Re: ngrok/sqlmw: an abstraction for database/sql interceptors and middleware

[Alan Shreve]

And of course I forgot to include a link to the code as well. Sorry for all the messages.

https://github.com/ngrok/sqlmw

On Thu, Jan 16, 2020 at 5:19 AM Alan Shreve <al...@inconshreveable.com> wrote:

Forgot to paste in an example, see below:

func run(dsn string) {
        // install the wrapped driver
        sql.Register("postgres-mw", sqlmw.Driver(pq.Dirver{}, new(sqlInterceptor)))
        db, err := sql.Open("postgres-mw", dsn)
        ...
}

type sqlInterceptor struct {
        sqlmw.NullInterceptor
}

func (in *sqlInterceptor) StmtQueryContext(ctx context.Context, conn driver.StmtQueryContext, query string, args []driver.NamedValue) (driver.Rows, error) {
        startedAt := time.Now()
        rows, err := conn.QueryContext(ctx, args)
        log.Debug("executed sql query", "duration", time.Since(startedAt), "query", query, "args", args, "err", err)
        return rows, err
}

On Thu, Jan 16, 2020 at 5:16 AM Alan Shreve <al...@inconshreveable.com> wrote:

Hi golang-nuts -

This is an abstraction that we needed at ngrok. It allows you to intermediate calls to a database/sql Driver just like a client-side grpc interceptor would. This makes it an excellent abstraction layer upon which to build instrumentation and other middleware-like functionality.

There are a number of similar projects which provided instrumentation for logging/tracing and a few others that were aimed solely at providing callbacks for instrumentation, but I realized a more general-purpose abstraction would provide more power to the programmer by providing the ability to intercept and modify calls and return values.

Hope it's helpful to others. Feedback appreciated.

[Alan Shreve]

[Alan Shreve]

Forgot to paste in an example, see below:

func run(dsn string) {
        // install the wrapped driver
        sql.Register("postgres-mw", sqlmw.Driver(pq.Dirver{}, new(sqlInterceptor)))
        db, err := sql.Open("postgres-mw", dsn)
        ...
}

type sqlInterceptor struct {
        sqlmw.NullInterceptor
}

func (in *sqlInterceptor) StmtQueryContext(ctx context.Context, conn driver.StmtQueryContext, query string, args []driver.NamedValue) (driver.Rows, error) {
        startedAt := time.Now()
        rows, err := conn.QueryContext(ctx, args)
        log.Debug("executed sql query", "duration", time.Since(startedAt), "query", query, "args", args, "err", err)
        return rows, err
}

On Thu, Jan 16, 2020 at 5:16 AM Alan Shreve <al...@inconshreveable.com> wrote: