The document discusses writing portable PostgreSQL applications for the open cloud. It covers open cloud platforms like OpenStack that avoid lock-in, and platforms like OpenShift that provide portable PostgreSQL applications using cartridges and scaling hooks. Examples are given of simple applications like a TODO app using Flask, SQLAlchemy and PostgreSQL that can be easily deployed to OpenShift.

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PG OPEN CLOUD
Portable PG applications
http://bit.ly/1eddml6
http://ryanjarvinen.com/presentations/pg_open_cloud

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presented by
/ryan jarvinen @ryanj

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Open Platforms Engineer
at
Red Hat
ryanj@redhat.com

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AGENDA
1. Open Cloud Overview
2. Learn how to write for the Open Cloud

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the Cloud
"what is it made of?"

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The cloud is:
hot air?
a series of tubes?
mostly cat photos✓

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INFRASTRUCTURE
Communications: fiber, switches, wireless
Storage and Compute: chips, servers, disks, databases
…
DevOps (and friction)
…
Software as a Service: Dropbox, Gmail

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IAAS
Amazon EC2
RackSpace
Linode
BlueHost
* Many are VM / VPS-based services

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BUILDING WITH POSTGRES NORMALLY LOOKS LIKE:

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1. Install Apache with Mod_WSGI
2. Make sure we have all the Python extensions set so
Apache can see them
3. Configure firewall so that only http, https, and ssh are
available to outside world
4. Install Postgresql, and plugins
5. update PG_hba.conf, create db user, create db user
password, set up access privs, and a test account
6. Create DB, give user permissions to the DB
7. Set up a git repository and then figure out how to
structure and deploy
8. Now I can write code - hello world, then database
connection, then real app
9. Get it working with a public DNS
10. Now you are stuck maintaining the machine

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OR - if your Ops team offers pre-built VMs:
1. Fill out a mile high stack of request forms for a VM
from Ops and wait
2. Then realize it's not configured properly, submit ticket
and wait
3. Repeat same information, and wait
4. Your ops person moves to a different group, GOTO
Line 1....

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As a sysadmin:
1. We're busy keeping the site up, we'll need to provision
your VM later
2. Developers always want to try a new language or
datastore that they don't know how to install, let alone
manage
3. There is whole bunch of account creation and
lockdown for each VM. I'll need to give them Sudo or
they'll annoy me all the time
4. Each machine ends up with a wildly different config
5. Developers never give up the resources from their
VMs - spreadsheets and emails
6. If there is a security fix I need to go into each VM and
update it
7. I don't want to spend my time updating DNS tables

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PLATFORMS PROVIDE A PEACEFUL ENVIRONMENT FOR
DEVS AND SYSADMINS
Operations can ensure stability and performance
Developers can self-provision environments without
waiting
The discussion shifts toward establishing policies for
scaling

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PUBLIC / HOSTED PAAS
Heroku
EngineYard
Google App Engine
Amazon BeanStalk
* usually VM-based or proprietary application container
technologies

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the public cloud

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This all sounds great, but what about…
LOCK-IN?

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THE OPEN CLOUD

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IAAS
OpenStack
Eucalptus
CloudStack
Or, roll your own

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OPEN PAAS
OpenShift
Cloud Foundry
Built around Containers

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TRIUMPH OF THE OPEN CLOUD
When "Big Cloud" fails you, you can always decide to host
your own

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TINYTINYRSS
Reusable, Redeployable code - host it anywhere
https://github.com/openshift-quickstart/tiny_tiny_rss-
openshift-quickstart
rhc app create rss php-5 postgresql-9 cron-1.4 --from-code=https:/
/github.com/openshift-quickstart/tiny_tiny_rss-openshift-quickstar
t.git
https://rss-shifter.rhcloud.com/

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ADDING POSTGRES TO EXISTING APPLICATIONS:
done!
rhc cartridge add postgres-8.4
rhc cartridge add postgres-9.2
blog post: PostgreSQL 9.2 Comes to OpenShift

