Up and Running
The aim of this first guide is to get a Phoenix application up and running as quickly as possible.
Before we begin, please take a minute to read the Installation Guide. By installing any necessary dependencies beforehand, we’ll be able to get our application up and running smoothly.
At this point, we should have Elixir, Erlang, Hex, and the Phoenix archive installed. We should also have PostgreSQL and node.js installed to build a default application.
Ok, we’re ready to go!
We can run
mix phx.new from any directory in order to bootstrap our Phoenix application. Phoenix will accept either an absolute or relative path for the directory of our new project. Assuming that the name of our application is
hello, let’s run the following command:
$ mix phx.new hello
A note about webpack before we begin: Phoenix will use webpack for asset management by default. Webpacks’ dependencies are installed via the node package manager, not mix. Phoenix will prompt us to install them at the end of the
mix phx.newtask. If we say “no” at that point, and if we don’t install those dependencies later with
npm install, our application will raise errors when we try to start it, and our assets may not load properly. If we don’t want to use webpack at all, we can simply pass
A note about Ecto: Ecto allows our Phoenix application to communicate with a data store, such as PostgreSQL or MongoDB. If our application will not require this component we can skip this dependency by passing the
mix phx.new. This flag may also be combined with
--no-webpackto create a skeleton application.
To learn more about
mix phx.newyou can read the Mix Tasks Guide.
mix phx.new hello * creating hello/config/config.exs * creating hello/config/dev.exs * creating hello/config/prod.exs ... * creating hello/assets/static/images/phoenix.png * creating hello/assets/static/favicon.ico Fetch and install dependencies? [Yn]
Phoenix generates the directory structure and all the files we will need for our application. When it’s done, it will ask us if we want it to install our dependencies for us. Let’s say yes to that.
Fetch and install dependencies? [Yn] Y * running mix deps.get * running mix deps.compile * running cd assets && npm install && node node_modules/webpack/bin/webpack.js --mode development We are almost there! The following steps are missing: $ cd hello Then configure your database in config/dev.exs and run: $ mix ecto.create Start your Phoenix app with: $ mix phx.server You can also run your app inside IEx (Interactive Elixir) as: $ iex -S mix phx.server
Once our dependencies are installed, the task will prompt us to change into our project directory and start our application.
Phoenix assumes that our PostgreSQL database will have a
postgres user account with the correct permissions and a password of “postgres”. If that isn’t the case, please see the
Mix Tasks Guide to learn more about the
mix ecto.create task.
Ok, let’s give it a try. First, we’ll
cd into the
hello/ directory we’ve just created:
$ cd hello
Now we’ll create our database:
$ mix ecto.create Compiling 13 files (.ex) Generated hello app The database for Hello.Repo has been created
Note: if this is the first time you are running this command, Phoenix may also ask to install Rebar. Go ahead with the installation as Rebar is used to build Erlang packages.
And finally, we’ll start the Phoenix server:
$ mix phx.server [info] Running HelloWeb.Endpoint with cowboy 2.5.0 at http://localhost:4000 Webpack is watching the files… ...
If we choose not to have Phoenix install our dependencies when we generate a new application, the
mix phx.new task will prompt us to take the necessary steps when we do want to install them.
Fetch and install dependencies? [Yn] n We are almost there! The following steps are missing: $ cd hello $ mix deps.get $ cd assets && npm install && node node_modules/webpack/bin/webpack.js --mode development Then configure your database in config/dev.exs and run: $ mix ecto.create Start your Phoenix app with: $ mix phx.server You can also run your app inside IEx (Interactive Elixir) as: $ iex -S mix phx.server
By default Phoenix accepts requests on port 4000. If we point our favorite web browser at http://localhost:4000, we should see the Phoenix Framework welcome page.
If your screen looks like the image above, congratulations! You now have a working Phoenix application. In case you can’t see the page above, try accessing it via http://127.0.0.1:4000 and later make sure your OS has defined “localhost” as “127.0.0.1”.
Locally, our application is running in an
iex session. To stop it, we hit
ctrl-c twice, just as we would to stop
The next step is customizing our application just a bit to give us a sense of how a Phoenix app is put together.