MySQL proxy

The MySQL proxy filter decodes the wire protocol between the MySQL client and server. It decodes the SQL queries in the payload (SQL99 format only). The decoded info is emitted as dynamic metadata that can be combined with access log filters to get detailed information on tables accessed as well as operations performed on each table.

Attention

The mysql_proxy filter is experimental and is currently under active development. Capabilities will be expanded over time and the configuration structures are likely to change.

Warning

The mysql_proxy filter was tested with MySQL v5.5. The filter may not work with other versions of MySQL due to differences in the protocol implementation.

Configuration

The MySQL proxy filter should be chained with the TCP proxy filter as shown in the configuration snippet below:

filter_chains:
- filters:
  - name: envoy.filters.network.mysql_proxy
    typed_config:
      "@type": type.googleapis.com/envoy.config.filter.network.mysql_proxy.v1alpha1.MySQLProxy
      stat_prefix: mysql
  - name: envoy.tcp_proxy
    typed_config:
      "@type": type.googleapis.com/envoy.config.filter.network.tcp_proxy.v2.TcpProxy
      stat_prefix: tcp
      cluster: ...

Statistics

Every configured MySQL proxy filter has statistics rooted at mysql.<stat_prefix>. with the following statistics:

Name	Type	Description
auth_switch_request	Counter	Number of times the upstream server requested clients to switch to a different authentication method
decoder_errors	Counter	Number of MySQL protocol decoding errors
login_attempts	Counter	Number of login attempts
login_failures	Counter	Number of login failures
protocol_errors	Counter	Number of out of sequence protocol messages encountered in a session
queries_parse_error	Counter	Number of MySQL queries parsed with errors
queries_parsed	Counter	Number of MySQL queries successfully parsed
sessions	Counter	Number of MySQL sessions since start
upgraded_to_ssl	Counter	Number of sessions/connections that were upgraded to SSL

Dynamic Metadata

The MySQL filter emits the following dynamic metadata for each SQL query parsed:

Name	Type	Description
<table.db>	string	The resource name in table.db format. The resource name defaults to the table being accessed if the database cannot be inferred.
[]	list	A list of strings representing the operations executed on the resource. Operations can be one of insert/update/select/drop/delete/create/alter/show.

RBAC Enforcement on Table Accesses

The dynamic metadata emitted by the MySQL filter can be used in conjunction with the RBAC filter to control accesses to individual tables in a database. The following configuration snippet shows an example RBAC filter configuration that denies SQL queries with _update_ statements to the _catalog_ table in the _productdb_ database.

filter_chains:
- filters:
  - name: envoy.filters.network.mysql_proxy
    typed_config:
      "@type": type.googleapis.com/envoy.config.filter.network.mysql_proxy.v1alpha1.MySQLProxy
      stat_prefix: mysql
  - name: envoy.filters.network.rbac
    typed_config:
      "@type": type.googleapis.com/envoy.config.filter.network.rbac.v2.RBAC
      stat_prefix: rbac
      rules:
        action: DENY
        policies:
          "product-viewer":
            permissions:
            - metadata:
                filter: envoy.filters.network.mysql_proxy
                path:
                - key: catalog.productdb
                value:
                  list_match:
                    one_of:
                      string_match:
                        exact: update
            principals:
            - any: true
  - name: envoy.tcp_proxy
    typed_config:
      "@type": type.googleapis.com/envoy.config.filter.network.tcp_proxy.v2.TcpProxy
      stat_prefix: tcp
      cluster: mysql