Infrastructure Automation

Lean .*

Continuous Delivery

DevOps

Pets vs Cattle

Goals

Deployments should be boring with no surprises

Deployments should be fast with minimal (or no) downtime

Deployments should be idempotently repeatable

Infrastructure as code: One source of truth

Salt

Key Features

Remote Execution

Configuration Management

Parallel, Lightweight

Flexible

Technologies

Python

YAML + Jinja

ZeroMQ + MsgPack

Master / Masterless

Linux, xBSD, Solaris, Windows

Components and Terminology

Master & Minions

Grains

Modules & Functions

States / Formulas

Pillar

Returners & Salt Mine

Reactor

Salt Cloud

Basic Usage

Bootstrapping

> wget -O install_salt.sh https://bootstrap.saltstack.com
> sudo sh install_salt.sh <args>

Install Master/Minion, preseed keys, set minion id + master dns, (not) start daemons

By hand or automated via Vagrant plugin, Terraform, AWS bootstrap shell script, ...

Configuration Master

gitfs_provider: gitpython
gitfs_remotes:
  - https://github.com/saltstack-formulas/postgres-formula.git
fileserver_backend:
  - roots
  - git
file_roots:
  base:
    - /srv/salt/states
    - /srv/salt/formulas/sun-java-formula
pillar_roots:
  base:
    - /srv/salt/pillars
ext_pillar:
  - git: master http://stash/project/conf.git root=subdirectory
log_level: debug

Configuration Minion

master: salt-master.etecture.com
log_level: debug
mine_interval: 1
grains:
  roles:
    - webserver
  somekey:
    - somevalue
id: some-node-name

Commands & Targeting

> salt '*' cmd.run 'uname -a'
> salt 'minion*' disk.usage
> salt -G 'roles:webserver' pkg.install vim
> salt -C 'G@os:Ubuntu and G@roles:webserver' network.interfaces

States: Formulas ("State Files")

include:
  - some-other-state

app-running:
    service.running:
    - name: apache
    - enable: True
    - require:
      - file: apache-config

States: Ordering, Requisites

Requistes match both state ID and name property

Pillar

apache:
  user: www-data
  group: www-data
  modules:
    enabled:
      - rewrite
    disabled:
      - php5
  sites:
    test:
      enabled: true
      ServerName: test.com

File Templates

/etc/apache2/sites.available/somevhost.conf:
  file.managed:
    source: salt://vhost.tmpl
    context: ...
            

Jinja2 Syntax

Conditional, Loops, Variables, Imports, ...

Template model is defined with context property in state

Top File

Pillar data is only synched to matching minions, state files to all machines.

Formulas

Ready to use "formulas" or blueprints, for managing e.g. services, system configuration or more complex scenarios like autoscaling or docker orchestration

https://github.com/saltstack-formulas

Demo

https://github.com/der-tale/salt-introduction-demo

Demo

Conclusion

Salt

is very flexible and performant

can be combined very well with other tools

supports a good number of OSs and cloud providers

can be daunting at first, lots (and lots) of documentation

reasonably sized community, growing steadily

References

Vagrant Salt PluginSalt Getting Started GuideSalt Reference DocumentationSources of the demo from this talk