feat: Add Sendgrid client to AppContext (#402)

src/app/context.rs

@@ -80,6 +80,9 @@ impl AppContext {
             #[cfg(feature = "email-smtp")]
             let mailer = lettre::SmtpTransport::try_from(&config.email.smtp.connection)?;
 
+            #[cfg(feature = "email-sendgrid")]
+            let sendgrid = sendgrid::v3::Sender::try_from(&config.email.sendgrid)?;
+
             let inner = AppContextInner {
                 config,
                 metadata,
@@ -92,6 +95,8 @@ impl AppContext {
                 redis_fetch,
                 #[cfg(feature = "email-smtp")]
                 mailer,
+                #[cfg(feature = "email-sendgrid")]
+                sendgrid,
             };
             AppContext {
                 inner: Arc::new(inner),
@@ -167,6 +172,11 @@ impl AppContext {
     pub fn mailer(&self) -> &lettre::SmtpTransport {
         self.inner.mailer()
     }
+
+    #[cfg(feature = "email-sendgrid")]
+    pub fn sendgrid(&self) -> &sendgrid::v3::Sender {
+        self.inner.sendgrid()
+    }
 }
 
 struct AppContextInner {
@@ -184,6 +194,8 @@ struct AppContextInner {
     redis_fetch: Option<sidekiq::RedisPool>,
     #[cfg(feature = "email-smtp")]
     mailer: lettre::SmtpTransport,
+    #[cfg(feature = "email-sendgrid")]
+    sendgrid: sendgrid::v3::Sender,
 }
 
 #[cfg_attr(test, mockall::automock)]
@@ -231,4 +243,9 @@ impl AppContextInner {
     fn mailer(&self) -> &lettre::SmtpTransport {
         &self.mailer
     }
+
+    #[cfg(feature = "email-sendgrid")]
+    fn sendgrid(&self) -> &sendgrid::v3::Sender {
+        &self.sendgrid
+    }
 }

src/config/email/sendgrid/mod.rs

@@ -1,6 +1,10 @@
+use crate::config::email::Email;
 use crate::config::environment::Environment;
 use crate::util::serde::default_true;
 use config::{FileFormat, FileSourceString};
+use lettre::message::Mailbox;
+use reqwest::Client;
+use sendgrid::v3::{Message, Sender};
 use serde_derive::{Deserialize, Serialize};
 use validator::Validate;
 
@@ -18,13 +22,57 @@ pub(crate) fn default_config_per_env(
 #[serde(rename_all = "kebab-case")]
 #[non_exhaustive]
 pub struct Sendgrid {
+    /// Your Sendgrid API key.
     pub api_key: String,
+
+    /// Whether messages should be sent in [sandbox mode](https://www.twilio.com/docs/sendgrid/for-developers/sending-email/sandbox-mode).
+    ///
+    /// Note that this is currently not supported by the [sendgrid crate](https://crates.io/crates/sendgrid).
     #[serde(default = "default_true")]
     pub sandbox: bool,
+
+    /// Whether the Sendgrid client should connect only with https.
+    ///
+    /// If `true`, the Sendgrid client will only be allowed to connect to the Sendgrid API using
+    /// https. If `false`, the Sendgrid client could in theory connect using http.
+    ///
+    /// This is automatically applied if creating a [`Sender`] using the provided
+    /// [`From<&Sendgrid>`] implementation.
     #[serde(default = "default_true")]
     pub https_only: bool,
 }
 
+impl From<&Email> for Message {
+    fn from(value: &Email) -> Self {
+        let message = Message::new(mailbox_to_email(&value.from));
+        let message = if let Some(reply_to) = value.reply_to.as_ref() {
+            message.set_reply_to(mailbox_to_email(reply_to))
+        } else {
+            message
+        };
+        message
+    }
+}
+
+fn mailbox_to_email(mailbox: &Mailbox) -> sendgrid::v3::Email {
+    let email = sendgrid::v3::Email::new(mailbox.email.to_string());
+    let email = if let Some(name) = mailbox.name.as_ref() {
+        email.set_name(name)
+    } else {
+        email
+    };
+    email
+}
+
+impl TryFrom<&Sendgrid> for Sender {
+    type Error = reqwest::Error;
+
+    fn try_from(value: &Sendgrid) -> Result<Self, Self::Error> {
+        let client = Client::builder().https_only(value.https_only).build()?;
+        Ok(Sender::new(value.api_key.clone(), Some(client)))
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/error/mod.rs

@@ -6,6 +6,7 @@ pub mod config;
 #[cfg(feature = "email")]
 pub mod email;
 pub mod other;
+pub mod reqwest;
 pub mod serde;
 #[cfg(feature = "sidekiq")]
 pub mod sidekiq;
@@ -21,6 +22,7 @@ use crate::error::axum::AxumError;
 #[cfg(feature = "email")]
 use crate::error::email::EmailError;
 use crate::error::other::OtherError;
+use crate::error::reqwest::ReqwestError;
 use crate::error::serde::SerdeError;
 #[cfg(feature = "sidekiq")]
 use crate::error::sidekiq::SidekiqError;
@@ -77,6 +79,9 @@ pub enum Error {
     #[error(transparent)]
     Tracing(#[from] TracingError),
 
+    #[error(transparent)]
+    Reqwest(#[from] ReqwestError),
+
     #[cfg(feature = "http")]
     #[error(transparent)]
     Axum(#[from] AxumError),

src/error/reqwest.rs

@@ -0,0 +1,17 @@
+use crate::error::Error;
+
+#[derive(Debug, Error)]
+#[non_exhaustive]
+pub enum ReqwestError {
+    #[error(transparent)]
+    Error(#[from] reqwest::Error),
+
+    #[error(transparent)]
+    Other(#[from] Box<dyn std::error::Error + Send + Sync>),
+}
+
+impl From<reqwest::Error> for Error {
+    fn from(value: reqwest::Error) -> Self {
+        Self::Reqwest(ReqwestError::from(value))
+    }
+}