Develop

.gitignore

@@ -2,3 +2,6 @@
 .env
 .vscode
 Cargo.lock
+.clj-kondo/
+.lsp/
+Dockerfile_test

Cargo.toml

@@ -12,10 +12,10 @@ dotenv = "0.15"
 reqwest = { version = "0.11", features = ["json"] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-tokio = { version = "1.38.0", features = ["macros", "rt-multi-thread"]}
-tokio-postgres = "0.7.10"
-diesel = { version = "2.2.0", features = ["postgres", "r2d2"] }
+tokio = { version = "1.38.0", features = ["macros", "rt-multi-thread", "full", "time", "signal"]}
+sqlx = { version = "0.7", features = [ "runtime-tokio", "postgres"] } 
 anyhow = "1.0.58"
+chrono = "0.4"
 
 # Logging
 tracing = "0.1.37"

README.md

@@ -0,0 +1,35 @@
+**FHIR2SQL**
+=====================
+
+A Rust-based application that synchronizes FHIR (Fast Healthcare Interoperability Resources) data with a PostgreSQL database.
+
+**Overview**
+------------
+
+This application connects to a FHIR server, retrieves data, and syncs it with a PostgreSQL database. It uses the `sqlx` library for database interactions and `reqwest` for making HTTP requests to the FHIR server. The application is designed to run continuously, syncing data at regular intervals.
+
+**Features**
+------------
+
+* Connects to a PostgreSQL database and creates necessary tables and triggers if they don't exist
+* Retrieves FHIR data from a specified server and syncs it with the PostgreSQL database
+* Supports regular syncing at a specified interval
+* Handles errors and retries connections to the FHIR server and PostgreSQL database
+* Supports graceful shutdown on SIGTERM and SIGINT signals
+
+**Components**
+--------------
+
+* `main.rs`: The main application entry point
+* `db_utils.rs`: Database utility functions for connecting to PostgreSQL and creating tables and triggers
+* `models.rs`: Data models for FHIR resources and database interactions
+* `graceful_shutdown.rs`: Functions for handling graceful shutdown on SIGTERM and SIGINT signals
+
+**Getting Started**
+-------------------
+
+To use this application, you'll need to:
+
+1. Install Rust and the required dependencies
+2. Configure the application by setting environment variables for the FHIR server URL, PostgreSQL connection details, and syncing interval
+3. Run the application using `cargo run`

