Loop de redirecionamento do Apache na instalação do Drupal no subdiretório VHost apenas no URL raiz

Question

Atualmente, estou tendo um problema com a página inicial do nosso site de produção de uma instalação do Drupal que falha com "ERR_TOO_MANY_REDIRECTS".

Algumas informações básicas sobre nossa configuração: Em nosso servidor, temos diferentes VHosts configurados para executar diferentes aplicativos.

A ideia é que cada instalação seja atendida em um subdiretório do nome de domínio, como subdomínio.example.com/app1 e subdomínio.example.com/app2.

Ele está em execução há quase um ano e, de repente, apenas a página inicial da instalação do Drupal começa a fazer loops de redirecionamento (subdomain.example.com/app). O ambiente de teste é configurado exatamente da mesma maneira e não exibe esse comportamento. Além disso, outras páginas do aplicativo de produção são veiculadas sem problemas (subdomain.example.com/app/page).

A instalação está localizada no servidor em /var/www/app. Isso deve servir como raiz do documento para a instalação quando visitado em subdomain.example.com/app/.

O VHOST para a instalação problemática é assim:

<Directory "/var/www/app">
    #
    # Possible values for the Options directive are "None", "All",
    # or any combination of:
    #   Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews
    #
    # Note that "MultiViews" must be named *explicitly* --- "Options All"
    # doesn't give it to you.
    #
    # The Options directive is both complicated and important.  Please see
    # http://httpd.apache.org/docs/2.4/mod/core.html#options
    # for more information.
    #
    Options Indexes FollowSymLinks

    #
    # AllowOverride controls what directives may be placed in .htaccess files.
    # It can be "All", "None", or any combination of the keywords:
    #   Options FileInfo AuthConfig Limit
    #
    AllowOverride All
    Order allow,deny
    Allow from all
    #
    # Controls who can get stuff from this server.
    #
    Require all granted
    RewriteEngine on
    RewriteBase /
    Include /var/www/app/.htaccess
</Directory>
NameVirtualHost *:80
<VirtualHost *:80>
    ServerName subdomain.example.com
    ServerPath /app
DocumentRoot /var/www/app
</VirtualHost>
# Set the Alias for the CLP installation
Alias "/app/" "/var/www/app/"
Alias "/app" "/var/www/app"

Também tenho um arquivo .htaccess dentro de cada um dos VHOSTS para direcionar o redirecionamento:

#
# Apache/PHP/Drupal settings:
#

SetEnvIfNoCase X-Forwarded-Proto https HTTPS=on

# Protect files and directories from prying eyes.
<FilesMatch "\.(engine|inc|info|install|make|module|profile|test|po|sh|.*sql|theme|tpl(\.php)?|xtmpl)(~|\.sw[op]|\.bak|\.orig|\.save)?$|^(\..*|Entries.*|Repository|Root|Tag|Template|composer\.(json|lock))$|^#.*#$|\.php(~|\.sw[op]|\.bak|\.orig\.save)$">
  Order allow,deny
</FilesMatch>

# Don't show directory listings for URLs which map to a directory.
Options -Indexes

# Follow symbolic links in this directory.
Options +FollowSymLinks

# Make Drupal handle any 404 errors.
# Relative to the DocumentRoot defined in httpd.conf
ErrorDocument 404 /app/index.php

# Set the default handler.
# Relative to the DocumentRoot defined in httpd.conf
DirectoryIndex /app/index.php /app/index.html /app/index.htm

# Override PHP settings that cannot be changed at runtime. See
# sites/default/default.settings.php and drupal_environment_initialize() in
# includes/bootstrap.inc for settings that can be changed at runtime.

php_value upload_max_filesize 500M
php_value post_max_size 500M
php_value memory_limit 500M
# PHP 5, Apache 1 and 2.
<IfModule mod_php5>
    php_flag magic_quotes_gpc                 off
    php_flag magic_quotes_sybase              off
    php_flag register_globals                 off
    php_flag session.auto_start               off
    php_value mbstring.http_input             pass
    php_value mbstring.http_output            pass
    php_flag mbstring.encoding_translation    off
</IfModule>

# Requires mod_expires to be enabled.
<IfModule mod_expires.c>
    # Enable expirations.
    ExpiresActive On

    # Cache all files for 2 weeks after access (A).
    ExpiresDefault A1209600

    <FilesMatch \.php$>
        # Do not allow PHP scripts to be cached unless they explicitly send cache
        # headers themselves. Otherwise all scripts would have to overwrite the
        # headers set by mod_expires if they want another caching behavior. This may
        # fail if an error occurs early in the bootstrap process, and it may cause
        # problems if a non-Drupal PHP file is installed in a subdirectory.
ExpiresActive Off
    </FilesMatch>
</IfModule>

