Trying to configure apache2 to load example.com/forum/ from a different document root, relative to the site root. Forums are installed somewhere else on the server.
Is there a directory alias command? I've found the alias configuration entry for apache, but had no luck.
Basically, I want example.com to have the same directory its always had, but example.com/forum/ to be hosted somewhere else, on the same server.
I tagged this question with mod_rewrite because I thought maybe it would be the key, here.
Cheers!
Alias is the right way, unless you have some subtlety that you didn't reveal in your question.
# http.conf
Alias /forum /usr/lib/bbs/ # or whatever
The job of Alias is to take the abstract URL coming into your system and map it to a concrete filesystem path. Once it has done that, the request is no longer an URL but a path. If there is no Alias or similar directive handling that URL, then it will get mapped to a conrete path via DocumentRoot.
If this isn't working, you have to debug it further. Are you getting errors when you access /forum? Look in the error log.
It all depends of what you want. You can "hardlink" with real path and it works (so you were right to think it could work with mod_rewrite).
Quick sample (that works on my production domains) to make an internal change (I add a subdirectory):
RewriteRule (.*) %{DOCUMENT_ROOT}/mysubfolder%{REQUEST_FILENAME} [QSA,L]
So you can easily do something like:
RewriteRule ^/forum/(.*) %{DOCUMENT_ROOT}/mysubfolder%{REQUEST_FILENAME} [QSA,L]
And my suggestion would be that if you plan to have more rewrite rules, keep everything homogeneous, i.e.: keep on using only rewrite rules, so use my suggestion above. This way you'll not get a bad mix of Alias, RewriteRules and so on. For nice and clean stuff: keep everything homogeneous.
Related
A simple Alias in Apache configuration not working -
Alias /url/path/some-deleted-page.html /url/path-modified/new-avatar-of-some-deleted-page.html
It gives "page not found".
However RewriteRule works as expected but it sends redirect status to browser. I want browser/user not to be aware of the redirect. Hence, I want to use Alias instead of RewriteRule. I want to confirm if mod_alias can be used to map individual URL.
I use ProxyPassMatch also which executes all html pages as PHP script. Also adding ProxyPass makes no diffrence.
ProxyPass /url/path/some-deleted-page.html !
Please help so that I can map individual URL (a bunch of them) with Alias instead of RewriteRule.
The purpose of mod_alias is to map requested URLs with a directory on the system running your httpd instance. It does not return anything to the browser (i.e. no redirection code, nothing). It is all done internally. Hence your client does not even know it is there.
Request: http://www.example.com/someurl/index.html
Configuration
[...]
DocumentRoot "/opt/apache/htdocs"
Alias "/someurl/" "/opt/other_path/someurl_files/"
[...]
In this scenario, users asking for any URL besides /someurl/ would receive files from /opt/apache/htdocs.
If a user asks for /someurl/, files from /opt/other_path/someurl_files/ will be used.
Still missing in this example is a <Directory> definition for securing the Alias directory.
You should read: https://httpd.apache.org/docs/2.4/mod/mod_alias.html
Alias will cover the case where you need to point a certain URL to a particular directory on the file system.
If you need to modify the filename (i.e. the client asks for file A, and you send back page B), you should use RewriteRule. And to hide the fact you changed the filename, use the [P] flag.
This directive allows you to use regex, yet still use a proxy mechanism. So your client does know what went on, as the address in his address bar does not change.
Just want to confirm something. From what I gather of how mod_rewrite works, Apache receives an URL and immediately mod_rewrite applies (non-<directory>) rules in httpd.conf, then per-directory mod-rewriting goes to work, then restarts the process with a new URL if any changes are made.
#JonLin's great answer to this question first says that when your per-directory rule specs an absolute replacement (ie. starting with a slash), it's assumed to be relative to the DocumentRoot which I get. But of relative replacements (no slash) Jon then says:
it's based on the directory that the rule is in. So if
RewriteRule ^foo$ bar.php [L]
is in the "root" and you go to http://example.com/foo, you get served http://example.com/bar.php. But if that rule is in the "subdir1" directory, and you go to http://example.com/subdir1/foo, you get served http://example.com/subdir1/bar.php. etc. This sometimes works and sometimes doesn't, as the documentation says, it's supposed to be required for relative paths, but most of the time it seems to work. Except when you are redirecting (using the R flag, or implicitly because you have http://host in your rule's target). That means this rule:
RewriteRule ^foo$ bar.php [L,R]
if it's in the "subdir2" directory, and you go to http://example.com/subdir2/foo, mod_rewrite will mistake the relative path as a file-path instead of a URL-path and because of the R flag, you'll end up getting redirected to something like: http://example.com/var/www/localhost/htdocs/subdir1.
