Ask Bjørn Hansen
d43ff0f2a9
Change MaxConns default from 25 to 4 to match pgxpool defaults. This ensures consistent behavior between DATABASE_URI and config file modes, and removes the warning log when using URI mode. Defaults now reference: https://pkg.go.dev/github.com/jackc/pgx/v5/pgxpool#Config
151 lines
3.7 KiB
Markdown
151 lines
3.7 KiB
Markdown
# pgdb - Native PostgreSQL Connection Pool
|
|
|
|
Primary package for PostgreSQL connections using native pgx pool (`*pgxpool.Pool`). Provides better performance and PostgreSQL-specific features compared to `database/sql`.
|
|
|
|
## Usage
|
|
|
|
### Basic Example
|
|
|
|
```go
|
|
import (
|
|
"context"
|
|
"go.ntppool.org/common/database/pgdb"
|
|
)
|
|
|
|
func main() {
|
|
ctx := context.Background()
|
|
|
|
// Open pool with default options
|
|
pool, err := pgdb.OpenPool(ctx, pgdb.DefaultPoolOptions())
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
defer pool.Close()
|
|
|
|
// Use the pool for queries
|
|
row := pool.QueryRow(ctx, "SELECT version()")
|
|
var version string
|
|
row.Scan(&version)
|
|
}
|
|
```
|
|
|
|
### With Custom Config File
|
|
|
|
```go
|
|
pool, err := pgdb.OpenPoolWithConfigFile(ctx, "/path/to/database.yaml")
|
|
```
|
|
|
|
### With Custom Pool Settings
|
|
|
|
```go
|
|
opts := pgdb.DefaultPoolOptions()
|
|
opts.MaxConns = 50
|
|
opts.MinConns = 5
|
|
opts.MaxConnLifetime = 2 * time.Hour
|
|
|
|
pool, err := pgdb.OpenPool(ctx, opts)
|
|
```
|
|
|
|
## Configuration Format
|
|
|
|
### Recommended: Nested Format (database.yaml)
|
|
|
|
```yaml
|
|
postgres:
|
|
host: localhost
|
|
port: 5432
|
|
user: myuser
|
|
pass: mypassword
|
|
name: mydb
|
|
sslmode: prefer
|
|
```
|
|
|
|
### Legacy: Flat Format (backward compatible)
|
|
|
|
```yaml
|
|
host: localhost
|
|
port: 5432
|
|
user: myuser
|
|
pass: mypassword
|
|
name: mydb
|
|
sslmode: prefer
|
|
```
|
|
|
|
## Configuration Options
|
|
|
|
### PoolOptions
|
|
|
|
Defaults match [pgxpool defaults](https://pkg.go.dev/github.com/jackc/pgx/v5/pgxpool#Config):
|
|
|
|
- `ConfigFiles` - List of config file paths to search (default: `database.yaml`, `/vault/secrets/database.yaml`)
|
|
- `MinConns` - Minimum connections (default: 0)
|
|
- `MaxConns` - Maximum connections (default: 4)
|
|
- `MaxConnLifetime` - Connection lifetime (default: 1 hour)
|
|
- `MaxConnIdleTime` - Idle timeout (default: 30 minutes)
|
|
- `HealthCheckPeriod` - Health check interval (default: 1 minute)
|
|
|
|
For higher connection limits, set via `PoolOptions` or URI query parameter `?pool_max_conns=25`.
|
|
|
|
### PostgreSQL Config Fields
|
|
|
|
- `host` - Database host (required)
|
|
- `user` - Database user (required)
|
|
- `pass` - Database password
|
|
- `name` - Database name (required)
|
|
- `port` - Port number (default: 5432)
|
|
- `sslmode` - SSL mode: `disable`, `allow`, `prefer`, `require`, `verify-ca`, `verify-full` (default: `prefer`)
|
|
|
|
## Environment Variables
|
|
|
|
- `DATABASE_URI` - PostgreSQL connection URI (takes precedence over config files)
|
|
- `DATABASE_CONFIG_FILE` - Override config file location
|
|
|
|
### URI Format
|
|
|
|
Standard PostgreSQL URI format:
|
|
```
|
|
postgresql://user:password@host:port/database?sslmode=require&pool_max_conns=10
|
|
```
|
|
|
|
Pool settings can be included in the URI query string:
|
|
- `pool_max_conns`, `pool_min_conns`
|
|
- `pool_max_conn_lifetime`, `pool_max_conn_idle_time`
|
|
- `pool_health_check_period`
|
|
|
|
When using `DATABASE_URI`, pool settings come from the URI. Since `PoolOptions` defaults match pgxpool defaults, behavior is consistent whether using URI or config files.
|
|
|
|
Example with CloudNativePG:
|
|
```yaml
|
|
# Mount the secret's 'uri' key as DATABASE_URI
|
|
env:
|
|
- name: DATABASE_URI
|
|
valueFrom:
|
|
secretKeyRef:
|
|
name: mydb-app
|
|
key: uri
|
|
```
|
|
|
|
## When to Use
|
|
|
|
**Use `pgdb.OpenPool()`** (this package) when:
|
|
- You need native PostgreSQL features (LISTEN/NOTIFY, COPY, etc.)
|
|
- You want better performance
|
|
- You're writing new PostgreSQL code
|
|
|
|
**Use `database.OpenDB()`** (sql.DB) when:
|
|
- You need database-agnostic code
|
|
- You're using SQLC or other tools that expect `database/sql`
|
|
- You need to support both MySQL and PostgreSQL
|
|
|
|
## Security
|
|
|
|
This package avoids password exposure by:
|
|
1. Never constructing DSN strings with passwords
|
|
2. Setting passwords separately in pgx config objects
|
|
3. Validating all configuration before connection
|
|
|
|
## See Also
|
|
|
|
- `database/` - Generic sql.DB support for MySQL and PostgreSQL
|
|
- pgx documentation: https://github.com/jackc/pgx
|