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#[cfg(feature = "unstable-runtime-predicates")]
use crate::utils::predicate::{Predicate, PredicateFilter};
use crate::{
utils::{event_flatten::EventFlatten, event_modify::EventModify, stream_backoff::StreamBackoff},
watcher,
};
use kube_client::Resource;
use crate::{reflector::store::Writer, utils::Reflect};
use crate::watcher::DefaultBackoff;
use backoff::backoff::Backoff;
use futures::{Stream, TryStream};
/// Extension trait for streams returned by [`watcher`](watcher()) or [`reflector`](crate::reflector::reflector)
pub trait WatchStreamExt: Stream {
/// Apply the [`DefaultBackoff`] watcher [`Backoff`] policy
///
/// This is recommended for controllers that want to play nicely with the apiserver.
fn default_backoff(self) -> StreamBackoff<Self, DefaultBackoff>
where
Self: TryStream + Sized,
{
StreamBackoff::new(self, DefaultBackoff::default())
}
/// Apply a specific [`Backoff`] policy to a [`Stream`] using [`StreamBackoff`]
fn backoff<B>(self, b: B) -> StreamBackoff<Self, B>
where
B: Backoff,
Self: TryStream + Sized,
{
StreamBackoff::new(self, b)
}
/// Flatten a [`watcher()`] stream into a stream of applied objects
///
/// All Added/Modified events are passed through, and critical errors bubble up.
fn applied_objects<K>(self) -> EventFlatten<Self>
where
Self: Stream<Item = Result<watcher::Event<K>, watcher::Error>> + Sized,
{
EventFlatten::new(self, false)
}
/// Flatten a [`watcher()`] stream into a stream of touched objects
///
/// All Added/Modified/Deleted events are passed through, and critical errors bubble up.
fn touched_objects<K>(self) -> EventFlatten<Self>
where
Self: Stream<Item = Result<watcher::Event<K>, watcher::Error>> + Sized,
{
EventFlatten::new(self, true)
}
/// Modify elements of a [`watcher()`] stream.
///
/// Calls [`watcher::Event::modify()`] on every element.
/// Stream shorthand for `stream.map_ok(|event| { event.modify(f) })`.
///
/// ```no_run
/// # use std::pin::pin;
/// # use futures::{Stream, StreamExt, TryStreamExt};
/// # use kube::{Api, Client, ResourceExt};
/// # use kube_runtime::{watcher, WatchStreamExt};
/// # use k8s_openapi::api::apps::v1::Deployment;
/// # async fn wrapper() -> Result<(), Box<dyn std::error::Error>> {
/// # let client: kube::Client = todo!();
/// let deploys: Api<Deployment> = Api::all(client);
/// let mut truncated_deploy_stream = pin!(watcher(deploys, watcher::Config::default())
/// .modify(|deploy| {
/// deploy.managed_fields_mut().clear();
/// deploy.status = None;
/// })
/// .applied_objects());
///
/// while let Some(d) = truncated_deploy_stream.try_next().await? {
/// println!("Truncated Deployment: '{:?}'", serde_json::to_string(&d)?);
/// }
/// # Ok(())
/// # }
/// ```
fn modify<F, K>(self, f: F) -> EventModify<Self, F>
where
Self: Stream<Item = Result<watcher::Event<K>, watcher::Error>> + Sized,
F: FnMut(&mut K),
{
EventModify::new(self, f)
}
/// Filter out a flattened stream on [`predicates`](crate::predicates).
///
/// This will filter out repeat calls where the predicate returns the same result.
/// Common use case for this is to avoid repeat events for status updates
/// by filtering on [`predicates::generation`](crate::predicates::generation).
///
/// **NB**: This is constructor requires an [`unstable`](https://github.com/kube-rs/kube/blob/main/kube-runtime/Cargo.toml#L17-L21) feature.
