move protobuf from GreptimeDB (#1)

* move protobuf from GreptimeDB

* add license check

* add other github actions

proto/greptime/v1/ddl.proto

@@ -0,0 +1,79 @@
+syntax = "proto3";
+
+package greptime.v1;
+
+import "greptime/v1/column.proto";
+
+// "Data Definition Language" requests, that create, modify or delete the database structures but not the data.
+// `DdlRequest` could carry more information than plain SQL, for example, the "table_id" in `CreateTableExpr`.
+// So create a new DDL expr if you need it.
+message DdlRequest {
+  oneof expr {
+    CreateDatabaseExpr create_database = 1;
+    CreateTableExpr create_table = 2;
+    AlterExpr alter = 3;
+    DropTableExpr drop_table = 4;
+  }
+}
+
+message CreateTableExpr {
+  string catalog_name = 1;
+  string schema_name = 2;
+  string table_name = 3;
+  string desc = 4;
+  repeated ColumnDef column_defs = 5;
+  string time_index = 6;
+  repeated string primary_keys = 7;
+  bool create_if_not_exists = 8;
+  map<string, string> table_options = 9;
+  TableId table_id = 10;
+  repeated uint32 region_ids = 11;
+}
+
+message AlterExpr {
+  string catalog_name = 1;
+  string schema_name = 2;
+  string table_name = 3;
+  oneof kind {
+    AddColumns add_columns = 4;
+    DropColumns drop_columns = 5;
+    RenameTable rename_table = 6;
+  }
+}
+
+message DropTableExpr {
+  string catalog_name = 1;
+  string schema_name = 2;
+  string table_name = 3;
+}
+
+message CreateDatabaseExpr {
+  //TODO(hl): maybe rename to schema_name?
+  string database_name = 1;
+  bool create_if_not_exists = 2;
+}
+
+message AddColumns {
+  repeated AddColumn add_columns = 1;
+}
+
+message DropColumns {
+  repeated DropColumn drop_columns = 1;
+}
+
+message RenameTable {
+  string new_table_name = 1;
+}
+
+message AddColumn {
+  ColumnDef column_def = 1;
+  bool is_key = 2;
+}
+
+message DropColumn {
+  string name = 1;
+}
+
+message TableId {
+  uint32 id = 1;
+}