Description

Provide LWRPs for installing (or requiring) unix command-line executables, without needing to know or specify the OS package that provides it.

You can do this:

unix_bin "nslookup" do
  action :install
end

unix_bin "mysqldump" do
  action :install
end

unix_bin "mail" do
  action :require
end

Instead of:

# Having to specify a less discernable name.
package "bind-utils" do
  action :install
end

# Having to switch between platforms.
case node[:platform]
  when "ubuntu","debian"
    package "mysql-client" do
      action :install
    end
  when "centos"
    package "mysql" do
      action :install
    end
  end
end

# Having to directly invoke the shell.
extend ::Chef::Mixin::ShellOut
shell_out!("/usr/bin/which mail")

Only the name of the executable needs specified in the recipe, the package is detected automatically.

Benefits realized by this functionality include:

• Increased portability

An install action works in any OS this cookbook does, even if the required package is different.

• Increased readability

Clarity in what resource you need even if the executable is part of a larger package.

• Simplified cookbook prep

Ensure the command-line tools you need are in-place, and optionally try to install missing ones, without extensive testing and/or causing more obscure errors later in your recipe.

Platforms

In general compatibility is dependent on the underlying OS package manager.

Current

At present yum and apt are supported -- by extension most redhat and debian distros.

Future

Support is eventually planned for zypper and thereby OpenSUSE and SLED

Test-Kitchen

This package is test-kitchen enabled and automatically tested against centos and ubuntu.

Detection method

Testing whether or not an executable is available is consistent across each OS.

The executable is determined to be INSTALLED if it exists in one of the paths specified in the configuration node['unix_bin']['search_paths'], which defaults to: /usr/bin : /usr/sbin : /bin : /sbin.

It is determined to be AVAILALBE if it can be invoked from the system's shell PATH.

By default the :require action ensures that a given executable be AVAILABLE, but this can be changed.

PLEASE NOTE: For safety reasons, no attempt will be made to install an executable that is either AVAILABLE or INSTALLED. As such, if you :install an excutable that is installed in a search path, but not available via the shell PATH, an exception will be raised (unless in_shell_path is false).

LWRP Usage

Requiring an executable

An exception will be raised if the executable is not available, no attempt will be made to install it. This is the default action.

As an example, we want to ensure "ifconfig" is available.

unix_bin "ifconfig"

If you don't want to require the executable be available in the system's shell PATH, but are satisfied with it only being installed (in one of the configured paths), you can use:

unix_bin "ifconfig"
  action :require
  in_shell_path false
end

Installing an executable (if it is missing)

This also requires the executable in general, so a failure to install will lead to an exception.

Say we want to use the convert utility, which is actually part of ImageMagick

unix_bin "convert"
  action :install
end

On redhat platforms you can also request the matching development package be installed. (This generates a warning on debian.)

unix_bin "convert"
  action :install
  with_devel true
end

Which would install the packages:

• ImageMagic
• ImageMagic-devel

Bulk syntax

As a convenience you can also use the following helper definition:

unix_binaries do
  install [ "nslookup", "ncat", "wget" ]
  require [ "ifconfig" ]
end

It also accepts the in_shell_path and with_devel flags (which are applied uniformly). You can use this definition multiple times in a row if you need different options.

Recipes

The default recipe is not required to use the LWRPs, however adding it to your run_list will automatically install any executables listed in an array under node['unix_bin']['install']. By default this list is empty.

Attributes

• node['unix_bin']['search_paths'] - An array of paths to check (non-recursively) that an executable is already installed.
• node['unix_bin']['install'] - An array of executable names to automatically install, if the default recipe is run.

Resource addons

This cookbook also provides a helper for use with only_if and not_if clauses in Chef resources.

Example:

cookbook_file "/etc/skel/.vimrc" do
  source "vimrc"
  only_if unix_bin_available("vim")
end

Bugs / Docs / Updates

• http://code.binbab.org

Authors and License

• Author:: BinaryBabel OSS (projects@binarybabel.org)
• Copyright:: 2013 sha1(OWNER) = df334a7237f10846a0ca302bd323e35ee1463931
• License:: Apache License, Version 2.0

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.