code in chapter 7.2.5.0.2

Add email client (for verification)
Work In Progress: this code exposes a compiler bug (1.72) encountered incremental compilation error with mir_shims(aa7d6ad7e64c8d82-9f4068ebffc54ad8)
  |

Cargo.toml

@@ -37,6 +37,12 @@ features = [
 #"offline", # sqlx 0.7 does not have 'offline'
 ]
 
+[dependencies.reqwest]
+version = "0.11"
+default-features = false
+# We need the `json` feature flag to serialize/deserialize JSON payloads
+features = ["json", "rustls-tls"]
+
 [lib]
 path = "src/lib.rs"
 name  = "zero2prod"
@@ -48,9 +54,10 @@ path = "src/main.rs"
 name = "zero2prod"
 
 [dev-dependencies]
-reqwest = "0.11"
 once_cell = "1"
 claims = "0.7"
 fake = "~2.3"
 quickcheck = "0.9.2"
-quickcheck_macros = "0.9.1"
+quickcheck_macros = "0.9.1"
+# tokio = { version = "1", features = ["rt", "macros"] } it compiles without?!
+wiremock = "0.5"

configuration/base.yaml

@@ -8,4 +8,9 @@ database:
   port: 5432
   username: "postgres"
   password: "password" # used locally only. When deploying to DigitalOcean, a strong password is used
-  database_name: "newsletter"
+  database_name: "newsletter"
+
+email_client:
+  base_url: "localhost"
+  sender_email: "test@gmail.com"
+  authorization_token: "873fa009-f43b-4494-a791-0d39c68792f4"

configuration/production.yaml

@@ -4,4 +4,10 @@ application:
 
 
 database:
-   require_ssl: true
+   require_ssl: true
+
+email_client:
+  # Value retrieved from Postmark's API documentation
+  base_url: "https://api.postmarkapp.com"
+  # Use the single sender email you authorised on Postmark!
+  sender_email: "something@gmail.com"

src/configuration.rs

@@ -1,18 +1,36 @@
 //! src/configuration.rs
 //!
 
-use secrecy::Secret;
 use secrecy::ExposeSecret;
+use secrecy::Secret;
 use serde_aux::field_attributes::deserialize_number_from_string;
-use sqlx::postgres::{PgConnectOptions,PgSslMode};
+use sqlx::postgres::{PgConnectOptions, PgSslMode};
+use crate::domain::SubscriberEmail;
 
 
 #[derive(serde::Deserialize)]
 pub struct Settings {
     pub database: DatabaseSettings,
     pub application: ApplicationSettings,
+    pub email_client: EmailClientSettings,
 }
 
+
+#[derive(serde::Deserialize)]
+pub struct EmailClientSettings {
+    pub base_url: String,
+    pub sender_email: String,
+    // New (secret) configuration value!
+    pub authorization_token: Secret<String>
+}
+
+impl EmailClientSettings {
+    pub fn sender(&self) -> Result<SubscriberEmail, String> {
+        SubscriberEmail::parse(self.sender_email.clone())
+    }
+}
+
+
 #[derive(serde::Deserialize)]
 pub struct DatabaseSettings {
     pub username: String,
@@ -37,6 +55,7 @@ pub enum Environment {
     Local,
     Production,
 }
+
 impl Environment {
     pub fn as_str(&self) -> &'static str {
         match self {
@@ -45,6 +64,7 @@ impl Environment {
         }
     }
 }
+
 impl TryFrom<String> for Environment {
     type Error = String;
 
@@ -62,7 +82,6 @@ impl TryFrom<String> for Environment {
 }
 
 pub fn get_configuration() -> Result<Settings, config::ConfigError> {
-
     let base_path = std::env::current_dir()
         .expect("Failed to determine the current directory");
     let configuration_directory = base_path.join("configuration");
@@ -96,14 +115,14 @@ impl DatabaseSettings {
         options
     }
 
-     pub fn without_db(&self) -> PgConnectOptions {
-         let ssl_mode = if self.require_ssl {
-             PgSslMode::Require
-         } else {
-             // Try an encrypted connection, fallback to unencrypted if it fails
-             PgSslMode::Prefer
-         };
-         PgConnectOptions::new()
+    pub fn without_db(&self) -> PgConnectOptions {
+        let ssl_mode = if self.require_ssl {
+            PgSslMode::Require
+        } else {
+            // Try an encrypted connection, fallback to unencrypted if it fails
+            PgSslMode::Prefer
+        };
+        PgConnectOptions::new()
             .host(&self.host)
             .username(&self.username)
             .password(&self.password.expose_secret())

src/domain/subscriber_email.rs

@@ -1,7 +1,7 @@
 //! src/domain/subscriber_email.rs
 use validator::validate_email;
 
