Add Serialize to ObjecList and add field-selector and jsonpath example (

#760)

* Add the example to demonstrate the use of field-selector and jsonpath

Signed-off-by: ChinYing-Li <chinying.li@mail.utoronto.ca>

* Modify the dynamic_jsonpath example to have a more advanced jsonpath

Signed-off-by: ChinYing-Li <chinying.li@mail.utoronto.ca>

Co-authored-by: Eirik A <sszynrae@gmail.com>

examples/Cargo.toml

@@ -30,6 +30,7 @@ validator = { version = "0.14.0", features = ["derive"] }
 anyhow = "1.0.44"
 env_logger = "0.9.0"
 futures = "0.3.17"
+jsonpath_lib = "0.3.0"
 kube = { path = "../kube", version = "^0.65.0", default-features = false, features = ["admission"] }
 kube-derive = { path = "../kube-derive", version = "^0.65.0", default-features = false } # only needed to opt out of schema
 k8s-openapi = { version = "0.13.1", default-features = false }
@@ -100,6 +101,10 @@ path = "deployment_reflector.rs"
 name = "dynamic_api"
 path = "dynamic_api.rs"
 
+[[example]]
+name = "dynamic_jsonpath"
+path = "dynamic_jsonpath.rs"
+
 [[example]]
 name = "dynamic_pod"
 path = "dynamic_pod.rs"

examples/README.md

@@ -19,6 +19,7 @@ cargo run --example job_api
 cargo run --example log_stream
 cargo run --example pod_api
 cargo run --example dynamic_api
+cargo run --example dynamic_jsonpath
 NAMESPACE=dev cargo run --example log_stream -- kafka-manager-7d4f4bd8dc-f6c44
 ```
 

examples/dynamic_jsonpath.rs

@@ -0,0 +1,32 @@
+use jsonpath_lib;
+use k8s_openapi::api::core::v1::Pod;
+use kube::{
+    api::{Api, ListParams},
+    Client,
+};
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    std::env::set_var("RUST_LOG", "info,kube=debug");
+    env_logger::init();
+    let client = Client::try_default().await?;
+
+    // Equivalent to `kubectl get pods --all-namespace \
+    // -o jsonpath='{.items[*].spec.containers[*].image}'`
+    let field_selector = std::env::var("FIELD_SELECTOR").unwrap_or_default();
+    let jsonpath = format!(
+        "{}{}",
+        "$",
+        std::env::var("JSONPATH").unwrap_or_else(|_| ".items[*].spec.containers[*].image".into())
+    );
+
+    let pods: Api<Pod> = Api::<Pod>::all(client);
+    let list_params = ListParams::default().fields(&*field_selector);
+    let list = pods.list(&list_params).await?;
+
+    // Use the given JSONPATH to filter the ObjectList
+    let list_json = serde_json::to_value(&list)?;
+    let res = jsonpath_lib::select(&list_json, &*jsonpath).unwrap();
+    println!("\t\t {:?}", res);
+    Ok(())
+}

kube-core/src/object.rs

@@ -16,7 +16,7 @@ use std::borrow::Cow;
 /// and is generally produced from list/watch/delete collection queries on an [`Resource`](super::Resource).
 ///
 /// This is almost equivalent to [`k8s_openapi::List<T>`](k8s_openapi::List), but iterable.
-#[derive(Deserialize, Debug)]
+#[derive(Serialize, Deserialize, Debug)]
 pub struct ObjectList<T>
 where
     T: Clone,