.. _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).
Enabling TLS support
=================================
Enable TLS support in the sample by building the project with the
``overlay-tls.conf`` overlay file enabled, for example, using these commands:
.. zephyr-app-commands::
:zephyr-app: samples/net/sockets/http_get
:board: qemu_x86
:conf: "prj.conf overlay-tls.conf"
:goals: build
:compact:
An alternative way is to specify ``-DOVERLAY_CONFIG=overlay-tls.conf`` when
running cmake.
The certificate used by the sample can be found in the sample's ``src``
directory. The certificate was selected to enable access to the default website
configured in the sample (https://google.com). To access a different web page
over TLS, provide an appropriate certificate to authenticate to that web server.
Note, that TLS support in the sample depends on non-posix, TLS socket
functionality. Therefore, it is only possible to run TLS in this sample
on Zephyr.
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.
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