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kube_derive/
lib.rs

1//! A crate for kube's derive macros.
2#![recursion_limit = "1024"]
3extern crate proc_macro;
4#[macro_use] extern crate quote;
5
6mod cel_schema;
7mod custom_resource;
8mod resource;
9
10/// A custom derive for kubernetes custom resource definitions.
11///
12/// This will generate a **root object** containing your spec and metadata.
13/// This root object will implement the [`kube::Resource`] trait
14/// so it can be used with [`kube::Api`].
15///
16/// The generated type will also implement kube's [`kube::CustomResourceExt`] trait to generate the crd
17/// and generate [`kube::core::ApiResource`] information for use with the dynamic api.
18///
19/// # Example
20///
21/// ```rust
22/// use serde::{Serialize, Deserialize};
23/// use kube::core::{Resource, CustomResourceExt};
24/// use kube_derive::CustomResource;
25/// use schemars::JsonSchema;
26///
27/// #[derive(CustomResource, Clone, Debug, Deserialize, Serialize, JsonSchema)]
28/// #[kube(group = "clux.dev", version = "v1", kind = "Foo", namespaced)]
29/// struct FooSpec {
30///     info: String,
31/// }
32///
33/// println!("kind = {}", Foo::kind(&())); // impl kube::Resource
34/// let f = Foo::new("foo-1", FooSpec {
35///     info: "informative info".into(),
36/// });
37/// println!("foo: {:?}", f); // debug print on root type
38/// println!("crd: {}", serde_saphyr::to_string(&Foo::crd()).unwrap()); // crd yaml
39/// ```
40///
41/// This example generates a `struct Foo` containing metadata, the spec,
42/// and optionally status. The **root** struct `Foo` can be used with the [`kube`] crate
43/// as an `Api<Foo>` object (`FooSpec` can not be used with [`Api`][`kube::Api`]).
44///
45/// ```no_run
46///  # use k8s_openapi::apiextensions_apiserver::pkg::apis::apiextensions::v1::CustomResourceDefinition;
47///  # use kube_derive::CustomResource;
48///  # use kube::{api::{Api, Patch, PatchParams}, Client, CustomResourceExt};
49///  # use serde::{Deserialize, Serialize};
50///  # async fn wrapper() -> Result<(), Box<dyn std::error::Error>> {
51///  # #[derive(CustomResource, Clone, Debug, Deserialize, Serialize, schemars::JsonSchema)]
52///  # #[kube(group = "clux.dev", version = "v1", kind = "Foo", namespaced)]
53///  # struct FooSpec {}
54///  # let client: Client = todo!();
55///  let foos: Api<Foo> = Api::default_namespaced(client.clone());
56///  let crds: Api<CustomResourceDefinition> = Api::all(client.clone());
57///  crds.patch("foos.clux.dev", &PatchParams::apply("myapp"), &Patch::Apply(Foo::crd())).await;
58/// # Ok(())
59/// # }
60///  ```
61///
62/// This example posts the generated `::crd` to the `CustomResourceDefinition` API.
63/// After this has been accepted (few secs max), you can start using `foos` as a normal
64/// kube `Api` object. See the `crd_` prefixed [examples](https://github.com/kube-rs/kube/blob/main/examples/)
65/// for details on this.
66///
67/// # Required properties
68///
69/// ## `#[kube(group = "mygroup.tld")]`
70/// Your cr api group. The part before the slash in the top level `apiVersion` key.
71///
72/// ## `#[kube(version = "v1")]`
73/// Your cr api version. The part after the slash in the top level `apiVersion` key.
74///
75/// ## `#[kube(kind = "Kind")]`
76/// Name of your kind, and implied default for your generated root type.
77///
78/// # Optional `#[kube]` attributes
79///
80/// ## `#[kube(singular = "nonstandard-singular")]`
81/// To specify the singular name. Defaults to lowercased `.kind` value.
82///
83/// ## `#[kube(plural = "nonstandard-plural")]`
84/// To specify the plural name. Defaults to inferring from singular.
85///
86/// ## `#[kube(namespaced)]`
87/// To specify that this is a namespaced resource rather than cluster level.
