Add datastore database driver for Hanzo Datastore

Registers "datastore://" as a URL scheme that delegates to the
ClickHouse driver. This allows golang-migrate to natively connect
to Hanzo Datastore instances without URL rewriting in scripts.

.gitignore

@@ -8,3 +8,4 @@ vendor/
 .vscode/
 .idea
 dist/
+migrate

Makefile

@@ -1,5 +1,5 @@
 SOURCE ?= file go_bindata github github_ee bitbucket aws_s3 google_cloud_storage godoc_vfs gitlab
-DATABASE ?= postgres mysql redshift cassandra spanner cockroachdb yugabytedb clickhouse mongodb sqlserver firebird neo4j pgx pgx5 rqlite
+DATABASE ?= postgres mysql redshift cassandra spanner cockroachdb yugabytedb clickhouse datastore mongodb sqlserver firebird neo4j pgx pgx5 rqlite
 DATABASE_TEST ?= $(DATABASE) sqlite sqlite3 sqlcipher
 VERSION ?= $(shell git describe --tags 2>/dev/null | cut -c 2-)
 TEST_FLAGS ?=

database/datastore/datastore.go

@@ -0,0 +1,47 @@
+// Package datastore implements the database.Driver interface for Hanzo Datastore
+// (a ClickHouse-compatible database engine). It registers the "datastore://" URL
+// scheme so that golang-migrate can connect to Datastore instances natively.
+//
+// Usage:
+//
+//	import _ "github.com/golang-migrate/migrate/v4/database/datastore"
+//
+// Then use a URL like:
+//
+//	datastore://host:9000?username=default&database=default&x-multi-statement=true
+package datastore
+
+import (
+	"database/sql"
+	"net/url"
+
+	"github.com/golang-migrate/migrate/v4/database"
+	"github.com/golang-migrate/migrate/v4/database/clickhouse"
+
+	_ "github.com/ClickHouse/clickhouse-go"
+)
+
+func init() {
+	database.Register("datastore", &Datastore{})
+}
+
+// Datastore wraps the ClickHouse driver, registering under the "datastore" scheme.
+type Datastore struct {
+	clickhouse.ClickHouse
+}
+
+// Open rewrites the "datastore://" scheme to "clickhouse://" and delegates
+// to the underlying ClickHouse driver.
+func (d *Datastore) Open(dsn string) (database.Driver, error) {
+	u, err := url.Parse(dsn)
+	if err != nil {
+		return nil, err
+	}
+	u.Scheme = "clickhouse"
+	return d.ClickHouse.Open(u.String())
+}
+
+// WithInstance creates a new Datastore driver from an existing sql.DB connection.
+func WithInstance(conn *sql.DB, config *clickhouse.Config) (database.Driver, error) {
+	return clickhouse.WithInstance(conn, config)
+}

internal/cli/build_datastore.go

@@ -0,0 +1,8 @@
+//go:build datastore
+
+package cli
+
+import (
+	_ "github.com/ClickHouse/clickhouse-go"
+	_ "github.com/golang-migrate/migrate/v4/database/datastore"
+)