#connection

The connection block declares external pools for relational databases and key-value stores.

#SQL connections

hclapi uses canonical SQL engine names:

connection "sql" "main" {
  engine = "postgres"
  source = "postgres://user:pass@localhost:5432/app?sslmode=disable"
  pool {
    max_open = 25
    max_idle = 25
  }
}

#Supported engines

Non-canonical engine names (like postgresql, sqlite3, mariadb, or mssql) are rejected at compile time so manifests remain consistent.

#Pool settings

Idle connections are recycled after 5 minutes, and connection lifetime is bounded to 15 minutes.

#Valkey and Redis connections

connection "valkey" "cache" {
  url = "redis://127.0.0.1:6379/0"
}