88///
89/// ## `#[kube(root = "StructName")]`
90/// Customize the name of the generated root struct (defaults to `.kind` value).
91///
92/// ## `#[kube(no_spec)]`
93/// For custom resources that have no `spec`, and sprawl their properties directly on the root
94/// object instead. Some CRDs in the wild are shaped this way, and without this they need
95/// [manual workarounds](https://github.com/kube-rs/kube/discussions/1762).
96///
97/// The derived struct is still the `spec` on the Rust side -- `HasSpec`,
98/// `Foo::new(name, spec)` and `Api<Foo>` all work unchanged -- but the field is
99/// [`#[serde(flatten)]`](https://serde.rs/attr-flatten.html)ed, so its properties sit at the top
100/// level both on the wire and in the generated schema:
101///
102/// ```ignore
103/// #[derive(CustomResource, Serialize, Deserialize, Debug, Clone, JsonSchema)]
104/// #[kube(group = "clux.dev", version = "v1", kind = "Bucket", namespaced, no_spec)]
105/// struct BucketFields {
106///     name: String,
107/// }
108/// ```
109///
110/// serializes as:
111///
112/// ```yaml
113/// apiVersion: clux.dev/v1
114/// kind: Bucket
115/// metadata:
116///   name: blobs
117/// name: blobs
118/// ```
119///
120/// Note that JSON paths in `printcolumn`, `selectable` and `scale` must drop the `.spec` prefix
121/// accordingly, and that the flattened struct must not itself declare `metadata`, `status`, `kind`
122/// or `apiVersion` fields (this is a compile error).
123///
124/// ## `#[kube(crates(kube_core = "::kube::core"))]`
125/// Customize the crate name the generated code will reach into (defaults to `::kube::core`).
126/// Should be one of `kube::core`, `kube_client::core` or `kube_core`.
127///
128/// ## `#[kube(crates(k8s_openapi = "::k8s_openapi"))]`
129/// Customize the crate name the generated code will use for [`k8s_openapi`](https://docs.rs/k8s-openapi/) (defaults to `::k8s_openapi`).
130///
131/// ## `#[kube(crates(schemars = "::schemars"))]`
132/// Customize the crate name the generated code will use for [`schemars`](https://docs.rs/schemars/) (defaults to `::schemars`).
133///
134/// ## `#[kube(crates(serde = "::serde"))]`
135/// Customize the crate name the generated code will use for [`serde`](https://docs.rs/serde/) (defaults to `::serde`).
136///
137/// ## `#[kube(crates(serde_json = "::serde_json"))]`
138/// Customize the crate name the generated code will use for [`serde_json`](https://docs.rs/serde_json/) (defaults to `::serde_json`).
139///
140/// ## `#[kube(status = "StatusStructName")]`
141/// Adds a status struct to the top level generated type and enables the status
142/// subresource in your crd.
143///
144/// ## `#[kube(derive = "Trait")]`
145/// Adding `#[kube(derive = "PartialEq")]` is required if you want your generated
146/// top level type to be able to `#[derive(PartialEq)]`
147///
148/// ## `#[kube(attr = "attribute")]`
149/// Adding `#[kube(attr = "attribute")]` is required if you want your generated
150/// top level type to have the `#[attribute]` type level attribute added.
151/// The attributes will be added after the `#[derive(...)]` attribute of the root type.
152/// The added attributes can either attribute macros or derive macro helper attributes.
153///
154/// Does not allow to set the `derive`, `serde` or `schemars` derive helper attributes.
155/// To add `derive`s the correct way to set it is `#[kube(derive = "Trait")]`.
156/// Setting derive helper attributes for `serde` and `schemars` is not supported as
157/// it might yield unexpected behaviour when interacting with the other generated code.
158///
159/// ```ignore
160/// #[kube(
161///     attr="allow(deprecated)",
162///     attr="cfg_attr(docsrs,doc(cfg(feature = \"latest\")))",
163/// )]
164/// ```
165///
166/// ## `#[kube(schema = "mode")]`
167/// Defines whether the `JsonSchema` of the top level generated type should be used when generating a `CustomResourceDefinition`.
