The Bash-Operated Reconciling Kludge
I still use Bork in the year 2021, so I forked it to fix it.
Bork puts the ‘sh’ back into IT. Bork Bork Bork.
Bork is a bash DSL for making declarative assertions about the state of a system.
Bork is written against Bash 3.2 and common unix utilities such as sed, awk and grep. It is designed to work on any UNIX-based system and maintain awareness of platform differences between BSD and GPL versions of unix utilities.
git clone https://github.com/borksh/bork /usr/local/src/bork
$PATH:
ln -sf /usr/local/src/bork/bin/bork /usr/local/bin/bork
brew install bork
npm install -g @borksh/bork
Starting with version 0.13.0, packages are available for a handful of operating systems on the GitHub releases page. These are generally from CI and built unsigned, but SHA-1 hashes are always available.
Bork can update itself as part of satisfying your config file. Your config file should look something like this to update via git:
ok github /usr/local/src/bork borksh/bork --branch=main
ok symlink /usr/local/bin/bork /usr/local/src/bork/bin/bork
(This example relies on you being able to write to /usr/local; if your Bork is
installed elsewhere you should replace the paths above.)
If you have Homebrew available to you, you can do this instead:
ok brew bork
You can also specify the --HEAD option on the assertion to install Bork’s
main branch via Homebrew:
ok brew bork --HEAD
This will always keep the latest commit installed. Note that the latest commit will contain unreleased code that might break, so take care when using it.
Using a package manager is the recommended way to install, as then you can
ensure you’re only installing released versions of Bork, and rely on it to
update Bork for you. If you prefer to use git, you can use bork version to
show the status of your local repo or installation. This command should be able
to tell you how you installed Bork (e.g. via git or Homebrew), and therefore how
you should go about updating it.
Running bork without arguments will output some help:
bork usage:
bork operation [config-file] [options]
where "operation" is one of:
- check: perform 'status' for a single command
example: bork check ok github skylarmacdonald/dotfiles
- compile: compile the config file to a self-contained script output to STDOUT
--conflicts=(y|yes|n|no) If given, sets an automatic answer for conflict resolution.
example: bork compile dotfiles.sh --conflicts=y > install.sh
- do: perform 'satisfy' for a single command
example: bork do ok github skylarmacdonald/dotfiles
- satisfy: satisfy the config file's conditions if possible
- status: determine if the config file's conditions are met
- inspect: output a Bork config file based on a type's current configuration
- types: list types and their usage information
- docgen: generates documentation under docs/_types for newly-added types
- version: get the currently installed version of bork
Let’s explore these in more depth:
At the heart of bork is making assertions in a declarative manner via
the ok and no functions. That is, you tell it what you want the system to
look like instead of how to make it look like that. An assertion takes a
type and a number of arguments. It invokes the type’s handler function with
an action such as status, install, or upgrade, which determines the
imperative commands needed to test the assertion or bring it up to date. There
are a number of included types in the types directory, and bork makes it easy
to create your own. The no function works as an opposite to ok – an ok
assertion will require the presence of something, and a no assertion will
require its absence.
Here’s a basic example:
ok brew # presence and updatedness of Homebrew
ok brew git # presence and updatedness of Homebrew git package
ok directory $HOME/code # presence of the ~/code directory
ok github $HOME/code/dotfiles skylarmacdonald/dotfiles # presence, drift of git repository in ~/code/dotfiles
cd $HOME
for file in $HOME/code/dotfiles/configs/.[!.]*
do # for each file in ~/code/dotfiles/configs,
ok symlink "$(basename $file)" $file # presense of a symlink to file in ~ with a leading dot
done
When run, bork will test each ok/no assertion and determine if it’s met or
not. If not, bork can go ahead and satisfy the assertion by installing,
upgrading, removing, or otherwise altering the configuration of the item to
match the assertion. It will then test the assertion again. Declarations are
idempotent – if the assertion is already met, bork will not do anything.
When you’re happy with your config script, you can compile it to a standalone script which does not require bork to run. The compiled script can be passed around via curl, scp or the like and run on completely new systems.
You can run bork types from the command line to get a list of the assertion
types and some basic information about their usage and options.
