feat: add SMTP provider configuration to support multiple email services

.github/workflows/deploy.yml

@@ -36,4 +36,5 @@ jobs:
           project-id: proj_01JNH9KPMRS34FKC2NHWQ5YNNB
           secrets: |
             SMTP_MAIL = '${{ secrets.SMTP_MAIL }}'
-            SMTP_SECRET = '${{ secrets.SMTP_SECRET }}'
+            SMTP_SECRET = '${{ secrets.SMTP_SECRET }}'
+            SMTP_PROVIDER = '${{ secrets.SMTP_PROVIDER }}'

src/api/v1/onboarding/registration.rs

@@ -47,7 +47,7 @@ pub async fn register(
     let credentials = Credentials::new(smtp.mail().to_string(), smtp.secret().to_string());
 
     #[allow(clippy::unwrap_used)]
-    let mailer = SmtpTransport::relay("smtp.gmail.com")
+    let mailer = SmtpTransport::relay(smtp.provider())
         .unwrap()
         .credentials(credentials)
         .build();

src/main.rs

@@ -7,6 +7,7 @@ async fn main(#[shuttle_runtime::Secrets] secrets: SecretStore) -> shuttle_axum:
     let smtp_config = digitaler_frieden::config::SMTPConfig::new(
         &secrets.get("SMTP_MAIL").expect("SMTP_MAIL not set"),
         &secrets.get("SMTP_SECRET").expect("SMTP_SECRET not set"),
+        &secrets.get("SMTP_PROVIDER").expect("SMTP_PROVIDER not set"),
     );
     let router = digitaler_frieden::new(smtp_config);
     Ok(router.into())

src/model/config/smtp_config.rs

@@ -5,13 +5,15 @@ use std::fmt::Debug;
 pub struct SMTPConfig {
     mail: String,
     secret: String,
+    provider: String,
 }
 
 impl SMTPConfig {
-    pub fn new<T: AsRef<str>>(mail: T, secret: T) -> Self {
+    pub fn new<T: AsRef<str>>(mail: T, secret: T, provider: T) -> Self {
         Self {
             mail: mail.as_ref().to_owned(),
             secret: secret.as_ref().to_owned(),
+            provider: provider.as_ref().to_owned(),
         }
     }
 
@@ -24,12 +26,18 @@ impl SMTPConfig {
     pub fn secret(&self) -> &str {
         &self.secret
     }
+
+    #[must_use]
+    pub fn provider(&self) -> &str {
+        &self.provider
+    }
 }
 
 impl Debug for SMTPConfig {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("SMTPConfig")
             .field("mail", &self.mail)
+            .field("provider", &self.provider)
             .field("secret", &"<reducted>")
             .finish()
     }