Dotfiles

This is a dotfiles repository to store the configuration files for my (Arch) Linux system and other systems that I may be using. These files may be freely copied for use by anybody.

The configuration files are grouped in the form of logical packages. Each directory inside the Packages/ directory represents a single, logical package. Each package contains an InstallScript which defines where each file should be placed. To install any package, use the master dotfiles script. Each package usually also contains a small README file describing the contents of the package.

Dotfiles Manager

Dotfiles Manager is a way of managing all your dotfiles on a *nix system with ease. This project spawned from the simple idea of writing a couple of scripts to automate the task of "installing" the configuration files to the right locations on a new machine. It was later extended to use the concept of packages to provide a finer granularity on which configuration files are installed on a new system. Configuration files which should ideally all be installed together, are grouped together as a single package.

When trying to keep a set of configuration files in a separate repository, it is important that the repository be able to automatically track the changes to the file. We should not have to remember to copy the file to the repository first. Hence, the simplest way to accomplish this is to keep all the configuration files in a single location which is tracked under a version control system. From this location, the files are symlinked to the specific locations in the filesystem where the relevant programs expect to find them. In this project, we use Git as the version control system.

This project works by creating a symlink for the file from the Package in the repository to the location on the system where it needs to be. As a result, any changes to the configuration files, AFTER the package has been installed will automatically be reflected in the repository. Since this is a Git repository, one can look at the diffs of the changes and revert back to the original state if need be. Upon confirming the changes are good, they should be immediately committed to the repository.

A lot of the design decisions in this project are inspired from Arch Linux's pacman and the format of the PKGBUILD files for defining a package.

Packaging

A package is a collection of files which configure a particular aspect of the system. Hence, one can have a package for Vim, Bash, SSH, X, etc. To create a new package, simply create a new directory with the package name within the Packages/ directory and populate it with the files and directories that will need to be tracked within this framework. Then write an InstallScript file which contains the mappings for where each of the files in the packages should be installed on the target system.

InstallScripts

The concept of an InstallScript is based on ArchLinux's PKGBUILDs. An InstallScript is a valid Bash script which is executed to install a particular package. The script must implement the following variables:

• PACKAGE_NAME: This is the name of the package being installed. It must contain the same name as that of the directory in which it resides. This variable is used to track Package Dependencies currently, though it may be used for other things in the future.

The master dotfiles script will invoke the following functions in the specified order from the InstallScript. Only the install() function is mandatory, the others may not be defined if there is no requirement.

1. prepare(): Used to perform initialization tasks before a package is installed. This is includes installing dependencies, creating the directory structure, setting environment variables, etc.
2. install(): This function is always called by the script and must always be defined. It is used for the actual installation of the files in the system.
3. post_install(): Used to perform some post-installation tasks like setting the attributes of some file, or installing files not included in dotfiles.

Sometimes a package may be dependent on settings that are provided by another packages. For example, a package may require using aliases or functions provided by the Bash package. In such a case, it is useful to ensure that the required package is installed first, before the current package is installed. For this, the framework provides the depends function. Add the following line for each package that must be installed before the current package at the top of the prepare() function:

depends $REQUIRED_PKG_NAME

The concept of dependencies can also be used to create meta packages. A meta package is one that installs no files of its own but instead a collection of smaller packages in a single go. An example of such a meta package could be one that installs the configuration packages for offlineimap, msmtp and mutt to provide a functioning console based email client.

"Installing" a file is the act of creating a symlink from the file in the repository to the path on the system where the configuration file is expected to exist. For example, the bashrc file is generally expected to exist at ~/.bashrc, hence installing the file is equivalent to running the command $ ln -s $PWD/Packages/Bash/bashrc $HOME/.bashrc from the root of the repository. To make things easier, the package manager provides some helper functions that can be utilized for installing files and directories:

• install_file(): Expects 4 parameters
  1. File Name: This is the exact name of the file as it exists in the package
  2. Final Location: The location where this file should be symlinked. It accepts full paths, up to the final directory but not the filename, or you can use one of the given shortcut paths:
     • home: Store in $HOME after adding a dot (.) prefix to the filename
     • etc: Store in /etc
     • userconf: Store the file in the user's config directory. This is always ~/.config
     • systemd-user: Store in $HOME/.config/systemd/user/ as a systemd user session unit
     • bin: Store in /usr/local/bin
     • autostart: A X autostart file, store in $HOME/.config/autostart
  3. Sudo: Boolean value. Does the file need to be linked with root privileges?
  4. Link Type: What kind of a link should be made? This should always be true, which implies soft links. Only certain files, such as systemd units should be hard linked.
• install_private_file(): This function is similar to install_file() except that it expects the file being symlinked to exist in /media/truecrypt1/ instead of in the dotfiles package. This function is used to install files which contain sensitive information and hence are stored in a secure container instead of committing them to a public repository.
• install_directory(): This function is used to install a complete directory as a symlink.

Usage

The central entity in this project is the dotfiles script available in the root directory of the repository. The script assumes that the user actually knows what he/she is doing and as a result does not implement many sanity checks. However, with a little bit of common, using this script shouldn't pose any problems at all. One of the chief limitations of the script is that it must always be called from the root directory of the repository since it uses relative paths from there. Since I don't care much about this restriction, I've decided not to work on it. However, if someone submits a patch, I would not mind merging it.

Usage: ./dotfiles [Options]
List of valid options:
-S package  : Install dotfiles package "package"
-l          : List available packages
-h          : Print this help and exit
Remember, this script must only be invoked from the root dir of the repository

TODO

1. Before backing up a file, allow the user to immediately merge the two
2. When installing a package, test if it has already been installed
3. Do not re-install a dependency package if it has already been installed
4. Before installing a file, try to figure out if the ln command will succeed. The most common failure is creating hard links across devices.
5. Be smart and try to set the right sudo and linktype variables based on the filetype and path. E.g.: Files in /etc/ need sudo. Systemd units need to be hardlinked.
6. Rework the concept of private files into private sub-packages that are stored in a non-public version control.
7. Remove the requirement that ./dotfiles be called from the root of the repository only.

License

MIT

Authors

Darshit Shah [email protected]

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