Intro to SaltStack

The New Configuration Management System

Presented by Justin Carmony / @JustinCarmony

Slides split up into multiple sections.

Slides both vertical and horizontal.

Test Vertical Slide

About Presenter

Director of Development
@ Deseret Digital Media
President of Utah PHP Usergroup
8+ years of professional web development
Goofy dad

About This Presentation

Slides & code examples will be posted online
Feel free to ask on-topic questions
We'll have time for questions at the end
Feel free to talk and/or contact me
afterward the presentation

Our Goal

Understand Some Server Challenges Facing Teams
Basic introduction to Salt about what it does
Live demo on how it can help solve common problems
Get you excited to go try out & learn more about salt

Lets Start

With a Story

You're a Happy Developer

You're Part of a
Small Team of Devs

You Have a New Website

On a small cloud server

You Start Getting Lots of Users ...

... and you need to quickly scale.

You ask your boss to hire a sys admin.

"We don't have the budget!"

So your team decides to ask:

who can run operations?

... and you start deploying more servers ...

... and some more ...

... and maybe just a few more ...

Until it is a giant mess!

Scenario: John gets Fired

You have a dozen servers

He has SSH keys on half of them.

How are you going to ensure you've

revoked his access everywhere?

The Problem:

Ad-Hoc Server Management

The Cloud

Problem: It's Easy!

Doesn't Require a Sys Admin
Simple to deploy many servers
But complex to solve large scaling issues
Long-term management requires
fore-thought & planning

The Developer

Problem: Lack of Ops Experience

Can relatively easily setup a production environment
Typically doesn't know how to manage many servers long-term
Busy programming, last priority is "sysadmin stuff"

The Business

Problem: Lack of Money

Hard to justify a "Sys Admin"
when devs can do "okay" job.
Usually hit scaling problems
before profitability

The Solution:

Developers need to think like Ops

DevOps

We've been putting more dev into ops, but we need to put more ops into dev. Ops is a state of mind. Theo Schlossnagle
CEO, OmniTI

Need to Apply Best Practices

For Server Environments

Source Control for Configuration
Ensure Servers are Configured The Same
Automate Upgrades, Changes, & new Deployments

Introducing

Configuration Management

Programmatic Approach
for Configuring Servers

What Can Configuration
Management Do?

Manage Packages
Manage Services
Manage Configuration
Manage Files
Manage Users

Popular Tools

Puppet
Chef
CFEngine

So what is salt?

and how is it going

to help with my problems?

What Is Salt

SaltStack takes a new approach to infrastructure management by developing software that is easy enough to get running in minutes, scalable enough to manage tens of thousands of servers, and fast enough to communicate with them in seconds. SaltStack delivers a dynamic infrastructure communication bus used for orchestration, remote execution, configuration management and much more. About SaltStack, SaltStack.org

A Different Approach

Salt is a simple system that focuses on two things:

Scalable, Fast Communication (Flow)
Quickly get information / data from a server (State)

Salt Basics

Minions connect to Master via ZeroMQ
Minions authenticate with master via AES (pub/priv) keys
Master can send module commands to minions to execute
Execution is in parallel
Modules are just python modules

What does this give us?

Extremely Scalable (~10k Minions per Server)
Great Flexibility (just write a python module for new functionality)
Simple, Avoids Complexity
Great Building Blocks for Automation

Built On Top of Salt

Configuration Management
Remote Execution

New / Upcoming Functionality

VM / Cloud Management
Monitoring

100% Open Source

Everything is open source! Apache License
No "watered-down" community edition
8th Most Unique Contributors on GitHub in 2012
Extremely Open & Friendly Community

Who Uses Salt

Installing Salt

Its so easy even I can do it

Basic Salt Setup

Setting Up The Master

Install salt-master via Salt Bootstrap, Pip, Apt, Yum, Source, etc

Edit Configuration (i.e. /etc/salt/master)

File Roots

file_roots:
  base:
    - /srv/salt

Pillar Roots

pillar_roots:
  base:
    - /srv/pillar

Restart salt-master (i.e. /etc/init.d/salt-master restart)

Setting Up The Minions

Install salt-minion via Salt Bootstrap, Pip, Apt, Yum, Source, etc
Set FQDN on the server (OR set ID Manually in Config)

Edit Configuration (i.e. /etc/salt/minion)

Set Master Server

master: master.saltdemo.com

Pillar Roots

pillar_roots:
  base:
    - /srv/pillar

Restart Minion

View Minion Keys

On the salt master, list the current keys

user@salt-master:~$ sudo salt-key -L
Accepted Keys:
Unaccepted Keys:
web1.salt-demo.com
Rejected Keys:

Accept Minion Keys

Accept the key (view it before hand to make sure it's legit)

user@salt-master:~$ sudo salt-key -a web1.salt-demo.com
Accepted Keys:
web1.salt-demo.com
Unaccepted Keys:
Rejected Keys:

That's it! We're ready to rock & roll.

Remote Execution

"Do my biding, minions!"