///
/// ## Usage
/// ```no_run
/// # use std::pin::pin;
/// # use futures::{Stream, StreamExt, TryStreamExt};
/// use kube::{Api, Client, ResourceExt};
/// use kube_runtime::{watcher, WatchStreamExt, predicates};
/// use k8s_openapi::api::apps::v1::Deployment;
/// # async fn wrapper() -> Result<(), Box<dyn std::error::Error>> {
/// # let client: kube::Client = todo!();
/// let deploys: Api<Deployment> = Api::default_namespaced(client);
/// let mut changed_deploys = pin!(watcher(deploys, watcher::Config::default())
/// .applied_objects()
/// .predicate_filter(predicates::generation));
///
/// while let Some(d) = changed_deploys.try_next().await? {
/// println!("saw Deployment '{} with hitherto unseen generation", d.name_any());
/// }
/// # Ok(())
/// # }
/// ```
#[cfg(feature = "unstable-runtime-predicates")]
fn predicate_filter<K, P>(self, predicate: P) -> PredicateFilter<Self, K, P>
where
Self: Stream<Item = Result<K, watcher::Error>> + Sized,
K: Resource + 'static,
P: Predicate<K> + 'static,
{
PredicateFilter::new(self, predicate)
}
/// Reflect a [`watcher()`] stream into a [`Store`] through a [`Writer`]
///
/// Returns the stream unmodified, but passes every [`watcher::Event`] through a [`Writer`].
/// This populates a [`Store`] as the stream is polled.
///
/// ## Usage
/// ```no_run
/// # use futures::{Stream, StreamExt, TryStreamExt};
/// # use std::time::Duration;
/// # use tracing::{info, warn};
/// use kube::{Api, Client, ResourceExt};
/// use kube_runtime::{watcher, WatchStreamExt, reflector};
/// use k8s_openapi::api::apps::v1::Deployment;
/// # async fn wrapper() -> Result<(), Box<dyn std::error::Error>> {
/// # let client: kube::Client = todo!();
///
/// let deploys: Api<Deployment> = Api::default_namespaced(client);
/// let (reader, writer) = reflector::store::<Deployment>();
///
/// tokio::spawn(async move {
/// // start polling the store once the reader is ready
/// reader.wait_until_ready().await.unwrap();
/// loop {
/// let names = reader.state().iter().map(|d| d.name_any()).collect::<Vec<_>>();
/// info!("Current {} deploys: {:?}", names.len(), names);
/// tokio::time::sleep(Duration::from_secs(10)).await;
/// }
/// });
///
/// // configure the watcher stream and populate the store while polling
/// watcher(deploys, watcher::Config::default())
/// .reflect(writer)
/// .applied_objects()
/// .for_each(|res| async move {
/// match res {
/// Ok(o) => info!("saw {}", o.name_any()),
/// Err(e) => warn!("watcher error: {}", e),
/// }
/// })
/// .await;
///
/// # Ok(())
/// # }
/// ```
///
/// [`Store`]: crate::reflector::Store
fn reflect<K>(self, writer: Writer<K>) -> Reflect<Self, K>
where
Self: Stream<Item = watcher::Result<watcher::Event<K>>> + Sized,
K: Resource + Clone + 'static,
K::DynamicType: Eq + std::hash::Hash + Clone,
{
Reflect::new(self, writer)
}
/// Reflect a shared [`watcher()`] stream into a [`Store`] through a [`Writer`]
///
/// Returns the stream unmodified, but passes every [`watcher::Event`]
/// through a [`Writer`]. This populates a [`Store`] as the stream is
/// polled. When the [`watcher::Event`] is not an error or a
/// [`watcher::Event::Deleted`] then its inner object will also be
/// propagated to subscribers.
///
/// Subscribers can be created by calling [`subscribe()`] on a [`Writer`].
/// This will return a [`ReflectHandle`] stream that should be polled
/// independently. When the root stream is dropped, or it ends, all [`ReflectHandle`]s
/// subscribed to the stream will also terminate after all events yielded by
/// the root stream have been observed. This means [`ReflectHandle`] streams
/// can still be polled after the root stream has been dropped.
