single.php

<?php get_header(); ?>

    <div class="container">

      <div class="row">
        <div class="col-md-9">

          <?php if (have_posts() ) : while ( have_posts() ) : the_post(); ?>

            <div class="page-header">

              <?php
                $thumbnail_id = get_post_thumbnail_id();
                $thumbnail_url = wp_get_attachment_image_src( $thumbnail_id, 'thumbnail-size', true );
                $thumbnail_meta = get_post_meta ( $thumbnail_id, '_wp_attachment_image_alt', true );
               ?>

              <p class="featured-image"><img src="<?php echo $thumbnail_url[0]; ?>" alt="<?php echo $thumbnail_meta; ?>"></p>
              <h1><?php the_title(); ?></h1>
              
              <p><em>
                By <?php the_author(); ?>
                on <?php the_time('l, F jS, Y'); ?>
                in <?php the_category( ', '); ?>
                <a href="<?php comments_link(); ?>"><?php comments_number(); ?> </a>
              </p></em>
            </div>

          <?php the_content(); ?>

          <hr>

          <?php comments_template(); ?>

          <?php endwhile; else: ?>

            <div class="page-header">
              <h1>Oh dammit!</h1>
            </div>

          <p>No content is available for this page</p>

          <?php endif; ?>
        </div>

        <?php get_sidebar( 'blog' ); ?>

       </div>


<?php get_footer(); ?>