Linecook - A Chef Alternative

Linecook(A Chef Alternative)

Simon Chiang

Tuesday, April 26, 2011

Chef


ChefRuby


ChefRuby

Opscode


ChefRuby

Opscode“Systems Integration

Framework”


ChefRuby


Framework”

Open Source


ChefRuby


Framework”

Automated

Open Source


ChefRuby


Framework”

AutomatedScalable

Open Source


ChefRuby


Framework”

AutomatedScalable

Open SourceServer Provisioning


ChefRuby


Framework”

AutomatedScalable

Open Source

Community

Server Provisioning


ChefRuby


Framework”

AutomatedScalable

Hotness

Open Source

Community

Server Provisioning


An alternative toshell scripts


Not dismissing Chef when I say that. The advantages over manually writing setup/maintenance script are not to be underestimated. But for the most part things you do with Chef are things you would otherwise do with shell scripts, and there are problems.

Never a quickQuickstart

“Before installing Chef, you should take a moment to understand the various "flavors" of chef: client-server, chef-solo, and the Opscode Platform. Deciding which one is right for you will impact your installation process. You may also want to take a quick look at Chef's architecture to get an idea of what you're installing before you proceed.”

http://wiki.opscode.com/display/chef/Installation




Not a script,but sort of...

[lib/chef/provider/package/zypper.rb] @ 0.10.0.rc.0

def install_package(name, version) if version run_command( :command => "zypper -n --no-gpg-checks install -l #{name}=#{version}" )


https://github.com/opscode/chef/blob/0.10.0.rc.0/chef/lib/chef/provider/package/zypper.rb





Fixed options :(







https://github.com/opscode/chef/pull/27

Error for version=""

Fixed options :(






Many moving parts

http://wiki.opscode.com/display/chef/Architecture




Many moving parts

http://wiki.opscode.com/display/chef/Vagrant







Many moving parts



http://community.opscode.com/cookbooks








Alternative?


Shell Scripts!


LinecookA Shell Script Generator


Established Tools(bash, ssh, gems, VirtualBox)


Just use the existing systems. Some ‘advanced’ techniques but all established, known systemsPrior experience applies any learning will feed back into existing workflow

Start with a ScriptEnd with a Script


Able to bring an existing script to Linecook, then rework to make it more powerful or maintainable. You will work with scripts directly. Again all prior experience applies.

Pretty quickQuickstart

Make a server

Make a script

Run script on server



Make a server

Make a script


1



Make a server

Make a script


1

2



Make a server

Make a script


1

2

3


An ERB Trick...


How to Make a Server

VirtualBox

Install OS

SSH Key Exchange localhost



VirtualBox

Install OS

SSH Key Exchange

VirtualBox

localhost



VirtualBox

Install OS

SSH Key Exchange

VirtualBox

abox-ubuntu

localhost


abox-ubuntu

localhost

VirtualBox

Port Forwarding

Access VM by ssh to localhost

ssh -p 2220 linecook@localhost

VBoxManage modifyvm abox --natpf1 'abox-ssh,tcp,,

2220,,22'


abox-ubuntu

localhost

bbox-ubuntu

Lather, rinse

Repeat as needed



...VBoxManage modifyvm bbox

--natpf1 'bbox-ssh,tcp,,2221,,22'


Advantages

No special prerequisites on servers

Fast Access (fast enough for TDD)

Cmdline control

Multiple VMs

Snapshots


How to Run Scripts

cat > script.sh <<"DOC"echo "# $(whoami)@$(hostname): hello world!"DOCchmod +x script.sh

scp -P 2220 script.sh linecook@localhost:/tmp/script.shssh -p 2220 linecook@localhost -- /tmp/script.sh# linecook@abox-ubuntu: hello world!


Redundany

cat > script.sh <<"DOC"echo "# $(whoami)@$(hostname): hello world!"DOCchmod +x script.sh

scp -P 2220 script.sh linecook@localhost:/tmp/script.shssh -p 2220 linecook@localhost -- /tmp/script.sh# linecook@abox-ubuntu: hello world!


Use SSH Configmkdir configcat > config/ssh <<"DOC" Host aboxPort 2220User linecookHostname localhostDOC

scp -F config/ssh script.sh abox:/tmp/script.shssh -F config/ssh abox -- /tmp/script.sh# linecook@abox-ubuntu: hello world!


Multiple Hostscat > config/ssh <<"DOC"Host aboxPort 2220

Host bboxPort 2221

Host *User linecookHostname localhostDOC

scp -F config/ssh script.sh bbox:/tmp/script.shssh -F config/ssh bbox -- /tmp/script.sh# linecook@bbox-ubuntu: hello world!


Redundancycat > config/ssh <<"DOC"Host aboxPort 2220

Host bboxPort 2221

Host *User linecookHostname localhostDOC

scp -F config/ssh script.sh bbox:/tmp/script.shssh -F config/ssh bbox -- /tmp/script.sh# linecook@bbox-ubuntu: hello world!


Make a “Package”Run with Linecook

[config/ssh] Host aboxPort 2220 Host bboxPort 2221

Host *User linecookHostname localhost

[packages/abox/script.sh]echo "# $(whoami)@$(hostname): hello world!"

