Accessing a docker container's IP address from a static client - docker

Question

I have a static Gatsby app that needs the uri from another container for a Hasura GraphQL connection.
The Problem
The Gatsby container finishes the docker build before Hasura's, so the URI in Gatsby is set to undefined.
How can I make it so the uri is dynamic and changes to Hasura's actual container IP address when it's done building?
What I tried
Add a depends_on in docker-compose.yml to force Gatsby to wait until the Hasura container is ready, so it'll have the IP by the time Gatsby container starts the build. But according to [0] it doesn't guarantee that Gatsby will wait until Hasura finishes to start itself.
It suggests adding a custom bash script to force the Gatsby container to wait. If I were to use wait-for-it.sh, what should the subcommand be (the command after the wait finishes)?
[0] https://docs.docker.com/compose/startup-order/
docker-compose.yml
version: '3.6'
services:
database:
image: postgres:12.2
container_name: 'postgres-db'
env_file:
- database.env
volumes:
- ./schema.sql:/docker-entrypoint-initdb.d/1-schema.sql
- ./seed.sql:/docker-entrypoint-initdb.d/2-seed.sql
hasura:
image: hasura/graphql-engine:v1.2.1
restart: on-failure
container_name: 'hasura'
depends_on:
- database
ports:
- '8180:8080'
env_file:
- hasura.env
web:
build: '.'
image: 'webserver'
container_name: 'nginx-webserver'
restart: on-failure
depends_on:
- hasura
ports:
- '8080:80'
volumes:
- /app/node_modules
- .:/app
env_file:
- webserver.env
webserver.env file
NODE_ENV=production
GATSBY_WEBPACK_PUBLICPATH=/
HASURA_ENDPOINT=http://hasura:8080/v1/graphql
GraphQL Apollo client that needs the Hasura URI:
export const client = new ApolloClient({
uri: process.env.HASURA_ENDPOINT,
fetch,
});

Answer 1

Found the solution.
I was thinking about the container network relationship incorrectly.
The client looks at the HOST'S ip address when connecting, not the container's.
Explanation
The Hasura container exposes itself to everyone via localhost:8180. If you look at the docker-compose file, port 8180:8080 means "Make Hasura's port 8080 accessible to localhost's port 8180".
The gatsby app (nginx-webserver) should point to localhost:8180, not hasura:8080.
My final docker-compose.yml:
version: '3.6'
services:
database:
image: postgres:12.2
container_name: 'postgres-db'
env_file:
- database.env
volumes:
- ./schema.sql:/docker-entrypoint-initdb.d/1-schema.sql
- ./seed.sql:/docker-entrypoint-initdb.d/2-seed.sql
hasura:
image: hasura/graphql-engine:v1.2.1
restart: on-failure
container_name: 'hasura'
depends_on:
- database
ports:
- '8180:8080'
env_file:
- hasura.env
web:
build: '.'
image: 'nginx-webserver'
container_name: 'web'
restart: on-failure
ports:
- '8080:80'
volumes:
- .:/app
- app/node_modules
env_file:
- webserver.env
ApolloClient setup:
import ApolloClient from 'apollo-boost';
import fetch from 'isomorphic-fetch';
export const HASURA_ENDPOINT_URI =
process.env.NODE_ENV === 'development'
? 'http://localhost:8090/v1/graphql'
: 'http://localhost:8180/v1/graphql';
export const client = new ApolloClient({
uri: HASURA_ENDPOINT_URI,
fetch
});