Node Postgres Docker - node.js

Question

I try to set up Docker with my node.js app which uses sequelize to connect to postgres.
const sequelize = new Sequelize(
process.env.DB_NAME,
process.env.DB_USER,
process.env.DB_PASS,
{
host: process.env.DB_HOST,
port: process.env.DB_PORT,
dialect: 'postgres',
},
);
In my .env file I declare
DB_HOST=postgres (which is the name of the service declared in the docker-conpose.yml) and DB_PORT=5432 among all the other environment variables.
My Dockerfile looks as follows:
FROM node:8.6.0
# Working directory for application
WORKDIR /usr/src/app
EXPOSE 8080
COPY . /usr/src/app
# In this file I create a user and a DB and give him the privlages
ADD init.sql /docker-entrypoint-initdb.d/
RUN npm install
And my docker-compose.yml looks as follows:
version: "2"
services:
postgres:
image: "postgres:9.4"
restart: always
ports:
- "5432:5432"
env_file:
- .env
node:
build: .
ports:
- "8080:8080"
depends_on:
- postgres
command: ["npm", "start"]
When I docker-compose up I get the error that the Sequelize is not able to connect to the DB.
Unhandled rejection SequelizeConnectionRefusedError: connect ECONNREFUSED 172.18.0.2:5431
Can someone help me with this error?
all the docker logs:
WARNING: Image for service node was built because it did not already exist. To rebuild this image you must use docker-compose build or docker-compose up --build.
Creating graphqlpostgrestemplate_postgres_1 ...
Creating graphqlpostgrestemplate_postgres_1 ... done
Creating graphqlpostgrestemplate_node_1 ...
Creating graphqlpostgrestemplate_node_1 ... done
Attaching to graphqlpostgrestemplate_postgres_1, graphqlpostgrestemplate_node_1
postgres_1 | The files belonging to this database system will be owned by user "postgres".
postgres_1 | This user must also own the server process.
postgres_1 |
postgres_1 | The database cluster will be initialized with locale "en_US.utf8".
postgres_1 | The default database encoding has accordingly been set to "UTF8".
postgres_1 | The default text search configuration will be set to "english".
postgres_1 |
postgres_1 | Data page checksums are disabled.
postgres_1 |
postgres_1 | fixing permissions on existing directory /var/lib/postgresql/data ... ok
postgres_1 | creating subdirectories ... ok
postgres_1 | selecting default max_connections ... 100
postgres_1 | selecting default shared_buffers ... 128MB
postgres_1 | selecting dynamic shared memory implementation ... posix
postgres_1 | creating configuration files ... ok
postgres_1 | creating template1 database in /var/lib/postgresql/data/base/1 ... ok
postgres_1 | initializing pg_authid ... ok
postgres_1 | initializing dependencies ... ok
postgres_1 | creating system views ... ok
node_1 | npm info it worked if it ends with ok
node_1 | npm info using npm#5.3.0
node_1 | npm info using node#v8.6.0
postgres_1 | loading system objects' descriptions ... ok
node_1 | npm info lifecycle graphql-postgres-template#1.0.0~prestart: graphql-postgres-template#1.0.0
node_1 | npm info lifecycle graphql-postgres-template#1.0.0~start: graphql-postgres-template#1.0.0
node_1 |
node_1 | > graphql-postgres-template#1.0.0 start /usr/src/app
node_1 | > nodemon --exec babel-node index.js
node_1 |
postgres_1 | creating collations ... ok
postgres_1 | creating conversions ... ok
postgres_1 | creating dictionaries ... ok
postgres_1 | setting privileges on built-in objects ... ok
postgres_1 | creating information schema ... ok
postgres_1 | loading PL/pgSQL server-side language ... ok
node_1 | [nodemon] 1.12.1
node_1 | [nodemon] to restart at any time, enter rs
node_1 | [nodemon] watching: .
node_1 | [nodemon] starting babel-node index.js
postgres_1 | vacuuming database template1 ... ok
postgres_1 | copying template1 to template0 ... ok
postgres_1 | copying template1 to postgres ... ok
postgres_1 | syncing data to disk ... ok
postgres_1 |
postgres_1 | Success. You can now start the database server using:
postgres_1 |
