From 4c684adc74cab04b3dd14db1192281cdae4cdf9c Mon Sep 17 00:00:00 2001
From: MOZGIII <mike-n@narod.ru>
Date: Wed, 10 Jun 2020 06:33:35 +0300
Subject: [PATCH] Add lock to the test framework

Signed-off-by: MOZGIII <mike-n@narod.ru>
---
 Cargo.lock                                |  1 +
 lib/kubernetes-test-framework/Cargo.toml  |  1 +
 lib/kubernetes-test-framework/src/lib.rs  |  2 ++
 lib/kubernetes-test-framework/src/lock.rs | 15 +++++++++++++++
 4 files changed, 19 insertions(+)
 create mode 100644 lib/kubernetes-test-framework/src/lock.rs

diff --git a/Cargo.lock b/Cargo.lock
index 2332e04f9caa39..71d2e4806de34c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2079,6 +2079,7 @@ name = "kubernetes-test-framework"
 version = "0.1.0"
 dependencies = [
  "k8s-openapi",
+ "once_cell",
  "serde_json",
  "tempfile",
 ]
diff --git a/lib/kubernetes-test-framework/Cargo.toml b/lib/kubernetes-test-framework/Cargo.toml
index bf5dd7b3fd08bf..6e423cb281af56 100644
--- a/lib/kubernetes-test-framework/Cargo.toml
+++ b/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"
diff --git a/lib/kubernetes-test-framework/src/lib.rs b/lib/kubernetes-test-framework/src/lib.rs
index e5709c32d67bc4..2e9b2eb1830c65 100644
--- a/lib/kubernetes-test-framework/src/lib.rs
+++ b/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>>;
diff --git a/lib/kubernetes-test-framework/src/lock.rs b/lib/kubernetes-test-framework/src/lock.rs
new file mode 100644
index 00000000000000..ecec583c33039b
--- /dev/null
+++ b/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(),
+    }
+}