MongoDB Golang driver trying to connect to localhost instead of docker host - mongodb

Question

ERROR
app | 2020/07/14 13:19:00 server selection error: server selection timeout, current topology: { Type: Unknown, Servers: [{ Addr: localhost:27017, Type: Unknown, State: Connected, Average RTT: 0, Last error: connection() : dial tcp 127.0.0.1:27017: connect: connection refused }, ] }
I am using docker-compose to manage golang app and mongo db (without replica set) instances. docker-compose file contents:
version: '3.1'
services:
mongodb:
image: mongo
container_name: mongodb
restart: always
ports:
- 27017:27017
environment:
MONGO_INITDB_ROOT_USERNAME: root
MONGO_INITDB_ROOT_PASSWORD: local
command: mongod --bind_ip mongodb
app:
image: app:1.4
container_name: app
environment:
- MONGO_URL=mongodb
ports:
- 80:8080
depends_on:
- mongodb
restart: always
Running Docker Containers:
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
d130336be71e app:1.4 "/app/main" 4 minutes ago Up 2 seconds 0.0.0.0:80->8080/tcp app
dc57dd2de645 mongo "docker-entrypoint.s…" 4 minutes ago Up 2 seconds 0.0.0.0:27017->27017/tcp mongodb
For Connecting Golang app with MongoDB
I am using official mongodb go driver (go.mongodb.org/mongo-driver/mongo) and my code is trying to connect to docker host (mongodb):
var dbUser string = "root"
var dbPassword string = "local"
dbURL := os.Getenv("MONGO_URL")
clientOptions := options.Client()
clientOptions.SetDirect(true).ApplyURI("mongodb://" + dbUser + ":" + dbPassword + "#" + dbURL +":27017/?connect=direct")
Troubleshooting
As part of trying to figure out what is wrong I looked at similar issues highlighted in stackoverflow and tried below options:
Tried to use connect=direct in connection URI
Tried to use SetDirect
Added --bindip as highlighted in my docker-compose file
I logged-in into the app container and tried to ping mongodb and it worked:
root#d130336be71e:/app# ping mongodb
PING mongodb (172.18.0.2) 56(84) bytes of data.
64 bytes from mongodb.app_default (172.18.0.2): icmp_seq=1 ttl=64 time=0.159 ms
64 bytes from mongodb.app_default (172.18.0.2): icmp_seq=2 ttl=64 time=0.200 ms
64 bytes from mongodb.app_default (172.18.0.2): icmp_seq=3 ttl=64 time=0.079 ms
64 bytes from mongodb.app_default (172.18.0.2): icmp_seq=4 ttl=64 time=0.087 ms
64 bytes from mongodb.app_default (172.18.0.2): icmp_seq=5 ttl=64 time=0.083 ms
^C
--- mongodb ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 60ms
rtt min/avg/max/mdev = 0.079/0.121/0.200/0.050 ms
After trying these options, I am seeking help from Golang community as I am fairly new to Golang.
Thanks in Advance.