[vtctld] Add GetSrvVSchemas command

[doeg]

Signed-off-by: Sara Bee 855595+doeg@users.noreply.github.com

Description

This is a precursor to adding an /api/srvvschemas endpoint to VTAdmin, which will return all of the SrvVSchemas for all cells (or optionally filtered by cell) in a cluster. #8208 was the first attempt at this, however: @ajm188 suggested adding this to the vtctld so that the vtctlds can query all of the topos in their region. This is more efficient than VTAdmin querying each individual cell.

vtctldclient GetSrvVSchemas zone1

{
  "zone1": {
    "keyspaces": {
      "commerce": {
        "tables": {
          "customer_seq": {
            "type": "sequence"
          },
          "order_seq": {
            "type": "sequence"
          },
          "product": {}
        }
      },
      "customer": {
        "sharded": true,
        "vindexes": {
          "hash": {
            "type": "hash"
          }
        },
        "tables": {
          "corder": {
            "column_vindexes": [
              {
                "column": "customer_id",
                "name": "hash"
              }
            ],
            "auto_increment": {
              "column": "order_id",
              "sequence": "order_seq"
            }
          },
          "customer": {
            "column_vindexes": [
              {
                "column": "customer_id",
                "name": "hash"
              }
            ],
            "auto_increment": {
              "column": "customer_id",
              "sequence": "customer_seq"
            }
          }
        }
      }
    },
    "routing_rules": {}
  }
}

vtctldclient GetSrvVSchemas nope

[]

vtctldclient GetSrvVSchemas zone1 nope

{
  "zone1": {
    "keyspaces": {
      "commerce": {
        "tables": {
          "customer_seq": {
            "type": "sequence"
          },
          "order_seq": {
            "type": "sequence"
          },
          "product": {}
        }
      },
      "customer": {
        "sharded": true,
        "vindexes": {
          "hash": {
            "type": "hash"
          }
        },
        "tables": {
          "corder": {
            "column_vindexes": [
              {
                "column": "customer_id",
                "name": "hash"
              }
            ],
            "auto_increment": {
              "column": "order_id",
              "sequence": "order_seq"
            }
          },
          "customer": {
            "column_vindexes": [
              {
                "column": "customer_id",
                "name": "hash"
              }
            ],
            "auto_increment": {
              "column": "customer_id",
              "sequence": "customer_seq"
            }
          }
        }
      }
    },
    "routing_rules": {}
  }
}

Related Issue(s)

• [vtctld] Add GetSrvVSchema command #7334, which added the initial GetSrvVSchema command

Checklist

• Tests were added or are not required
• Documentation was added or is not required

Deployment Notes

N/A

[ajm188]

lgtm (and thank you for adding the help texts to the others! ❤️ )