Immutable WindowsFrom pets to cattle

About me

Jorrit SalverdaTechnical architect at Travix

I automate…

● builds● deployments● infrastructure

Where we’re coming from...

Benefits of immutable infra

● “Config management” from scratch● No config drift● Forces automation● Spend less time fixing machines

Bonus

● Fast recovery after disaster● Audit trail

Goals

● Scripted vm images● New vms for every deploy● Zero downtime deployments● Make devs autonomous● Auto-scale

Bonus

● Auto-created certificates● Set dns records

Taking our servers from pets...

http://media0.giphy.com/media/abZ5exGrse0W4/giphy.gif

...to cattle

http://www.myspotlightmagazines.com/wp-content/uploads/2015/01/shutterstock_131280110-beef.jpg

Dockerfile

FROM alpine:3.3

RUN apk --update add \ haproxy=1.6.2-r0 \ && rm /var/cache/apk/*

EXPOSE 80 443

COPY docker-entrypoint.sh /

ENTRYPOINT ["/docker-entrypoint.sh"]

Docker vs packer + boxstarter

Docker

● FROM● RUN● ENTRYPOINT / CMD● ENV● COPY

● VOLUME● EXPOSE

Packer + boxstarter

● Upstream pipeline dependency● Packerfile.ps1● Entrypoint.ps1● VM metadata● Download into vm during bake

● Still a lot of effort● Always port 80

Packerfile.ps1

# install .net framework 4.6.1cinst dotnet4.6.1 -version 4.6.01055.00

# install 7-zipcinst 7zip.commandline -version 15.12

# disable windows updatesDisableService "wuauserv"

Entrypoint.ps1

# get environment name from metadata$Environment = GetCustomMetadata("ENVIRONMENT_NAME")

# replace placeholders in config filesReplacePlaceholders

# start all applicationsStartApplications

Pipeline dependencies

Create infra from the deployment pipeline

Learnings

● Windows automation is hard● Pin versions of installed software● Some 3rd parties require static ips● Google’s http load balancer isn’t http 1.1 compliant● To avoid tunneling client-side certificates work well● Training is required

What’s next?

● Phased rollouts● Automated rollbacks● Improve monitoring● Speed speed speed● Migrate more to Kubernetes

Thanks

jsalverda@travix.com

● slideshare.net/JorritSalverda● github.com/Travix-International● travix.com/jobs/