## Crate k8s_openapi

Source
Expand description

Bindings for the Kubernetes client API, generated from the OpenAPI spec.

Each supported version of Kubernetes is represented by a feature name (like `v1_9`). Only one such feature can be enabled at a time.

These docs have been generated with the `v1_35` feature enabled. To see docs for one of the other supported versions, please generate the docs locally with `cargo doc --features 'v1_<>'`

## §Examples

### §Resources

This example creates an instance of `api::core::v1::PodSpec` with no other properties set, and pretty-prints it.

    use k8s_openapi::api::core::v1 as api;

    fn main() {
        let pod_spec: api::PodSpec = Default::default();
        println!("{pod_spec:#?}");
    }

## §Crate features

This crate contains several `v1_*` features. Enabling one of the `v1_*` features selects which version of the Kubernetes API server this crate should target. For example, enabling the `v1_50` feature means the crate will only contain the API exposed by Kubernetes 1.50. It will not expose API that were removed in 1.50 or earlier, nor any API added in 1.51 or later.

One and only one of the `v1_*` features must be enabled at the same time, otherwise the crate will not compile. This ensures that all crates in the crate graph use the same types. If it was possible for one library crate to use `api::core::v1::Pod` corresponding to v1.50 and another to use the type corresponding to v1.51, an application would not be able to use the same `Pod` value with both.

Thus, it is recommended that only application crates must enable one of the `v1_*` features, corresponding to the version of Kubernetes that the application wants to support.

    # For application crates

    [dependencies]
    k8s-openapi = { version = "...", features = ["v1_50"] }

If you’re writing a library crate, your crate must not enable any features of `k8s-openapi` directly. The choice of which feature to enable must be left to any application crates that use your library. This ensures that all `k8s-openapi`-using dependencies in that application crate’s dependency graph use the same set of `k8s-openapi` types and are interoperable.

If your library crate has tests or examples, you should also add a dev-dependency on `k8s-openapi` in addition to the direct dependency, and enable a version feature only for that dev-dependency.

    # For library crates

    [dependencies]
    k8s-openapi = "..."

    [dev-dependencies]
    k8s-openapi = { version = "...", features = ["v1_50"] }

However, commands like `cargo check` and `cargo doc` do not build dev dependencies, so they will not enable the feature and will fail to build. There are two ways you can resolve this:

1. Add a feature to your library that enables one of the k8s-openapi `v1_*` features, and then remember to enable this feature when running such commands.

       [features]
       __check = ["k8s-openapi/v1_50"]

       $ cargo check --features __check

2. Define the `K8S_OPENAPI_ENABLED_VERSION` env var when running such commands:

       $ K8S_OPENAPI_ENABLED_VERSION=1.50 cargo check

## §Conditional compilation

As the previous section explained, library crates must not enable any version features in their `k8s-openapi` dependency. However, your library crate may need to know about which version gets selected eventually.

For example:

1. Your crate creates a `PodSpec` and wants to set the `hostname_override` field. This field is only available in Kubernetes 1.34+, so you want your crate to fail to compile if a lower feature was enabled.

2. Your crate creates a `PodSpec` and wants to set the `hostname_override` field, but it’s okay to not set it when compiling for older versions.

There are two ways for your crate to determine which feature of `k8s-openapi` is enabled:

1. The `k8s-openapi` crate exports `k8s_if_*` macros, which either expand to their contents or don’t. See the docs of the macros for more details.

   With these macros, the two cases above would be solved like this:

   - ⓘ

         // The compile_error!() is only emitted if 1.33 or lower is selected.
         k8s_openapi::k8s_if_le_1_33! {
             compile_error!("This crate requires the v1_34 (or higher) feature to be enabled on the k8s-openapi crate.");
         }

         ...

         let pod_spec = k8s_openapi::api::core::v1::PodSpec {
             hostname_override: ...,
             ...
         };

   - ⓘ

         let mut pod_spec = k8s_openapi::api::core::v1::PodSpec {
             ...
         };

         k8s_openapi::k8s_if_ge_1_31! {
             pod_spec.hostname_override = ...;
         }

2. The `k8s-openapi` crate emits the selected version number as metadata that your crate can read in a build script from the `DEP_K8S_OPENAPI_*_VERSION` env var.

       // Your crate's build.rs

       fn main() {
           let k8s_openapi_version: u32 =
               std::env::vars_os()
               .find_map(|(key, value)| {
                   let key = key.into_string().ok()?;
                   if key.starts_with("DEP_K8S_OPENAPI_") && key.ends_with("_VERSION") {
                       let value = value.into_string().ok()?;
                       Some(value)
                   }
                   else {
                       None
                   }
               }).expect("DEP_K8S_OPENAPI_*_VERSION must have been set by k8s-openapi")
               .parse().expect("DEP_K8S_OPENAPI_*_VERSION is malformed");

           // k8s_openapi_version has the format 0x00_MM_NN_00.
           //
           // - MM is the major version.
           // - NN is the minor version.
           //
           // Thus, if the v1_34 feature was enabled, k8s_openapi_version would be 0x00_01_22_00

