mesh-sdk/go/catalogue/contributes_test.go

package catalogue

import (
	"encoding/json"
	"testing"
)

// The other half of an edge.
//
// `requires` says a thing must be there. It never said what to do with it — a web application
// requiring a reverse proxy has to say *which name, which port*, and there was nowhere to put
// that. The two modules that needed it most, the proxy and the VPN, went round the outside and
// opened a connection to the control plane's database, which is why every node held a credential
// to it permanently.

// A provision answered from anywhere in the mesh has consumers on other machines, and the
// provider has to know who they are. Contributions were node-local until this, which meant the
// one case that most needed them was the one they did not reach.

func provider() Manifest {
	return Manifest{Module: "postgres", Version: "1",
		Provides: FromAnywhere("postgres-database"),
		Receives: map[string]string{"postgres-database": "/var/lib/postgres/grants/mesh.json"},
		Grants:   map[string]string{"postgres-database": "/var/lib/postgres/grants"},
	}
}

func grantedTo(t *testing.T, out []map[string]any) []Contribution {
	t.Helper()
	for _, r := range out {
		if r["path"] != "/var/lib/postgres/grants/mesh.json" {
			continue
		}
		var parsed struct {
			Given []Contribution `json:"given"`
		}
		if err := json.Unmarshal([]byte(r["content"].(string)), &parsed); err != nil {
			t.Fatal(err)
		}
		return parsed.Given
	}
	t.Fatalf("the provider was given no manifest: %v", out)
	return nil
}