This document discusses reworking a monolithic architecture into a containerized Docker architecture. It begins by describing Docker and how it provides lightweight virtualization using containers. It then outlines the steps taken to rework an existing monolithic setup into a Docker container architecture by first creating data containers, then leaf service containers, and finally linked service containers. This provides benefits like improved configuration, isolation of services, and extensibility without downtime. The end result is 21 containers organized into sets for each environment (blessed, staging, external), following best practices of separating data from services. This allows the architecture to be treated as container-as-a-service (CaaS).

1. Docker
Architecture Rework Case Study

2. Daniel CHAFFIOL
Softeam Cadextan
(1999)
BNP-Paribas
Société Générale
Amundi Asset Management
HSBC

3. VonC
Stack Overflow
(2008)
Git - Hg – SVN - ClearCase
Golang - Docker
Eclipse - Jenkins

4. slideshare & Intranet

5. slideshare & Intranet

6. slideshare & Intranet

7. slideshare & Intranet

8. Project
From: Blessed Staging External
Company Outside
master master_ext
mastermaster_ext

9. What are the issues?
Example: Monolithic service => Isolation (processes) issue
Blessed /
Staging /
External /
Internal
NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCronData
SSHD

10. What are the issues?
Example: Monolithic service => Isolation (processes) issue
Blessed /
Staging /
External /
Internal
Apache
SSHD
NGiNX LDAP
Gpg2
Gitolite
Data MCron

11. What are the issues?
Example: Replicated Git repos hosting servers
Blessed Staging ExternalInternal
● Isolation (server)
● Configuration
● Reproducibility

12. Docker:
○ Why?
○ How?
○ Benefits?

13. Why?
Why “container”?

17. Project
To: NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCronData
SSHD

18. What is Docker
Lightweight virtualization

19. What is Docker
Lightweight virtualization OS distro (Host)
Linux distro (VM)
OS
Kernel
Hardware
Hypervisor (type 2)
Linux
Kernel
Hardware
Application
Virtual Machine
Lightweight virtualization

20. What is Docker
Lightweight virtualization OS distro (Host)
Linux distro (VM)
OS
Kernel
Hardware
Hypervisor (type 2)
Linux
Kernel
Hardware
Application
Virtual Machine
Linux distro (Host)
Files (Docker)
Linux
Kernel
Hardware
Docker Engine
[Application]
Docker

21. What is Docker?
Containers

22. What is Docker?
Containers Linux distro (Host)
Container
(user space)
Kernel
Space
Process
System calls

23. What is Docker?
Containers Linux distro (Host)
Container
(user space)
Kernel
Space
Process
System calls
Linux distro (Host)
Data Container
(for instance)
/home/git/repositories
Kernel
Space

24. What is Docker?
Images: docker build Linux distro (Host)
Dockerfile:
FROM ubuntu
Ubuntu

25. What is Docker?
Images: docker build Linux distro (Host)
Dockerfile:
FROM ubuntu
Ubuntu
NGiNXRUN
add-apt-repository -y ppa:nginx/stable &&
apt-get update &&
apt-get install -y nginx

26. What is Docker?
Images: docker build Linux distro (Host)
Dockerfile:
FROM ubuntu
Ubuntu
NGiNXRUN
add-apt-repository -y ppa:nginx/stable &&
apt-get update &&
apt-get install -y nginx
Config file
COPY env.conf /home/git/
RUN ln -fs /home/git/env.conf /etc/nginx/nginx.conf
EXPOSE 80
EXPOSE 443
ENTRYPOINT ["/bin/sh", "-c"]
CMD ["nginx"]

27. StatusCommands
What is Docker?
Layered file system: Linux distro (Host)
Config file
NGiNX
Ubuntu
Ubuntu
NGiNX
Config files

28. StatusCommands
What is Docker?
Layered file system: Linux distro (Host)
Config file
NGiNX
Ubuntu
Ubuntu
NGiNX
Config files
docker create Created

