AFA Med's questions

I have a protected admin area that is only accessible for my IP. However, I am using a proxy that has a lot of IPs. It's not practical to whitelist all its list of IPs.

The proxy sends the HTTP_X_FORWARDED_FOR header that contains the real IP.

I can get that information in PHP with $_SERVER['HTTP_X_FORWARDED_FOR'].

My objective is to whitelist that IP contained in "HTTP_X_FORWARDED_FOR" if it equals my own IP.

Here’s the code I want to set in my Apache config file:

# The value is hardcoded and will be edited if my real IP is changed.
DEFINE myRealIp "XXX.XXX.XXX.XXX"

# That's what I am looking for.
DEFINE originIpFromProxy variable_method_to_get_that_value

<LocationMatch "/admin/">
    Order deny,allow
    Deny from all

    <If "'${originIpFromProxy}' == '${myRealIp}'">
        Allow from ${originIpFromProxy}
    </If>
</LocationMatch>

There's also a problem, the header HTTP_X_FORWARDED_FOR may contain many IPs separated with commas.

Sometimes, I need to make some changes to Centos like installing and testing some utilities or trying a complex tutorial to install an advanced program for which the outcome is unknown.

How can I revert back to the state before doing changes.

A practical case: I want to install PHP7 besides PHP5.6, there are many tutorials, I want to test each one and if I fail, I want at least to revert back to the previous state.

I have a Centos 7 server which has tens of domain names and IPs.

The IP addresses are pointing to my server.

Each domain name is pointing to its own IP via A record.

I want to configure my FQDN in order to install Postfix.

/etc/hostname contains myproject.localdomain

/etc/hosts contains:

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

Command hostname returns:

myproject.localdomain

hostname -f returns:

localhost

domainname returns (none)

Do I have to choose a real domain purchased and prepend to it the hostname like this:

ip    hotname.domainame    hostname

Could someone explain me the difference between these certificates in a simplified way? I read some articles but it sounds like they do the same job, namely encrypting many domains with one certificate.

I have many sites to configure, each domain targets a specific department, so my virtual host segments are practically the same, I already optimized with include directive, but I think there are other things to squeeze down.

<VirtualHost *:80>
    ServerName www.domain-department-1.com
    DocumentRoot /var/www/html/domain-department-1.com

    <Directory "/var/www/html/domain-department-1.com">
        Include  conf.d/folder-config.conf
    </Directory>
</VirtualHost>

<VirtualHost *:80>
    ServerName www.domain-department-2.com
    DocumentRoot /var/www/html/domain-department-2.com

    <Directory "/var/www/html/domain-department-2.com">
        Include  conf.d/folder-config.conf
    </Directory>
</VirtualHost>

I have an already optimized JPEG image in my server 32.07 kB (and in my local computer), 800px * 534px, if I request it via browser, it keeps the same width * height, but its size gets smaller 17,97 Ko and becomes pixelated.

I checked Apache configuration:

# LoadModule deflate_module modules/mod_deflate.so

Response Headers:

HTTP/1.1 200 OK
Date: Sat, 30 Jan 2016 11:31:50 GMT
Server: Apache
Last-Modified: Sat, 26 Dec 2015 11:56:02 GMT
ETag: "804c-527cbc1833880"
Accept-Ranges: bytes
Content-Length: 32844
Content-Type: image/jpeg
Connection: keep-alive

I am working on a LAMP environment installed on a VPS server. I sent a ticket to OVH to ask them if they are compressing images on a superior level, but still waiting for a response.

Are there other places to inpect instead of Apache ?

Another thing, I can bet it's not related to browser, because I got the same result in Firefox and Chrome.

My images whose names contain accented letters (é, à etc.) are not accessible via Apache (404 error).

I think it's not related to Apache. I checked the configuration file:

AddDefaultCharset UTF-8

When I connect via Putty, and run the command "ls -la" to list the images, the accented letters are replaced with "?" in the console.

Here's the relevant info that may help:

> echo $LANG
en_US.UTF-8
> cat /etc/environment
empty file
> locale
LANG=en_US.UTF-8
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=

I found some tutorials, but they are applicable to Centos 5/6.

PS: Renaming files is a possible solution, but not envisageable in my case.

I recently purchased a VPS from OVH with Centos 7 preinstalled. I want to make sure my hostname is correctly set.

According to some tutorials:

hostname returns the hostname
hostname -f returns the FQDN

After executing these commands, I got the same result: vpsxxxxxxxx.ovh.net I thought hostname and FQDN are different!

cat /etc/hosts

127.0.0.1 - localhost
IP - vpsxxxxxxxx.ovh.net - vpsxxxxxxxx

I am confused, I have linked a domain name that I have purchased separately to my VPS, I am also planning to add another domain name to run two sites in my VPS.

Is my hostname correct?
How can we call vpsxxxxxxxx.ovh.net? An external domain name, an internal domain, a hostname, a subdomain of ovh.net?
What about the two domains names that I have linked to the VPS? Do they need some configurations in /etc/hosts?

I have to fix these issues to enable postfix mail server.