168///
169/// Legal values:
170/// - `"derived"`: A `JsonSchema` implementation is automatically derived
171/// - `"manual"`: `JsonSchema` is not derived, but used when creating the `CustomResourceDefinition` object
172/// - `"disabled"`: No `JsonSchema` is used
173///
174/// This can be used to provide a completely custom schema, or to interact with third-party custom resources
175/// where you are not responsible for installing the `CustomResourceDefinition`.
176///
177/// Defaults to `"derived"`.
178///
179/// NOTE: `CustomResourceDefinition`s require a schema. If `schema = "disabled"` then
180/// `Self::crd()` will not be installable into the cluster as-is.
181///
182/// ## `#[kube(scale(...))]`
183///
184/// Allow customizing the scale struct for the [scale subresource](https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/#subresources).
185/// It should be noted, that the status subresource must also be enabled to use the scale subresource. This is because
186/// the `statusReplicasPath` only accepts JSONPaths under `.status`.
187///
188/// ```ignore
189/// #[kube(scale(
190///     spec_replicas_path = ".spec.replicas",
191///     status_replica_path = ".status.replicas",
192///     label_selector_path = ".spec.labelSelector"
193/// ))]
194/// ```
195///
196/// The deprecated way of customizing the scale subresource using a raw JSON string is still
197/// support for backwards-compatibility.
198///
199/// ## `#[kube(printcolumn(...))]`
200///
201/// Allows adding a custom column to the [printcolumns](https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/#additional-printer-columns).
202///
203/// ```ignore
204/// #[kube(printcolumn(
205///     name = "CustomColumn",
206///     type_ = "integer",
207///     json_path = ".spec.someField",
208///     description = "a custom column", // optional
209///     format = "int32",                // optional
210///     priority = "1",                  // optional
211/// ))]
212/// ```
213///
214/// The older method of supplying raw json is still supported:
215///
216/// ```ignore
217/// printcolumn = r#"{"name":"Spec", "type":"string", "description":"name of foo", "jsonPath":".spec.name"}"#,
218/// ```
219///
220/// ## `#[kube(shortname = "sn")]`
221/// Add a single shortname to the generated crd.
222///
223/// ## `#[kube(category = "apps")]`
224/// Add a single category to `crd.spec.names.categories`.
225///
226/// ## `#[kube(selectable = "fieldSelectorPath")]`
227/// Adds a Kubernetes >=1.30 `selectableFields` property ([KEP-4358](https://github.com/kubernetes/enhancements/blob/master/keps/sig-api-machinery/4358-custom-resource-field-selectors/README.md)) to the schema.
228/// Unlocks `kubectl get kind --field-selector fieldSelectorPath`.
229///
230/// ## `#[kube(doc = "description")]`
231/// Sets the description of the schema in the generated CRD. If not specified
232/// `Auto-generated derived type for {customResourceName} via CustomResource` will be used instead.
233///
234/// ## `#[kube(annotation("ANNOTATION_KEY", "ANNOTATION_VALUE"))]`
235/// Add a single annotation to the generated CRD.
236///
237/// ## `#[kube(label("LABEL_KEY", "LABEL_VALUE"))]`
238/// Add a single label to the generated CRD.
239///
240/// ## `#[kube(storage = true)]`
241/// Sets the `storage` property to `true` or `false`.
242///
243/// ## `#[kube(served = true)]`
244/// Sets the `served` property to `true` or `false`.
245///
246/// ## `#[kube(deprecated [= "warning"])]`
247/// Sets the `deprecated` property to `true`.
248///
249/// ```ignore
250/// #[kube(deprecated)]
251/// ```
252///
253/// Additionally, you can provide a `deprecationWarning` using the following example.
254///
255/// ```ignore
256/// #[kube(deprecated = "Replaced by other CRD")]
257/// ```
258///
259/// ## `#[kube(validation = Rule::new("self == oldSelf").message("field is immutable"))]`
260/// Inject a top level CEL validation rule for the top level generated struct.
261/// This attribute is for resources deriving [`KubeSchema`] instead of [`schemars::JsonSchema`].
