Static diesel r2d2 connection pooling.
DATABASE_URL env sets postgres database url within connection manager
MAX_DB_CONNECTIONS env sets max postgres connections within connection pool
This library uses booter::boot() to initialize.
The tracing feature flag substitutes connections instrumented with opentelemetry. See diesel-tracing for details.
```rust
async fn main() -> Result<(), PoolError> { // Env can be configured before booter::boot giving fine-grain initialization control dotenv().expect("Unable to load .env file"); envlogger::init(); // This calls registered initialization functions; with this we initialize our static connection pool booter::boot(); let conn = getconnection()?; } ```