Failed to connect: :nxdomain

1

Hey guys, I’m trying to deploy me phoenix app but for some reason I’m getting a DB connection error of

Postgrex.Protocol (#PID<0.2336.0>) failed to connect: ** (DBConnection.ConnectionError) tcp connect (dpg-c6npuk7s437rbk6vm9bg:5432): non-existing domain - :nxdomain

I’ve checked and I made sure that:

so I have a feeling it has something to do with my deployment config. So here’s what I got

build.sh

#!/usr/bin/env bash

# exit on error

set -o errexit

# Initial setup

mix deps.get --only prod

MIX_ENV=prod mix compile

# Compile assets

npm install -f --prefix ./assets

npm run deploy --prefix ./assets

mix phx.digest

# Build the release and overwrite the existing release directory

MIX_ENV=prod mix release --overwrite

config/prod.exs

  database_url =
    System.get_env("DATABASE_URL") ||
      raise """
      environment variable DATABASE_URL is missing.
      For example: ecto://USER:PASS@HOST/DATABASE
      """

  secret_key_base =
    System.get_env("SECRET_KEY_BASE") ||
      raise """
      environment variable SECRET_KEY_BASE is missing.
      You can generate one by calling: mix phx.gen.secret
      """
  config :serotana_ex, SerotanaExWeb.Endpoint,
    server: true,
    url: [host: System.get_env("RENDER_EXTERNAL_HOSTNAME") || "localhost", port: 80],
    http: [
      ip: {0, 0, 0, 0, 0, 0, 0, 0},
      port: String.to_integer(System.get_env("PORT") || "4000")
    ],
    secret_key_base: secret_key_base,
    cache_static_manifest: "priv/static/cache_manifest.json"

  database_url =
    System.get_env("DATABASE_URL") ||
      raise """
      environment variable DATABASE_URL is missing.
      For example: ecto://USER:PASS@HOST/DATABASE
      """

  config :serotana_ex, SerotanaEx.Repo,
    url: database_url,
    # IMPORTANT: Or it won't find the DB server
    socket_options: [:inet6],
    pool_size: String.to_integer(System.get_env("POOL_SIZE") || "10")

config/config.exs

import Config

config :serotana_ex,
  ecto_repos: [SerotanaEx.Repo]

# Configures the endpoint
config :serotana_ex, SerotanaExWeb.Endpoint,
  url: [host: System.get_env("RENDER_EXTERNAL_HOSTNAME") || "localhost", port: 80],
  render_errors: [view: SerotanaExWeb.ErrorView, accepts: ~w(html json), layout: false],
  pubsub_server: SerotanaEx.PubSub,
  live_view: [signing_salt: "yI1LL+Ed"]

config :serotana_ex, SerotanaEx.Mailer, adapter: Swoosh.Adapters.Local

config :swoosh, :api_client, false

config :esbuild,
  version: "0.12.18",
  default: [
    args: ~w(js/app.js --bundle --target=es2016 --outdir=../priv/static/assets),
    cd: Path.expand("../assets", __DIR__),
    env: %{"NODE_PATH" => Path.expand("../deps", __DIR__)}
  ]

config :dart_sass,
  version: "1.43.1",
  default: [
    args: ~w(css/app.scss ../priv/static/assets/app.css),
    cd: Path.expand("../assets", __DIR__)
  ]

config :logger, :console,
  format: "$time $metadata[$level] $message\n",
  metadata: [:request_id]

config :phoenix, :json_library, Jason

import_config "#{config_env()}.exs"

repo.exs

use Ecto.Repo,
    otp_app: :serotana_ex,
    adapter: Ecto.Adapters.Postgres

Sorry for the long post, just wanted to cover my bases. Any help would be warmly welcomed!

Thank you in advance!

2

Hey Chris,

The first thing worth checking is that your webservice can communicate with your database, dropping into the shell tab for the service and running psql $DATABASE_URL - if this drops you into a Postgres session this I’m afraid confirms your suspicions that it’s an application/deployment config issue and not an issue related to the platform.

Your question might be better suited to the wider Phoenix community as it seems it comes up quite a lot with differing solutions - unless any of our other Phoenix customers can assist here?

John B

3

Have you solved this issue? I am having this issue right now. Thanks!

4

I was searching around and found this (which might be helpful)

5

Hi, I fixed my issue on this by adding the domains on check_origin: ["//yourdomain.com"] of my prod config.

6

I am having this same issue, but I have not set up custom domains yet.

Solution:

remove this line from your config.