postgres: databroker storage backend (#3370)

* wip

* storage: add filtering to SyncLatest

* don't increment the record version, so intermediate changes are requested

* databroker: add support for query filtering

* fill server and record version

* postgres: databroker storage backend

* wip

* serialize puts

* add test

* skip tests for macos

* add test

* return error from protojson

* set data

* exclude postgres from cover tests

internal/testutil/postgres.go

@@ -0,0 +1,55 @@
+package testutil
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/jackc/pgx/v4"
+	"github.com/ory/dockertest/v3"
+
+	"github.com/pomerium/pomerium/internal/log"
+)
+
+// WithTestPostgres starts a test DB and runs the given handler with the connection to it.
+func WithTestPostgres(handler func(dsn string) error) error {
+	ctx, clearTimeout := context.WithTimeout(context.Background(), maxWait)
+	defer clearTimeout()
+
+	// uses a sensible default on windows (tcp/http) and linux/osx (socket)
+	pool, err := dockertest.NewPool("")
+	if err != nil {
+		return err
+	}
+
+	resource, err := pool.RunWithOptions(&dockertest.RunOptions{
+		Repository: "postgres",
+		Tag:        "14",
+		Env:        []string{"POSTGRES_DB=pomeriumtest", "POSTGRES_HOST_AUTH_METHOD=trust"},
+	})
+	if err != nil {
+		return err
+	}
+	_ = resource.Expire(uint(maxWait.Seconds()))
+
+	dsn := fmt.Sprintf("postgresql://postgres@localhost:%s/pomeriumtest?sslmode=disable", resource.GetPort("5432/tcp"))
+	if err := pool.Retry(func() error {
+		conn, err := pgx.Connect(ctx, dsn)
+		if err != nil {
+			log.Error(ctx).Err(err).Send()
+			return err
+		}
+		_ = conn.Close(ctx)
+		return nil
+	}); err != nil {
+		_ = pool.Purge(resource)
+		return err
+	}
+
+	e := handler(dsn)
+
+	if err := pool.Purge(resource); err != nil {
+		return err
+	}
+
+	return e
+}