chore(examples): Remove unnecessary asyncronous file io to read data for example (#1219)

examples/src/gcp/client.rs

@@ -24,10 +24,10 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let bearer_token = format!("Bearer {}", token);
     let header_value: MetadataValue<_> = bearer_token.parse()?;
 
-    let certs = tokio::fs::read("examples/data/gcp/roots.pem").await?;
+    let certs = std::fs::read_to_string("examples/data/gcp/roots.pem")?;
 
     let tls_config = ClientTlsConfig::new()
-        .ca_certificate(Certificate::from_pem(certs.as_slice()))
+        .ca_certificate(Certificate::from_pem(certs))
         .domain_name("pubsub.googleapis.com");
 
     let channel = Channel::from_static(ENDPOINT)

examples/src/tls/client.rs

@@ -7,7 +7,7 @@ use tonic::transport::{Certificate, Channel, ClientTlsConfig};
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let pem = tokio::fs::read("examples/data/tls/ca.pem").await?;
+    let pem = std::fs::read_to_string("examples/data/tls/ca.pem")?;
     let ca = Certificate::from_pem(pem);
 
     let tls = ClientTlsConfig::new()

examples/src/tls/server.rs

@@ -36,8 +36,8 @@ impl pb::echo_server::Echo for EchoServer {
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let cert = tokio::fs::read("examples/data/tls/server.pem").await?;
-    let key = tokio::fs::read("examples/data/tls/server.key").await?;
+    let cert = std::fs::read_to_string("examples/data/tls/server.pem")?;
+    let key = std::fs::read_to_string("examples/data/tls/server.key")?;
 
     let identity = Identity::from_pem(cert, key);
 

examples/src/tls_client_auth/client.rs

@@ -7,10 +7,10 @@ use tonic::transport::{Certificate, Channel, ClientTlsConfig, Identity};
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let server_root_ca_cert = tokio::fs::read("examples/data/tls/ca.pem").await?;
+    let server_root_ca_cert = std::fs::read_to_string("examples/data/tls/ca.pem")?;
     let server_root_ca_cert = Certificate::from_pem(server_root_ca_cert);
-    let client_cert = tokio::fs::read("examples/data/tls/client1.pem").await?;
-    let client_key = tokio::fs::read("examples/data/tls/client1.key").await?;
+    let client_cert = std::fs::read_to_string("examples/data/tls/client1.pem")?;
+    let client_key = std::fs::read_to_string("examples/data/tls/client1.key")?;
     let client_identity = Identity::from_pem(client_cert, client_key);
 
     let tls = ClientTlsConfig::new()

examples/src/tls_client_auth/server.rs

@@ -27,11 +27,11 @@ impl pb::echo_server::Echo for EchoServer {
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let cert = tokio::fs::read("examples/data/tls/server.pem").await?;
-    let key = tokio::fs::read("examples/data/tls/server.key").await?;
+    let cert = std::fs::read_to_string("examples/data/tls/server.pem")?;
+    let key = std::fs::read_to_string("examples/data/tls/server.key")?;
     let server_identity = Identity::from_pem(cert, key);
 
-    let client_ca_cert = tokio::fs::read("examples/data/tls/client_ca.pem").await?;
+    let client_ca_cert = std::fs::read_to_string("examples/data/tls/client_ca.pem")?;
     let client_ca_cert = Certificate::from_pem(client_ca_cert);
 
     let addr = "[::1]:50051".parse().unwrap();

examples/src/uds/server.rs

@@ -45,7 +45,7 @@ impl Greeter for MyGreeter {
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let path = "/tmp/tonic/helloworld";
 
-    tokio::fs::create_dir_all(Path::new(path).parent().unwrap()).await?;
+    std::fs::create_dir_all(Path::new(path).parent().unwrap())?;
 
     let greeter = MyGreeter::default();