src/db_utils.rs

@@ -0,0 +1,144 @@
+use sqlx::{postgres::PgPoolOptions, PgPool, Row};
+use tracing::{error, info};
+use anyhow::anyhow;
+use reqwest::Client;
+
+pub async fn get_pg_connection_pool(pg_url: &str, num_attempts: u32) -> Result<PgPool, anyhow::Error> {
+    info!("Trying to establish a PostgreSQL connection pool");
+
+    let mut attempts = 0;
+    let mut err: Option<anyhow::Error> = None;
+
+    while attempts < num_attempts {
+        info!("Attempt to connect to PostgreSQL {} of {}", attempts + 1, num_attempts);
+        match PgPoolOptions::new()
+            .max_connections(10)
+            .connect(&pg_url)
+            .await
+        {
+            Ok(pg_con_pool) => {
+                info!("PostgreSQL connection successfull");
+                return Ok(pg_con_pool)
+            },
+            Err(e) => {
+                error!("Failed to connect to PostgreSQL. Attempt {} of {}: {}", attempts + 1, num_attempts, e);
+                err = Some(anyhow!(e));
+            }
+        }
+        attempts += 1;
+        tokio::time::sleep(std::time::Duration::from_secs(5)).await; //@todo: move param somewhere else?
+    }
+    Err(err.unwrap_or_else(|| anyhow!("Failed to connect to PostgreSQL")))
+}
+
+
+pub async fn check_blaze_connection(blaze_base_url: &str, num_attempts: u32) -> Result<bool, anyhow::Error> {
+    info!("Attempting to connect to Blaze");
+
+    let mut attempts = 0;
+    let mut err: Option<anyhow::Error> = None;
+    let client = Client::new();
+
+    while attempts < num_attempts {
+        info!("Attempt to connect to Blaze {} of {}", attempts + 1, num_attempts);
+        match client.get(format!("{}/health", blaze_base_url)).send().await {
+            Ok(_) => {
+                info!("Blaze connection successfull");
+                return Ok(true)
+            },
+            Err(e) => {
+                error!("Failed to connect to Blaze. Attempt {} of {}: {}", attempts + 1, num_attempts, e);
+                err = Some(anyhow!(e));
+            }
+        }
+        attempts += 1;
+        tokio::time::sleep(std::time::Duration::from_secs(5)).await; //@todo: move param somewhere else?
+    }
+    Err(err.unwrap_or_else(|| anyhow!("Failed to connect to Blaze")))
+
+}
+
+
+//function that checks wheter a given list of required tables exist in pg
+pub async fn pred_tables_exist(pg_con_pool: &PgPool, table_names: &Vec<&str>) -> Result<bool, anyhow::Error> {
+    info!("Checking whether PostgreSQL tables exist");    
+
+    let table_query: &str = r#"select table_name from information_schema.tables;"#;
+
+    let rows = sqlx::query(table_query)
+        .fetch_all(pg_con_pool)
+        .await
+        .map_err(|err| {
+            error!("Failed to execute query: {}", err);
+            anyhow::Error::new(err)
+        })?;
+
+    let pg_table_names: Vec<String> = rows.into_iter().map(|row| row.get(0)).collect();
+    let all_tables_exist = table_names.iter().all(|table_name| pg_table_names.contains(&table_name.to_string()));
+
+
+    Ok(all_tables_exist)
+}
+
+//create necessary tables and triggers in pg if they don't exist yet
+pub async fn create_tables(pg_con_pool: &PgPool) -> Result<(), anyhow::Error> {
+    info!("Creating PostgreSQL tables");
+
+    let create_tables_queries = vec![
+        "CREATE TABLE IF NOT EXISTS patient (
+            id SERIAL PRIMARY KEY,
+            created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+            last_updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+            resource JSONB NOT NULL
+        )",
+        "CREATE TABLE IF NOT EXISTS specimen (
+            id SERIAL PRIMARY KEY,
+            created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+            last_updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+            resource JSONB NOT NULL
+        )",
+        "CREATE TABLE IF NOT EXISTS condition (
+            id SERIAL PRIMARY KEY,
+            created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+            last_updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+            resource JSONB NOT NULL
+        )",
+        "CREATE TABLE IF NOT EXISTS observation (
+            id SERIAL PRIMARY KEY,
+            created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+            last_updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+            resource JSONB NOT NULL
+        )",
+        "CREATE OR REPLACE FUNCTION update_last_updated()
+            RETURNS TRIGGER AS $$
+            BEGIN
+                NEW.last_updated_at = CURRENT_TIMESTAMP;
+                RETURN NEW;
+            END;
+            $$ LANGUAGE plpgsql;",
+        "CREATE TRIGGER update_last_updated_trigger
+            BEFORE UPDATE ON patient
+            FOR EACH ROW
+            EXECUTE PROCEDURE update_last_updated();",
+        "CREATE TRIGGER update_last_updated_trigger
+            BEFORE UPDATE ON specimen
+            FOR EACH ROW
+            EXECUTE PROCEDURE update_last_updated();",
+        "CREATE TRIGGER update_last_updated_trigger
+            BEFORE UPDATE ON condition
+            FOR EACH ROW
+            EXECUTE PROCEDURE update_last_updated();",
+        "CREATE TRIGGER update_last_updated_trigger
+            BEFORE UPDATE ON observation
+            FOR EACH ROW
+            EXECUTE PROCEDURE update_last_updated();",
+    ];
+
+    for query in create_tables_queries {
+        sqlx::query(query)
+            .execute(pg_con_pool)
+            .await?;
+    }
+
+    Ok(())
+}

src/graceful_shutdown.rs

@@ -0,0 +1,16 @@
+use tracing::info;
+
+pub async fn wait_for_signal() {
+    use tokio::signal::unix::{signal,SignalKind};
+    let mut sigterm = signal(SignalKind::terminate())
+        .expect("Unable to register shutdown handler");
+    let mut sigint = signal(SignalKind::interrupt())
+        .expect("Unable to register shutdown handler");
+    let signal = tokio::select! {
+        _ = sigterm.recv() => "SIGTERM",
+        _ = sigint.recv() => "SIGINT"
+    };
+    // The following does not print in docker-compose setups but it does when run individually.
+    // Probably a docker-compose error.
+    info!("Received signal ({signal}) - shutting down gracefully.");
+}