Implement short retries in single threaded context

Also, fix round retry mechanism not being used for login
This two are merged because the changing of the `next_instance` signature
showed that `login()` did not use the retry mechanism

pkcs11/src/backend/login.rs

@@ -15,13 +15,30 @@ use std::{
     time::Duration,
 };
 
-use crate::config::{
-    config_file::{RetryConfig, UserConfig},
-    device::{InstanceAttempt, InstanceData, Slot},
+use crate::{
+    config::{
+        config_file::{RetryConfig, UserConfig},
+        device::{InstanceAttempt, InstanceData, Slot},
+    },
+    data::THREADS_ALLOWED,
 };
 
 use super::{ApiError, Error};
 
+#[derive(Debug)]
+enum ShouldHealthCheck {
+    /// The instance is ready to be used
+    RunDirectly,
+    /// The instance needs to first be health checked
+    HealthCheckFirst,
+}
+
+impl ShouldHealthCheck {
+    fn should_check(&self) -> bool {
+        matches!(self, ShouldHealthCheck::HealthCheckFirst)
+    }
+}
+
 #[derive(Debug)]
 pub struct LoginCtx {
     slot: Arc<Slot>,
@@ -71,6 +88,34 @@ impl std::fmt::Display for LoginError {
     }
 }
 
+/// Perform a health check with a timeout of 1 second
+fn health_check_get_timeout(instance: &InstanceData) -> bool {
+    let config = &instance.config;
+    let uri_str = format!("{}/health/ready", config.base_path);
+    let mut req = config.client.get(&uri_str).timeout(Duration::from_secs(1));
+    if let Some(ref user_agent) = config.user_agent {
+        req = req.set("user-agent", user_agent);
+    }
+
+    match req.call() {
+        Ok(r) => {
+            if r.status() == 200 {
+                instance.clear_failed();
+                return true;
+            }
+            log::warn!("Failed retry {}", r.status_text());
+            instance.bump_failed();
+            false
+        }
+
+        Err(err) => {
+            log::warn!("Failed retry {err:?}");
+            instance.bump_failed();
+            false
+        }
+    }
+}
+
 impl LoginCtx {
     pub fn new(slot: Arc<Slot>, admin_allowed: bool, operator_allowed: bool) -> Self {
         let mut ck_state = CKS_RO_PUBLIC_SESSION;
@@ -113,7 +158,7 @@ impl LoginCtx {
     pub fn login(&mut self, user_type: CK_USER_TYPE, pin: String) -> Result<(), LoginError> {
         trace!("Login as {:?} with pin", user_type);
 
-        let expected = match user_type {
+        let (user_status, user_mode) = match user_type {
             CKU_CONTEXT_SPECIFIC => return Err(LoginError::InvalidUser),
             CKU_SO => {
                 trace!("administrator: {:?}", self.slot.administrator);
@@ -126,7 +171,7 @@ impl LoginCtx {
                     }),
                 };
                 self.admin_allowed = true;
-                (UserStatus::Administrator, self.administrator())
+                (UserStatus::Administrator, UserMode::Administrator)
             }
             CKU_USER => {
                 self.operator_login_override = match self.operator_config() {
@@ -137,69 +182,85 @@ impl LoginCtx {
                     }),
                 };
                 self.operator_allowed = true;
-                (UserStatus::Operator, self.operator())
+                (UserStatus::Operator, UserMode::Operator)
             }
             _ => return Err(LoginError::BadArgument),
         };
 
-        trace!("Config: {:?}", expected.1);
+        let got_user = self
+            .try_(get_current_user_status, user_mode)
+            .map_err(|err| {
+                error!("Login check failed: {err:?}");
+                LoginError::UserNotPresent
+            })?;
 
-        let config = expected.1.ok_or(LoginError::UserNotPresent)?.config;
-
-        if get_current_user_status(&config) == expected.0 {
-            self.ck_state = match expected.0 {
+        if got_user == user_status {
+            self.ck_state = match user_status {
                 UserStatus::Operator => CKS_RW_USER_FUNCTIONS,
                 UserStatus::Administrator => CKS_RW_SO_FUNCTIONS,
                 UserStatus::LoggedOut => CKS_RO_PUBLIC_SESSION,
             };
             Ok(())
         } else {
-            error!("Failed to login as {:?} with pin", expected.0);
+            error!("Failed to login as {user_mode:?} with pin, got user {got_user:?}");
             Err(LoginError::IncorrectPin)
         }
     }
 
