Cloud SQL for PostgreSQL on Google App Engine
Disclaimer
This is not a Google product, and is unsupported.
It uses the google.golang.org/appengine/cloudsql package, which is supported for MySQL, but not for Postgres.
It happens to work right now, but may not forever.
Example
app.yaml
runtime: go
api_version: go1
handlers:
- url: /.*
script: _go_app
env_variables:
# Replace INSTANCE_CONNECTION_NAME with the value obtained when configuring your
# Cloud SQL instance, available from the Google Cloud Console or from the Cloud SDK.
# For Cloud SQL 2nd generation instances, this should be in the form of "project:region:instance".
CLOUDSQL_CONNECTION_NAME: 'INSTANCE_CONNECTION_NAME'
# Replace username and password if you aren't using the root user.
CLOUDSQL_USER: postgres
CLOUDSQL_PASSWORD: pwcloudsql.go
// Copyright 2017 Google Inc. All rights reserved.
// Use of this source code is governed by the Apache 2.0
// license that can be found in the LICENSE file.
// Sample cloudsql_postgres demonstrates connection to a Cloud SQL for Postgres instance from App Engine standard.
package main
import (
"bytes"
"database/sql"
"fmt"
"log"
"net/http"
"os"
"google.golang.org/appengine"
_ "github.com/broady/gae-postgres"
)
var db *sql.DB
func main() {
var (
connectionName = mustGetenv("CLOUDSQL_CONNECTION_NAME")
user = mustGetenv("CLOUDSQL_USER")
password = os.Getenv("CLOUDSQL_PASSWORD") // NOTE: password may be empty
)
var err error
db, err = sql.Open("gae-postgres", fmt.Sprintf("cloudsql=%s user=%s password='%s'", connectionName, user, password))
if err != nil {
log.Fatalf("Could not open db: %v", err)
}
http.HandleFunc("/", handler)
appengine.Main()
}
func handler(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.NotFound(w, r)
return
}
w.Header().Set("Content-Type", "text/plain")
rows, err := db.Query("SELECT datname FROM pg_database")
if err != nil {
http.Error(w, fmt.Sprintf("Could not query db: %v", err), 500)
return
}
defer rows.Close()
buf := bytes.NewBufferString("Databases:\n")
for rows.Next() {
var dbName string
if err := rows.Scan(&dbName); err != nil {
http.Error(w, fmt.Sprintf("Could not scan result: %v", err), 500)
return
}
fmt.Fprintf(buf, "- %s\n", dbName)
}
w.Write(buf.Bytes())
}
func mustGetenv(k string) string {
v := os.Getenv(k)
if v == "" {
log.Panicf("%s environment variable not set.", k)
}
return v
}