Unable to run postgresql for Phoenix - macos

Question

18:37:55.291 [error] GenServer #PID<0.191.0> terminating
** (DBConnection.ConnectionError) tcp connect (localhost:5432): connection refused - :econnrefused
(db_connection) lib/db_connection/connection.ex:148: DBConnection.Connection.connect/2
(connection) lib/connection.ex:622: Connection.enter_connect/5
(stdlib) proc_lib.erl:247: :proc_lib.init_p_do_apply/3
Last message: nil
State: Postgrex.Protocol
** (Mix) The database for Hello.Repo couldn't be created: an exception was raised:
** (DBConnection.ConnectionError) tcp connect (localhost:5432): connection refused - :econnrefused
(db_connection) lib/db_connection/connection.ex:148: DBConnection.Connection.connect/2
(connection) lib/connection.ex:622: Connection.enter_connect/5
(stdlib) proc_lib.erl:247: :proc_lib.init_p_do_apply/3
but I ran ~/brew services start postgresql
==> Successfully startedpostgresql(label: homebrew.mxcl.postgresql) first ..
So I try
~/locate psql
WARNING: The locate database (/var/db/locate.database) does not exist.
To create the database, run the following command:
sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.locate.plist
Please be aware that the database can take some time to generate; once
the database has been created, this message will no longer appear.
~/ sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.locate.plist
/System/Library/LaunchDaemons/com.apple.locate.plist: service already loaded
How do I get my database up and running for Phoenix?
```
Error on npm install:
```
~/hello/npm install
module.js:538
throw err;
^
Error: Cannot find module 'semver'
at Function.Module._resolveFilename (module.js:536:15)
at Function.Module._load (module.js:466:25)
at Module.require (module.js:579:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (/usr/local/lib/node_modules/npm/lib/utils/unsupported.js:2:14)
at Module._compile (module.js:635:30)
at Object.Module._extensions..js (module.js:646:10)
at Module.load (module.js:554:32)
at tryModuleLoad (module.js:497:12)
at Function.Module._load (module.js:489:3)
~/hello/
```

Answer 1

After creating a new Phoenix:
mix phx.new foo
It tells you what to do:
We are almost there! The following steps are missing:
$ cd foo
$ mix deps.get
$ cd assets && npm install && node node_modules/brunch/bin/brunch build
Then configure your database in config/dev.exs and run:
$ mix ecto.create # <----- you need this one
Start your Phoenix app with:
$ mix phx.server
You can also run your app inside IEx (Interactive Elixir) as:
$ iex -S mix phx.server