Hi.
Error says that the connection string that is executed is pointing to TCP
127.0.0.1:5432
from your docker compose file there is no such string, you are correctly
using go_db host name to work inside the docker network.
So my guess is that you are not executing what you think you are executing
3 hypotesis:
+ in the docker image that is created for app you are launching a bash file
that overrides the environment variable (easy to find: look at the content
and look for 127.0.0.1 or DATABASE_URL)
+ you introduced the environment variable and just forgot to rebuild the
container (can happen, it happens, no shame)
+ the real code tries to connect (probably somewhere else) to 127.0.0.1 in
a block of code that you forgot to cancel/delete/modify to use environment
variables
If launched manually, it honors the environment variable. At least the
block of code you posted.
So my thoughts are that there's something around it or in the real code
Hope that this can help
Suggestion: put a dependency clause, to be sure to start db before the app,
and consider some retries.
DB does not start immediately. It can run some more task at power on that
can delay the effective startup by some seconds.
Usually you say that go_db must be started before starting go_app and
inside go_app you try multiple times (or retry if db shuts down and
restarts during the app execution), but this depends on the type of
application you are writing.
24/7 application should (I would say "must") consider some db downtime
without crashing. Personal home application can be less refined.
PSK
On Sun, Feb 18, 2024 at 5:55 AM Sunday Ajayi <sunnexaj...@gmail.com> wrote:
> Hi guys,
> Please I am having a little issue with my go project using docker.
>
> I set up my Postgres db in docker with my go app but it is unable to
> connect. Please what could be the issue?
>
> I will share the docker-compose file and the main.go here
>
> main.go
>
> package main
>
> import (
> "database/sql"
> "encoding/json"
> "log"
> "net/http"
> "os"
>
> "github.com/gorilla/mux"
> _ "github.com/lib/pq"
> )
>
> type User struct {
> ID int `json:"id"`
> Name string `json:"name"`
> Email string `json:"email"`
> }
>
> var db *sql.DB
> var err error
>
> func main() {
> //connect to database
> db, err = sql.Open("postgres", os.Getenv("DATABASE_URL"))
> log.Println("DATABASE_URL:", os.Getenv("DATABASE_URL"))
>
> if err != nil {
> log.Fatal("Error connecting to database: ", err)
> }
> if db != nil {
> log.Println("Database connected")
> }
> if err := db.Ping(); err != nil {
> log.Fatal("Error pinging database: ", err)
> }
>
> defer db.Close()
>
> //create the table if it doesn't exist
> _, err = db.Exec("CREATE TABLE IF NOT EXISTS users (id SERIAL PRIMARY
> KEY, name TEXT, email TEXT)")
>
> if err != nil {
> log.Fatal("Error creating table: ", err)
> }
>
> //create router
> router := mux.NewRouter()
> router.HandleFunc("/users", getUsers(db)).Methods("GET")
> router.HandleFunc("/users/{id}", getUser(db)).Methods("GET")
> router.HandleFunc("/users", createUser(db)).Methods("POST")
> router.HandleFunc("/users/{id}", updateUser(db)).Methods("PUT")
> router.HandleFunc("/users/{id}", deleteUser(db)).Methods("DELETE")
>
> //start server
> log.Fatal(http.ListenAndServe(":8088", jsonContentTypeMiddleware(router)))
> }
>
> func jsonContentTypeMiddleware(next http.Handler) http.Handler {
> return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
> w.Header().Set("Content-Type", "application/json")
> next.ServeHTTP(w, r)
> })
> }
>
> // get all users
> func getUsers(db *sql.DB) http.HandlerFunc {
> return func(w http.ResponseWriter, r *http.Request) {
> rows, err := db.Query("SELECT * FROM users")
> if err != nil {
> log.Fatal(err)
> }
> defer rows.Close()
>
> users := []User{}
> for rows.Next() {
> var u User
> if err := rows.Scan(&u.ID, &u.Name, &u.Email); err != nil {
> log.Fatal(err)
> }
> users = append(users, u)
> }
> if err := rows.Err(); err != nil {
> log.Fatal(err)
> }
>
> json.NewEncoder(w).Encode(users)
> }
> }
>
> // get user by id
> func getUser(db *sql.DB) http.HandlerFunc {
> return func(w http.ResponseWriter, r *http.Request) {
