Continuous Delivery and Continuous Deployment

 From CI to Continuous Delivery deployment

What exactly is Continuous Delivery, Its attitude to make software safe and to go fast
Lets begin with basics, How much time does it take to deploy one line change or a small bug fix in to the production? Exactly, our goal should be to achieve this as fast as we can.

Why We Need Continuous Delivery?

• Yes, its Speed which is needed in current fast paced software industry.
• Stop waiting around on each other to provide go ahead and open the gate.
• Quality – It raises the overall quality of your application – No surprises.
• Capacity and Clarity – Get every team on one tool – Eliminate manual error

How are we going to do this…..

Key Areas:-

• Speed is essential because there is an opportunity and cost associated with not delivering Software
• Frequent Releases, How frequent is frequent? Why do developers need to wait after writing code?
• Every build can be potential release candidate.

Bottom Line

Remove Manual Work/Steps.
Move towards complete automation

Delivery Flow

Here is the Delivery Flow.

Ingredients:-

Configuration Management
continuous integration/ Automated Build
Automated Deployment
Automated Testing

Obviously no single team in a company alone can achieve CD without the help of other teams. It needs collaboration and team work to implement it, Lets take a look at what do we need from various teams

Dev Team

• Collaboration – Integration is no longer an event
• Check in regularly
• Make small frequent releases because Big Change -> Big risk –> Big effort and Small Change –> Small risk –> Small effort

QA team

• Should have complete automation or whatever max is possible. More manual testing leads to more delay.
• Keep the Build and Test Process Short
• Break the QA automation into small pieces so that they can run simultaneously and do the QA frequently.
• Publish the report

Environment

• Should have complete Environment to test everything.
• Flexible and scalable so that multiple env can be spawn any time and can be extended.
• Managed as prod or at least similar to prod

This increases Confidence in build’s production readiness reducing release risk.

Main blocker to achieve CD

1. manual work
2. Lengthy Process
3. ticket system
4. approval

Now, How do we deal with blockers

Do not add gates, add only checks. Adding gates to prevent issues from creeping into prod is not so smart. There are many more issues hiding, you just don’t know them

Approval!!! Why do we need CAB?

Dev Sign off
QA sign off
Ops and Dependency sign off
Infra sign off

Dev Sign off -> Use proper project mgmt tool to track everything that goes in to software with adequate workflow. Get everyone together at the beginning so that these will not be surprises at the last moment. Keep meeting across the team during entire development. This way you don’t need any approval since you have already taken care of all necessary elements during the entire development process.

QA Sign off -> Publish consolidated QA report with each and every build which should be visible to everyone. You should have proper definition of “Go Ahead” instead of just random checks, Nobody has to ask QA for a thumbs up for the go. • Minimum criteria for Q has to be set.

Ops, Dependency and Infra Sign off -> Include them at the beginning of the project. Have capacity and change planning during requirement gathering, This gives enough time for ops and infra to get ready for the release.

Role of SCM/ Release Mgmt

SCM/ Release Mgmt provide the workflow, tools and necessary filler to enable all teams to interact and automate their part.
The picture below shows How SCM and Release Management help each team.