262///
263/// ## Example with all properties
264///
265/// ```rust
266/// use serde::{Serialize, Deserialize};
267/// use kube_derive::CustomResource;
268/// use schemars::JsonSchema;
269///
270/// #[derive(CustomResource, Serialize, Deserialize, Debug, PartialEq, Clone, JsonSchema)]
271/// #[kube(
272///     group = "clux.dev",
273///     version = "v1",
274///     kind = "Foo",
275///     root = "FooCrd",
276///     namespaced,
277///     doc = "Custom resource representing a Foo",
278///     status = "FooStatus",
279///     derive = "PartialEq",
280///     singular = "foot",
281///     plural = "feetz",
282///     shortname = "f",
283///     scale = r#"{"specReplicasPath":".spec.replicas", "statusReplicasPath":".status.replicas"}"#,
284///     printcolumn(
285///         name = "Spec",
286///         type_ = "string",
287///         description = "name of foo",
288///         json_path = ".spec.name"
289///     ),
290///     selectable = "spec.replicasCount"
291/// )]
292/// #[serde(rename_all = "camelCase")]
293/// struct FooSpec {
294///     #[schemars(length(min = 3))]
295///     data: String,
296///     replicas_count: i32
297/// }
298///
299/// #[derive(Serialize, Deserialize, Debug, PartialEq, Clone, JsonSchema)]
300/// struct FooStatus {
301///     replicas: i32
302/// }
303/// ```
304///
305/// # Enums
306///
307/// Kubernetes requires that the generated [schema is "structural"](https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/#specifying-a-structural-schema).
308/// This means that the structure of the schema must not depend on the particular values. For enums this imposes a few limitations:
309///
310/// - Only [externally tagged enums](https://serde.rs/enum-representations.html#externally-tagged) are supported
311/// - Unit variants may not be mixed with struct or tuple variants (`enum Foo { Bar, Baz {}, Qux() }` is invalid, for example)
312///
313/// If these restrictions are not followed then `YourCrd::crd()` may panic, or the Kubernetes API may reject the CRD definition.
314///
315/// # Generated code
316///
317/// The example above will **roughly** generate:
318/// ```compile_fail
319/// #[derive(Serialize, Deserialize, Debug, PartialEq, Clone, JsonSchema)]
320/// #[serde(rename_all = "camelCase")]
321/// pub struct FooCrd {
322///     api_version: String,
323///     kind: String,
324///     metadata: ObjectMeta,
325///     spec: FooSpec,
326///     status: Option<FooStatus>,
327/// }
328/// impl kube::Resource for FooCrd { .. }
329///
330/// impl FooCrd {
331///     pub fn new(name: &str, spec: FooSpec) -> Self { .. }
332///     pub fn crd() -> CustomResourceDefinition { .. }
333/// }
334/// ```
335///
336/// # Customizing Schemas
337/// Should you need to customize the schemas, you can use:
338/// - [Serde/Schemars Attributes](https://graham.cool/schemars/examples/3-schemars_attrs/) (no need to duplicate serde renames)
339/// - [`#[schemars(schema_with = "func")]`](https://graham.cool/schemars/examples/7-custom_serialization/) (e.g. like in the [`crd_derive` example](https://github.com/kube-rs/kube/blob/main/examples/crd_derive.rs))
340/// - `impl JsonSchema` on a type / newtype around external type. See [#129](https://github.com/kube-rs/kube/issues/129#issuecomment-750852916)
341/// - [`#[garde(...)]` field attributes for client-side validation](https://github.com/jprochazk/garde) (see [`crd_api` example](https://github.com/kube-rs/kube/blob/main/examples/crd_api.rs))
342///
343/// You might need to override parts of the schemas (for fields in question) when you are:
344/// - **using complex enums**: enums do not currently generate [structural schemas](https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/#specifying-a-structural-schema), so kubernetes won't support them by default
345/// - **customizing [merge-strategies](https://kubernetes.io/docs/reference/using-api/server-side-apply/#merge-strategy)** (e.g. like in the [`crd_derive_schema` example](https://github.com/kube-rs/kube/blob/main/examples/crd_derive_schema.rs))
346///
347/// See [kubernetes openapi validation](https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/#validation) for the format of the OpenAPI v3 schemas.
