Entropy Package Management in Gentoo
Entropy Package Manager is written by Fabio Erculliani from Sabayon GNU/Linux as an extension to Portage in order to install binary package same as in other binary-based distros. The package manager syncronises itself automatically with Portage once you installed entropy binary packages, but instead Portage must be syncronised with Entropy in order for Entropy to know what packages you have emerged. Fully written in python, it is a stable application with many binary-oriented features and options, including a complete set of repository creation and entropy server features fully based on Portage ebuild packaging. Henceforth, developers must ( there is no other way ) emerge packages in order to create entropy packages, the procedure will be detailed in this tutorial.
 Instructions of creating your own Entropy Repository
First of all, you must have package named entropy-server instaled. It contains a /etc/entropy/server.conf that itself contains the next, most important lines of the configuration:
community-mode = enable < if you wish to cope with more than 1 repository in one system community-mode = disable <if you want to have a self-sustainable dependency repository ...(descriptions) default-repository = yourreponame ...(descriptions)
#example: #=> repository = myserverrepo|My Server Repository|ftp://user:firstname.lastname@example.org/ ssh://username@host:~user/path:port just an example of repo mode
repository = yourreponame|My Server Repository|ftp://user:email@example.com/ ssh://username@host:~user/path:port
The rest of them you don't need necessarily to bother. Of course, as in the example, you need either a SSH server or FTP server with upload permissions obviously. The structure of the repository should look like this:
P.S.: I considered this step as being the most important one, since everybody firstly installs the package before reading the article/tutorial on how to use :)
 Installation and package management instructions
Start emerging the following packages:
emerge sys-apps/entropy equo entropy-server -vp
It should produce something like this: http://pastebin.com/cy7X38ia ( public and permanent pastebin ). Notes: these packages have been built on 5 minutes funtoo tar.gz unpacking and chrooting and after, a emerge --sync and a eselect profile set. You should have now a working equo, so run the command: equo --help. Should show up all the help commands:
blacknoxis / # equo --help usage: equo [-h] [--color] (...)
In this moment you should have a working repository and SSH/FTP server with /etc/entropy/server.conf pointed to it. Start learning the commands also.
If you look into /etc/entropy/repositories.conf.d/ there's the repositories location with all the entropy_* files. You can take that example in order to put your own repository for client use.
 Working with EIT
First things first, you must 'regenerate' the Entropy database system by running the command:
equo rescue generate
EIT is the tool that actually packages already emerged packages and introduces them into your remote repository. First initialize repo ( after configurind your /etc/entropy/server.conf ) with the command:
eit init reponame
And a demonstration of adding a package to a repo by using these three commands:
eit add packagename
All demo in: http://pastebin.com/k3PNpPdD ( public permanent pastebin )
 Useful and important Tips and Tricks
As foretold, Entropy does not recognize Portage installs unless you do a little step. There's a slight trick here on how to make Entropy keep your emerged package with your options. First, emerge a package, any package, then run the command:
equo rescue spmsync --ask
( Accept but be careful, it sometimes takes something that you do not want ) This command will make Entropy aware that you installed/compiled something with Portage, but Entropy will still try to upgrade it and return it to the generic entropy repository one. Therefor, you must change the entropy client.conf from file /etc/entropy/client.conf:
ignore-spm-downgrades = enable < keep this enabled
After this, equo update should do the trick and equo ugprade will not try to overwrite your portage emerged packages. Referential documentation in: http://wiki.sabayon.org/ on Equo / Entropy and short and old doc on EIT http://lxnay.wordpress.com/2011/10/18/eit-the-stupid-package-tracker-reinvented/
If you want to have a nice, eye catchy GUI installer for your entropy repository, just install Rigo with either equo or portage. If you want to test the concept further, use emerge to install app-admin/rigo and then, equo rescue spmsync --ask. Actually, it is mandatory after each emerge package, you should run equo rescue spmsync --ask in order to at least make Entropy aware of your Portage changes.