-    fn next_instance(&self) -> &InstanceData {
+    fn next_instance(&self) -> (&InstanceData, ShouldHealthCheck) {
+        let threads_allowed = THREADS_ALLOWED.load(Relaxed);
         let index = self.slot.instance_balancer.fetch_add(1, Relaxed);
         let index = index % self.slot.instances.len();
         let instance = &self.slot.instances[index];
-        match instance.should_try() {
-            InstanceAttempt::Failed => {}
-            InstanceAttempt::Working | InstanceAttempt::Retry => return instance,
+        match (instance.should_try(), threads_allowed) {
+            (InstanceAttempt::Failed, _) | (InstanceAttempt::Retry, true) => {}
+            (InstanceAttempt::Working, _) => return (instance, ShouldHealthCheck::RunDirectly),
+            (InstanceAttempt::Retry, false) => {
+                return (instance, ShouldHealthCheck::HealthCheckFirst)
+            }
         }
         for i in 0..self.slot.instances.len() - 1 {
             let instance = &self.slot.instances[index + i];
 
-            match instance.should_try() {
-                InstanceAttempt::Failed => continue,
-                InstanceAttempt::Working | InstanceAttempt::Retry => {
+            match (instance.should_try(), threads_allowed) {
+                (InstanceAttempt::Failed, _) | (InstanceAttempt::Retry, true) => continue,
+                (InstanceAttempt::Working, _) => {
+                    // This not true round-robin in case of multithreaded acces
+                    // This is degraded mode so best-effort is attempted at best
+                    self.slot.instance_balancer.fetch_add(i, Relaxed);
+                    return (instance, ShouldHealthCheck::RunDirectly);
+                }
+                (InstanceAttempt::Retry, false) => {
                     // This not true round-robin in case of multithreaded acces
                     // This is degraded mode so best-effort is attempted at best
                     self.slot.instance_balancer.fetch_add(i, Relaxed);
-                    return instance;
+                    return (instance, ShouldHealthCheck::HealthCheckFirst);
                 }
             }
         }
 
         // No instance is valid, return a failed instance for an attempt
         let index = self.slot.instance_balancer.fetch_add(1, Relaxed);
         let index = index % self.slot.instances.len();
-        &self.slot.instances[index]
+        // Instance is not valid, don't try health check, it would only slow things down
+        (&self.slot.instances[index], ShouldHealthCheck::RunDirectly)
     }
 
-    fn operator(&self) -> Option<InstanceData> {
-        get_user_api_config(self.operator_config(), self.next_instance())
+    fn operator(&self) -> Option<(InstanceData, ShouldHealthCheck)> {
+        let (instance, should_health_check) = self.next_instance();
+        get_user_api_config(self.operator_config(), instance).map(|c| (c, should_health_check))
     }
 
-    fn administrator(&self) -> Option<InstanceData> {
-        get_user_api_config(self.admin_config(), self.next_instance())
+    fn administrator(&self) -> Option<(InstanceData, ShouldHealthCheck)> {
+        let (instance, should_health_check) = self.next_instance();
+        get_user_api_config(self.admin_config(), instance).map(|c| (c, should_health_check))
     }
 
-    fn operator_or_administrator(&self) -> Option<InstanceData> {
+    fn operator_or_administrator(&self) -> Option<(InstanceData, ShouldHealthCheck)> {
         self.operator().or_else(|| self.administrator())
     }
 
-    fn guest(&self) -> &InstanceData {
+    fn guest(&self) -> (&InstanceData, ShouldHealthCheck) {
         self.next_instance()
     }
 
@@ -225,11 +286,17 @@ impl LoginCtx {
         self.ck_state = CKS_RO_PUBLIC_SESSION;
     }
 