348///
349/// If you have to override a lot, [you can opt-out of schema-generation entirely](#kubeschema--mode)
350///
351/// # Advanced Features
352///
353/// - **embedding k8s-openapi types** can be done by enabling the `schemars` feature of `k8s-openapi` from [`0.13.0`](https://github.com/Arnavion/k8s-openapi/blob/master/CHANGELOG.md#v0130-2021-08-09)
354/// - **adding validation** via [validator crate](https://github.com/Keats/validator) is supported from `schemars` >= [`0.8.5`](https://github.com/GREsau/schemars/blob/master/CHANGELOG.md#085---2021-09-20)
355/// - **generating rust code from schemas** can be done via [kopium](https://github.com/kube-rs/kopium) and is supported on stable crds (> 1.16 kubernetes)
356///
357/// ## Schema Validation
358/// There are two main ways of doing validation; **server-side** (embedding validation attributes into the schema for the apiserver to respect), and **client-side** (provides `validate()` methods in your code).
359///
360/// Client side validation of structs can be achieved by hooking up `#[garde]` attributes in your struct and is a replacement of the now unmaintained [`validator`](https://github.com/Keats/validator/issues/201) crate.
361/// Server-side validation require mutation of your generated schema, and can in the basic cases be achieved through the use of `schemars`'s [validation attributes](https://graham.cool/schemars/deriving/attributes/#supported-validator-attributes).
362/// For complete control, [parts of the schema can be overridden](https://github.com/kube-rs/kube/blob/e01187e13ba364ccecec452e023316a62fb13e04/examples/crd_derive.rs#L37-L38) to support more advanced [Kubernetes specific validation rules](https://kubernetes.io/blog/2022/09/23/crd-validation-rules-beta/).
363///
364/// When using `garde` directly, you must add it to your dependencies (with the `derive` feature).
365///
366/// ### CEL validation (client-side)
367/// CEL rules declared with `#[kube(validation = ...)]` / `#[x_kube(validation = ...)]` are normally
368/// enforced server-side by the apiserver. With `#[kube(cel)]` the derive also generates client-side
369/// methods so you can run the same rules locally without a cluster:
370/// - `Foo::validate_cel(&self) -> Result<(), ValidationErrors>` evaluates creation rules.
371/// - `Foo::validate_cel_update(&self, old: &Self) -> Result<(), ValidationErrors>` also evaluates
372///   transition rules (rules using `oldSelf`), comparing against `old`.
373///
374/// Likewise, `#[x_kube(cel)]` on any `KubeSchema` struct generates a static
375/// `T::validate_cel(value, old)` usable on a fragment in unit tests (see [`KubeSchema`]).
376/// Both require the downstream crate to enable the **`kube/cel`** feature, since the generated code
377/// references `kube::core::cel`. `#[kube(cel)]` requires a derived schema (it cannot be combined with
378/// `schema = "manual"`). See the [`crd_derive_cel`](https://github.com/kube-rs/kube/blob/main/examples/crd_derive_cel.rs) example.
379///
380/// ### Validation Caveats
381/// Make sure your validation rules are static and handled by `schemars`:
382/// - validations from `#[garde(custom(my_func))]` will not show up in the schema.
383/// - similarly; [nested / must_match / credit_card were unhandled by schemars at time of writing](https://github.com/GREsau/schemars/pull/78)
384/// - encoding validations specified through garde (i.e. #[garde(ascii)]), are currently not supported by schemars
385/// - to validate required attributes client-side, garde requires a custom validation function (`#[garde(custom(my_required_check))]`)
386/// - when using garde, fields that should not be validated need to be explicitly skipped through the `#[garde(skip)]` attr
387///
388/// For sanity, you should review the generated schema before sending it to kubernetes.
389///
390/// ## Versioning
391/// Note that any changes to your struct / validation rules / serialization attributes will require you to re-apply the
392/// generated schema to kubernetes, so that the apiserver can validate against the right version of your structs.