postgres_1 | postgres -D /var/lib/postgresql/data
postgres_1 | or
postgres_1 | pg_ctl -D /var/lib/postgresql/data -l logfile start
postgres_1 |
postgres_1 |
postgres_1 | WARNING: enabling "trust" authentication for local connections
postgres_1 | You can change this by editing pg_hba.conf or using the option -A, or
postgres_1 | --auth-local and --auth-host, the next time you run initdb.
postgres_1 | ****************************************************
postgres_1 | WARNING: No password has been set for the database.
postgres_1 | This will allow anyone with access to the
postgres_1 | Postgres port to access your database. In
postgres_1 | Docker's default configuration, this is
postgres_1 | effectively any other container on the same
postgres_1 | system.
postgres_1 |
postgres_1 | Use "-e POSTGRES_PASSWORD=password" to set
postgres_1 | it in "docker run".
postgres_1 | ****************************************************
postgres_1 | waiting for server to start....LOG: could not bind IPv6 socket: Cannot assign requested address
postgres_1 | HINT: Is another postmaster already running on port 5432? If not, wait a few seconds and retry.
postgres_1 | LOG: database system was shut down at 2017-10-10 12:17:15 UTC
postgres_1 | LOG: MultiXact member wraparound protections are now enabled
postgres_1 | LOG: database system is ready to accept connections
postgres_1 | LOG: autovacuum launcher started
postgres_1 | done
postgres_1 | server started
postgres_1 | ALTER ROLE
postgres_1 |
postgres_1 |
postgres_1 | /usr/local/bin/docker-entrypoint.sh: ignoring /docker-entrypoint-initdb.d/*
postgres_1 |
postgres_1 | waiting for server to shut down....LOG: received fast shutdown request
postgres_1 | LOG: aborting any active transactions
postgres_1 | LOG: autovacuum launcher shutting down
postgres_1 | LOG: shutting down
postgres_1 | LOG: database system is shut down
node_1 | Tue, 10 Oct 2017 12:17:16 GMT sequelize deprecated String based operators are now deprecated. Please use Symbol based operators for better security, read more at http://docs.sequelizejs.com/manual/tutorial/querying.html#operators at node_modules/sequelize/lib/sequelize.js:236:13
node_1 | WARNING: No configurations found in configuration directory:/usr/src/app/config
node_1 | WARNING: To disable this warning set SUPPRESS_NO_CONFIG_WARNING in the environment.
node_1 | Tue, 10 Oct 2017 12:17:17 GMT body-parser deprecated undefined extended: provide extended option at index.js:53:30
node_1 | Unhandled rejection SequelizeConnectionRefusedError: connect ECONNREFUSED 172.18.0.2:5431
node_1 | at connection.connect.err (/usr/src/app/node_modules/sequelize/lib/dialects/postgres/connection-manager.js:96:24)
node_1 | at Connection.connectingErrorHandler (/usr/src/app/node_modules/pg/lib/client.js:123:14)
node_1 | at emitOne (events.js:115:13)
node_1 | at Connection.emit (events.js:210:7)
node_1 | at Socket. (/usr/src/app/node_modules/pg/lib/connection.js:71:10)
node_1 | at emitOne (events.js:115:13)
node_1 | at Socket.emit (events.js:210:7)
node_1 | at emitErrorNT (internal/streams/destroy.js:64:8)
node_1 | at _combinedTickCallback (internal/process/next_tick.js:138:11)
node_1 | at process._tickDomainCallback (internal/process/next_tick.js:218:9)
node_1 | [nodemon] clean exit - waiting for changes before restart
postgres_1 | done
postgres_1 | server stopped
postgres_1 |
postgres_1 | PostgreSQL init process complete; ready for start up.
postgres_1 |
postgres_1 | LOG: database system was shut down at 2017-10-10 12:17:16 UTC
postgres_1 | LOG: MultiXact member wraparound protections are now enabled
postgres_1 | LOG: database system is ready to accept connections
postgres_1 | LOG: autovacuum launcher started

Answer 1

To your Docker-compose add link configuration option in your service node point to service postgres something like this:
node:
links:
- postgres
Then you can connect to postgresdb point with name service postgres