Setting up http-proxy in ubuntu and fedora

In fedora ,centos,fuduntu

http://www.centos.org/docs/5/html/yum/sn-yum-proxy-server.html

10. Using yum with a Proxy Server

By default, yum accesses network repositories with HTTP. All yum HTTP operations use HTTP/1.1, and are compatible with web proxy servers that support this standard. You may also access FTP repositories, and configure yum to use an FTP proxy server. The squid package provides a proxy service for both HTTP/1.1 and FTP connections.

	Modifying yum for Network Compatibility
	Refer to the man page for yum.conf for information on HTTP settings that may be modified for compatibility with nonstandard web proxy servers. Alternatively, configure yum to use an FTP proxy server, and access repositories that support FTP. The Fedora repositories support both HTTP and FTP.

10.1. Configuring Proxy Server Access

To enable all yum operations to use a proxy server, specify the proxy server details in /etc/yum.conf. The proxy setting must specify the proxy server as a complete URL, including the TCP port number. If your proxy server requires a username and password, specify these by adding proxy_username and proxy_password settings.
The settings below enable yum to use the proxy server mycache.mydomain.com, connecting to port 3128, with the username yum-user and the password qwerty.

# The proxy server - proxy server:port number
proxy=http://mycache.mydomain.com:3128
# The account details for yum connections
proxy_username=yum-user
proxy_password=qwerty

Example 3. Configuration File Settings for Using A Proxy Server

10.2. Configuring Proxy Server Access for a Single User

To enable proxy access for a specific user, add the lines in the example box below to the user's shell profile. For the default bash shell, the profile is the file ~/.bash_profile. The settings below enable yum to use the proxy server mycache.mydomain.com, connecting to port 3128.

# The Web proxy server used by this account
http_proxy="http://mycache.mydomain.com:3128"
export http_proxy

Example 4. Profile Settings for Using a Proxy Server

If the proxy server requires a username and password, add these to the URL. To include the username yum-user and the password qwerty, add these settings:

# The Web proxy server, with the username and password for this account
http_proxy="http://yum-user:qwerty@mycache.mydomain.com:3128"
export http_proxy

Example 5. Profile Settings for a Secured Proxy Server

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In case of UBUNTU  

https://help.ubuntu.com/community/AptGet/Howto

Setting up apt-get to use a http-proxy

These are three methods of using apt-get with a http-proxy.

Temporary proxy session

This is a temporary method that you can manually use each time you want to use apt-get through a http-proxy. This method is useful if you only want to temporarily use a http-proxy.

Enter this line in the terminal prior to using apt-get (substitute your details for yourproxyaddress and proxyport).

export http_proxy=http://yourproxyaddress:proxyport

If you normally use sudo to run apt-get you will need to login as root first for this to work unless you also add some explicit environment settings to /etc/sudoers, e.g.

Defaults env_keep = "http_proxy https_proxy ftp_proxy"

APT configuration file method

This method uses the apt.conf file which is found in your /etc/apt/ directory. This method is useful if you only want apt-get (and not other applications) to use a http-proxy permanently.

On some installations there will be no apt-conf file set up. This procedure will either edit an existing apt-conf file or create a new apt-conf file.

gksudo gedit /etc/apt/apt.conf

Add this line to your /etc/apt/apt.conf file (substitute your details for yourproxyaddress and proxyport).

Acquire::http::Proxy "http://yourproxyaddress:proxyport";

Save the apt.conf file.

BASH rc method

This method adds a two lines to your .bashrc file in your $HOME directory. This method is useful if you would like apt-get and other applications for instance wget, to use a http-proxy.

gedit ~/.bashrc

Add these lines to the bottom of your ~/.bashrc file (substitute your details for yourproxyaddress and proxyport)

http_proxy=http://yourproxyaddress:proxyport
export http_proxy

Save the file. Close your terminal window and then open another terminal window or source the ~/.bashrc file:

source ~/.bashrc

Test your proxy with sudo apt-get update and whatever networking tool you desire. You can use firestarter or conky to see active connections.

If you make a mistake and go back to edit the file again, you can close the terminal and reopen it or you can source ~/.bashrc as shown above.

source ~/.bashrc

How to login a proxy user

If you need to login to the Proxy server this can be achieved in most cases by using the following layout in specifying the proxy address in http-proxy. (substitute your details for username, password, yourproxyaddress and proxyport)

http_proxy=http://username:password@yourproxyaddress:proxyport

ref

http://www.ubuntugeek.com/how-to-configure-ubuntu-desktop-to-use-your-proxy-server.html

http://support.citrix.com/article/CTX132001