# Various rewrite rules.
<IfModule mod_rewrite.c>
    RewriteEngine on
    # Set "protossl" to "s" if we were accessed via https://.  This is used later
    # if you enable "www." stripping or enforcement, in order to ensure that
    # you don't bounce between http and https.
    RewriteRule ^ - [E=protossl]
    RewriteCond %{HTTPS} on
    RewriteRule ^ - [E=protossl:s]

    # Make sure Authorization HTTP header is available to PHP
    # even when running as CGI or FastCGI.
    RewriteRule ^ - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]

    # Block access to "hidden" directories whose names begin with a period. This
    # includes directories used by version control systems such as Subversion or
    # Git to store control files. Files whose names begin with a period, as well
    # as the control files used by CVS, are protected by the FilesMatch directive
    # above.
    #
    # NOTE: This only works when mod_rewrite is loaded. Without mod_rewrite, it is
    # not possible to block access to entire directories from .htaccess, because
    # <DirectoryMatch> is not allowed here.
    #
    # If you do not have mod_rewrite installed, you should remove these
    # directories from your webroot or otherwise protect them from being
    # downloaded.
    RewriteRule "/\.|^\.(?!well-known/)" - [F]

    # If your site can be accessed both with and without the 'www.' prefix, you
    # can use one of the following settings to redirect users to your preferred
    # URL, either WITH or WITHOUT the 'www.' prefix. Choose ONLY one option:
    #
    # To redirect all users to access the site WITH the 'www.' prefix,
    # (http://example.com/... will be redirected to http://www.example.com/...)
    # uncomment the following:
    # RewriteCond %{HTTP_HOST} .
    # RewriteCond %{HTTP_HOST} !^www\. [NC]
    # RewriteRule ^ http%{ENV:protossl}://www.%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
    #
    # To redirect all users to access the site WITHOUT the 'www.' prefix,
    # (http://www.example.com/... will be redirected to http://example.com/...)
    # uncomment the following:
    # RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
    # RewriteRule ^ http%{ENV:protossl}://%1%{REQUEST_URI} [L,R=301]

    # Modify the RewriteBase if you are using Drupal in a subdirectory or in a
    # VirtualDocumentRoot and the rewrite rules are not working properly.
    # For example if your site is at http://example.com/drupal uncomment and
    # modify the following line:
    RewriteBase /app/
    #
    # If your site is running in a VirtualDocumentRoot at http://example.com/,
    # uncomment the following line:
    #RewriteBase /

    # Pass all requests not referring directly to files in the filesystem to
    # index.php. Clean URLs are handled in drupal_environment_initialize().
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteCond %{REQUEST_URI} !=/favicon.ico
    RewriteRule ^ index.php [L]

    # Rules to correctly serve gzip compressed CSS and JS files.
    # Requires both mod_rewrite and mod_headers to be enabled.
<IfModule mod_headers.c>
# Serve gzip compressed CSS files if they exist and the client accepts gzip.
RewriteCond %{HTTP:Accept-encoding} gzip
RewriteCond %{REQUEST_FILENAME}\.gz -s
RewriteRule ^(.*)\.css $1\.css\.gz [QSA]

# Serve gzip compressed JS files if they exist and the client accepts gzip.
RewriteCond %{HTTP:Accept-encoding} gzip
RewriteCond %{REQUEST_FILENAME}\.gz -s
RewriteRule ^(.*)\.js $1\.js\.gz [QSA]

# Serve correct content types, and prevent mod_deflate double gzip.
RewriteRule \.css\.gz$ - [T=text/css,E=no-gzip:1]
RewriteRule \.js\.gz$ - [T=text/javascript,E=no-gzip:1]

<FilesMatch "(\.js\.gz|\.css\.gz)$">
  # Serve correct encoding type.
  Header set Content-Encoding gzip
  # Force proxies to cache gzipped & non-gzipped css/js files separately.
  Header append Vary Accept-Encoding
</FilesMatch>
</IfModule>
RedirectMatch ^(.*)/app/course-page/CP([0-9]*)$ $1/app/course-page/$2
RedirectMatch ^(.*)/app/ramping-site/RS([0-9]*)$ $1/app/ramping-site/$2
RedirectMatch ^(.*)/app/content/BCTID([0-9]*)$ $1/app/content/$2
</IfModule>

# Add headers to all responses.
<IfModule mod_headers.c>
  # Disable content sniffing, since it's an attack vector.
  Header always set X-Content-Type-Options nosniff
</IfModule>

Já estou há dois dias sem serviço e não consigo encontrar uma solução.

Answer 1

Obrigado a todos pela sua contribuição. Acabou sendo um arquivo corrompido na VM que eventualmente causou sua falha. Ainda não tenho certeza do que foi.

Se eu conseguir descobrir o que realmente foi corrompido, colocarei aqui para referência.

No entanto, antes de travar, o Apache (HTTPD) para de executar o PHP 7.0 no navegador. Ele executaria scripts PHP na CLI, mas mostraria apenas o texto PHP em navegadores da web. Algumas horas depois, o servidor travou.