Postgres database connectivity issues when using docker-compose - postgresql

Question

I am trying to dockerize the REST api written in golang, but having troubles connecting to postgres database (the app works fine without docker). Below are my Dockerfile and docker-compose.yml
FROM golang:alpine
RUN mkdir /app
ADD . /app
WORKDIR /app
COPY go.mod .
RUN go mod download
COPY . .
RUN go build -o main .
CMD ["/app/main"]
docker-compose.yml
version: '3'
volumes:
postgres_data:
driver: local
services:
postgres:
image: postgres
environment:
POSTGRES_DB: test_db
POSTGRES_USER: postgres
POSTGRES_PASSWORD: 1234
ports:
- 5432:5432
my-go-app:
restart: always
build:
dockerfile: Dockerfile
context: .
environment:
# Postgres Details
DB_HOST: postgres
DB_DRIVER: postgres
DB_USER: postgres
DB_PASSWORD: 1234
DB_NAME: test_db
DB_PORT: 5432
# APP details
APP_PROTOCOL: http
APP_HOST: localhost
APP_PORT: 10000
ALLOWED_ORIGINS: "*"
ports:
- 10000:10000
depends_on:
- postgres
Database properties: host = "localhost", port = 5432, user = "postgres", password="1234", dbname="test_db" (all specified in docker-compose.yml). App itself runs on port 10000
When running docker up and docker-compose up --build I'm getting sql: database is closed error
Starting rest_db_my-go-app_1 ... done
Attaching to rest_db_postgres_1, rest_db_my-go-app_1
my-go-app_1 | 2021/04/02 12:54:07 Connection Failed to Open
my-go-app_1 | 2021/04/02 12:54:07 Starting development server at http://127.0.0.1:10000/
my-go-app_1 | 2021/04/02 12:54:07 Quit the server with CONTROL-C.
my-go-app_1 |
my-go-app_1 | (/app/main.go:185)
my-go-app_1 | [2021-04-02 12:54:07] sql: database is closed
postgres_1 |
postgres_1 | PostgreSQL Database directory appears to contain a database; Skipping initialization
postgres_1 |
postgres_1 | 2021-04-02 12:02:15.807 UTC [1] LOG: starting PostgreSQL 13.2 (Debian 13.2-1.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit
postgres_1 | 2021-04-02 12:02:15.808 UTC [1] LOG: listening on IPv4 address "0.0.0.0", port 5432
postgres_1 | 2021-04-02 12:02:15.808 UTC [1] LOG: listening on IPv6 address "::", port 5432
postgres_1 | 2021-04-02 12:02:15.815 UTC [1] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
postgres_1 | 2021-04-02 12:02:15.831 UTC [26] LOG: database system was shut down at 2021-04-02 12:02:14 UTC
postgres_1 | 2021-04-02 12:02:15.837 UTC [1] LOG: database system is ready to accept connections
postgres_1 | 2021-04-02 12:02:25.830 UTC [1] LOG: received fast shutdown request
postgres_1 | 2021-04-02 12:02:25.834 UTC [1] LOG: aborting any active transactions
postgres_1 | 2021-04-02 12:02:25.835 UTC [1] LOG: background worker "logical replication launcher" (PID 32) exited with exit code 1
postgres_1 | 2021-04-02 12:02:25.835 UTC [27] LOG: shutting down
postgres_1 | 2021-04-02 12:02:25.862 UTC [1] LOG: database system is shut down
How to solve this database connectivity issue? Thanks in advance