Merge pull request #238 from bikeshedder/async_pg_better_instructions

Improve async_pg example

async_pg/.gitignore

@@ -1,2 +1,3 @@
 /target
 **/*.rs.bk
+.env

async_pg/Cargo.toml

@@ -4,13 +4,14 @@ version = "0.1.0"
 authors = ["dowwie <[email protected]>"]
 edition = "2018"
 
-
 [dependencies]
 actix-rt = "1.0.0"
 actix-web = "2.0.0"
-deadpool-postgres = "0.4.3"
+config = "0.10.1"
+deadpool-postgres = "0.5.0"
 derive_more = "0.99.2"
-serde = { version = "1.0.104", features=["derive"] }
+dotenv = "0.15.0"
+serde = { version = "1.0.104", features = ["derive"] }
 tokio-pg-mapper = "0.1.4"
 tokio-pg-mapper-derive = "0.1.4"
 tokio-postgres = "0.5.1"

async_pg/README.md

@@ -1,12 +1,72 @@
-This example illustrates:
-  - tokio_postgres
-  - use of tokio_pg_mapper for postgres data mapping
-  - deadpool_postgres for connection pooling
-
-
-# Instructions 
-1. Set up the testing database by running /sql/create_db.sh
-2. `cargo run`
-3. from the command line (linux), POST a user to the endpoint:
-	echo '{"email": "[email protected]", "first_name": "ferris", "last_name": "crab", "username": "ferreal"}' | http -f --json --print h POST http://127.0.0.1:8080/users
-	- a unique constraint exists for username, so running this twice will return a 500
+# async_pg example
+
+## This example illustrates
+
+- `tokio_postgres`
+- use of `tokio_pg_mapper` for postgres data mapping
+- `deadpool_postgres` for connection pooling
+- `dotenv` + `config` for configuration
+
+## Instructions
+
+1. Create database user
+
+    ```shell
+    createuser -P test_user
+    ```
+
+    Enter a password of your choice. The following instructions assume you
+    used `testing` as password.
+
+    This step is **optional** and you can also use an existing database user
+    for that. Just make sure to replace `test_user` by the database user
+    of your choice in the following steps and change the `.env` file
+    containing the configuration accordingly.
+
+2. Create database
+
+    ```shell
+    createdb -O test_user testing_db
+    ```
+
+3. Initialize database
+
+    ```shell
+    psql -f sql/schema.sql testing_db
+    ```
+
+    This step can be repeated and clears the database as it drops and
+    recreates the schema `testing` which is used within the database.
+
+4. Create `.env` file:
+
+    ```ini
+    SERVER_ADDR=127.0.0.1:8080
+    PG.USER=test_user
+    PG.PASSWD=testing
+    PG.HOST=127.0.0.1
+    PG.PORT=5432
+    PG.DBNAME=testing_db
+    PG.POOL.MAX_SIZE=16
+    ```
+
+5. Run the server:
+
+    ```shell
+    cargo run
+    ```
+
+6. Using a different terminal send an HTTP POST request to the running server:
+
+    ```shell
+    echo '{"email": "[email protected]", "first_name": "ferris", "last_name": "crab", "username": "ferreal"}' | http -f --json --print h POST http://127.0.0.1:8080/users
+    ```
+
+    **...or using curl...**
+
+    ```shell
+    curl -d '{"email": "[email protected]", "first_name": "ferris", "last_name": "crab", "username": "ferreal"}' -H 'Content-Type: application/json' http://127.0.0.1:8080/users
+    ```
+
+    A unique constraint exists for username, so sending this request twice
+    will return an internal server error (HTTP 500).

async_pg/sql/setup_db_and_user.sql → async_pg/sql/schema.sql

@@ -1,15 +1,6 @@
-DROP DATABASE IF EXISTS testing_db;
-
-CREATE USER test_user WITH PASSWORD 'testing';
-
-CREATE DATABASE testing_db OWNER test_user;
-
-\connect testing_db;
-
 DROP SCHEMA IF EXISTS testing CASCADE;
 CREATE SCHEMA testing;
 
-
 CREATE TABLE testing.users (
 	id  BIGSERIAL PRIMARY KEY,
 	email       VARCHAR(200) NOT NULL,

async_pg/src/main.rs

@@ -1,3 +1,20 @@
+mod config {
+    use serde::Deserialize;
+    pub use ::config::ConfigError;
+    #[derive(Deserialize)]
+    pub struct Config {
+        pub server_addr: String,
+        pub pg: deadpool_postgres::Config,
+    }
+    impl Config {
+        pub fn from_env() -> Result<Self, ConfigError> {
+            let mut cfg = ::config::Config::new();
+            cfg.merge(::config::Environment::new())?;
+            cfg.try_into()
+        }
+    }
+}
+
 mod models {
     use serde::{Deserialize, Serialize};
     use tokio_pg_mapper_derive::PostgresMapper;
@@ -88,31 +105,25 @@ mod handlers {
 }
 
 use actix_web::{web, App, HttpServer};
-use deadpool_postgres::{Manager, Pool};
+use dotenv::dotenv;
 use handlers::add_user;
-use tokio_postgres::{Config, NoTls};
+use tokio_postgres::NoTls;
 
 #[actix_rt::main]
 async fn main() -> std::io::Result<()> {
-    const SERVER_ADDR: &str = "127.0.0.1:8080";
-
-    let pg_config = "postgres://test_user:[email protected]:5432/testing_db"
-        .parse::<Config>()
-        .unwrap();
+    dotenv().ok();
 
-    let pool = Pool::new(
-        Manager::new(pg_config, NoTls),
-        16, // # of connections in pool
-    );
+    let config = crate::config::Config::from_env().unwrap();
+    let pool = config.pg.create_pool(NoTls).unwrap();
 
     let server = HttpServer::new(move || {
         App::new()
             .data(pool.clone())
             .service(web::resource("/users").route(web::post().to(add_user)))
     })
-    .bind(SERVER_ADDR)?
+    .bind(config.server_addr.clone())?
     .run();
-    println!("Server running at http://{}/", SERVER_ADDR);
+    println!("Server running at http://{}/", config.server_addr);
 
     server.await
 }