-name> displays the latest recorded information for the resource in the Status and Events sections:

...
Status:
...
  Conditions:
    Last Transition Time:  2022-02-14T09:40:27Z
    Message:               processing object: new generation 1 -> 2
    Observed Generation:   2
    Reason:                ProgressingWithRetry
    Status:                True
    Type:                  Reconciling
    Last Transition Time:  2022-02-14T09:40:27Z
    Message:               failed to pull artifact from 'oci://ghcr.io/stefanprodan/manifests/podinfo': couldn't find tag "0.0.1"
    Observed Generation:   2
    Reason:                OCIOperationFailed
    Status:                False
    Type:                  Ready
    Last Transition Time:  2022-02-14T09:40:27Z
    Message:               failed to pull artifact from 'oci://ghcr.io/stefanprodan/manifests/podinfo': couldn't find tag "0.0.1"
    Observed Generation:   2
    Reason:                OCIOperationFailed
    Status:                True
    Type:                  FetchFailed
  Observed Generation:     1
  URL:                     http://source-controller.source-system.svc.cluster.local./ocirepository/default/podinfo/latest.tar.gz
Events:
  Type     Reason                      Age                  From               Message
  ----     ------                      ----                 ----               -------
  Warning  OCIOperationFailed          2s (x9 over 4s)      source-controller  failed to pull artifact from 'oci://ghcr.io/stefanprodan/manifests/podinfo': couldn't find tag "0.0.1"

Trace emitted Events

To view events for specific OCIRepository(s), kubectl events can be used in combination with --for to list the Events for specific objects. For example, running

kubectl events --for OCIRepository/<repository-name>

lists

LAST SEEN   TYPE     REASON                OBJECT                               MESSAGE
2m14s       Normal   NewArtifact           ocirepository/<repository-name>      stored artifact for revision 'latest@sha256:3b6cdcc7adcc9a84d3214ee1c029543789d90b5ae69debe9efa3f66e982875de'
36s         Normal   ArtifactUpToDate      ocirepository/<repository-name>      artifact up-to-date with remote revision: 'latest@sha256:3b6cdcc7adcc9a84d3214ee1c029543789d90b5ae69debe9efa3f66e982875de'
94s         Warning  OCIOperationFailed    ocirepository/<repository-name>      failed to pull artifact from 'oci://ghcr.io/stefanprodan/manifests/podinfo': couldn't find tag "0.0.1"

Besides being reported in Events, the reconciliation errors are also logged by the controller. The Flux CLI offer commands for filtering the logs for a specific OCIRepository, e.g. flux logs --level=error --kind=OCIRepository --name=<repository-name>.

OCIRepository Status

Artifact

The OCIRepository reports the latest synchronized state from the OCI repository as an Artifact object in the .status.artifact of the resource.

The .status.artifact.revision holds the tag and SHA256 digest of the upstream OCI artifact.

The .status.artifact.metadata holds the upstream OCI artifact metadata such as the OpenContainers standard annotations. If the OCI artifact was created with flux push artifact, then the metadata will contain the following annotations:

  • org.opencontainers.image.created the date and time on which the artifact was built
  • org.opencontainers.image.source the URL of the Git repository containing the source files
  • org.opencontainers.image.revision the Git branch and commit SHA1 of the source files

The Artifact file is a gzip compressed TAR archive (<commit sha>.tar.gz), and can be retrieved in-cluster from the .status.artifact.url HTTP address.

Artifact example

apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: OCIRepository
metadata:
  name: <repository-name>
status:
  artifact:
    digest: sha256:9f3bc0f341d4ecf2bab460cc59320a2a9ea292f01d7b96e32740a9abfd341088
    lastUpdateTime: "2022-08-08T09:35:45Z"
    metadata:
      org.opencontainers.image.created: "2022-08-08T12:31:41+03:00"
      org.opencontainers.image.revision: 6.1.8/b3b00fe35424a45d373bf4c7214178bc36fd7872
      org.opencontainers.image.source: https://github.com/stefanprodan/podinfo.git
    path: ocirepository/<namespace>/<repository-name>/<digest>.tar.gz
    revision: <tag>@<digest>
    size: 1105
    url: http://source-controller.<namespace>.svc.cluster.local./ocirepository/<namespace>/<repository-name>/<digest>.tar.gz

Default exclusions

The following files and extensions are excluded from the Artifact by default:

  • Git files (.git/, .gitignore, .gitmodules, .gitattributes)
  • File extensions (.jpg, .jpeg, .gif, .png, .wmv, .flv, .tar.gz, .zip)
  • CI configs (.github/, .circleci/, .travis.yml, .gitlab-ci.yml, appveyor.yml, .drone.yml, cloudbuild.yaml, codeship-services.yml, codeship-steps.yml)
  • CLI configs (.goreleaser.yml, .sops.yaml)
  • Flux v1 config (.flux.yaml)

To define your own exclusion rules, see excluding files.

Conditions

OCIRepository has various states during its lifecycle, reflected as Kubernetes Conditions. It can be reconciling while fetching the remote state, it can be ready, or it can fail during reconciliation.

The OCIRepository API is compatible with the kstatus specification, and reports Reconciling and Stalled conditions where applicable to provide better (timeout) support to solutions polling the OCIRepository to become Ready.

