swarm-secret-client: bound vault requests with a 30s timeout

vaultrs sets no request timeout by default, so a store that accepts a connection and never answers hung every SecretStore call forever. connect_with_identity now sets VAULT_REQUEST_TIMEOUT; a stalled store surfaces as Error::Vault.

swarm-secret-client/src/client.rs

@@ -1,10 +1,12 @@
 //! A logged-in handle on the store, built from this deployment's environment.
 
+use std::time::Duration;
+
 use rustify_derive::Endpoint;
 use serde::{Serialize, de::DeserializeOwned};
 use vaultrs::{
     api::pki::{requests::GenerateCertificateRequest, responses::GenerateCertificateResponse},
-    client::{Client, VaultClient, VaultClientSettingsBuilder},
+    client::{Client, VaultClient, VaultClientSettings, VaultClientSettingsBuilder},
 };
 
 use crate::{Error, mtls, path::MOUNT};
@@ -23,6 +25,13 @@ pub const ENV_CACERT: &str = "BAO_CACERT";
 /// The auth mount a cert login goes through, unless a caller says otherwise.
 pub const DEFAULT_CERT_MOUNT: &str = "cert";
 
+/// Upper bound on one request to the store, login included.
+///
+/// vaultrs sets no timeout by default, so a store that accepts the connection
+/// and never answers would hold every [`SecretStore`] call open forever; with
+/// this bound the call fails with [`Error::Vault`] instead.
+const VAULT_REQUEST_TIMEOUT: Duration = Duration::from_secs(30);
+
 /// Where the store is and which identity we present to it.
 ///
 /// Separate from the connect so the environment can be checked without one:
@@ -37,6 +46,22 @@ pub struct Settings {
 }
 
 impl Settings {
+    /// The vaultrs settings for this store, presenting `identity`.
+    fn client_settings(
+        &self,
+        identity: Option<reqwest::Identity>,
+    ) -> Result<VaultClientSettings, Error> {
+        let mut builder = VaultClientSettingsBuilder::default();
+        builder
+            .address(self.address.clone())
+            .identity(identity)
+            .timeout(Some(VAULT_REQUEST_TIMEOUT));
+        if let Some(ca) = &self.ca_path {
+            builder.ca_certs(vec![ca.clone()]);
+        }
+        builder.build().map_err(|e| Error::Settings(e.to_string()))
+    }
+
     /// Read the `BAO_*` variables from the process environment.
     ///
     /// # Errors
@@ -147,16 +172,7 @@ impl SecretStore {
     ) -> Result<Self, Error> {
         let identity = reqwest::Identity::from_pem(identity_pem).map_err(Error::Tls)?;
 
-        let mut builder = VaultClientSettingsBuilder::default();
-        builder
-            .address(settings.address.clone())
-            .identity(Some(identity));
-        if let Some(ca) = &settings.ca_path {
-            builder.ca_certs(vec![ca.clone()]);
-        }
-        let built = builder
-            .build()
-            .map_err(|e| Error::Settings(e.to_string()))?;
+        let built = settings.client_settings(Some(identity))?;
 
         let mut inner = VaultClient::new(built)?;
         let auth = vaultrs::auth::cert::login(&inner, cert_mount, cert_role).await?;
@@ -471,6 +487,13 @@ mod tests {
         }
     }
 
+    #[test]
+    fn the_client_is_built_with_a_request_timeout() {
+        let s = Settings::from_lookup(full).expect("every required variable is set");
+        let built = s.client_settings(None).expect("settings build");
+        assert_eq!(built.timeout, Some(VAULT_REQUEST_TIMEOUT));
+    }
+
     #[test]
     fn a_complete_environment_is_accepted() {
         // The control: without this, every assertion below could be passing

swarm-secret-client/src/lib.rs

@@ -74,8 +74,8 @@ pub enum Error {
     #[error("the store's settings are unusable: {0}")]
     Settings(String),
 
-    /// The store refused us, was unreachable, or answered something we could
-    /// not parse.
+    /// The store refused us, was unreachable, did not answer within the
+    /// client's request timeout, or answered something we could not parse.
     #[error(transparent)]
     Vault(#[from] Box<vaultrs::error::ClientError>),