///
/// **NB**: This adapter requires an
/// [`unstable`](https://github.com/kube-rs/kube/blob/main/kube-runtime/Cargo.toml#L17-L21)
/// feature
///
/// ## Warning
///
/// If the root [`Stream`] is not polled, [`ReflectHandle`] streams will
/// never receive any events. This will cause the streams to deadlock since
/// the root stream will apply backpressure when downstream readers are not
/// consuming events.
///
///
/// [`Store`]: crate::reflector::Store
/// [`subscribe()`]: crate::reflector::store::Writer::subscribe()
/// [`Stream`]: futures::stream::Stream
/// [`ReflectHandle`]: crate::reflector::dispatcher::ReflectHandle
/// ## Usage
/// ```no_run
/// # use futures::{pin_mut, Stream, StreamExt, TryStreamExt};
/// # use std::time::Duration;
/// # use tracing::{info, warn};
/// use kube::{Api, Client, ResourceExt};
/// use kube_runtime::{watcher, WatchStreamExt, reflector};
/// use k8s_openapi::api::apps::v1::Deployment;
/// # async fn wrapper() -> Result<(), Box<dyn std::error::Error>> {
/// # let client: kube::Client = todo!();
///
/// let deploys: Api<Deployment> = Api::default_namespaced(client);
/// let subscriber_buf_sz = 100;
/// let (reader, writer) = reflector::store_shared::<Deployment>(subscriber_buf_sz);
/// let subscriber = &writer.subscribe().unwrap();
///
/// tokio::spawn(async move {
/// // start polling the store once the reader is ready
/// reader.wait_until_ready().await.unwrap();
/// loop {
/// let names = reader.state().iter().map(|d| d.name_any()).collect::<Vec<_>>();
/// info!("Current {} deploys: {:?}", names.len(), names);
/// tokio::time::sleep(Duration::from_secs(10)).await;
/// }
/// });
///
/// // configure the watcher stream and populate the store while polling
/// watcher(deploys, watcher::Config::default())
/// .reflect_shared(writer)
/// .applied_objects()
/// .for_each(|res| async move {
/// match res {
/// Ok(o) => info!("saw in root stream {}", o.name_any()),
/// Err(e) => warn!("watcher error in root stream: {}", e),
/// }
/// })
/// .await;
///
/// // subscriber can be used to receive applied_objects
/// subscriber.for_each(|obj| async move {
/// info!("saw in subscriber {}", &obj.name_any())
/// }).await;
///
/// # Ok(())
/// # }
/// ```
#[cfg(feature = "unstable-runtime-subscribe")]
fn reflect_shared<K>(self, writer: Writer<K>) -> impl Stream<Item = Self::Item>
where
Self: Stream<Item = watcher::Result<watcher::Event<K>>> + Sized,
K: Resource + Clone + 'static,
K::DynamicType: Eq + std::hash::Hash + Clone,
{
crate::reflector(writer, self)
}
}
impl<St: ?Sized> WatchStreamExt for St where St: Stream {}
// Compile tests
#[cfg(feature = "unstable-runtime-predicates")]
#[cfg(test)]
pub(crate) mod tests {
use super::*;
use crate::predicates;
use futures::StreamExt;
use k8s_openapi::api::core::v1::Pod;
use kube_client::{Api, Resource};
fn compile_type<T>() -> T {
unimplemented!("not called - compile test only")
}
pub fn assert_stream<T, K>(x: T) -> T
where
T: Stream<Item = watcher::Result<K>> + Send,
K: Resource + Clone + Send + 'static,
{
x
}
// not #[test] because this is only a compile check verification
#[allow(dead_code, unused_must_use)]
fn test_watcher_stream_type_drift() {
let pred_watch = watcher(compile_type::<Api<Pod>>(), Default::default())
.touched_objects()
.predicate_filter(predicates::generation)
.boxed();
assert_stream(pred_watch);
}
}