Micro services infrastructure with AWS and ansible

1. Micro services infrastructure
With Ansible and AWS
Bamdad Dashtban
@bamdad

2. ScienceDirect.com Story

3. Legacy code
● C++ monolithic legacy code.
● Not fast enough response time.
● Maintenance was hard and expensive.
● Development of new features was hard.
● Wasn’t Multi region.
● Not so exciting stack.

4. New stack
● Faster delivery of features using CD.
● Improve performance.
● Make it exciting stack to work with.
● Scalable for higher load.

5. Strangler Pattern
User
Router
Apps

6. Micro services
● Scalable
● Micro services in front of the current stack.
● Caching.
● Adding new features.
● Shape teams based on the MicroServices.

7. Cloud
● AWS
○ Phoenix Pattern (immutable servers)
○ DNS for semantic versioning
○ VPC networking ( public and private )
○ ELB
○ Autoscaling

8. Ansible
● Provisioning
● Deployment
Amazon EC2
Instance AMI

9. ● Automatic Trigger
● RPM build
● Yum update on 1 instance
Deployment Iteration 0

10. Deployment Iteration 1
● RPM build
● Manual Trigger
● Bake AMI with RPM
● New ASG with ELB
AMI

11. Deployment Iteration 2
● Automatic Trigger
● RPM pull with user-data
● New ASG with ELB
AMI
user-data
executable script

12. Deployment Iteration 3
● Automatic Trigger
● RPM pull with user-data
● reuse of the ELBs
AMI
user-data
executable script

13. Continuous Delivery
● Jenkins to GoCD.
● Pipelines instead of Tasks.
● Concept of Environments.
● Environment Specific Agents.
● Resource Specific Agents.

14. Problems
● Complexity
● Service Discovery.
● ELB resizing.
● CDN routing.
● Deployment Time.
● Ansible Changes.
● Cost.

15. Complexity
App
Request Request
Method Call
HTTP
Request

16. Service Discovery
V n-2
V n-1
V n
V n -1
V n
?
App 1 App 2

17. Service Discovery
● We are not currently using service discovery tools.
● Predictable DNS endpoints.
● Amazon Route53 Aliases instead of CNAMEs.
● Looking at other solutions like Consul, etcd, Mesos DNS

18. ELB resizing
ELB
App
ELB
App
ELB

19. CDN Routing
● Routing based on files on a network file system.
(Slow)
● Slow on making configuration changes to CDN.

20. Deployment Time
● Bake AMI (15-25 mins)
● Deploy (1-2 mins)
● Smoke Test (2-4 mins for DNS)
● Service Test (1 min)
● Switch (1 min)
● Get rid of old instances. (1 min)
(repeat [“Dev” “QA” “Perf” “Stage” “Prod”])

21. Ansible
● Started with ansible 1.7
● pulled some changes from 1.8
● Patched some modules
● Ansible splitted Modules to a separate repo.
● Our pull requests have not got accepted.

22. Question?

23. Thanks
● ThoughtWorks and Elsevier are both both hiring.
● Feel free to come and talk to us.
@bamdad