Add pgroll latest url command

[andrew-farries]

Add a pgroll latest url command to the CLI. The command returns a Postgres connection string with the search_path option set to the latest version schema name. This can be used to set the connection string for an application to work with the latest schema version.

By default, with no arguments, pgroll latest url will use the connection string set via the global --postgres-url (or PGROLL_PG_URL env var). If an argument is given to pgroll latest url, the command will use that as the base connection string instead.

The resulting connection string sets the search_path by setting the options parameter in the URL query string:

options=-c search_path='public_01_some_migration'

As described in the Postgres libpq documentation.

Examples

With no connection string argument, use the connection string used by pgroll itself:

$ export PGROLL_PG_URL=postgres://postgres:postgres@localhost:5432?sslmode=disable
$ pgroll latest url

postgres://postgres:postgres@localhost:5432?options=-c%20search_path%3Dpublic_05_some_migration&sslmode=disable

Take the connection string as a command line argument:

$ pgroll latest url postgres://me:mypass@example.com:5432

postgres://me:mypass@example.com:5432?options=-c%20search_path%3Dpublic_05_some_migration

Like pgroll latest migration and pgroll latest schema, pgroll latest url takes a --local/-l flag to take the latest version schema name from a directory of migration files rather than the target database. This allows for a connection string to be constructed offline, without having to lookup the latest version schema name in the target database.

$ pgroll latest url --local migrations/ postgres://me:mypass@localhost:5432

postgres://me:mypass@localhost:5432?options=-c%20search_path%3Dpublic_05_some_migration

The resulting connection string can be used directly as an argument to tools like psql that accept a connection string on the command line:

psql $(pgroll . latest url)

Documentation for the new command is added in #928

Closes #900

[github-actions]

Merging this branch will increase overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/xataio/pgroll/cmd	0.00% (ø)
github.com/xataio/pgroll/internal/connstr	90.91% (+90.91%)	🌟

---

Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/xataio/pgroll/cmd/latest.go	0.00% (ø)	5 (+1)	0	5 (+1)
github.com/xataio/pgroll/cmd/latest_url.go	0.00% (ø)	16 (+16)	0	16 (+16)
github.com/xataio/pgroll/internal/connstr/connstr.go	90.91% (+90.91%)	11 (+11)	10 (+10)	1 (+1)	🌟

Please note that the "Total", "Covered", and "Missed" counts above refer to code statements instead of lines of code. The value in brackets refers to the test coverage of that file in the old version of the code.

Changed unit test files

• github.com/xataio/pgroll/internal/connstr/connstr_test.go

[divyenduz]

LGTM ✅