-    pub fn get_config_user_mode(&self, user_mode: &UserMode) -> Option<InstanceData> {
+    fn get_config_user_mode(
+        &self,
+        user_mode: &UserMode,
+    ) -> Option<(InstanceData, ShouldHealthCheck)> {
         match user_mode {
             UserMode::Operator => self.operator(),
             UserMode::Administrator => self.administrator(),
-            UserMode::Guest => Some(self.guest().clone()),
+            UserMode::Guest => {
+                let (instance, should_health_check) = self.guest();
+                Some((instance.clone(), should_health_check))
+            }
             UserMode::OperatorOrAdministrator => self.operator_or_administrator(),
         }
     }
@@ -240,7 +307,8 @@ impl LoginCtx {
         F: FnOnce(&Configuration) -> Result<R, apis::Error<T>> + Clone,
     {
         // we loop for a maximum of instances.len() times
-        let Some(mut instance) = self.get_config_user_mode(&user_mode) else {
+        let Some((mut instance, mut should_health_check)) = self.get_config_user_mode(&user_mode)
+        else {
             return Err(Error::Login(LoginError::UserNotPresent));
         };
 
@@ -262,6 +330,12 @@ impl LoginCtx {
                 );
                 return Err(ApiError::InstanceRemoved.into());
             }
+
+            if should_health_check.should_check() && !health_check_get_timeout(&instance) {
+                // Instance is not valid, we try the next one
+                continue;
+            }
+
             retry_count += 1;
             let api_call_clone = api_call.clone();
             match api_call_clone(&instance.config) {
@@ -280,8 +354,11 @@ impl LoginCtx {
 
                     warn!("Connection attempt {retry_count} failed: Status error connecting to the instance, {:?}, retrying in {delay_seconds}s", err.status);
                     thread::sleep(delay);
-                    if let Some(new_conf) = self.get_config_user_mode(&user_mode) {
-                        instance = new_conf;
+                    if let Some((new_instance, new_should_health_check)) =
+                        self.get_config_user_mode(&user_mode)
+                    {
+                        instance = new_instance;
+                        should_health_check = new_should_health_check;
                     }
                 }
 
@@ -296,8 +373,11 @@ impl LoginCtx {
                     instance.bump_failed();
                     warn!("Connection attempt {retry_count} failed: IO error connecting to the instance, {err}, retrying in {delay_seconds}s");
                     thread::sleep(delay);
-                    if let Some(new_conf) = self.get_config_user_mode(&user_mode) {
-                        instance = new_conf;
+                    if let Some((new_instance, new_should_health_check)) =
+                        self.get_config_user_mode(&user_mode)
+                    {
+                        instance = new_instance;
+                        should_health_check = new_should_health_check;
                     }
                 }
                 // Otherwise, return the error
@@ -349,7 +429,7 @@ impl LoginCtx {
     }
 }
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum UserMode {
     Operator,
     Administrator,
@@ -366,29 +446,23 @@ pub enum UserStatus {
 
 pub fn get_current_user_status(
     api_config: &nethsm_sdk_rs::apis::configuration::Configuration,
-) -> UserStatus {
+) -> Result<UserStatus, apis::Error<default_api::UsersUserIdGetError>> {
     let auth = match api_config.basic_auth.as_ref() {
         Some(auth) => auth,
-        None => return UserStatus::LoggedOut,
+        None => return Ok(UserStatus::LoggedOut),
     };
 
     if auth.1.is_none() {
-        return UserStatus::LoggedOut;
+        return Ok(UserStatus::LoggedOut);
     }
 
-    let user = match default_api::users_user_id_get(api_config, auth.0.as_str()) {
-        Ok(user) => user.entity,
-        Err(err) => {
-            error!("Failed to get user: {:?}", err);
-            return UserStatus::LoggedOut;
-        }
-    };
+    let user = default_api::users_user_id_get(api_config, auth.0.as_str())?;
 
-    match user.role {
+    Ok(match user.entity.role {
         UserRole::Operator => UserStatus::Operator,
         UserRole::Administrator => UserStatus::Administrator,
         _ => UserStatus::LoggedOut,
-    }
+    })
 }
 // Check if the user is logged in and then return the configuration to connect as this user
 fn get_user_api_config(