Targeting Minions

Use "salt" command on master to communicate to minions

Example: Test Ping to All Minions

user@salt-master:~$ sudo salt '*' test.ping
web1.saltdemo.com:
    True

Targeting types of minions

salt 'db*' test.ping
salt -L web1.saltdemo.com,db2.saltdemo.com test.ping
salt -G 'os:Ubuntu' test.ping
salt -C 'G@os:Debian and web*' test.ping

Execute Command on Servers

Example: Restart Apache

user@master:~$ sudo salt 'web*' cmd.run "/etc/init.d/apache2 restart"

Execute Modules on Servers

Example: Restart Apache

user@salt-master:~$ sudo salt 'web*' apache.signal restart

Lots of Modules

Here are just some of them:

apache, apt, cron, disk, file, mount, mysql, network, puppet, service, solr, state, test, useradd, win_disk, win_service, win_useradd

Configuration Management

Keeping your servers configured the same

Overview

Define a State Tree
Assign Parts of State Tree to Servers
Minion will download it's state definition from the tree
Minion will compare its current state vs state tree
Minion will make changes to match state tree & report back

What is State?

Example using English:

State Tree: Apache is installed & running
Server Minion: Apache is not installed nor running

Top.sls File

Defines which servers have which parts of the state tree applied to them.

Example top.sls file:

base:
    '*':
        - core.tools
        - core.users
    'web1.saltdemo.com':
        - apache2
        - php5

Different Environments

base:
    '*':
        # Stuff for all servers
dev:
    '*':
        # stuff for dev stage
stage:
    '*':
        # stuff for stable stage
prod:
    '*':
        # stuff for prod stage

Tree Maps to Files

Base is your file_roots

apache2 => apache2/init.sls
core => core/init.sls
core.tools => core/tools.sls

Anatomy of a State Declaration

Example of a user definition

justin:                         ## ID
    user:                       ## Type
        - present               ## Function
        - shell: /bin/bash
        - home: /home/justin
        - password: $1$MG4PbsH9$.w68M3yd/kUmESwq3cRM91

Lets Install & Manage Apache2

apache2:
    pkg:
        - installed
    service:
        - running

/etc/apache2/apache2.conf:
    file:
        - managed
        - source: salt://files/etc/apache2/apache2.conf
        - watch_in:
            - service: apache2

Jinja Templates

apache:
  pkg.installed:
    {% if grains['os'] == 'RedHat' %}
    - name: httpd
    {% elif grains['os'] == 'Ubuntu' %}
    - name: apache2
    {% endif %}

Applying the High State

You just call the state.highstate function

salt '*' state.highstate

Random Tips for Using Salt

Common pitfalls while getting started with Salt

Debugging Salt

Run things in the foreground:

# Run master in foreground
/etc/init.d/salt-master stop
salt-master -L

# Run minion in foreground
/etc/init.d/salt-minion stop
salt-minion -L

Debugging Salt

Run things manualy from the minion

salt-call -l debug state.highstate

Other Tidbits

yaml chokes on tabs, make sure you use spaces
I use sublime text configured to always use spaces
Use 127.0.1.1 in hosts file to set FQDN
Test what is the FQDN with:

python -c 'import socket;print(socket.getfqdn());'

You've been introduced to Salt

Now What?

Checkout My Salt AWS Demo

https://github.com/JustinCarmonyDotCom/salt-demo

Uses Vagrant & AWS to setup a test 5 server environment.

Checkout Salt's Documentation & Tutorials

Salt has some very good docs (and getting better all the time).

Join the Super Friendly IRC Channel

irc.freenode.net #salt

TRY IT OUT!

Blog/tweet/discuss your experience

It's Open Source, Get Involved

Very Pull Request friendly

(They even have accepted PR's from me!)

Intro to SaltStack

The New Configuration Management System

About Presenter

About This Presentation

Our Goal

Lets Start

With a Story

You're a Happy Developer

You're Part of a Small Team of Devs

You Have a New Website

On a small cloud server

You Start Getting Lots of Users ...

... and you need to quickly scale.

You ask your boss to hire a sys admin.

"We don't have the budget!"

So your team decides to ask:

who can run operations?

... and you start deploying more servers ...

... and some more ...

... and maybe just a few more ...

Until it is a giant mess!

Scenario: John gets Fired

You have a dozen servers

He has SSH keys on half of them.

How are you going to ensure you've

revoked his access everywhere?

The Problem:

Ad-Hoc Server Management

The Cloud

The Developer

The Business

The Solution:

Developers need to think like Ops

DevOps

Need to Apply Best Practices

For Server Environments

Introducing

Configuration Management

Programmatic Approach for Configuring Servers

What Can Configuration Management Do?

Popular Tools

So what is salt?

and how is it going

to help with my problems?

What Is Salt

A Different Approach

Salt Basics

What does this give us?

Built On Top of Salt

New / Upcoming Functionality

100% Open Source

Who Uses Salt

Installing Salt

Its so easy even I can do it

Basic Salt Setup

Setting Up The Master

Setting Up The Minions

View Minion Keys

Accept Minion Keys

That's it! We're ready to rock & roll.

Remote Execution

"Do my biding, minions!"

Targeting Minions

Targeting types of minions

Execute Command on Servers

Execute Modules on Servers

Lots of Modules

Configuration Management

Keeping your servers configured the same

Overview

What is State?

Top.sls File

Different Environments

Tree Maps to Files

Anatomy of a State Declaration

Lets Install & Manage Apache2

Jinja Templates

Applying the High State

Random Tips for Using Salt

Common pitfalls while getting started with Salt

You're Part of a
Small Team of Devs

Programmatic Approach
for Configuring Servers

What Can Configuration
Management Do?