unix_bin cookbook

Cookbook for Opscode Chef.

http://community.opscode.com/cookbooks/unix_bin

Description

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

For supported platforms and operating systems, see below.

Example Usage

You want an executable whose package doesn't match its name

Ex. we want nslookup (which is really provided by bind-utils)

unix_bin "nslookup" do
  action :install
end

##--  instead of  --##

package "bind-utils" do
  action :install
end

The package name is different between operating systems

Ex. we want mysqldump (which can be in mysql or mysql-client depending)

unix_bin "mysqldump" do
  action :install
end

##--  instead of  --##

case node[:platform]
  when "ubuntu","debian"
    package "mysql-client" do
      action :install
    end
  when "centos"
    package "mysql" do
      action :install
    end
  end
end

You want the "mail" command and don't care where it comes from

The sendmail binary could come from postfix, sendmail, or exim. Demanding a specific package is an unnecessary headache if any of them meet your needs.

You can specify a default preference if the command is missing, or the first package offered will be selected automatically

# Install sendmail, only if no mail command already installed.

unix_bin "mail" do
  action :install
  package "sendmail"     # OPTIONAL, default preference
end


##--  instead of  --##


# Assuming sendmail, causing your recipe to fail on exim or postfix.

package "sendmail" do
  action :install
end

# Assuming the path is the same across all operating systems,
# and with more verbose code.

package "sendmail" do
  action :install
  not_if { ::File.exists?("/usr/sbin/sendmail") }
end

You want to require any "java", but not attempt to install it.

Since java can come from many sources, requiring a package is problematic. In this case your recipe will error out at runtime if java is not installed.

unix_bin "java" do
  action :require
end

##--  instead of  --##

extend ::Chef::Mixin::ShellOut
shell_out!("/usr/bin/which mail")

Your cookbook's user can solve the requirement by adding a Java recipe to the server's run_list, or by installing manually via the operating system.

Rationale and Benefits

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.

LWRP Documentation

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).

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 add-ons

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

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

Platforms

Compatibility is largely dependent on the underlying OS package manager.

Current Platforms

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

There are subtleties with every operating system however, we welcome bug reports.

Future Platforms

Support is already planned for zypper and thereby OpenSUSE and SLED.

Feel free to open a ticket (see below) to request any platforms that are missing.

Test-Kitchen

This package is test-kitchen enabled and automatically tested against:

• CentOS 5 and 6
• Ubuntu 10 and 12

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 AVAILABLE 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.

However, 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 the in_shell_path attribute is false).

Development and Maintenance

• Found a bug?
• Need some help?
• Have a suggestion?
• Want to contribute?

Please visit: code.binbab.org

Authors and License

• Author:: BinaryBabel OSS ([email protected])
• 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.