Add lock to the test framework

Signed-off-by: MOZGIII <[email protected]>

lib/kubernetes-test-framework/Cargo.toml

@@ -9,3 +9,4 @@ description = "Kubernetes Test Framework used to test Vector in Kubernetes"
 k8s-openapi = { version = "0.7", default-features = false, features = ["v1_15"] }
 serde_json = "1"
 tempfile = "3"
+once_cell = "1"

lib/kubernetes-test-framework/src/lib.rs

@@ -18,6 +18,7 @@
 
 pub mod framework;
 pub mod interface;
+mod lock;
 pub mod log_lookup;
 pub mod namespace;
 mod resource_file;
@@ -30,5 +31,6 @@ pub mod wait_for_rollout;
 
 pub use framework::Framework;
 pub use interface::Interface;
+pub use lock::lock;
 
 type Result<T> = std::result::Result<T, Box<dyn std::error::Error>>;

lib/kubernetes-test-framework/src/lock.rs

@@ -0,0 +1,15 @@
+use once_cell::sync::OnceCell;
+use std::sync::{Mutex, MutexGuard};
+
+/// A shared lock to use commonly among the tests.
+/// The goal is to guranatee that only one test is executing concurrently, since
+/// tests use a shared resource - a k8s cluster - and will conflict with each
+/// other unless they're executing sequentially.
+pub fn lock() -> MutexGuard<'static, ()> {
+    static INSTANCE: OnceCell<Mutex<()>> = OnceCell::new();
+    match INSTANCE.get_or_init(|| Mutex::new(())).lock() {
+        Ok(guard) => guard,
+        // Ignore poison error.
+        Err(err) => err.into_inner(),
+    }
+}