           // The build script can now do arbitrary things with the information.
           // For example, it could define custom cfgs:
           if k8s_openapi_version >= 0x00_01_22_00 {
               println!(r#"cargo::rustc-cfg=k8s_pod_spec_supports_hostname_override"#);
           }

           // ... or emit new source code files under OUT_DIR, or anything else a build script can do.
       }

   With this cfg, the two cases above would be solved like this:

   - ⓘ

         // The compile_error!() is only emitted if 1.33 or lower is selected.
         #[cfg(not(k8s_pod_spec_supports_hostname_override))]
         compile_error!("This crate requires the v1_34 (or higher) feature to be enabled on the k8s-openapi crate.");

         ...

         let pod_spec = k8s_openapi::api::core::v1::PodSpec {
             hostname_override: ...,
             ...
         };

   - ⓘ

         let pod_spec = k8s_openapi::api::core::v1::PodSpec {
             #[cfg(not(k8s_pod_spec_supports_hostname_override))]
             hostname_override: ...,
             ...
         };

Note that both approaches require your crate to have a direct dependency on the `k8s-openapi` crate. Neither approach is available if your crate only has a transitive dependency on the `k8s-openapi` crate.

The macros approach is easier to use since it doesn’t require a build script.

The build script method lets you emit arbitrary cfgs, emit arbitrary source code, and generally gives you more options, at the cost of needing a build script. `cfg()`s can be used in places where macros cannot, such as how the second example above shows it being used on a single field in a struct literal.

## §Custom resource definitions

The `k8s-openapi-derive` crate provides a custom derive for generating types for custom resources. See that crate’s docs for more information.

## Re-exports§

`pub use jiff;`
`pub use serde;`
`pub use serde_json;`

## Modules§

api
apiextensions_apiserver
apimachinery
kube_aggregator
merge_strategies
  Strategies for merging collections.

## Macros§

k8s_if_1_31
  This macro evaluates to its contents if the `v1_31` feature is enabled, otherwise it evaluates to nothing.
k8s_if_1_32
  This macro evaluates to its contents if the `v1_32` feature is enabled, otherwise it evaluates to nothing.
k8s_if_1_33
  This macro evaluates to its contents if the `v1_33` feature is enabled, otherwise it evaluates to nothing.
k8s_if_1_34
  This macro evaluates to its contents if the `v1_34` feature is enabled, otherwise it evaluates to nothing.
k8s_if_1_35
  This macro evaluates to its contents if the `v1_35` feature is enabled, otherwise it evaluates to nothing.
k8s_if_ge_1_31
  This macro evaluates to its contents if the `v1_31` or higher feature is enabled, otherwise it evaluates to nothing.
k8s_if_ge_1_32
  This macro evaluates to its contents if the `v1_32` or higher feature is enabled, otherwise it evaluates to nothing.
k8s_if_ge_1_33
  This macro evaluates to its contents if the `v1_33` or higher feature is enabled, otherwise it evaluates to nothing.
k8s_if_ge_1_34
  This macro evaluates to its contents if the `v1_34` or higher feature is enabled, otherwise it evaluates to nothing.
k8s_if_ge_1_35
  This macro evaluates to its contents if the `v1_35` or higher feature is enabled, otherwise it evaluates to nothing.
k8s_if_le_1_31
  This macro evaluates to its contents if the `v1_31` or lower feature is enabled, otherwise it evaluates to nothing.
k8s_if_le_1_32
  This macro evaluates to its contents if the `v1_32` or lower feature is enabled, otherwise it evaluates to nothing.
k8s_if_le_1_33
  This macro evaluates to its contents if the `v1_33` or lower feature is enabled, otherwise it evaluates to nothing.
k8s_if_le_1_34
  This macro evaluates to its contents if the `v1_34` or lower feature is enabled, otherwise it evaluates to nothing.
k8s_if_le_1_35
  This macro evaluates to its contents if the `v1_35` or lower feature is enabled, otherwise it evaluates to nothing.
k8s_match
  A macro that emits a `match` expr with the given test expression and arms. The match arms can be annotated with the other conditional compilation macros in this crate so that they’re only emitted if the predicate is true.

## Structs§

ByteString
  A wrapper around a list of bytes.
ClusterResourceScope
  Indicates that a `Resource` is cluster-scoped.
List
  List is a list of resources.
NamespaceResourceScope
  Indicates that a `Resource` is namespace-scoped.
SubResourceScope
  Indicates that a `Resource` is neither cluster-scoped nor namespace-scoped.

## Traits§

DeepMerge
  A trait applies to types that support deep merging.
ListableResource
  A trait applied to all Kubernetes resources that can be part of a corresponding list.
Metadata
  A trait applied to all Kubernetes resources that have metadata.
Resource
  A trait applied to all Kubernetes resources.
ResourceScope
  The scope of a `Resource`.

## Functions§

api_version
  Extracts the API version of the given resource value.
group
  Extracts the group of the given resource value.
kind
  Extracts the kind of the given resource value.
version
  Extracts the version of the given resource value.