I'm new to GoLang and I`ve an issue with connecting my Go webserver with Postgres Database.
Can someone tell me what I'm doing wrong here?
All these credentials are correct btw. User exists, Password is correct, DB exists and belongs to the user.
package app
import (
"github.com/jinzhu/gorm"
_ "github.com/jinzhu/gorm/dialects/postgres"
)
func connectDB(){
db, err := gorm.Open("postgres", "host=localhost port=5432 user=power_user dbname=local_db password=power_user")
if err != nil {
log.Fatal("DB Connection failed")
}
}
If you're sure about psql server is running, try to modify pg_hba.conf, locates at /etc/postgresql/${version}/main/pg_hba.conf usually:
# TYPE DATABASE USER ADDRESS METHOD
local all all trust
Related
From code
The code bellow outputs the following:
2022/06/21 16:01:07 Failed to connect to db: failed to connect to 'host=localhost user=postgres database=local': server error (FATAL: Ident authentication failed for user "postgres" (SQLSTATE 28000)) exit status 1
import (
"context"
"log"
"github.com/jackc/pgx/v4"
)
func main() {
dbCtx := context.Background()
db, err := pgx.Connect(
dbCtx,
"postgres://postgres:smashthestate#localhost:5432/local",
)
if err != nil {
log.Fatalf("Failed to connect to db: %v\n", err)
}
defer db.Close(dbCtx)
// do stuff with db...
}
From terminal
However, connection to db is possible from terminal. For example, this command if run with the same parameters (db name, user name, password) will give correct output:
psql -d local -U postgres -W -c 'select * from interest;'
Notes
Command works correctly even if sent by user that is neither root nor postgres.
Authentication method for local connection is set to trust inside pg_hba.conf:
local all all trust
So, what am I missing here? Why everything works fine from the command line but doesn't work from code?
Go's defaults are different from psql's. If no hostname is given, Go defaults to using localhost, while psql defaults to using the Unix domain sockets.
To specify a Unix domain socket to Go, you need to do it oddly to get it to survive URI validation:
postgres://postgres:smashthestate#:5432/local?host=%2Ftmp
Though the end might need to be more like ?host=%2Fvar%2Frun%2Fpostgresql, depending on how the server was configured.
But why are you specifying a password which is not needed? That is going to cause pointless confusion.
I'm unable to connect an AWS SAM lambda function to a local postgres instance. I'll be specific in a moment, but first let me say that the same code works for my coworker and that I've tried using Postgres within a docker container as well as installed manually. To simplify the problem I started over with the SAM helloworld golang example and added the following:
import (
_ "github.com/lib/pq"
"database/sql"
)
.
.
.
const (
host = "localhost"
port = 5432
user = "postgres"
password = "postgres"
dbname = "postgres"
)
.
.
.
.
psqlInfo := fmt.Sprintf("host=%s port=%d user=%s "+
"password=%s dbname=%s sslmode=disable",
host, port, user, password, dbname)
db, err := sql.Open("postgres", psqlInfo)
if err != nil {
panic(err)
}
defer db.Close()
err = db.Ping()
if err != nil {
panic(err)
}
fmt.Println("Successfully connected!")
And I get the following error:
dial tcp 127.0.0.1:5432: connect: connection refused: OpError
[{"path":"github.com/aws/aws-lambda-go#v1.13.3/lambda/function.go","line":35,"label":"(*Function).Invoke.func1"},{"path":"runtime/panic.go","line":969,"label":"gopanic"},{"path":"hello-world/main.go","line":67,"label":"handler"},{"path":"reflect/value.go","line":475,"label":"Value.call"},{"path":"reflect/value.go","line":336,"label":"Value.Call"},{"path":"github.com/aws/aws-lambda-go#v1.13.3/lambda/handler.go","line":124,"label":"NewHandler.func1"},{"path":"github.com/aws/aws-lambda-go#v1.13.3/lambda/handler.go","line":24,"label":"lambdaHandler.Invoke"},{"path":"github.com/aws/aws-lambda-go#v1.13.3/lambda/function.go","line":67,"label":"(*Function).Invoke"},{"path":"reflect/value.go","line":475,"label":"V
alue.call"},{"path":"reflect/value.go","line":336,"label":"Value.Call"},{"path":"net/rpc/server.go","line":377,"label":"(*service).call"},{"path":"runtime/asm_amd64.s","line":1374,"label":"goexit"}]
SAM CLI, version 1.21.1
I've now tried this on two machines and get the same error. Is there there something that I'm just missing there? I can confirm that the the database is receiving connections fine. I hit it every day from a node app. Also, I can build the golang code outside of SAM and it will work fine. So there's something with my SAM setup that's wrong.
Figured it out. Within the lambda I needed to set the postgres connection string to hit host.docker.internal
I spend a lot of time figuring out how to connect using AWS SAM to a local Postgres and finally found that changing the dbhostname from localhost to host.docker.internal works.
connectionString = 'postgresql://dbuser:dbpassword#host.docker.internal:5432/dbname';
For a project i'm trying to connection a cloud function to a cloud sql database setup as described in this quickstart guide.
