This type of matching should be used sparingly and carefully as it will instruct the API server to send every eligible resource type to Kyverno, greatly increasing the amount of processing performed by Kyverno. Typical uses for this type of wildcard matching are elements within the metadata object. WarningKeep in mind that when matching on all kinds ( *) the policy you write must be applicable across all of them. In this snippet, the match statement matches on all resources that EITHER have the kind Service with name “staging” OR have the kind Service and are being created in the “prod” Namespace. match statements also require an any or all expression allowing greater flexibility in treating multiple conditions. Variable substitution is not currently supported in match or exclude statements. The most common type of element in a match statement is one which filters on categories of Kubernetes resources, for example Pods, Deployments, Services, Namespaces, etc. Although the match statement can be complex having many different elements, there must be at least one. In every rule, there must be a single match statement to function as the filter to which the rule will apply. If both checks pass, then the rule logic to mutate, validate, or generate resources is applied. When Kyverno receives an AdmissionReview request (i.e., from a validation or mutation webhook), it first checks to see if the resource and user information matches or should be excluded from processing. Specifying a subresource in the format PodExecOptions is not supported. Use of a parent resource followed by its subresource is necessary to be explicit in the matching decision. Due to this, matching on Scale may apply to resources like Deployment as well as ReplicationController since Scale is common between both. Some subresources are shared by multiple API resources, for example the Scale resource. Wildcards are also supported when referencing subresources, for example */Node/status. They may be combined with previous naming as well, for example apps/v1/Deployment/scale or v1/Pod.eviction. For example, Pods/status or Pods.status will match on the /status subresource for a Pod. as a separator between parent and subresource. Subresources may be specified with either a / or. For the mutate rule type, a policy can only deal with the metadata object.For the validate rule type, a policy can only deal with deny statements and the metadata object in either pattern or anyPattern blocks.A policy using wildcards does not support generate or verifyImages rule types, and does not support forEach declarations. A policy using wildcards in match or exclude or that validates subresources is not allowed in background mode.This usually consists of machine-generated data, and can even be stored in JSON form. The reason why labels are used as selectors as opposed to annotations is because most Kubernetes implementation index labels in etcd.Īnnotations are used to store data about the resource itself Merge and stream logs of the various pod that share the same label Nonidentifying information that can be leveraged by tools andįind all pods that have a value associated with the key Resembles labels: annotations are key/value pairs designed to hold Provide the foundation for grouping objects.Īnnotations, on the other hand, provide a storage mechanism that They can be arbitrary, and are usefulįor attaching identifying information to Kubernetes objects. Labels are key/value pairs that can be attached to Kubernetes objects My understanding is rather limited here, however reading the official docs has not really helped me understand the use case of when do I use annotations vs labels. When do we use annotations over labels and vice-versa? What are the pros and cons of each? Is this right? If this is so, then what is the practical use of annotations? Is it something to do with performance? Where labels are under the scanner of Kubernetes for filters and annotations are purely for adding metadata that is just informational?īut I've seen in cases where deployments needing Nginx or ingress capabilities using annotations. Labels on the other hand are metadata key-value pairs that can be used by Kubernetes to identify/filter the resource. My understanding of annotations is that it is metadata that adds key-value pairs that cannot be used by Kubernetes for identifying/filtering the resource. I'm trying to wrap my head around the difference between annotations and labels.
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