Modularize Alerts (#1390)

* Modularize Alerts
New traits-
- `AlertTrait`: A trait describing alerts in Parseable
- `AlertManagerTrait`: A trait describing the methods for in-memory alerts structure
New structs-
- `ThresholdAlert`: A struct describing threshold type alerts
* Coderabbit suggestions
* rename version

Author: parmesant

src/alerts/alert_types.rs

@@ -0,0 +1,250 @@
+/*
+ * Parseable Server (C) 2022 - 2024 Parseable, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+use std::time::Duration;
+
+use chrono::{DateTime, Utc};
+use tonic::async_trait;
+use ulid::Ulid;
+
+use crate::{
+    alerts::{
+        AlertConfig, AlertError, AlertState, AlertType, AlertVersion, EvalConfig, Severity,
+        ThresholdConfig,
+        alerts_utils::{evaluate_condition, execute_alert_query, extract_time_range},
+        is_query_aggregate,
+        target::{self, TARGETS},
+        traits::AlertTrait,
+    },
+    handlers::http::query::create_streams_for_distributed,
+    option::Mode,
+    parseable::PARSEABLE,
+    query::resolve_stream_names,
+    rbac::map::SessionKey,
+    utils::user_auth_for_query,
+};
+
+/// Struct which defines the threshold type alerts
+#[derive(Debug, serde::Serialize, serde::Deserialize, Clone)]
+pub struct ThresholdAlert {
+    pub version: AlertVersion,
+    #[serde(default)]
+    pub id: Ulid,
+    pub severity: Severity,
+    pub title: String,
+    pub query: String,
+    pub alert_type: AlertType,
+    pub threshold_config: ThresholdConfig,
+    pub eval_config: EvalConfig,
+    pub targets: Vec<Ulid>,
+    // for new alerts, state should be resolved
+    #[serde(default)]
+    pub state: AlertState,
+    pub created: DateTime<Utc>,
+    pub tags: Option<Vec<String>>,
+    pub datasets: Vec<String>,
+}
+
+#[async_trait]
+impl AlertTrait for ThresholdAlert {
+    async fn eval_alert(&self) -> Result<(bool, f64), AlertError> {
+        let time_range = extract_time_range(&self.eval_config)?;
+        let final_value = execute_alert_query(self.get_query(), &time_range).await?;
+        let result = evaluate_condition(
+            &self.threshold_config.operator,
+            final_value,
+            self.threshold_config.value,
+        );
+        Ok((result, final_value))
+    }
+
+    async fn validate(&self, session_key: &SessionKey) -> Result<(), AlertError> {
+        // validate alert type
+        // Anomaly is only allowed in Prism
+        if self.alert_type.eq(&AlertType::Anomaly) && PARSEABLE.options.mode != Mode::Prism {
+            return Err(AlertError::CustomError(
+                "Anomaly alert is only allowed on Prism mode".into(),
+            ));
+        }
+
+        // validate evalType
+        let eval_frequency = match &self.eval_config {
+            EvalConfig::RollingWindow(rolling_window) => {
+                if humantime::parse_duration(&rolling_window.eval_start).is_err() {
+                    return Err(AlertError::Metadata(
+                        "evalStart should be of type humantime",
+                    ));
+                }
+                rolling_window.eval_frequency
+            }
+        };
+
+        // validate that target repeat notifs !> eval_frequency
+        for target_id in &self.targets {
+            let target = TARGETS.get_target_by_id(target_id).await?;
+            match &target.notification_config.times {
+                target::Retry::Infinite => {}
+                target::Retry::Finite(repeat) => {
+                    let notif_duration =
+                        Duration::from_secs(60 * target.notification_config.interval)
+                            * *repeat as u32;
+                    if (notif_duration.as_secs_f64()).gt(&((eval_frequency * 60) as f64)) {
+                        return Err(AlertError::Metadata(
+                            "evalFrequency should be greater than target repetition  interval",
+                        ));
+                    }
+                }
+            }
+        }
+
+        // validate that the query is valid
+        if self.query.is_empty() {
+            return Err(AlertError::InvalidAlertQuery);
+        }
+
+        let tables = resolve_stream_names(&self.query)?;
+        if tables.is_empty() {
+            return Err(AlertError::InvalidAlertQuery);
+        }
+        create_streams_for_distributed(tables)
+            .await
+            .map_err(|_| AlertError::InvalidAlertQuery)?;
+
+        // validate that the user has access to the tables mentioned in the query
+        user_auth_for_query(session_key, &self.query).await?;
+
+        // validate that the alert query is valid and can be evaluated
+        if !is_query_aggregate(&self.query).await? {
+            return Err(AlertError::InvalidAlertQuery);
+        }
+        Ok(())
+    }
+
+    fn get_id(&self) -> &Ulid {
+        &self.id
+    }
+
+    fn get_query(&self) -> &str {
+        &self.query
+    }
+
+    fn get_severity(&self) -> &Severity {
+        &self.severity
+    }
+
+    fn get_title(&self) -> &str {
+        &self.title
+    }
+
+    fn get_alert_type(&self) -> &AlertType {
+        &self.alert_type
+    }
+
+    fn get_threshold_config(&self) -> &ThresholdConfig {
+        &self.threshold_config
+    }
+
+    fn get_eval_config(&self) -> &EvalConfig {
+        &self.eval_config
+    }
+
+    fn get_targets(&self) -> &Vec<Ulid> {
+        &self.targets
+    }
+
+    fn get_state(&self) -> &AlertState {
+        &self.state
+    }
+
+    fn get_eval_frequency(&self) -> u64 {
+        match &self.eval_config {
+            EvalConfig::RollingWindow(rolling_window) => rolling_window.eval_frequency,
+        }
+    }
+
+    fn get_eval_window(&self) -> String {
+        match &self.eval_config {
+            EvalConfig::RollingWindow(rolling_window) => rolling_window.eval_start.clone(),
+        }
+    }
+
+    fn get_created(&self) -> String {
+        self.created.to_string()
+    }
+
+    fn get_tags(&self) -> &Option<Vec<String>> {
+        &self.tags
+    }
+
+    fn get_datasets(&self) -> &Vec<String> {
+        &self.datasets
+    }
+
+    fn to_alert_config(&self) -> AlertConfig {
+        let clone = self.clone();
+        clone.into()
+    }
+
+    fn clone_box(&self) -> Box<dyn AlertTrait> {
+        Box::new(self.clone())
+    }
+
+    fn set_state(&mut self, new_state: AlertState) {
+        self.state = new_state
+    }
+}
+
+impl From<AlertConfig> for ThresholdAlert {
+    fn from(value: AlertConfig) -> Self {
+        Self {
+            version: value.version,
+            id: value.id,
+            severity: value.severity,
+            title: value.title,
+            query: value.query,
+            alert_type: value.alert_type,
+            threshold_config: value.threshold_config,
+            eval_config: value.eval_config,
+            targets: value.targets,
+            state: value.state,
+            created: value.created,
+            tags: value.tags,
+            datasets: value.datasets,
+        }
+    }
+}
+
+impl From<ThresholdAlert> for AlertConfig {
+    fn from(val: ThresholdAlert) -> Self {
+        AlertConfig {
+            version: val.version,
+            id: val.id,
+            severity: val.severity,
+            title: val.title,
+            query: val.query,
+            alert_type: val.alert_type,
+            threshold_config: val.threshold_config,
+            eval_config: val.eval_config,
+            targets: val.targets,
+            state: val.state,
+            created: val.created,
+            tags: val.tags,
+            datasets: val.datasets,
+        }
+    }
+}