.. _install:

Installation
============

The release page has `pre-compiled binaries for Mac OS X, Windows, Linux and FreeBSD <https://github.com/PostgREST/postgrest/releases/latest>`_ .
The Linux binary is a static executable that can be run on any Linux distribution.

You can also use your OS package manager.

.. tabs::

  .. group-tab:: Mac OSX

    You can install PostgREST from the `Homebrew official repo <https://formulae.brew.sh/formula/postgrest>`_.

    .. code:: bash

      brew install postgrest

  .. group-tab:: FreeBSD

    You can install PostgREST from the `official ports <https://www.freshports.org/www/hs-postgrest>`_.

    .. code:: bash

      pkg install hs-postgrest

  .. group-tab:: Linux

    .. tabs::

      .. tab:: Arch Linux

        You can install PostgREST from the `community repo <https://archlinux.org/packages/community/x86_64/postgrest>`_.

        .. code:: bash

          pacman -S postgrest

      .. tab:: Nix

        You can install PostgREST from nixpkgs.

        .. code:: bash

          nix-env -i haskellPackages.postgrest

  .. group-tab:: Windows

    You can install PostgREST using `Chocolatey <https://community.chocolatey.org/packages/postgrest>`_ or `Scoop <https://github.com/ScoopInstaller/Scoop>`_.

    .. code:: bash

      choco install postgrest
      scoop install postgrest

Running PostgREST
=================

If you downloaded PostgREST from the release page, first extract the compressed file to obtain the executable.

.. code-block:: bash

  # For UNIX platforms
  tar Jxf postgrest-[version]-[platform].tar.xz

  # On Windows you should unzip the file

Now you can run PostgREST with the :code:`--help` flag to see usage instructions:

.. code-block:: bash

  # Running postgrest binary
  ./postgrest --help

  # Running postgrest installed from a package manager
  postgrest --help

  # You should see a usage help message

The PostgREST server reads a configuration file as its only argument:

.. code:: bash

  postgrest /path/to/postgrest.conf

  # You can also generate a sample config file with
  # postgrest -e > postgrest.conf
  # You'll need to edit this file and remove the usage parts for postgrest to read it

For a complete reference of the configuration file, see :ref:`configuration`.

.. note::

  If you see a dialog box like this on Windows, it may be that the :code:`pg_config` program is not in your system path.

  .. image:: _static/win-err-dialog.png

  It usually lives in :code:`C:\Program Files\PostgreSQL\<version>\bin`. See this `article <https://www.howtogeek.com/118594/how-to-edit-your-system-path-for-easy-command-line-access/>`_ about how to modify the system path.

  To test that the system path is set correctly, run ``pg_config`` from the command line. You should see it output a list of paths.

.. _pg-dependency:

PostgreSQL dependency
---------------------

To use PostgREST you will need an underlying database. We require PostgreSQL 9.6 or greater. You can use something like `Amazon RDS <https://aws.amazon.com/rds/>`_ but installing your own locally is cheaper and more convenient for development. You can also run PostgreSQL in a :ref:`docker container<pg-in-docker>`.

Docker
======

You can get the `official PostgREST Docker image <https://hub.docker.com/r/postgrest/postgrest>`_ with:

.. code-block:: bash

  docker pull postgrest/postgrest

To configure the container image, use :ref:`env_variables_config`.

There are two ways to run the PostgREST container: with an existing external database, or through docker-compose.

Containerized PostgREST with native PostgreSQL
----------------------------------------------

The first way to run PostgREST in Docker is to connect it to an existing native database on the host.

.. code-block:: bash

  # Run the server
  docker run --rm --net=host \
    -e PGRST_DB_URI="postgres://app_user:password@localhost/postgres" \
    postgrest/postgrest

The database connection string above is just an example. Adjust the role and password as necessary. You may need to edit PostgreSQL's :code:`pg_hba.conf` to grant the user local login access.

.. note::

  Docker on Mac does not support the :code:`--net=host` flag. Instead you'll need to create an IP address alias to the host. Requests for the IP address from inside the container are unable to resolve and fall back to resolution by the host.

  .. code-block:: bash

    sudo ifconfig lo0 10.0.0.10 alias

  You should then use 10.0.0.10 as the host in your database connection string. Also remember to include the IP address in the :code:`listen_address` within postgresql.conf. For instance:

  .. code-block:: bash

    listen_addresses = 'localhost,10.0.0.10'

  You might also need to add a new IPv4 local connection within pg_hba.conf. For instance:

  .. code-block:: bash

    host    all             all             10.0.0.10/32            trust

  The docker command will then look like this:

  .. code-block:: bash

    # Run the server
    docker run --rm -p 3000:3000 \
      -e PGRST_DB_URI="postgres://app_user:password@10.0.0.10/postgres" \
      postgrest/postgrest

.. _pg-in-docker:

Containerized PostgREST *and* db with docker-compose
----------------------------------------------------

To avoid having to install the database at all, you can run both it and the server in containers and link them together with docker-compose. Use this configuration:

.. code-block:: yaml

  # docker-compose.yml

  version: '3'
  services:
    server:
      image: postgrest/postgrest
      ports:
        - "3000:3000"
      environment:
        PGRST_DB_URI: postgres://app_user:password@db:5432/app_db
        PGRST_OPENAPI_SERVER_PROXY_URI: http://127.0.0.1:3000
      depends_on:
        - db
    db:
      image: postgres
      ports:
        - "5432:5432"
      environment:
        POSTGRES_DB: app_db
        POSTGRES_USER: app_user
        POSTGRES_PASSWORD: password
    # Uncomment this if you want to persist the data.
    # volumes:
    #   - "./pgdata:/var/lib/postgresql/data"

Go into the directory where you saved this file and run :code:`docker-compose up`. You will see the logs of both the database and PostgREST, and be able to access the latter on port 3000.

