Elixir on docker cannot connect to postgres - postgresql

Question

I am trying to deploy elixir application on Docker container, it is successfully deployed but when I run an API endpoint it shows following error
{
errors: {
detail: "Internal Server Error"
}
}
after check logs docker logs [CONTAINER_ID] the following errors occurred (it cannot connect to database)
my database is on AWS Aurora and I am able to connect to it using pgadmin
18:21:26.624 [error] #PID<0.652.0> running ABC.Endpoint (connection #PID<0.651.0>, stream id 1) terminated
Server: localhost:4000 (http)
Request: GET /api/v1/popular-searches/us/en
** (exit) an exception was raised:
** (DBConnection.ConnectionError) connection not available and request was dropped from queue after 2850ms. This means requests are coming in and your connection pool cannot serve them fast enough. You can address this by:
1. Tracking down slow queries and making sure they are running fast enough
2. Increasing the pool_size (albeit it increases resource consumption)
3. Allowing requests to wait longer by increasing :queue_target and :queue_interval
See DBConnection.start_link/2 for more information
(ecto_sql 3.5.3) lib/ecto/adapters/sql.ex:751: Ecto.Adapters.SQL.raise_sql_call_error/1
(ecto_sql 3.5.3) lib/ecto/adapters/sql.ex:684: Ecto.Adapters.SQL.execute/5
(ecto 3.5.5) lib/ecto/repo/queryable.ex:229: Ecto.Repo.Queryable.execute/4
(ecto 3.5.5) lib/ecto/repo/queryable.ex:17: Ecto.Repo.Queryable.all/3
(ecto 3.5.5) lib/ecto/repo/queryable.ex:157: Ecto.Repo.Queryable.one!/3
(_api 0.1.1) lib/api_web/controllers/V1/cms_data_controller.ex:14: ApiWeb.V1.CMSDataController.get_popular_searches/2
(_api 0.1.1) lib/_api_web/controllers/V1/cms_data_controller.ex:1: ApiWeb.V1.CMSDataController.action/2
(_api 0.1.1) lib/_api_web/controllers/V1/cms_data_controller.ex:1: ApiWeb.V1.CMSDataController.phoenix_controller_pipeline/2
18:21:26.695 [error] Postgrex.Protocol (#PID<0.487.0>) failed to connect: ** (DBConnection.ConnectionError) tcp connect (postgres:5432): non-existing domain - :nxdomain
18:21:26.714 [error] Postgrex.Protocol (#PID<0.479.0>) failed to connect: ** (DBConnection.ConnectionError) tcp connect (postgres:5432): non-existing domain - :nxdomain
18:21:26.718 [error] Postgrex.Protocol (#PID<0.469.0>) failed to connect: ** (DBConnection.ConnectionError) tcp connect (postgres:5432): non-existing domain - :nxdomain
18:21:26.810 [error] Postgrex.Protocol (#PID<0.493.0>) failed to connect: ** (DBConnection.ConnectionError) tcp connect (postgres:5432): non-existing domain - :
I have checked the env variables in the container which are correct, database URL is correct, my Docker file looks file this:
# base image elixer to start with
FROM elixir:1.13.4
# install hex package manager
RUN mix local.hex --force
RUN curl -o phoenix_new.ez https://github.com/phoenixframework/archives/raw/master/phoenix_new.ez
RUN mix archive.install ./phoenix_new.ez
RUN mkdir /app
COPY . /app
WORKDIR /app
ENV MIX_ENV=prod
ENV PORT=4000
ENV DATABASE_URL=postgres://[URL]
RUN mix local.rebar --force
RUN mix deps.get --only prod
RUN mix compile
RUN mix phx.digest
CMD mix phx.server
after building the images i start it like this:
docker build . -t [name]
docker run --name [name] -p 4000:4000 -d [name]
What am I doing wrong?
any help would be appreciated.