Programmatically support checking if there are any pending migrations

[wendorf]

In my CI pipeline, I want to fail a code deploy if there are any pending migrations so a human can look at them manually. I currently do that by running ! goose status 2>&1 | grep Pending > /dev/null. If that returns 0, then I know I have no pending migrations and can continue with my deploy.

This works, but it feels a bit brittle to grep for a string. I'd prefer to have explicit support in goose for programmatically knowing if migrations are pending.

Some possible solutions:

• Provide a flag that sets the exit code to non-zero if any are pending: goose status --fail-if-pending
• Provide a flag that outputs status in JSON so it can be parsed: goose status --json | jq '.migrations[] | select(.pending)' -e

[mfridman]

@wendorf Interesting suggestion, I like it. Just thinking out-loud, would something like this work, pseudo based on your suggestion?

{
    "migrations": [
        {
            "name": "000001_baseline_schema.sql",
            "applied_at": "2020-08-24T19:40:36-04:00",
            "is_applied": true,
            "version_id": 0
        },
        {
            "name": "000057_drop_a_table.go",
            "applied_at": "2020-08-24T19:40:40-04:00",
            "is_applied": true,
            "version_id": 45
        },
        {
            "name": "20200808122156_backfill_data.go",
            "applied_at": "",
            "is_applied": false,
            "version_id": 20200808122156
        }
    ]
}

[wendorf]

That would work quite well :) To bikeshed, I might omit the applied_at field when is_applied is false, but I don't think it matters much.

[ezk84]

Would be useful to have this also accessible from the go package's interface.

In our case we use goose programmatically to set up the database for integration tests, and it would be good to be able to know is there are pending migrations when a test suite is first run.

something like:

goose.DetailedStatus(db *sql.DB, dir string, opts ...goose.OptionsFunc) ([]goose.MigrationStatus, error)

[mfridman]

Would be useful to have this also accessible from the go package's interface.

The goose provider now has a .HasPending() method which enables you to check whether there are any pending migrations. A bit more details in this PR, #751

func (p *Provider) HasPending(context.Context) (bool, error) {}

I'm going to keep this issue open until there is --json support in the CLI to allow folks to programmatically check for pending migrations with goose ... | jq, I actually already have this working on this branch, so we're not far away. #741