If you want to have a visual overview of your API in your browser you can add swagger-ui to your :code:`docker-compose.yml`:

.. code-block:: yaml

  swagger:
    image: swaggerapi/swagger-ui
    ports:
      - "8080:8080"
    expose:
      - "8080"
    environment:
      API_URL: http://localhost:3000/

With this you can see the swagger-ui in your browser on port 8080.

.. _build_source:

Building from Source
====================

When a pre-built binary does not exist for your system you can build the project from source.

.. note::

  We discourage building and using PostgREST on **Alpine Linux** because of a reported GHC memory leak on that platform.

You can build PostgREST from source with `Stack <https://github.com/commercialhaskell/stack>`_. It will install any necessary Haskell dependencies on your system.

* `Install Stack <https://docs.haskellstack.org/en/stable/#how-to-install-stack>`_ for your platform
* Install Library Dependencies

  =====================  =======================================
  Operating System       Dependencies
  =====================  =======================================
  Ubuntu/Debian          libpq-dev, libgmp-dev, zlib1g-dev
  CentOS/Fedora/Red Hat  postgresql-devel, zlib-devel, gmp-devel
  BSD                    postgresql12-client
  OS X                   libpq, gmp
  =====================  =======================================

* Build and install binary

  .. code-block:: bash

    git clone https://github.com/PostgREST/postgrest.git
    cd postgrest

    # adjust local-bin-path to taste
    stack build --install-ghc --copy-bins --local-bin-path /usr/local/bin

.. note::

   - If building fails and your system has less than 1GB of memory, try adding a swap file.
   - `--install-ghc` flag is only needed for the first build and can be omitted in the subsequent builds.

* Check that the server is installed: :code:`postgrest --help`.

.. _deploy_heroku:

Deploying to Heroku
===================

1.  Log into Heroku using the `Heroku CLI <https://devcenter.heroku.com/articles/heroku-cli>`_:

  .. code-block:: bash

    # If you have multiple Heroku accounts, use flag '--interactive' to switch between them
    heroku login --interactive


2.  Create a new Heroku app using the PostgREST buildpack:

  .. code-block:: bash

    mkdir ${YOUR_APP_NAME}
    cd ${YOUR_APP_NAME}
    git init .

    heroku apps:create ${YOUR_APP_NAME} --buildpack https://github.com/PostgREST/postgrest-heroku.git
    heroku git:remote -a ${YOUR_APP_NAME}

3.  Create a new Heroku PostgreSQL add-on attached to the app and keep notes of the assigned add-on name (e.g. :code:`postgresql-curly-58902`) referred later as ${HEROKU_PG_DB_NAME}

  .. code-block:: bash

    heroku addons:create heroku-postgresql:standard-0 -a ${YOUR_APP_NAME}
    # wait until the add-on is available
    heroku pg:wait -a ${YOUR_APP_NAME}

4.  Create the necessary user roles according to the 
    `PostgREST documentation <https://postgrest.org/en/stable/auth.html>`_:

  .. code-block:: bash

    heroku pg:credentials:create --name api_user -a ${YOUR_APP_NAME}
    # use the following command to ensure the new credential state is active before attaching it
    heroku pg:credentials -a ${YOUR_APP_NAME}

    heroku addons:attach ${HEROKU_PG_DB_NAME} --credential api_user -a ${YOUR_APP_NAME}

5.  Connect to the PostgreSQL database and create some sample data:

  .. code-block:: bash

    heroku psql -a ${YOUR_APP_NAME}

  .. code-block:: postgres

    # from the psql command prompt execute the following commands:
    create schema api;

    create table api.todos (
    id serial primary key,
    done boolean not null default false,
    task text not null,
    due timestamptz
    );

    insert into api.todos (task) values
    ('finish tutorial 0'), ('pat self on back');

    grant usage on schema api to api_user;
    grant select on api.todos to api_user;

6.  Create the :code:`Procfile`:

  .. code-block:: bash

    web: PGRST_SERVER_HOST=0.0.0.0 PGRST_SERVER_PORT=${PORT} PGRST_DB_URI=${PGRST_DB_URI:-${DATABASE_URL}} ./postgrest-${POSTGREST_VER}
  ..
    
  Set the following environment variables on Heroku:

  .. code-block:: bash

    heroku config:set POSTGREST_VER=10.0.0
    heroku config:set PGRST_DB_SCHEMA=api
    heroku config:set PGRST_DB_ANON_ROLE=api_user
  ..

  PGRST_DB_URI can be set if an external database is used or if it's different from the default Heroku DATABASE_URL. This latter is used if nothing is provided.  
  POSTGREST_VER is mandatory to select and build the required PostgREST release.

  See https://postgrest.org/en/stable/configuration.html#environment-variables for the full list of environment variables.

7.  Build and deploy your app:

  .. code-block:: bash

    git add Procfile
    git commit -m "PostgREST on Heroku"
    git push heroku master
  ..

  Your Heroku app should be live at :code:`${YOUR_APP_NAME}.herokuapp.com`

8.  Test your app

    From a terminal display the application logs:

  .. code-block:: bash

    heroku logs -t
  ..

  From a different terminal retrieve with curl the records previously created:

  .. code-block:: bash
 
    curl https://${YOUR_APP_NAME}.herokuapp.com/todos
  .. 

  and test that any attempt to modify the table via a read-only user is not allowed:

  .. code-block:: bash

    curl https://${YOUR_APP_NAME}.herokuapp.com/todos -X POST \
     -H "Content-Type: application/json" \
     -d '{"task": "do bad thing"}'