-#[derive(Debug)]
+#[derive(Debug,Clone)]
 pub struct SubscriberEmail(String);
 
 impl SubscriberEmail {

src/email_client.rs

@@ -0,0 +1,119 @@
+//! src/email_client.rs
+use reqwest::Client;
+use secrecy::{ExposeSecret, Secret};
+
+use crate::domain::SubscriberEmail;
+
+#[derive(Clone)]
+pub struct EmailClient {
+    http_client: Client,
+    base_url: String,
+    sender: SubscriberEmail,
+    // We don't want to log this by accident
+    authorization_token: Secret<String>,
+}
+
+impl EmailClient {
+    pub fn new(base_url: String, sender: SubscriberEmail,
+               authorization_token: Secret<String>) -> Self {
+        Self {
+            http_client: Client::new(),
+            base_url,
+            sender,
+            authorization_token,
+        }
+    }
+
+
+    pub async fn send_email(
+        &self,
+        recipient: SubscriberEmail,
+        subject: &str,
+        html_content: &str,
+        text_content: &str,
+    ) -> Result<(), reqwest::Error> {
+        let url = format!("{}/email", self.base_url);
+        let request_body = SendEmailRequest {
+            from: self.sender.as_ref().to_owned(),
+            to: recipient.as_ref().to_owned(),
+            subject: subject.to_owned(),
+            html_body: html_content.to_owned(),
+            text_body: text_content.to_owned(),
+        };
+
+        self
+            .http_client
+            .post(&url)
+            .header(
+                "X-Postmark-Server-Token",
+                self.authorization_token.expose_secret(),
+            )
+            .json(&request_body)
+            .send()
+            .await?;
+        Ok(())
+    }
+}
+
+#[derive(serde::Serialize)]
+struct SendEmailRequest {
+    from: String,
+    to: String,
+    subject: String,
+    html_body: String,
+    text_body: String,
+}
+
+/* password: KsgAcS!aaJm3WLj
+api token:
+*/
+#[cfg(test)]
+mod tests {
+    use fake::{Fake, Faker};
+    use fake::faker::internet::en::SafeEmail;
+    use fake::faker::lorem::en::{Paragraph, Sentence};
+    use secrecy::Secret;
+
+    use wiremock::{Mock, MockServer, Request, ResponseTemplate};
+    use wiremock::matchers::{header, header_exists, method, path};
+
+    use crate::domain::SubscriberEmail;
+    use crate::email_client::EmailClient;
+
+    struct SendEmailBodyMatcher;
+
+    impl wiremock::Match for SendEmailBodyMatcher {
+        fn matches(&self, request: &Request) -> bool {
+            unimplemented!()
+        }
+    }
+
+    #[tokio::test]
+    async fn send_email_fires_a_request_to_base_url() {
+        // Arrange
+        let mock_server = MockServer::start().await;
+        let sender = SubscriberEmail::parse(SafeEmail().fake()).unwrap();
+        let email_client = EmailClient::new(
+            mock_server.uri(),
+            sender,
+            Secret::new(Faker.fake()),
+        );
+        Mock::given(header_exists("X-Postmark-Server-Token"))
+            .and(header("Content-Type", "application/json"))
+            .and(path("/email"))
+            .and(method("POST"))
+            .respond_with(ResponseTemplate::new(200))
+            .expect(1)
+            .mount(&mock_server)
+            .await;
+        let subscriber_email = SubscriberEmail::parse(SafeEmail().fake()).unwrap();
+        let subject: String = Sentence(1..2).fake();
+        let content: String = Paragraph(1..10).fake();
+        // Act
+        let _ = email_client
+            .send_email(subscriber_email, &subject, &content, &content)
+            .await;
+        // Assert
+        // When going out of scope, the Mock::expect() are checked
+    }
+}

src/lib.rs

@@ -1,11 +1,8 @@
 //! lib.rs
 
-
-
-
-
 pub mod configuration;
 pub mod domain;
+pub mod email_client;
 pub mod routes;
 pub mod startup;
 pub mod telemetry;

src/main.rs

@@ -1,10 +1,13 @@
 //! main.rs
 
 use std::net::TcpListener;
+
+use sqlx::postgres::PgPoolOptions;
+
 use zero2prod::configuration::get_configuration;
+use zero2prod::email_client::EmailClient;
 use zero2prod::startup::run;
 use zero2prod::telemetry::{get_subscriber, init_subscriber};
-use sqlx::postgres::PgPoolOptions;
 
