chore(rust): used portpicker crate to avoid port clash in ockam examples

examples/rust/tcp_inlet_and_outlet/Cargo.toml

@@ -9,6 +9,7 @@ rust-version = "1.56.0"
 
 [dependencies]
 ockam = { path = "../../../implementations/rust/ockam/ockam" }
+portpicker = "0.1.1"
 
 [dev-dependencies]
 example_test_helper = { path = "../../../tools/docs/example_test_helper" }

examples/rust/tcp_inlet_and_outlet/tests/tests.rs

@@ -1,10 +1,9 @@
 use example_test_helper::{CmdBuilder, Error};
-use ockam::compat::rand;
-use ockam::compat::rand::Rng;
+use portpicker::pick_unused_port;
 
 #[test]
 fn run_01_inlet_outlet_one_process() -> Result<(), Error> {
-    let port = rand::thread_rng().gen_range(10000..65535);
+    let port = pick_unused_port().expect("No free ports available");
     // Spawn example, wait for it to start up
     let runner = CmdBuilder::new(&format!(
         "cargo run --example 01-inlet-outlet 127.0.0.1:{port} ockam.io:80"
@@ -24,8 +23,8 @@ fn run_01_inlet_outlet_one_process() -> Result<(), Error> {
 
 #[test]
 fn run_02_inlet_outlet_separate_processes() -> Result<(), Error> {
-    let routing_port = rand::thread_rng().gen_range(10000..65535);
-    let inlet_port = rand::thread_rng().gen_range(10000..65535);
+    let routing_port = pick_unused_port().expect("No free ports available");
+    let inlet_port = pick_unused_port().expect("No free ports available");
     // Spawn outlet, wait for it to start up
     let outlet = CmdBuilder::new(&format!("cargo run --example 02-outlet ockam.io:80 {routing_port}")).spawn()?;
     outlet.match_stdout(r"(?i)Waiting for incoming TCP connection")?;
@@ -52,8 +51,8 @@ fn run_02_inlet_outlet_separate_processes() -> Result<(), Error> {
 #[test]
 #[ignore]
 fn run_03_inlet_outlet_separate_processes_secure_channel() -> Result<(), Error> {
-    let routing_port = rand::thread_rng().gen_range(10000..65535);
-    let inlet_port = rand::thread_rng().gen_range(10000..65535);
+    let routing_port = pick_unused_port().expect("No free ports available");
+    let inlet_port = pick_unused_port().expect("No free ports available");
     // Spawn outlet, wait for it to start up
     let outlet = CmdBuilder::new(&format!("cargo run --example 03-outlet ockam.io:80 {routing_port}")).spawn()?;
     outlet.match_stdout(r"(?i)Waiting for incoming TCP connection")?;
@@ -80,7 +79,7 @@ fn run_03_inlet_outlet_separate_processes_secure_channel() -> Result<(), Error>
 #[test]
 #[ignore]
 fn run_04_inlet_outlet_seperate_processes_secure_channel_via_ockam_hub() -> Result<(), Error> {
-    let port = rand::thread_rng().gen_range(10000..65535);
+    let port = pick_unused_port().expect("No free ports available");
     // Spawn outlet, wait for it to start up, grab dynamic forwarding address
     let outlet = CmdBuilder::new("cargo run --example 04-outlet ockam.io:80").spawn()?;
     outlet.match_stdout(r"(?i)RemoteRelay was created on the node")?;