Merge pull request #301 from MikailBag/discovery

Add functions for runtime API discovery

kube/src/api/dynamic.rs

@@ -2,6 +2,7 @@ use crate::{
     api::{typed::Api, Resource},
     Client, Error, Result,
 };
+use k8s_openapi::apimachinery::pkg::apis::meta::v1::APIResource;
 use std::convert::TryFrom;
 
 use inflector::{cases::pascalcase::is_pascal_case, string::pluralize::to_plural};
@@ -99,6 +100,51 @@ impl DynamicResource {
             phantom: iter::empty(),
         })
     }
+
+    /// Creates `DynamicResource`, based on `metav1::APIResource`.
+    /// If it does not specify version and/or group, they will be taken
+    /// from `api_resource_list_group_version`.
+    /// Example usage:
+    /// ```
+    /// use kube::api::DynamicResource;
+    /// # async fn scope(client: kube::Client) -> Result<(), Box<dyn std::error::Error>> {
+    /// let apps_apis = client.list_api_group_resources("apps", "v1").await?;
+    /// for api_res in &apps_apis.resources {
+    ///     let kube_resource = DynamicResource::from_metav1_api_resource(api_res, &apps_apis.group_version);
+    ///     // do not forget to select a namespace
+    ///     let kube_resource = kube_resource.within("kube-system").into_resource();
+    ///     dbg!(kube_resource);
+    /// } 
+    /// # Ok(())
+    /// # }   
+    /// ```
+    pub fn from_metav1_api_resource(
+        k8s_resource: &APIResource,
+        api_resource_list_group_version: &str,
+    ) -> Self {
+        let (default_group, default_version) = if api_resource_list_group_version.contains('/') {
+            let mut iter = api_resource_list_group_version.splitn(2, '/');
+            let g = iter.next().unwrap();
+            let v = iter.next().unwrap();
+            (g, v)
+        } else {
+            ("", api_resource_list_group_version)
+        };
+        let version = k8s_resource
+            .version
+            .clone()
+            .unwrap_or_else(|| default_version.to_string());
+        let group = k8s_resource
+            .group
+            .clone()
+            .unwrap_or_else(|| default_group.to_string());
+        DynamicResource {
+            kind: k8s_resource.kind.clone(),
+            version: Some(version),
+            group: Some(group),
+            namespace: None,
+        }
+    }
 }
 
 impl TryFrom<DynamicResource> for Resource {

kube/src/client/mod.rs

@@ -16,7 +16,7 @@ use crate::{
 use bytes::Bytes;
 use either::{Either, Left, Right};
 use futures::{self, Stream, TryStream, TryStreamExt};
-use http::{self, StatusCode};
+use http::{self, Request, StatusCode};
 use serde::{de::DeserializeOwned, Deserialize};
 use serde_json::{self, Value};
 
@@ -268,6 +268,49 @@ impl Client {
 
         Ok(stream.map_ok(futures::stream::iter).try_flatten())
     }
+
+    /// Returns apiserver version.
+    pub async fn apiserver_version(&self) -> Result<k8s_openapi::apimachinery::pkg::version::Info> {
+        self.request(Request::builder().uri("/version").body(Vec::new())?)
+            .await
+    }
+
+    /// Lists api groups that apiserver serves.
+    pub async fn list_api_groups(&self) -> Result<k8s_openapi::apimachinery::pkg::apis::meta::v1::APIGroupList> {
+        self.request(Request::builder().uri("/apis").body(Vec::new())?)
+            .await
+    }
+
+    /// Lists resources served in given API group.
+    /// There resources can be then converted to `kube::api::DynamicResource`
+    /// using the `from_metav1_api_resource` method.
+    pub async fn list_api_group_resources(
+        &self,
+        group: &str,
+        version: &str,
+    ) -> Result<k8s_openapi::apimachinery::pkg::apis::meta::v1::APIResourceList> {
+        let url = format!("/apis/{}/{}", group, version);
+        self.request(Request::builder().uri(url).body(Vec::new())?).await
+    }
+
+    /// Lists versions of `core` a.k.a. `""` API group.
+    pub async fn list_core_api_versions(
+        &self,
+    ) -> Result<k8s_openapi::apimachinery::pkg::apis::meta::v1::APIVersions> {
+        self.request(Request::builder().uri("/api").body(Vec::new())?)
+            .await
+    }
+
+    /// Lists resources served in particular `core` group version.
+    /// There resources can be then converted to `kube::api::DynamicResource`
+    /// using the `from_metav1_api_resource` method.
+    pub async fn list_core_api_resources(
+        &self,
+        version: &str,
+    ) -> Result<k8s_openapi::apimachinery::pkg::apis::meta::v1::APIResourceList> {
+        let url = format!("/api/{}", version);
+        self.request(Request::builder().uri(url).body(Vec::new())?).await
+    }
 }
 
 /// Kubernetes returned error handling