As Jon explains in the last bit, when a redirect will occur and when there's no rewriteBase, a string intended as filepath gets appended to the site's base address to create a phony URL. But just to confirm, even in the former case Jon mentions, ie. not an actual redirect, the substituted string does get sent back to Apache's URL-reception code, restarting the whole process, correct? The diagram on this page of the spec seems to imply that until no rules make a change, the process keeps restarting. These non-redirect cases would seem to be the time when it WOULD make sense to tack the filepath right from the file system root to the htaccess directory onto the beginning of the substitution. But how does that get turned into a proper URL as expected by the URL-reception code - does http://localhost get prepended? I think that would make everything relative to the documentroot, not the actual file system root.
Thanks!
Been doing some more reading and think I've got this explained, for anyone who's interested.
Regarding my question about how a file system absolute path gets turned into a valid url for the internal redirect, I was thinking that the URI in an HTTP request contained "http://hostname", but this has been cut off ie. the URI is like /this/is/a/path. The host name is in a separate "Host" header field, and is no longer a vital piece of information by the time mod_rewrite is running, as Apache's initial Post Read Request phase has already noticed the GET request on the port and, if Name-Based Virtual Hosting is in use, interpreted things like the DocumentRoot from the Host header field, and finally called the URI Translation Phase where mod_rewrite executes. So any time mod_rewrite is running, there could be only one host name that got us here.
So to summarize, what I had called the "URL-reception" part of Apache always deals with /paths/like/this/without/hostname, not just after internal redirects. The spec does say that rewriteCond/rewriteRule match against such paths, but I figured the host name was there initially and got removed. So then all that's left is to ensure our rules are prepared for cases where they are running in an internal redirect spawned by an earlier runthrough of themselves, and not do something inadvertent when they see a file system absolute path caused by a replacement that didn't start with a slash. What a mouthful.
I'm having some trouble with Apache's mod_rewrite. One of the things I'm trying to get it to do is hide some of my implementation details, so that, for example, the user sees the URL http://www.mysite.com/login but Apache responds with the page at http://www.mysite.com/doc_root/login.php instead (preferably without showing the user that it's a PHP file or the directory structure). Here's what I have in my .htaccess file:
RewriteEngine on
RewriteCond %{HTTP_HOST} ^(www.)?mysite.com*
RewriteRule ^/(\w+) /doc_root/$1.php [L]
#Redirect http://www.mysite.com to the login page
RewriteRule ^/?$ https://www.mysite.com/doc_root/login.php
But when I go to http://www.mysite.com/login, I get a 404 error even though the page exists. I clearly don't have a great understanding of how the mod_rewrite conditionals and rules work, so can anyone please tell me what I'm doing wrong? Thanks.
Take doc_root out of all the stuff you have it in. That will give you the result you're asking for. However I'm not sure if it's desired or not. How are you going to force someone to login if they manually type http://www.mysite.com/index.php?
Also if you're trying to force all traffic to SSL it's better to use a second VirtualHost and Redirect instead of mod_rewrite. Those are all questions probably better suited for ServerFault
Unless your site has a bunch of different domain names, and you only want mysite.com to do the rewriting, you don't need the RewriteCond. (Potential problem. Apache likes to dick around with the domain name unless you set UseCanonicalName off. If the name isn't what it's expecting, the rewrite won't happen.)
In RewriteCond (and RewriteRule) patterns, . matches any character. Add a backslash before them. (Minor bug. Shouldn't cause rewrites to fail, but they would match stuff like "mysite-com" as well.)
mod_rewrite is actually a URL-to-filename filter. Though it is often used to rewrite URLs to other URLs, sometimes it will misbehave if what you're rewriting to is a URL and it can't tell. (Especially if what it's rewriting to would be an alias, or would otherwise not translate directly to a real filename.) If you add a [PT] flag onto your rule, though, it will consider the rewritten thing a URL and pass it along to the other filters (including the ones that turn URLs into filenames).
Do you really need "/doc_root"? The document root should already be set up in Apache using the DocumentRoot directive, and shouldn't need to be part of the URL unless you have multiple apps on the same domain (in which case it's the app root; the document root doesn't change).
UPDATE:
Another thing i just thought about: Rewrite rules work differently in .htaccess files. Apache likes to strip off the leading slash. So you will probably want to get rid of the first slash in your patterns, or at least make it optional (^/?login instead of ^/login).
^/?(\w+) will match /doc_root/login.php, and cause a rewrite to /doc_root/doc_root.php. You should probably have a $ at the end of your pattern.
I want to map a number of directories in a URL:
www.example.com/manual
www.example.com/login
to directories outside the web root.
My web root is
/www/htdocs/customername/site
the manual I want to redirect to is in
/www/customer/some_other_dir/manual
In mod_alias, this would be equal to
Alias /manual /www/customer/some_other_dir/manual
but as I have access only to .htaccess, I can't use Alias, so I have to use mod_rewrite.
