Add a requeue channel (#8)

As a controller processes events, it may not be able to act successfully
on these events: there may be a transient problem when writing to the
API server, or the system may not be in a converged state and it may be
necessary to reprocess the update at a later time.

The `requeue` channel provides a bounded, multi-producer/single-
consumer, delay-queue channel. Applications can use this channel to
reschedule updates for a later time. While this is especially useful for
controllers, this channel is not inherently tied to Kubernetes in any
way.

.github/workflows/lints.yml → .github/workflows/lint.yml

@@ -1,10 +1,10 @@
-name: lints
+name: lint
 
 on:
   pull_request:
     paths:
       - '**/*.rs'
-      - .github/workflows/lints.yml
+      - .github/workflows/lint.yml
 
 permissions:
   contents: read

.github/workflows/test.yml

@@ -0,0 +1,36 @@
+name: test
+
+on:
+  pull_request:
+    paths:
+      - Cargo.lock
+      - '**/*.rs'
+      - .github/workflows/test.yml
+
+permissions:
+  contents: read
+
+env:
+  CARGO_ACTION_FMT_VERSION: v0.1.3
+  CARGO_INCREMENTAL: 0
+  CARGO_NET_RETRY: 10
+  RUST_BACKTRACE: short
+  RUSTUP_MAX_RETRIES: 10
+
+jobs:
+  test:
+    timeout-minutes: 10
+    runs-on: ubuntu-latest
+    container:
+      image: docker://rust:1.58.1
+    steps:
+      - name: install cargo-action-fmt
+        run: |
+          curl --proto =https --tlsv1.3 -vsSfLo /usr/local/bin/cargo-action-fmt "https://github.com/olix0r/cargo-action-fmt/releases/download/release%2F${CARGO_ACTION_FMT_VERSION}/cargo-action-fmt-x86_64-unknown-linux-gnu"
+          chmod 755 /usr/local/bin/cargo-action-fmt
+      - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579
+      - run: cargo fetch
+      - name: cargo test --no-run
+        run: cargo test --frozen --workspace --all-features --no-run --message-format=json | cargo-action-fmt
+      - name: cargo test
+        run: cargo test --frozen --workspace --all-features

deny.toml

@@ -13,7 +13,7 @@ ignore = [
 
 [licenses]
 unlicensed = "deny"
-allow = ["Apache-2.0", "ISC", "MIT"]
+allow = ["Apache-2.0", "BSD-3-Clause", "ISC", "MIT"]
 deny = []
 copyleft = "deny"
 allow-osi-fsf-free = "neither"

kubert/Cargo.toml

@@ -13,6 +13,7 @@ keywords = ["kubernetes", "client", "runtime", "server"]
 client = ["kube-client", "thiserror"]
 # TODO controller = ["client", "kube/runtime"]
 log = ["thiserror", "tracing-subscriber"]
+requeue = ["futures-core", "tokio/macros", "tokio/sync", "tokio-util/time"]
 # TODO runtime = ["clap", "drain", "log", "tokio/signal"]
 server = [
     "drain",
@@ -44,10 +45,12 @@ features = [
 
 [dependencies]
 drain = { version = "0.1.0", optional = true, default-features = false }
+futures-core = { version = "0.3", optional = true, default-features = false }
 hyper = { version = "0.14.17", optional = true, default-features = false }
 rustls-pemfile = { version = "0.3.0", optional = true }
 thiserror = { version = "1.0.30", optional = true }
 tokio = { version = "1.17.0", optional = false, default-features = false }
+tokio-util = { version = "0.7", optional = true, default-features = false }
 tokio-rustls = { version = "0.23.2", optional = true, default-features = false }
 tower-service = { version = "0.3.1", optional = true }
 tracing = "0.1.31"
@@ -64,6 +67,16 @@ optional = true
 default-features = false
 features = ["client", "config"]
 
+[dependencies.kube-core]
+version = "0.69.1"
+optional = true
+default-features = false
+
+[dependencies.kube-runtime]
+version = "0.69.1"
+optional = true
+default-features = false
+
 [dependencies.tracing-subscriber]
 version = "0.3.9"
 optional = true
@@ -77,4 +90,12 @@ features = [
 ]
 
 [dev-dependencies]
+kube = { version = "0.69.1", default-features = false, features = ["runtime"] }
 k8s-openapi = { version = "0.14.0", default-features = false, features = ["v1_23"] }
+tracing-subscriber = { version = "0.3", features = ["ansi"] }
+tokio-test = "0.4"
+
+[dev-dependencies.tokio]
+version = "1.17"
+default-features = false
+features = ["macros", "test-util"]

kubert/src/lib.rs

@@ -22,6 +22,10 @@ pub mod log;
 #[cfg_attr(docsrs, doc(cfg(any(feature = "shutdown"))))]
 pub mod shutdown;
 
+#[cfg(feature = "requeue")]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "requeue"))))]
+pub mod requeue;
+
 #[cfg(feature = "server")]
 #[cfg_attr(docsrs, doc(cfg(any(feature = "shutdown"))))]
 pub mod server;