If adding features to Bork core, you can also use the command bork docgen to
generate GitHub Pages-compatible Markdown files based on how a type responds to
the desc action.
check: runs a given command. OK if returns 0, FAILED otherwise.
directory: asserts presence of a directory
file: asserts the presence, checksum, owner and permissions of a file
download: asserts the presence of a file compared to an http(s) url
symlink: assert presence and target of a symlink
git: asserts presence and state of a git repository
github: front-end for git type, uses github urls
gem: asserts the presence of a gem in the environment's ruby
npm: asserts the presence of a nodejs module in npm's global installation
pip: asserts presence of packages installed via pip
pip3: asserts presence of packages installed via pip3
pipsi: asserts presence of pipsi or packages installed via pipsi
apm: asserts the presence of an atom package
go-get: asserts the presence of a go package
brew: asserts presence of packages installed via Homebrew on macOS
brew-tap: asserts a Homebrew formula repository has been tapped; does NOT assert updatedness of a tap's formula. Use `ok brew` for that.
cask: asserts presence of apps installed via caskroom.io on macOS
defaults: asserts settings for macOS's 'defaults' system
mas: asserts a Mac app is installed and up-to-date from the App Store
via the 'mas' utility https://github.com/argon/mas
scutil: verifies macOS machine name with scutil
apt: asserts packages installed via apt-get on Debian or Ubuntu Linux
apk: asserts packages installed via apk (Alpine Linux)
yum: asserts packages installed via yum on CentOS or RedHat Linux
zypper: asserts packages installed via zypper (SUSE)
group: asserts presence of a unix group (Linux only, for now)
user: assert presence of a user on the system
iptables: asserts presence of iptables rule
shells: asserts presence of a shell in /etc/shells
Per the usage guide, bork has a few main modes of operation:
status: Reports on the status of the assertions in a config file.satisfy: Checks the status of assertions in a config file, satisfying them
where needed.compile: Compiles a config file to a standalone script.check: Performs a status report on a single assertion.do: Performs a satisfy operation on a single assertion.inspect: Output a Bork-compatible config file based on the current state of
the system.The status command will confirm that assertions are met or not, and output
their status. It will not take any action to satisfy those assertions. There are
a handful of statuses an assertion can return, and this since this mode is the
closest bork can do to a true ‘dry run’*, you can use it to test a script
against a pre-existing machine.
* Some types, such as git, need to modify local state by talking to the
network (such as performing git fetch), without modifying the things the
assertion aims to check.
The status command will give you output such as:
outdated: brew
ok: brew git
missing: brew zsh
ok: directory /Users/skylar/code
conflict (upgradable): github skylarmacdonald/dotfiles
local git repository has uncommitted changes
ok: symlink /Users/skylar/.gitignore /Users/skylar/code/dotfiles/configs/gitignore
conflict (clobber required): symlink /Users/skylar/.lein /Users/skylar/code/dotfiles/configs/lein
not a symlink: /Users/skylar/.lein
mismatch (upgradable): defaults com.apple.dock tilesize integer 36
expected type: integer
received type: float
expected value: 36
received value: 55
Each item reports its status like so:
ok: The assertion is met as best we can determine.no: The assertion is met, because the item is absent from the system.missing: The assertion is not met, and no trace of it ever being met was found.present: The assertion is not met, as something is present on the system
that shouldn’t be. It can be satisfied by removing the item.outdated: The assertion is met, but can be upgraded to a newer version.mismatch (upgradable): The assertion is not met as specified, something is
different. It can be satisfied easily. An explanation will be given.conflict (upgradable): The assertion is not met as specified. It can be
satisfied easily, but doing so may result in data loss.conflict (clobber required): The assertion is not met as specified. Bork
cannot currently satisfy this assertion. In the future, it will be able to,
but doing so may result in data loss.The check command will take a single assertion on the command line and perform
a status check as above for it.
The satisfy command is where the real magic happens. For every assertion in
the config file, bork will check its status as described in the status command
above, and if it is not ok or no it will attempt to make it ok or no,
typically via installing, upgrading or removing something – but sometimes
a conflict is detected which could lose data, such as a local git repository
having uncommitted changes. In that case, bork will warn you about the problem
and ask if you want to proceed. Sometimes conflicts are detected which bork does
not know how to resolve — it will warn you about the problem so you can fix it
yourself.
The do command will take a single assertion on the command line and perform a
satisfy operation on it as above.