What I have got right now after this question is the following:
RewriteRule ^manual(/(.*))?$ /www/htdocs/customername/manual/$2 [L]
this works in the sense that requests are recognized and redirected properly, but I get a 404 that looks like this (note the absolute path):
The requested URL /www/htdocs/customername/manual/resourcename.htm
was not found on this server.
However, I have checked with PHP: echo file_exists(...) and that file definitely exists.
why would this be? According to the mod_rewrite docs, this is possible, even in a .htaccess file. I understand that when doing mod_rewrite in .htaccess, there will be an automated prefix, but not to absolute paths, will it?
It shouldn't be a rights problem either: It's not in the web root, but within the FTP tree to which only one user, the main FTP account, has access.
I can change the web root in the control panel anytime, but I want this to work the way I described.
This is shared hosting, so I have no access to the error logs.
I just checked, this is not a wrongful 301 redirection, just an internal rewrite.
In .htaccess, you cannot rewrite to files outside the wwwroot.
You need to have a symbolic link within the webroot that points to the location of the manual.
Then in your .htaccess you need the line:
Options +SymLinksIfOwnerMatch
or maybe a little more blindly
Options +FollowSymlinks
Then you can
RewriteRule ^manual(/(.*))?$ /www/htdocs/customername/site/manual/$2 [L]
where manual under site is a link to /www/customer/some_other_dir/manual
You create the symlink on the command line with:
ln -s /www/htdocs/customername/site/manual /www/customer/some_other_dir/manual
But I imagine you're on shared hosting without shell access, so look into creating symbolic links within CPanel,Webmin, or whatever your admin interface is. There are php/cgi scripts that do it as well. Of course, you're still limited to the permissions that the host has given you. If they don't allow you to follow symlinks as a policy, you cannot override that within your .htaccess.
AFAIK mod_rewrite works at the 'protocol' level (meaning on the wire HTTP). So I suspect you are getting HTTP 302 with your directory path in the location.
So I'm afraid you might be stuck unless.. your hosting lets you follow symbolic links; so you can link to that location (assuming you have shell access or this is possible using FTP or your control panel) under your current document root.
Edit: It actually mentions URL-file phase hook in the docs so now I suspect the directory directives aren't allowing enough permissions.
This tells you what you need to know.
The requested URL /www/htdocs/customername/manual/resourcename.htm
was not found on this server.
It interprets RewriteRule ^manual(/(.*))?$ /www/htdocs/customername/manual/$2 [L] to mean rewrite example.com/manual/ as if it were example.com/www/htdocs/customername/manual/.
Try
RewriteRule ^manual(/(.*))?$ /customername/manual/$2 [L]
instead.
I'm starting up a new web-site, and I'm having difficulties enforcing my desired file/folder organization:
For argument's sake, let's say that my website will be hosted at:
http://mywebsite.com/
I'd like (have set up) Apache's Virtual Host to map http://mywebsite.com/ to the /fileserver/mywebsite_com/www folder.
The problem arises when I've decided that I'd like to put a few files (favicon.ico and robots.txt) into a folder that is ABOVE the /www that Apache is mounting the http://mywebsite.com/ into
robots.txt+favicon.ico go into => /fileserver/files/mywebsite_com/stuff
So, when people go to http://mywebsite.com/robots.txt, Apache would be serving them the file from /fileserver/mywebsite_com/stuff/robots.txt
I've tried to setup a redirection via mod_rewrite, but alas:
RewriteRule ^(robots\.txt|favicon\.ico)$ ../stuff/$1 [L]
did me no good, because basically I was telling apache to serve something that is above it's mounted root.
Is it somehow possible to achieve the desired functionality by setting up Apache's (2.2.9) Virtual Hosts differently, or defining a RewriteMap of some kind that would rewrite the URLs in question not into other URLs, but into system file paths instead?
If not, what would be the preffered course of action for the desired organization (if any)?
I know that I can access the before mentioned files via PHP and then stream them - say with readfile(..), but I'd like to have Apache do as much work as necessary - it's bound to be faster than doing I/O through PHP.
Thanks a lot, this has deprived me of hours of constructive work already. Not to mention poor Apache getting restarted every few minutes. Think of the poor Apache :)
It seems you are set to using a RewriteRule. However, I suggest you use an Alias:
Alias /robots.txt /fileserver/files/mywebsite_com/stuff/robots.txt
Additionally, you will have to tell Apache about the restrictions on that file. If you have more than one file treated this way, do it for the complete directory:
<Directory /fileserver/files/mywebsite_com/stuff>
Order allow,deny
Allow from all
</Directory>
Can you use symlinks?
ln -s /fileserver/files/mywebsite_com/stuff/robots.txt /fileserver/files/mywebsite_com/stuff/favicon.ico /fileserver/mywebsite_com/www/
(ln is like cp, but creates symlinks instead of copies with -s.)