The document details the development of a microservices architecture emphasizing separation, scalability, and fault tolerance. It discusses technological choices, specifically using tools like Rancher for orchestration and JWT for authentication, while also addressing challenges such as inter-service communication and versioning. The experience includes lessons learned during the process and recommendations for effectively managing and integrating multiple services.

1. How we built microservices
Ihor Harahatyi

2. Disclaimer
This is a story about how we built project
Yes, it can be done better
Yes, we broke some rules

3. We google it

4. 12 factor apps
(https://12factor.net/)
Codebase, Dependencies, Con g, Backing services,
Build - release - run, Processes, Port binding,
Concurrency, Disposability, Dev/prod parity, Logs,
Admin processes

5. Monolith <--> Microservices

6. Why we use them?
Separate development of each one
Scale them separately
Fault tolerancy
Use technology we want for each one
Small services with clean code

7. Rancher
(https://rancher.com/)

8. Rancher-compose
#rancher-compose.yml
version: '2'
services:
mysql:
scale: 1
uwsgi:
scale: 2
health_check:
port: 9000
interval: 2000
unhealthy_threshold: 3
request_line: GET / HTTP/1.0
healthy_threshold: 2
response_timeout: 2000
upgrade_strategy:
start_first: true

9. JWT
(https://tools.ietf.org/html/rfc7519, https://jwt.io)
Smaller then json
Custom data (serialize user model)
Signature
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3O
DkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWV9.TJVA95OrM7
E2cBab30RMHrHDcEfxjoYZgeFONFh7HgQ

10. Local environment
:8000 - frontend
:8001 - auth
:8002 - ms1
:8003 - ms3
...

11. New local env
add api.local.com -> 127.0.0.1 to /etc/hosts
map api.local.com/v1/ms/ to right docker
container
????
PROFIT!

12. Kong
(https://getkong.org/)

13. Docker tags
(https://github.com/ogir-ok/kong-companion)
#docker-compose.yml
microservice:
build: .
volumes:
- .:/src/
labels:
kong.uris: /v1/ms/
kong.port: '8080'

14. Kong versioning plugin
I want to work on issue #123
I add tag v123 to all my call
My call is mapped to right backend service

15. Inter ms communtication

16. CherryPy
(http://cherrypy.org/)
class Blog(object):
def item(self, id):
return "Post {}".format(id)
def index(self, id):
return "Blog"
class Root(object):
def index(self):
return "hello world!"
blog = Blog

17. Inter MS client
# client.auth.register.post(email='foo@bar.com')
requests.post(
'api.local/v1/auth/register',
json={'email': 'foo@bar.com'},
headers={pass headers here}
)

18. Rest is not silver bullet
RPC
Queue
Soap
???

19. Structlog
(https://structlog.readthedocs.io/en/stable/)
logger.bind(tracking_code=UUID4)
logger.bind(microservice_name=ms_name)
...

20. User's data
No DB relations
No User model
request.user = jwt.decode()

21. Common code?
I'll fork boilerplate

22. Submodule?

23. Pypi
Build it in jenkins
Opensource it one day
At least I can unfreeze version

24. Complex update
I updated common library and prod is down
We changed account_id, update all servers

25. It's not my job
Each team says that issue is on other side

26. Bulk operations

27. Yes we have docs

28. When to use?
You have free time
You need many programming languages
You have parts that are good to reuse
You have many teams

29. Q & A