Taiga don't connect to postgres

[evandroteixeira1710]

Good morning people,
Today I started testing Taiga for the company I work for, created taiga.yml and went up with the docker-compose -f taiga.yml up -d.
When I check the taiga log, it is looping for not connecting to the database.
"Failed to connect to database server or database does not exist.
Running database check
Connecting to database:
dbname = 'taigadb' user = 'taiga' host = 'localhost' password = 'password'
Traceback (most recent call last):
File "/checkdb.py", line 14, in
conn = psycopg2.connect (conn_string)
File "/usr/local/lib/python3.5/site-packages/psycopg2/init.py", line 130, in connect
conn = _connect (dsn, connection_factory = connection_factory, ** kwasync)
psycopg2.OperationalError: could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP / IP connections on port 5432?
could not connect to server: Network is unreachable
Is the server running on host "localhost" (:: 1) and accepting
TCP / IP connections on port 5432? "

My taiga.yml

version: '3'

services:
taiga:
container_name: Taiga
image: benhutchins / taiga
restart: always
build: ../
ports:
- 8085: 80
# - 443: 443 # To enable SSL, uncomment this line. See "Enable SSL" below.
depends_on:
- db
# To enable taiga-events, uncomment the following lines:
# - events
# - rabbit
# - redis
environment:
# Hostname for your instance of Taiga. Required.
TAIGA_HOSTNAME: localhost
# Database variables. Required.
TAIGA_DB_HOST: localhost
TAIGA_DB_NAME: taigadb
TAIGA_DB_USER: taiga
TAIGA_DB_PASSWORD: password

    # Enable SSL internally, within the Docker container. Optional.
    # This is not great. I suggest using something on top of this
    # to enable SSL. See the example example-nginx-ssl.conf file
    # for an alternative way to enable SSL.
    # TAIGA_SSL: 'True'
    
    # Enable SSL externally, preferred method
    # TAIGA_SSL_BY_REVERSE_PROXY: 'True'
volumes:
    # Media and uploads directory. Required (or you will lose all uploads)
    - ./media:/usr/src/taiga-back/media

    # Taiga configuration directory. Makes it easier to change configuration.
    - ./taiga-conf:/taiga

db:
container_name: Postgres_taiga
image: postgres: 9.6
environment:
POSTGRES_DB: taigadb
POSTGRES_USER: taiga
POSTGRES_PASSWORD: password
ports:
- 49155: 5432
volumes:
# Postgres data directory. This ensures the database is not lost.
- ./pgdata:/var/lib/postgresql/data

OBS. I can access via pgadmin and connecting to postgres as well.

[dnx-xy]

same issues here.. any help would be appreaciated