A tour of

from the

Command Line

featuring:

ssh, git, and rhc

bit.ly/1mq7s5h

socuteurl.com/widdlepuppytail

presented by

ryan jarvinen / @ryanj

Open Source Evangelist

Red Hat

ryanj@redhat.com

Agenda

State of the Open Cloud
rhc
ssh
git
Release Management
Scaling

State of the Open Cloud

Has it been

Liberated?

The OS ✓
The Cloud ?
Infrastructure as a service ✓
Platform as a service ✓
Software as a service ×

cloud autopsy

OpenShift is…

OPEN SOURCE

hosting,

build,

and

auto-scaling

for applications

providing instant access to all of this, and more:

these technolgies are bundled / made available as

Cartridges

rhc cartridge list

On OpenShift, your application environment is securely incapsulated within a 'Gear', providing guaranteed access to system resources

using SELinux, and Cgroups

OpenShift provides a peaceful environment for Devs AND SysAdmins to work together in

Operations care about stability and performance
Developers just want environments without waiting
And neither one wants to have to fight the other to get their work done

rhc

rhc makes it easy for developers to talk to your OpenShift REST API

pre-requisites:

rubygems, git

sudo gem install rhc

rhc setup

Will automatically:

authenticate your OpenShift account
verify your local ssh key configuration
configure your host url identifier

Create an application

Start by provisioning your application environment and database in a single step:

rhc app create APP_NAME CARTRIDGE CART2 CART3

for a basic Nodejs and MongoDB application, run:

rhc app create scale12x nodejs-0.10 mongodb-2.2

<command-line output>

Application Options
-------------------
  Namespace:   shifter
  Cartridges:  nodejs-0.10, mongodb-2.2
  Gear Size:   default
  Scaling:     no

Creating application 'scale12x' ... done

Waiting for your DNS name to be available ... done

Downloading the application Git repository ...
Cloning into 'scale12x'...

Your application code is now in 'scale12x'

scale12x @ http://scale12x-shifter.rhcloud.com/ (uuid: 5175981a5973ca7a69000501)
-------------------------------------------------------------
  Created:         1:05 PM
  Gears:           1 (defaults to small)
  Git URL:        
ssh://5175981a5973ca7a69000501@scale12x-shifter.rhcloud.com/~/git/scale12x.git/
  SSH:             5175981a5973ca7a69000501@scale12x-shifter.rhcloud.com

  nodejs-0.10 (Node.js 0.10)
  ------------------------
    Gears: Located with mongodb-2.2

  mongodb-2.2 (MongoDB NoSQL Database 2.2)
  ----------------------------------------
    Gears:          Located with nodejs-0.10
    Connection URL:
mongodb://$OPENSHIFT_MONGODB_DB_HOST:$OPENSHIFT_MONGODB_DB_PORT/
    Database Name:  scale12x
    Password:       PTk4cCetTj2w
    Username:       admin

RESULT:
Application scale12x was created.

Success!

You now have a basic node.js and MongoDB skeleton application live on the Internet!

http://scale12x-shifter.rhcloud.com/

Your gear is now configured with:

it's own git repo
it's own web server
ssh access
logging
a database
publicly accessible hostnames, automatic DNS

Application details are always available via:

rhc app show scale12x

You can tail your remote logs with:

rhc tail scale12x

or, connect directly to your app via ssh:

rhc ssh scale12x

SSH

Environment Variables

Allow you to write code that will run anywhere

//provide a sensible default for local development
mongodb_connection_string = 'mongodb://127.0.0.1:27017/' + db_name;
//take advantage of openshift env vars when available:
if(process.env.OPENSHIFT_MONGODB_DB_URL){
  mongodb_connection_string = process.env.OPENSHIFT_MONGODB_DB_URL + db_name;
}

//same advice applies for your webserver's PORT and IP address
var port = process.env.PORT || process.env.OPENSHIFT_NODEJS_PORT || 3000
var ip   = process.env.OPENSHIFT_NODEJS_IP || '127.0.0.1'

Application passwords, keys, and secrets can be abstracted using the same technique:

rhc env set SECRET_KEY=0P3N_S0URC3

rhc env list

rhc env help

Team members can supply their own keys during app creation, for a single step clone+deploy:

rhc app create scale12x nodejs-0.10 mongodb-2.2 \
--from-code=http://github.com/USER/TEAM_REPO.git \
--env SECRET_KEY=0P3N_S0URC3

Team Collaboration

There are several ways to collaborate:

using github or bitbucket
using ssh keys
or, using OpenShift's new team collaboration tools

git

Deploying updates

A standard git development workflow can be used to rebuild and update your remote application:

Add your changes to a changeset
```
git add index.html
```
Mark the changeset as a Commit
```
git commit -m 'updating H1'
```
Push the Commit to OpenShift
```
git push
```

Adding cartridges to existing apps is easy:

rhc cartridge add jenkins-1

adds jenkins CI to your application's build cycle

Release Management

Release Tracking & Rollbacks

rhc deployment list

rhc deployment activate CHECKSUM

Want to deploy a different branch (not 'master')?

rhc app configure --deployment-branch MY_BRANCH

https://www.openshift.com/blogs/introduction-to-deployments-and-rollbacks-on-openshift

Tips for Local Development

Use port-forwarding to create a local connection to your remote database instance:

rhc port-forward scale12

Starting a local webserver is different in each language.
For nodejs, you can start a local server with:

npm install

npm start

https://www.openshift.com/blogs/set-up-local-access-to-openshift-hosted-services-with-port-forwarding

Scaling

Spinning up an auto-scaling Linux environment:

rhc app create scale12 -s nodejs-0.10 mongodb-2.2

just add "-s" to your app create command

Set a min and max scale

rhc cartridge scale nodejs-0.10 -a scale12 --min 2 --max 12

or, manually scale an application

rhc app scale-up

rhc app scale-down

From inside a hosted environment:

haproxy_ctld --up

haproxy_ctld --down

HAProxy on / off switches

haproxy_ctld_daemon start

haproxy_ctld_daemon stop

haproxy_ctld_daemon restart

generating load

For scalable applications, generate load from the command line to see automatic scaling in action:

while true ; do ab -n 1000 -c 50 https://scale12-shifter.rhcloud.com/ ; done

HAProxy Web UI

http://$YOUR_APP_DNS/haproxy-status/

HAProxy raw data

http://$YOUR_APP_DNS/haproxy-status/;csv

Questions?

Want to learn more?

Come hang out with us on IRC: #openshift on Freenode
Link to these slides: http://socuteurl.com/widdlepuppytail
Free hosting on OpenShift: OpenShift Online
OpenShift source code: OpenShift Origin
Red Hat Enterprise Support: OpenShift Enterprise

presented by:

ryan jarvinen / @ryanj