zephyr/samples/net/sockets/http_get
Sebastian Bøe 55ee53ce91 cmake: Prepend 'cmake_minimum_required()' into 'app' build scripts
Prepend the text 'cmake_minimum_required(VERSION 3.8.2)' into the
application and test build scripts.

Modern versions of CMake will spam users with a deprecation warning
when the toplevel CMakeLists.txt does not specify a CMake
version. This is documented in bug #8355.

To resolve this we include a cmake_minimum_required() line into the
toplevel build scripts. Additionally, cmake_minimum_required is
invoked from within boilerplate.cmake. The highest version will be
enforced.

This patch allows us to afterwards change CMake policy CMP000 from OLD
to NEW which in turn finally rids us of the verbose warning.

The extra boilerplate is considered more acceptable than the verbosity
of the CMP0000 policy.

Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
2018-08-15 04:06:50 -07:00
..
src net: samples: Add CA certificates to http_get and big_http_download 2018-07-26 12:13:15 -04:00
CMakeLists.txt cmake: Prepend 'cmake_minimum_required()' into 'app' build scripts 2018-08-15 04:06:50 -07:00
Makefile.posix samples: net: sockets: Reinstate POSIX Makefiles. 2017-11-13 16:41:14 -05:00
prj_tls.conf net: config: Rename Kconfig options to correspond to library name 2018-08-13 18:42:31 -07:00
prj.conf net: config: Rename Kconfig options to correspond to library name 2018-08-13 18:42:31 -07:00
README.rst samples: net: Update compilation instructions for cmake 2017-11-10 11:36:33 -05:00
sample.yaml samples: exclude socket samples on esp32 2018-07-16 19:00:32 -04:00

.. _sockets-http-get:

Socket HTTP GET Example
#######################

Overview
********

The sockets/http_get sample application for Zephyr implements a simple
HTTP GET client using a BSD Sockets compatible API. The purpose of this
sample is to show how it's possible to develop a sockets application
portable to both POSIX and Zephyr. As such, it is kept minimal and
supports only IPv4.

The source code for this sample application can be found at:
:file:`samples/net/sockets/http_get`.

Requirements
************

- :ref:`networking_with_qemu`
- or, a board with hardware networking
- NAT/routing should be set up to allow connections to the Internet
- DNS server should be available on the host to resolve domain names

Building and Running
********************

Build the Zephyr version of the application like this:

.. zephyr-app-commands::
   :zephyr-app: samples/net/sockets/http_get
   :board: <board_to_use>
   :goals: build
   :compact:

``board_to_use`` defaults to ``qemu_x86``. In this case, you can run the
application in QEMU using ``make run``. If you used another BOARD, you
will need to consult its documentation for application deployment
instructions. You can read about Zephyr support for specific boards in
the documentation at :ref:`boards`.

After the sample starts, it issues HTTP GET request to "google.com:80"
and dumps the response. You can edit the source code to issue a request
to any other site on the Internet (or on the local network, in which
case no NAT/routing setup is needed).

Running application on POSIX Host
=================================

The same application source code can be built for a POSIX system, e.g.
Linux. (Note: if you look at the source, you will see that the code is
the same except the header files are different for Zephyr vs POSIX.)

To build for a host POSIX OS:

.. code-block:: console

    $ make -f Makefile.posix

To run:

.. code-block:: console

    $ ./http_get

As can be seen, the behavior of the application is the same as the Zephyr
version.