Reconciling OCIRepository

The source-controller marks an OCIRepository as reconciling when one of the following is true:

  • There is no current Artifact for the OCIRepository, or the reported Artifact is determined to have disappeared from the storage.
  • The generation of the OCIRepository is newer than the Observed Generation.
  • The newly resolved Artifact digest differs from the current Artifact.

When the OCIRepository is “reconciling”, the Ready Condition status becomes Unknown when the controller detects drift, and the controller adds a Condition with the following attributes to the OCIRepository’s .status.conditions:

  • type: Reconciling
  • status: "True"
  • reason: Progressing | reason: ProgressingWithRetry

If the reconciling state is due to a new revision, an additional Condition is added with the following attributes:

  • type: ArtifactOutdated
  • status: "True"
  • reason: NewRevision

Both Conditions have a “negative polarity”, and are only present on the OCIRepository while their status value is "True".

Ready OCIRepository

The source-controller marks an OCIRepository as ready when it has the following characteristics:

  • The OCIRepository reports an Artifact.
  • The reported Artifact exists in the controller’s Artifact storage.
  • The controller was able to communicate with the remote OCI repository using the current spec.
  • The digest of the reported Artifact is up-to-date with the latest resolved digest of the remote OCI repository.

When the OCIRepository is “ready”, the controller sets a Condition with the following attributes in the OCIRepository’s .status.conditions:

  • type: Ready
  • status: "True"
  • reason: Succeeded

This Ready Condition will retain a status value of "True" until the OCIRepository is marked as reconciling, or e.g. a transient error occurs due to a temporary network issue.

When the OCIRepository Artifact is archived in the controller’s Artifact storage, the controller sets a Condition with the following attributes in the OCIRepository’s .status.conditions:

  • type: ArtifactInStorage
  • status: "True"
  • reason: Succeeded

This ArtifactInStorage Condition will retain a status value of "True" until the Artifact in the storage no longer exists.

Failed OCIRepository

The source-controller may get stuck trying to produce an Artifact for a OCIRepository without completing. This can occur due to some of the following factors:

  • The remote OCI repository URL is temporarily unavailable.
  • The OCI repository does not exist.
  • The Secret reference contains a reference to a non-existing Secret.
  • The credentials in the referenced Secret are invalid.
  • The OCIRepository spec contains a generic misconfiguration.
  • A storage related failure when storing the artifact.

When this happens, the controller sets the Ready Condition status to False, and adds a Condition with the following attributes to the OCIRepository’s .status.conditions:

  • type: FetchFailed | type: IncludeUnavailable | type: StorageOperationFailed
  • status: "True"
  • reason: AuthenticationFailed | reason: OCIArtifactPullFailed | reason: OCIArtifactLayerOperationFailed

This condition has a “negative polarity”, and is only present on the OCIRepository while the status value is "True". There may be more arbitrary values for the reason field to provide accurate reason for a condition.

In addition to the above Condition types, when the signature verification fails. A condition with the following attributes is added to the GitRepository’s .status.conditions:

  • type: SourceVerified
  • status: "False"
  • reason: VerificationError

While the OCIRepository has one or more of these Conditions, the controller will continue to attempt to produce an Artifact for the resource with an exponential backoff, until it succeeds and the OCIRepository is marked as ready.

Note that a OCIRepository can be reconciling while failing at the same time, for example due to a newly introduced configuration issue in the OCIRepository spec. When a reconciliation fails, the Reconciling Condition reason would be ProgressingWithRetry. When the reconciliation is performed again after the failure, the reason is updated to Progressing.

Content Configuration Checksum

The source-controller calculates the SHA256 checksum of the various configurations of the OCIRepository that indicate a change in source and records it in .status.contentConfigChecksum. This field is used to determine if the source artifact needs to be rebuilt.

Deprecation Note: contentConfigChecksum is no longer used and will be removed in the next API version. The individual components used for generating content configuration checksum now have explicit fields in the status. This makes the observations used by the controller for making artifact rebuild decisions more transparent and easier to debug.

Observed Ignore

The source-controller reports an observed ignore in the OCIRepository’s .status.observedIgnore. The observed ignore is the latest .spec.ignore value which resulted in a ready state, or stalled due to error it can not recover from without human intervention. The value is the same as the ignore in spec. It indicates the ignore rules used in building the current artifact in storage. It is also used by the controller to determine if an artifact needs to be rebuilt.

Example:

status:
  ...
  observedIgnore: |
    hpa.yaml
    build    
  ...

Observed Layer Selector

The source-controller reports an observed layer selector in the OCIRepository’s .status.observedLayerSelector. The observed layer selector is the latest .spec.layerSelector value which resulted in a ready state, or stalled due to error it can not recover from without human intervention. The value is the same as the layer selector in spec. It indicates the layer selection configuration used in building the current artifact in storage. It is also used by the controller to determine if an artifact needs to be rebuilt.

Example:

status:
  ...
  observedLayerSelector:
    mediaType: application/vnd.docker.image.rootfs.diff.tar.gzip
    operation: copy
  ...

Observed Generation

The source-controller reports an observed generation in the OCIRepository’s .status.observedGeneration. The observed generation is the latest .metadata.generation which resulted in either a ready state, or stalled due to error it can not recover from without human intervention.

Last Handled Reconcile At

The source-controller reports the last reconcile.fluxcd.io/requestedAt annotation value it acted on in the .status.lastHandledReconcileAt field.

For practical information about this field, see triggering a reconcile.