[packages/bbox/script.sh]echo "# $(whoami)@$(hostname): Hullo Wurld!"

linecook run --script script.sh --remote-dir /tmp abox bbox# linecook@abox-ubuntu: hello world!# linecook@bbox-ubuntu: Hullo Wurld!


Leverge Defaults

[config/ssh] Host aboxPort 2220 Host bboxPort 2221

Host *User linecookHostname localhost

[packages/abox/run]echo "# $(whoami)@$(hostname): hello world!"

[packages/bbox/run]echo "# $(whoami)@$(hostname): Hullo Wurld!"

linecook run# linecook@abox-ubuntu: hello world!# linecook@bbox-ubuntu: Hullo Wurld!

script: runremote dir: ~/linecookhosts: *


Easy Way To Test![packages/abox/run]echo "hello world" > /tmp/message.txt

[packages/abox/test]if [ $(cat /tmp/message.txt) == "hello world" ]then echo "# success"else echo "# fail"fi

linecook run --script test# faillinecook run linecook run --script test# success


Cmdline Dev Cycle

linecook startlinecook runlinecook run --script testlinecook ssh aboxlinecook snapshot modifiedlinecook stop

linecook start --snapshot modified...


Advantages

Standard use of SSH

One standard config file

Ordinary inputs (directories, scripts)

Multiple VMs

Flexible!


How to Make a Script


How to Make a Script(boring alert)


Start with a Script

[packages/abox/run]echo "# I will not manually configure my server"

linecook run# I will not manually configure my server


Convert to Recipe[packages/abox.yml]linecook: package: recipes: run: abox

[recipes/abox.rb]target <<"SCRIPT"echo "# I will not manually configure my server"SCRIPT

A package file


Convert to Recipe[packages/abox.yml]linecook: package: recipes: run: abox


A tempfile(packages/abox/run)


Simplify

[packages/abox.yml]{}

If default, nomanifest needed



Build and Run

[packages/abox.yml]{}


linecook buildlinecook run# I will not manually configure my server


Ok... that was boring.


Seems pointless, but here is where it gets cool.

Use Recipe asContext for ERB


ERB Compiles to Ruby

require 'erb'

compiler = ERB::Compiler.new("<>") compiler.put_cmd = "target<<"compiler.insert_cmd = "target<<"compiler.compile "got <%= obj %>"

# => "target<<\"got \"; target<<(( obj ).to_s)"


InstanceEval for Contextclass Recipe attr_accessor :target def initialize @target = "" end def obj "milk" endend

code = "target<<\"got \"; target<<(( obj ).to_s)"

recipe = Recipe.newrecipe.instance_eval(code) recipe.target

# => "got milk"


Make a Modulemodule Helper def get(obj) target<<"got "; target<<(( obj ).to_s) endend

recipe = Recipe.newrecipe.extend Helperrecipe.instance_eval %q{ get "milk" target << ", " get "cookies"}recipe.target

# => "got milk, got cookies"


Make a Modulemodule Helper def get(obj) target<<"got "; target<<(( obj ).to_s) endend

recipe = Recipe.newrecipe.extend Helperrecipe.instance_eval %q{ get "milk" target << ", " get "cookies"}recipe.target

# => "got milk, got cookies"

This is a recipe!


Helpers[helpers/example/echo.erb]Write an echo statement(str)--echo "<%= str %>"

[recipes/abox.rb]helpers "example"echo "# I will not manually configure my server"




[lib/example.rb]module Example # Write an echo ... def echo(str) target<< "echo ";... endend




require "example"extend Example


Capture (no write)[helpers/example/color.erb]Add color to a string(color, str) codes = Hash[*%W{red 0;31 white 1;37 blue 0;34}]--\033[<%= codes[color.to_s] %>m<%= str %>\033[0m

[recipes/abox.rb]helpers "example"msg = "# I will not manually configure my server"echo _color("blue", msg)




Prefix with underscoreString output used as input


Recipes are Ruby

[recipes/abox.rb]helpers "example"

msg = "# I will not manually configure my server"3.times do echo _color("blue", msg)end

linecook buildlinecook run# I will not manually configure my server# I will not manually configure my server# I will not manually configure my server


Advantages

Easily extensible DSL

Produces ordinary modules

Test as any other Ruby

Distribute as Gems (versions, bundler)

Reprocessing of output

Also, kind of cool...


Linebook(Standard Library for Linecook)


Logic + Pipelines[recipes/demo.rb]helpers 'linebook/shell'

unless_ _file?('/tmp/message') do cat.to('/tmp/message').heredoc do writeln 'hello world!' endend

cat('/tmp/message')


Logic + Pipelines[packages/demo/run]

if ! [ -f "/tmp/message" ]then cat > /tmp/message << HEREDOC_0hello world!HEREDOC_0fi

cat "/tmp/message"


Under Construction

Exit status checks, ‘stack trace’

Helpers for login/su

User and File Management

Server-side testing (assert_script)

Installs, config, deployments, etc.


No need to wait!


Linecook

Recipes Packages

Server

AttributesHelpers

FilesTemplates


Learn More

GitHub:

pinnacol/linecook.git

pinnacol/linebook.git

Me:

github.com/thinkerbot

@thinkerbot


Thanks Pinnacol!


Thanks Derailed!


Questions?


Linecook - A Chef Alternative

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