 #[tokio::main]
 async fn main() -> Result<(), std::io::Error> {
@@ -13,13 +16,22 @@ async fn main() -> Result<(), std::io::Error> {
 
     // read configuration
     let configuration = get_configuration().expect("Failed to read configuration.");
-    let connection_pool =  PgPoolOptions::new()
-        .acquire_timeout(std::time::Duration:: from_secs(2))
+    let connection_pool = PgPoolOptions::new()
+        .acquire_timeout(std::time::Duration::from_secs(2))
         .connect_lazy_with(configuration.database.with_db());
 
-    // We have removed the hard-coded `8000` - it's now coming from our settings!
+    // Build an `EmailClient` using `configuration`
+    let sender_email = configuration.email_client.sender()
+        .expect("Invalid sender email address.");
+    let email_client = EmailClient::new(
+        configuration.email_client.base_url,
+        sender_email,
+        configuration.email_client.authorization_token
+    );
+
+
     let address = format!("{}:{}",
-        configuration.application.host, configuration.application.port);
+                          configuration.application.host, configuration.application.port);
     let listener = TcpListener::bind(address)?;
-    run(listener, connection_pool)?.await
+    run(listener, connection_pool, email_client)?.await
 }

src/startup.rs

@@ -5,8 +5,9 @@ use std::net::TcpListener;
 use sqlx::PgPool;
 use crate::routes::{health_check::health_check, subscriptions::subscribe};
 use tracing_actix_web::TracingLogger;
+use crate::email_client:: EmailClient;
 
-pub  fn run(listener: TcpListener, db_pool: PgPool) -> Result<Server, std::io::Error> {
+pub  fn run(listener: TcpListener, db_pool: PgPool,email_client: EmailClient,) -> Result<Server, std::io::Error> {
     // Wrap the connection in a smart pointer
     let db_pool = web::Data::new(db_pool);
     // Capture `connection` from the surrounding environment ---> add "move"
@@ -18,6 +19,7 @@ pub  fn run(listener: TcpListener, db_pool: PgPool) -> Result<Server, std::io::E
             .route("/subscriptions", web::post().to(subscribe))
             // Register the connection as part of the application state
             .app_data(db_pool.clone()) // this will be used in src/routes/subscriptions handler
+            .app_data(email_client.clone())
     })
         .listen(listener)?
         .run();

tests/health_check.rs

@@ -8,6 +8,9 @@ use zero2prod::configuration::{DatabaseSettings, get_configuration};
 use zero2prod::telemetry::{get_subscriber, init_subscriber};
 use once_cell::sync::Lazy;
 
+use zero2prod::email_client::EmailClient;
+
+
 // `tokio::test` is the testing equivalent of `tokio::main`.
 // It also spares you from having to specify the `#[test]` attribute.
 //
@@ -78,7 +81,13 @@ async fn spawn_app() -> TestApp {
     configuration.database.database_name = Uuid::new_v4().to_string(); // random DB name to run tests in isolation
     let connection_pool = configure_database(&configuration.database).await;
 
-    let server = zero2prod::startup::run(listener, connection_pool.clone()).expect("Failed to bind address");
+    let sender_email = configuration.email_client.sender().expect("Invalid sender email address.");
+    let email_client = EmailClient::new(
+        configuration.email_client.base_url,
+        sender_email,
+        configuration.email_client.authorization_token,
+    );
+    let server = zero2prod::startup::run(listener, connection_pool.clone(), email_client).expect("Failed to bind address");
     let _ = tokio::spawn(server);
 
     TestApp {
@@ -93,6 +102,7 @@ pub async fn configure_database(config: &DatabaseSettings) -> PgPool {
     let mut connection = PgConnection::connect_with(&config.without_db())
         .await
         .expect("Failed to connect to Postgres");
+
     connection
         .execute(format!(r#"CREATE DATABASE "{}";"#, config.database_name).as_str())
         .await