The compile command will output to STDOUT a standalone shell script that does
not require bork to run. You may pass this around as with any file via curl or
scp or whatever you like and run it. Any sub-configs via include will be
included in the output, and any type that needs to include resources to do what
it does, such as the file type, will include their resources in the script as
base64 encoded data.
The inspect command will ask a type for a current inventory of how a system is
configured, and output to STDOUT a Bork-compatible config file to configure the
same state. For example, when used with the brew type, this will list all
formulae installed with Homebrew and output a config file to check for those
same formulae. Not all types will work with this command. Bork will exit
with code 1 if a type has not implemented inspect.
Writing new types is pretty straightforward, and there is a guide to writing
them in the docs/ directory. If you wish to use a type that is not in bork’s
types directory, you can let bork know about it with the register
declaration:
register etc/pgdb.sh
ok pgdb my_app_db
You may compose config files into greater operations with the include
directive with a path to a script relative to the current script’s directory.
# this is main.sh
include databases.sh
include etc/projects.sh
# this is etc/projects.sh
include project-one.sh
include project-two.sh
# these will be read from the etc/ directory
Bork has two types of callback: before and after functions. These are only used
when Bork is satisfying assertions (i.e. when running bork satisfy).
Until Bork starts processing an assertion made with ok or no, there’s no way
to know if anything will change. Therefore, Bork will look for and execute
functions with known names while it processes an assertion, before making the
change.
The functions Bork expects are named:
bork_will_change: Bork will make any change at all to the system, i.e., the
assertion is not satisfied and Bork will change it.bork_will_install: The assertion is completely missing, and Bork will
install something fresh to satisfy it.bork_will_upgrade: The assertion is partially satisfied, but needs upgrading
(e.g. an outdated package, a file with the wrong permissions). Bork will
change it in-place to satisfy it fully.bork_will_remove: The assertion specifies the removal of something that is
present on the system, and Bork will remove it to satisfy the assertion.Each of these will be unset by Bork after it has run them. You should only define these functions immediately before the assertion you wish to apply them to.
Bork will also call all of these functions with _any appended to the names
(e.g. bork_will_change_any) – these callbacks will not be unset, and will be
called every time it applies.
These are used as follows:
bork_will_install () {
echo "callback says hello world"
}
ok directory foo
Bork will then output the following if (and only if) the directory foo has
been newly created:
missing: directory foo
callback says hello world
verifying install: directory foo
* success
If the directory had already existed, the bork_will_install function would not
have been called. Bork would also not have called the function if it had
upgraded the state of the system, e.g. if the directory had existed but had the
incorrect permissions.
After Bork has made a change, you may call a provided function in your script to determine the outcome of the change. These are used as follows:
ok brew fish
if did_install; then
ok shells $(brew --prefix)/bin/fish
chsh -s $(brew --prefix)/bin/fish
fi
There are five functions to help you take further actions after a change:
did_install: did the previous assertion result in the item being installed
from scratch?did_upgrade: did the previous assertion result in the existing item being
upgraded?did_update: did the previous assertion result in either the item being
installed or upgraded?did_remove: did the previous assertion result in the existing item being
removed (e.g. deleted or uninstalled)?did_error: did attempting to install or upgrade the previous assertion
result in an error?Unlike with before callbacks, Bork will not call any functions after making a change. It is up to you to handle the logic however you wish. As with the before callbacks, you are strongly advised to use these functions immediately after the assertion you wish to check.
git checkout -b feature/my-new-featuregit commit -am 'Add some feature'git push origin feature/my-new-featurePrefer clarity of intent over brevity. Bash can be an obtuse language, but it doesn’t have to be. Many people have said bork has some of the clearest bash code they’ve ever seen, and that’s a standard to strive for.
Favor helper abstractions over arbitrary platform-specific checks. See
md5cmd, http, and
permission_cmd, and look at how they’re
used.
Types are independent, stateless, and atomic. Do not attempt to maintain a cache in a type file unless you’re talking to the network. An assertion is the whole of the assertion — don’t attempt to create a multi-stage assertion type that depends on maintaining state. Find a way to express the whole of the assertion in one go.
Leave Dependency Management to the user. Is a needed binary not installed for
a type? Return $STATUS_FAILED_PRECONDITION in your status check. Let the
user decide the best way to satisfy any dependencies.
Discuss on GitHub Discussions
0.14.0