393///
394/// **Backwards compatibility** between schema versions is **recommended** unless you are in a controlled environment
395/// where you can migrate manually. I.e. if you add new properties behind options, and simply mark old fields as deprecated,
396/// then you can safely roll schema out changes **without bumping** the version.
397///
398/// If you need **multiple versions**, then you need:
399///
400/// - one **module** for **each version** of your types (e.g. `v1::MyCrd` and `v2::MyCrd`)
401/// - use the [`merge_crds`](https://docs.rs/kube/latest/kube/core/crd/fn.merge_crds.html) fn to combine crds
402/// - roll out new schemas utilizing conversion webhooks / manual conversions / or allow kubectl to do its best
403///
404/// See the [crd_derive_multi](https://github.com/kube-rs/kube/blob/main/examples/crd_derive_multi.rs) example to see
405/// how this upgrade flow works without special logic.
406///
407/// The **upgrade flow** with **breaking changes** involves:
408///
409/// 1. upgrade version marked as `storage` (from v1 to v2)
410/// 2. read instances from the older `Api<v1::MyCrd>`
411/// 3. perform conversion in memory and write them to the new `Api<v2::MyCrd>`.
412/// 4. remove support for old version
413///
414/// If you need to maintain support for the old version for some time, then you have to repeat or continuously
415/// run steps 2 and 3. I.e. you probably need a **conversion webhook**.
416///
417/// **NB**: kube does currently [not implement conversion webhooks yet](https://github.com/kube-rs/kube/issues/865).
418///
419/// ## Debugging
420/// Try `cargo-expand` to see your own macro expansion.
421///
422/// # Installation
423/// Enable the `derive` feature on the `kube` crate:
424///
425/// ```toml
426/// kube = { version = "...", features = ["derive"] }
427/// ```
428///
429/// ## Runtime dependencies
430/// Due to [rust-lang/rust#54363](https://github.com/rust-lang/rust/issues/54363), we cannot be resilient against crate renames within our generated code.
431/// It's therefore **required** that you have the following crates in scope, not renamed:
432///
433/// - `serde_json`
434/// - `k8s_openapi`
435/// - `schemars` (by default, unless `schema` feature disabled)
436///
437/// You are ultimately responsible for maintaining the versions and feature flags of these libraries.
438///
439/// [`kube`]: https://docs.rs/kube
440/// [`kube::Api`]: https://docs.rs/kube/*/kube/struct.Api.html
441/// [`kube::Resource`]: https://docs.rs/kube/*/kube/trait.Resource.html
442/// [`kube::core::ApiResource`]: https://docs.rs/kube/*/kube/core/struct.ApiResource.html
443/// [`kube::CustomResourceExt`]: https://docs.rs/kube/*/kube/trait.CustomResourceExt.html
444#[proc_macro_derive(CustomResource, attributes(kube))]
445pub fn derive_custom_resource(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
446    custom_resource::derive(proc_macro2::TokenStream::from(input)).into()
447}
448
449/// Generates a JsonSchema implementation a set of CEL validation rules applied on the CRD.
450///
451/// ```rust
452/// use kube::KubeSchema;
453/// use kube::CustomResource;
454/// use serde::Deserialize;
455/// use serde::Serialize;
456/// use kube::core::crd::CustomResourceExt;
457///
458/// #[derive(CustomResource, KubeSchema, Serialize, Deserialize, Clone, Debug)]
459/// #[kube(
460///     group = "kube.rs",
461///     version = "v1",
462///     kind = "Struct",
463///     validation = "self.metadata.name == 'singleton'",
464/// )]
465/// #[x_kube(validation = "self == oldSelf")]
466/// struct MyStruct {
467///     #[serde(default = "default")]
468///     #[x_kube(validation = Rule::new("self != ''").message("failure message"))]
469///     field: String,
470/// }
471///
472/// fn default() -> String {
473///     "value".into()
474/// }
475///
476/// assert!(serde_json::to_string(&Struct::crd()).unwrap().contains("x-kubernetes-validations"));
477/// assert!(serde_json::to_string(&Struct::crd()).unwrap().contains(r#""rule":"self == oldSelf""#));
478/// assert!(serde_json::to_string(&Struct::crd()).unwrap().contains(r#""rule":"self != ''""#));
479/// assert!(serde_json::to_string(&Struct::crd()).unwrap().contains(r#""message":"failure message""#));
480/// assert!(serde_json::to_string(&Struct::crd()).unwrap().contains(r#""default":"value""#));
481/// assert!(serde_json::to_string(&Struct::crd()).unwrap().contains(r#""rule":"self.metadata.name == 'singleton'""#));
482/// ```
483///
484/// ## Client-side CEL validation with `#[x_kube(cel)]`
485///
486/// Adding `cel` to `#[x_kube(...)]` generates a static `T::validate_cel(value, old)` method that
487/// evaluates this type's CEL rules locally, without an apiserver — handy in unit tests on a struct
488/// fragment. `value` is the serialized form (`serde_json::to_value(&instance)`); `old` supplies the
489/// previous state for transition rules (rules using `oldSelf`), or `None` on creation.