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Or, while connected over ssh:
rhc app show rss
env | grep DB
OPENSHIFT_POSTGRESQL_DB_PASSWORD=lXcFVx4hIZgR
OPENSHIFT_POSTGRESQL_DB_SOCKET=/var/lib/openshift/523672f7e0b8cd02
d70003bc/postgresql/socket/
OPENSHIFT_POSTGRESQL_DB_HOST=127.7.8.130
OPENSHIFT_POSTGRESQL_DB_PID=/var/lib/openshift/523672f7e0b8cd02d70
003bc/postgresql/pid/postgres.pid
OPENSHIFT_POSTGRESQL_DB_USERNAME=adminpahue6e
OPENSHIFT_POSTGRESQL_DB_URL=postgresql://adminpahue6e:lXcFVx4hIZgR
@127.7.8.130:5432
OPENSHIFT_POSTGRESQL_DB_PORT=5432
OPENSHIFT_POSTGRESQL_DB_LOG_DIR=/var/lib/openshift/523672f7e0b8cd0
2d70003bc/postgresql/log/

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TERMINOLOGY (RED HAT)
Broker – Management host, orchestration of Nodes
Node – Compute host containing Gears
Gear – Allocation of fixed memory, compute, and
storage resources for running applications
Cartridge – A technology/framework (Python, Ruby,
Javascript, PHP, Perl, Java/JEE, PG, MySQL, etc.) for
application service dependencies

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GEARS: SECURE AND EFFICIENT
,SELinux Cgroups

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AN OPEN CARTRIDGE FORMAT
cart developer's guide

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OPEN, AND WORKING IN THE UPSTREAM

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WRITING APPS FOR THE OPEN CLOUD

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TODO APP
(FLASK AND SQLALCHEMY)
https://github.com/shekhargulati/todo-flask-openshift-
quickstart
blog post: Build Your App on OpenShift Using Flask,
SQLAlchemy, and PostgreSQL 9.2

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rhc app create -s task python-2.7 postgresql-9.2 --from-code=https
://github.com/shekhargulati/todo-flask-openshift-quickstart.git
http://task-shifter.rhcloud.com/

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OPENSHIFT SCALING HOOKS
Setting a min and max scale from the command line
rhc cartridge-scale python-2.7 -a task --min 3 --max 5

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SCALING WEB UI

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HAPROXY SCALING HOOKS
Adding and removing instances / scaling up and down
HAProxy on / off switches
These hooks are available on the command line within
your gear, and via a REST API
haproxy_ctld --up
haproxy_ctld --down
haproxy_ctld_daemon start
haproxy_ctld_daemon stop
haproxy_ctld_daemon restart

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HAPROXY WEB UI
http://$YOUR_APP_DNS/haproxy-status/
HAPROXY RAW DATA
http://$YOUR_APP_DNS/haproxy-status/;csv

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LIVING IN THE CLOUDS
Code for America

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ADOPT A CAUSE
This app should be using PostGIS for spatial queries:
https://github.com/openshift-quickstart/adopt-a-
hydrant-openshift-quickstart
blog post: More Spatial in Your Database with PostGIS
2.0

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Persist configuration details,
while keeping your source clean:
rhc app create hydrant ruby-1.9 postgresql-8.4 --from=code=http://
github.com/ryanj/adopt-a-hydrant.git --env SECRET_TOKEN="YOUR_SECR
ET_TOKEN"
http://hydrant-shifter.rhcloud.com/

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ENVIRONMENT VARIABLES
Listing your custom env vars:
Setting a variable:
Help with configuration:
cd hydrant
rhc env list
rhc env set SECRET_TOKEN="a1fdacc3b1d14d6a92ed1219ed304d02529f5350
85262a90c39f072ef6de0ee9fe3a3d0194f02a2a8eb3"
rhc help env

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DEPENDENCIES
Automatic support for dependency resolution using
standard packaging, native to each language:
(ruby), (python), and (node.js)gems eggs npm modules

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ACTION HOOKS
1. enable postgis
2. bootstrap your db
https://github.com/ryanj/pg_parks/tree/master/.openshift/action_ho

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BANNERS?
http://citibike-shifter.rhcloud.com/
rhc env set CITIBIKE_NEARBY_STATIONS="268,257,258" -a citibikes

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DISTRIBUTED MULTI-CLOUD FEDERATED APPLICATIONS

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JOIN THE COMMUNITY
Meritocracy for our pull requests
Help with anything from core, quickstarts, and
cartridges, to small typo fixes in the command line tools
PEPs for major feature enhancements
Contribution Guidelines
Public Trello cards
Public Test plans
Public Bugzilla
Vote on Features

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Check out the upstream source:
Try our hosted solution (3 apps free):
Request an evaluation for:
OpenShift Origin
OpenShift Online
OpenShift Enterprise

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Thanks for following along! --ryanj
slides: http://bit.ly/1eddml6