Golang context.WithValue: how to add several key-value pairs

Question

With Go\'s context package it is possible to pass request-specific data to the stack of request handling functions using

func WithValue(parent C         


        

Answer 1

As "icza" said you can group the values in one struct:

type vars struct {
    lock    sync.Mutex
    db      *sql.DB
}

Then you can add this struct in context:

ctx := context.WithValue(context.Background(), "values", vars{lock: mylock, db: mydb})

And you can retrieve it:

ctxVars, ok := r.Context().Value("values").(vars)
if !ok {
    log.Println(err)
    return err
}
db := ctxVars.db
lock := ctxVars.lock