go - Where should I store global database instance? -


where should store database instance after initializing in go? want access them request handlers.

// server.go storage, err := config.getfilestorage(viper.getviper()) if err != nil {     log.fatal(fmt.sprintf("failed configure file storage: %v\n", err)) }  db, err := config.getdatabase(viper.getviper()) if err != nil {     log.fatal(fmt.sprintf("failed configure database: %v\n", err)) }

this local variables in main function. how expose them go package handlers?

you can wrap db connection in struct, , have return http handlers. this:

package main  import (     "database/sql"     "log"     "net/http" )  type dbmanager struct {     db *sql.db }  func (m *dbmanager) hellohandler() http.handler {     return http.handlerfunc(func(w http.responsewriter, r *http.request) {         rows, err := m.db.query("select hello world")         if err != nil {             http.error(w, err.error(), http.statusinternalservererror)             return         }         defer rows.close()         rows.next() {             // stuff         }     }) }  func main() {     db, err := sql.open("", "")     if err != nil {         panic(err)     }     m := dbmanager{db: db}     http.handle("/", m.hellohandler())     log.fatal(http.listenandserve(":8080", nil)) }

also make sure object can handle concurrent access *sql.db https://golang.org/pkg/database/sql/#db

if want/need share more across handlers can take @ environment pattern: http://www.jerf.org/iri/post/2929


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