> vars := mux.Vars(r)
> id := vars["id"]
>
> var u User
> err := db.QueryRow("SELECT * FROM users WHERE id = $1", id).Scan(&u.ID,
> &u.Name,
> &u.Email)
> if err != nil {
> w.WriteHeader(http.StatusNotFound)
> return
> }
>
> json.NewEncoder(w).Encode(u)
> }
> }
>
> // create user
> func createUser(db *sql.DB) http.HandlerFunc {
> return func(w http.ResponseWriter, r *http.Request) {
> var u User
> json.NewDecoder(r.Body).Decode(&u)
>
> err := db.QueryRow("INSERT INTO users (name, email) VALUES ($1, $2)
> RETURNING id", u.Name, u.Email).Scan(&u.ID)
> if err != nil {
> log.Fatal(err)
> }
>
> json.NewEncoder(w).Encode(u)
> }
> }
>
> // update user
> func updateUser(db *sql.DB) http.HandlerFunc {
> return func(w http.ResponseWriter, r *http.Request) {
> var u User
> json.NewDecoder(r.Body).Decode(&u)
>
> vars := mux.Vars(r)
> id := vars["id"]
>
> _, err := db.Exec("UPDATE users SET name = $1, email = $2 WHERE id = $3",
> u.Name, u.Email, id)
> if err != nil {
> log.Fatal(err)
> }
>
> json.NewEncoder(w).Encode(u)
> }
> }
>
> // delete user
> func deleteUser(db *sql.DB) http.HandlerFunc {
> return func(w http.ResponseWriter, r *http.Request) {
> vars := mux.Vars(r)
> id := vars["id"]
>
> var u User
> err := db.QueryRow("SELECT * FROM users WHERE id = $1", id).Scan(&u.ID,
> &u.Name,
> &u.Email)
> if err != nil {
> w.WriteHeader(http.StatusNotFound)
> return
> } else {
> _, err := db.Exec("DELETE FROM users WHERE id = $1", id)
> if err != nil {
> //todo : fix error handling
> w.WriteHeader(http.StatusNotFound)
> return
> }
>
> json.NewEncoder(w).Encode("User deleted")
> }
> }
> }
>
>
> Docker compose file:
>
> version: '3.9'
>
> services:
> go-app:
> container_name: go-app
> image: sunnex/go-app:1.0.0
> build: .
> environment:
> - DATABASE_URL="host=go_db port=5432 user=postgres password=postgres
> dbname=go_db sslmode=disable"
> ports:
> - "8088:8088"
> networks:
> - backend
> depends_on:
> - go_db
> go_db:
> container_name: go_db
> image: postgres:13
> environment:
> POSTGRES_USER: postgres
> POSTGRES_PASSWORD: postgres
> POSTGRES_DB: go_db
> ports:
> - "5432:5432"
> networks:
> - backend
> volumes:
> - pgdata:/var/lib/postgresql/data
>
> volumes:
> pgdata: {}
>
> networks:
> backend:
> driver: bridge
>
> Keep getting this error:
> Error pinging database: *dial tcp 127.0.0.1:5432 <http://127.0.0.1:5432>:
> connect: connection refused*
>
>
> Please where am I getting it wrong?
>
> Regards
>
>
> *AJAYI Sunday *
> (+234) 806 771 5394
> *sunnexaj...@gmail.com <sunnexaj...@gmail.com>*
>
>
>
> On Sat, Feb 17, 2024 at 11:38 PM Pilar Garcia <prototect...@gmail.com>
> wrote:
>
>> hi everyone. my name is pilar. im trying to learn coding for the first
>> time in my life......im sooooo lost can anyone let me know how to even
>> begin on this mission......... please any advise will be greatly
>> appreciated..... you folks have a great day cant waint to hear from ya
>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "golang-nuts" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to golang-nuts+unsubscr...@googlegroups.com.
>> To view this discussion on the web visit
>> https://groups.google.com/d/msgid/golang-nuts/9b1fee4f-919f-4bee-a7f0-2fe2ae685542n%40googlegroups.com
>> <https://groups.google.com/d/msgid/golang-nuts/9b1fee4f-919f-4bee-a7f0-2fe2ae685542n%40googlegroups.com?utm_medium=email&utm_source=footer>
>> .
>>
> --
> You received this message because you are subscribed to the Google Groups
> "golang-nuts" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to golang-nuts+unsubscr...@googlegroups.com.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/golang-nuts/CAKYSAw1%2B5J-TUFkPD30XROdd%3DFHfTMsPy6O3a5rYffzaJK4cpQ%40mail.gmail.com
> <https://groups.google.com/d/msgid/golang-nuts/CAKYSAw1%2B5J-TUFkPD30XROdd%3DFHfTMsPy6O3a5rYffzaJK4cpQ%40mail.gmail.com?utm_medium=email&utm_source=footer>
> .
>
--
You received this message because you are subscribed to the Google Groups
"golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to golang-nuts+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/golang-nuts/CAJNBTxJUpQ36AodBi3eUL1BCn7t1V%3DcLXdeb-5wEg%2BiCEiFkzA%40mail.gmail.com.
