Database and other connection URLs

A database or a cache takes its address from a setting. Each one is a connection in the connections: block of app.jadpo, with a driver that says what kind of store it is (How packages, connections, capabilities and services fit together says what a connection, a driver and a provider package are):

application {    connections: {        main: {            driver: Driver.postgres            url: config.database_url        }        cache: {            driver: Driver.redis            url: config.redis_url        }    }}

config {    database_url: PostgresUrl    redis_url: RedisUrl}

A project that declares no database has one called main on PostgreSQL. It opens at config.database_url when the project declares that setting as a PostgresUrl.

Connection types

Url accepts only http:// and https://, so it can't hold an address such as postgres://user:password@host/db. Each driver has a built-in type that can:

• PostgresUrl, for postgres:// or postgresql://;
• RedisUrl, for redis:// or rediss://.

They are always secret, because they normally carry a password. A connection's url: must read a setting of the type its driver: needs (configuration.url_type), and an address written in source is refused the same way. The runtime opens the connection only through that setting.

A connection type checks the address's structure as well as its scheme, with the same check for literals, the check before the app starts and jadpo config check. Checking never looks up a name or opens a connection. These are invalid:

• an empty target after the user information;
• a malformed percent escape;
• an invalid port;
• broken IPv6 brackets.

These pass: PostgreSQL addresses with several hosts, encoded credentials, bracketed IPv6, and explicit socket addresses (postgres://%2Ftmp/app, postgresql:///app?host=/tmp). The type also accepts postgres:///app, but that alone gives the driver no socket folder, and the driver assumes no default one. The driver checks its own options, and whether the database can be reached, separately. A Redis address needs a host and, when it has a database path, a number from 0. Every invalid declaration is reported at once, and credentials are never shown.

TLS and certificates

A PostgresUrl can't set TLS itself (sslmode and libpq's other ssl… settings), because its connection in app.jadpo decides that (PostgreSQL over TLS). Such a value is configuration.value_invalid, which says so.

A setting can be a Certificate, read from its PEM text. It is what a database connection's authority: reads: the authority that signed the database server's certificate.

Provider packages

A connection to a provider package, a package that calls an outside service (Connecting in app.jadpo), reads its settings the same way, never a value written in source:

• credential: reads a secret: true setting;
• environment: reads a ProviderEnvironment setting, the built-in enum .sandbox or .live, which chooses between the package's hosts;
• host:, for a package with no fixed hosts, reads a Url setting.

A wrong one is connection.value_invalid.

// config.jadpoconfig {    couriers_api_key: Text {        secret: true    }    couriers_environment: ProviderEnvironment}