How to install pg gem in rails
<p>I tried to install pg gem. But it produce the following error. Can anyone help me to solve this problem ?</p>

<pre><code>root@localhost:/home/rails/Project# gem install pg
Building native extensions.  This could take a while...
ERROR:  Error installing pg:
    ERROR: Failed to build gem native extension.

    current directory: /var/lib/gems/2.3.0/gems/pg-0.18.4/ext
/usr/bin/ruby2.3 -r ./siteconf20160908-9582-xu3pmx.rb extconf.rb
checking for pg_config... yes
Using config values from /usr/bin/pg_config
You need to install postgresql-server-dev-X.Y for building a server-side extension or libpq-dev for building a client-side application.
You need to install postgresql-server-dev-X.Y for building a server-side extension or libpq-dev for building a client-side application.
checking for libpq-fe.h... no
Can't find the 'libpq-fe.h header
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
    --with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
    --without-make-prog
    --srcdir=.
    --curdir
    --ruby=/usr/bin/$(RUBY_BASE_NAME)2.3
    --with-pg
    --without-pg
    --enable-windows-cross
    --disable-windows-cross
    --with-pg-config
    --without-pg-config
    --with-pg_config
    --without-pg_config
    --with-pg-dir
    --without-pg-dir
    --with-pg-include
    --without-pg-include=${pg-dir}/include
    --with-pg-lib
    --without-pg-lib=${pg-dir}/lib

To see why this extension failed to compile, please check the mkmf.log which can be found here:

  /var/lib/gems/2.3.0/extensions/x86-linux/2.3.0/pg-0.18.4/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /var/lib/gems/2.3.0/gems/pg-0.18.4 for inspection.
Results logged to /var/lib/gems/2.3.0/extensions/x86-linux/2.3.0/pg-0.18.4/gem_make.out
root@localhost:/home/rails/Project# 
</code></pre>