[Feature] Add client_protocol_version query parameter to allowed params

[ValManP]

Is your feature request related to a problem? Please describe.

When attempting to connect to ClickHouse via chproxy using the clickhouse-go driver, the connection fails with the following error:

failed to query server hello: failed to query server hello info: readData: block decode: raw: read str: unexpected EOF

This appears to happen because chproxy does not proxy the client_protocol_version parameter to ClickHouse. As a result, the server and client protocol versions become mismatched, leading to a failed handshake. clickhouse-go client set client_protocol_version parameter here.

Steps to Reproduce:

1. Run ClickHouse server.

2. Start chproxy in front of ClickHouse.

3. Connect via the clickhouse-go driver:

import (
	"database/sql"

	_ "github.com/ClickHouse/clickhouse-go/v2" // Import the ClickHouse driver
)

func main() {
    dsn := `http://chproxy:8123/db?username=USER&password=PASS`
    conn, err := sql.Open("clickhouse", dsn)
    if err != nil {
        panic(err)
    }
    
    if err := conn.Ping(); err != nil {
        panic(err)
    }
}

Describe the solution you'd like

Add client_protocol_version to allowedParams

Describe alternatives you've considered

Workaround: hardcode client_protocol_version in param_groups

param_groups:
  - name: "protocol_version"
    params:
      - key: "client_protocol_version"
        value: "54460"

Additional context

chproxy version v1.28.0
clickhouse-go version v2.40.1
clickhouse version v25.3.6.56

[ValManP]

Here is PR

[hileef]

Thank you for the report @ValManP , let's get your PR merged ASAP as soon as tests pass 🙏

[SpencerTorres]

Perhaps I can have this be a toggleable feature for the go driver for backwards compatibility, seems like it's only related to chproxy though. Thanks for reporting this.

The behavior of client_protocol_version can be confusing for the HTTP interface. At the moment it only applies for receiving data, not encoding data. The Go driver handles this difference, but in the future I will likely open a PR to apply it to both on the server side.