490///
491/// This requires the downstream crate to enable the **`kube/cel`** feature, since the generated code
492/// references `kube::core::cel`.
493///
494/// ```rust
495/// # use kube::KubeSchema;
496/// # use serde::{Deserialize, Serialize};
497/// #[derive(KubeSchema, Serialize, Deserialize, Clone, Debug)]
498/// #[x_kube(cel, validation = "self.max >= self.min")]
499/// struct Range {
500///     min: i32,
501///     max: i32,
502/// }
503///
504/// let ok = serde_json::json!({"min": 1, "max": 5});
505/// assert!(Range::validate_cel(&ok, None).is_ok());
506///
507/// let bad = serde_json::json!({"min": 5, "max": 1});
508/// assert!(Range::validate_cel(&bad, None).is_err());
509/// ```
510#[proc_macro_derive(KubeSchema, attributes(x_kube, schemars, validate))]
511pub fn derive_schema_validation(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
512    cel_schema::derive_validated_schema(input.into()).into()
513}
514
515/// A custom derive for inheriting Resource impl for the type.
516///
517/// This will generate a [`kube::Resource`] trait implementation,
518/// inheriting from a specified resource trait implementation.
519///
520/// This allows strict typing to some typical resources like `Secret` or `ConfigMap`,
521/// in cases when implementing CRD is not desirable or it does not fit the use-case.
522///
523/// Once derived, the type can be used with [`kube::Api`].
524///
525/// # Example
526///
527/// ```rust,no_run
528/// use kube::api::ObjectMeta;
529/// use k8s_openapi::api::core::v1::ConfigMap;
530/// use kube_derive::Resource;
531/// use kube::Client;
532/// use kube::Api;
533/// use serde::Deserialize;
534///
535/// #[derive(Resource, Clone, Debug, Deserialize)]
536/// #[resource(inherit = "ConfigMap")]
537/// struct FooMap {
538///     metadata: ObjectMeta,
539///     data: Option<FooMapSpec>,
540/// }
541///
542/// #[derive(Clone, Debug, Deserialize)]
543/// struct FooMapSpec {
544///     field: String,
545/// }
546///
547/// let client: Client = todo!();
548/// let api: Api<FooMap> = Api::default_namespaced(client);
549/// let config_map = api.get("with-field");
550/// ```
551///
552/// The example above will generate:
553/// ```
554/// // impl kube::Resource for FooMap { .. }
555/// ```
556/// [`kube`]: https://docs.rs/kube
557/// [`kube::Api`]: https://docs.rs/kube/*/kube/struct.Api.html
558/// [`kube::Resource`]: https://docs.rs/kube/*/kube/trait.Resource.html
559/// [`kube::core::ApiResource`]: https://docs.rs/kube/*/kube/core/struct.ApiResource.html
560/// [`kube::CustomResourceExt`]: https://docs.rs/kube/*/kube/trait.CustomResourceExt.html
561#[proc_macro_derive(Resource, attributes(resource))]
562pub fn derive_resource(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
563    resource::derive(proc_macro2::TokenStream::from(input)).into()
564}