The function is configured in the same region, the service account has the Role Cloud SQL-Client. I called the function through my computer like this:
gcloud functions call <function-name> --region=<region> --data '{"recipient":"hello","requester":"hello","message":"test"}'
The connection to the function is working, it seems like just the authentication to the database doesn't work but i don't get where i failed.
I checked the password, user and connection name multiple times, reset the password and it still doesn't work.
I found the issue here related to connecting cloud functions to cloud sql.
I tried surrounding the password in the dsn-string with single-quotes just to be sure escaping of characters in the password isn't a problem.
I also checked the environment variables coming in and they are the ones i entered in the configuration.
The function just pings the database for test purposes:
package receiver
import (
"database/sql"
"fmt"
"net/http"
"os"
// Import Postgres SQL driver
_ "github.com/lib/pq"
)
// Receives a message and stores it
func Receive(w http.ResponseWriter, r *http.Request) {
connectionName := os.Getenv("POSTGRES_INSTANCE_CONNECTION_NAME")
dbUser := os.Getenv("POSTGRES_USER")
dbPassword := os.Getenv("POSTGRES_PASSWORD")
dsn := fmt.Sprintf("user=%s password='%s' host=/cloudsql/%s dbname=messages", dbUser, dbPassword, connectionName)
var err error
db, err := sql.Open("postgres", dsn)
if err != nil {
fmt.Fprintf(w, "Could not open db: %v \n", err)
}
// Only allow 1 connection to the database to avoid overloading
db.SetMaxIdleConns(1)
db.SetMaxOpenConns(1)
defer db.Close()
if pingerror := db.Ping(); pingerror != nil {
fmt.Fprintf(w, "Failed to ping database: %s \n", pingerror)
return
}
}
The variable POSTGRES_INSTANCE_CONNECTION_NAME is formatted as described here as ProjectID:Region:InstanceID.
Expected is a success message or no error and i'm actually getting this message:
pq: password authentication failed for user "postgres"
Note: I also created a function containing the demo code from here with my sql database settings and the error is the same. It seems like i missed some step while setting up the user or sql instance. But i can't find out which.
Feels strange to answer my own question but here it is: For some reason connecting with the postgres user doesn't work. Finally i created a new database user for the function and a password containing only alphanumeric characters.
The unix socket at /cloudsql/{connectionName} is only provided in the GCF runtime. When running locally, you either need change your connection string or use the Cloud SQL proxy to simulate a unix socket at the same path.
I'm trying to connect to my localhost postgresql server without SSL and I'm getting this error:
pq: SSL is not enabled on the server
That's fine, I know how to fix it:
type App struct {
Router *mux.Router
DB *sql.DB
}
func (a *App) Initialize(dbname string) {
connectionString := fmt.Sprintf("dbname=%s sslmode=disable", dbname)
var err error
a.DB, err = sql.Open("postgres", connectionString)
if err != nil {
log.Fatal(err)
}
defer a.DB.Close()
}
However I'm still getting the error!
I was able to recreate your error with a fresh install of postgres. While the error output was
pq: SSL is not enabled on the server
the real error was not having any databases created. To create a testdb let's run
createdb testdb
in your terminal with postgres already running in the background.
I think the answer comes more just to assign a parameter flag to your Postgres connection string url.
I was connecting to an AWS RDS by URL and I've just change to localhost on 5432 default port.
http://127.0.0.1:5432?sslmode=disable
or
http://localhost:5432?sslmode=disable
I stumbled upon this trying to connect to Postgresql server from my Go program with wrong password.
I am making a web app in Go and PostgreSQL using two different computers. The setup is the same on both computers (Ubuntu with last versions of Go and PostgreSQL). The problem is that I cannot get my app to connect to the database on my laptop.
I use this piece of code:
func (db *Database) Dial(user string, password string, dbname string) {
var err error
db.Conn, err = sql.Open("postgres", "user="+user+" password="+password+" dbname="+dbname+" sslmode=require")
if err != nil {
fmt.Println("Connection to " + dbname + " not possible!")
log.Fatal(err)
}
err = db.Conn.Ping()
if err != nil {
fmt.Println("Ping to " + dbname + " not possible!")
fmt.Println(err)
}
}
And I get:
Ping to my_database not possible!
driver: bad connection
I found many questions on SO with the same error, but I found no solution that would solve my case.
Also, on my laptop, just like on my desktop computer, there is a user postgres and I can connect to the database through psql, so the daemon is active and the password is right. I use the exact same setup and code on both computers.
My question is: how do I get more information about the error? I find "bad connection" to be too vague. I'm sure that a bit more of information would help me a lot.
Also, do you have an idea of would could cause the error?
Update
The PostgreSQL log says this:
2014-09-29 14:23:26 EDT FATAL: password authentication failed for user "postgres"
2014-09-29 14:23:26 EDT DETAIL: Connection matched pg_hba.conf line 92: "host all all 127.0.0.1/32 md5"
But I double checked the password and it shoud be fine. I can also log in as the posgres user, run the psql command and execute queries.
I found a way to fix this.
I log in as postgres and run psql postgres. In other words, I connect to the postgres database. Then I run the command \password and enter a new password.
I entered the exact same password that I have been using since the beginning and somehow now it works.
The problem is solved, but if someone has an idea about what could have been the cause, I'm interested. Maybe it has something to do with password expiration?