29. StatusCommands
What is Docker?
Layered file system: Linux distro (Host)
Config file
NGiNX
Ubuntu
Ubuntu
NGiNX
Config files
files updates
docker start/run Up
docker create Created

30. StatusCommands
What is Docker?
Layered file system: Linux distro (Host)
Config file
NGiNX
Ubuntu
Ubuntu
NGiNX
Config files
files updates
docker start/run Up
docker create Created
docker stop/kill Exited

31. StatusCommands
What is Docker?
Layered file system: Linux distro (Host)
Config file
NGiNX
Ubuntu
Ubuntu
NGiNX
Config files
docker rm
docker start/run Up
docker create Created
docker stop/kill Exited

32. How?
Container ordonnancement

33. Docker rework
Data Container first
Gpg2
Gitolite
HooksGit
repos
Data

34. Docker rework
Data Container first
Gpg2
Gitolite
HooksGit
repos
Data

35. Docker rework
Data Container first
Gpg2
Gitolite
HooksGit
repos
Data
docker create --name=gitolite.
repos.blessed.cont
gitolite.repos
/home/git/repositories

36. Docker rework
Leaf containers second
LDAP
Gpg2
Gitolite
HooksGit
repos
MCronData
SSHD

37. Docker rework
Leaf containers second
LDAP
Gpg2
Gitolite
HooksGit
repos
MCronData
SSHD

38. Docker rework
Leaf containers second
LDAP
Gpg2
Gitolite
HooksGit
repos
MCronData
SSHD
docker run --name=mcron.blessed.
cont --volumes-from gitolite.
blessed.cont
--volumes-from data.blessed.cont

39. /home/git/repositories
/home/git/gitolite
/home/git/data
Docker rework
Leaf containers second
LDAP
Gpg2
Gitolite
HooksGit
repos
MCronData
SSHD
docker run --name=mcron.blessed.
cont --volumes-from gitolite.
blessed.cont
--volumes-from data.blessed.cont

40. Docker rework
Linked containers last
NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCron
SSHD
Data

41. Docker rework
Linked containers last
NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCron
SSHD
Data

42. Docker rework
Linked containers last
NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCron
SSHD
docker run --name=apache.blessed.
cont --volumes-from gitolite
--volumes-from repos
--volumes-from gpg2
--volumes-from data
Data

43. Docker rework
Linked containers last
NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCron
SSHD
docker run --name=apache.blessed.
cont --volumes-from gitolite
--volumes-from repos
--volumes-from gpg2
--volumes-from data
--link ldap.cont:apache.ldap.cont
Data

44. Docker rework
Linked containers last
NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCron
SSHD
docker run --name=apache.blessed.
cont --volumes-from gitolite
--volumes-from repos
--volumes-from gpg2
--volumes-from data
--link ldap.cont:apache.ldap.cont
--link apache.staging.cont:
apache.upstream.cont
Data
Apache
staging

45. Docker rework
Linked containers last
NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCron
SSHD
Apache
staging
docker run --name=apache.blessed.
cont --volumes-from gitolite
--volumes-from repos
--volumes-from gpg2
--volumes-from data
--link ldap.cont:apache.ldap.cont
--link apache.staging.cont:
apache.upstream.cont
-p 6043:8543
-p 6053:8553 Data

46. Docker rework
Linked containers last
NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCron
SSHD
Apache
staging
Data

47. Docker rework
Linked containers last
NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCron
SSHD
Apache
staging
Data
docker run --name=nginx.blessed.
cont

48. Docker rework
Linked containers last
NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCron
SSHD
Apache
staging
Data
docker run --name=nginx.blessed.
cont
--link apache.blessed.cont:
nginx.apache.cont

49. Docker rework
Linked containers last
NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCron
SSHD
Apache
staging
Data
docker run --name=nginx.repos.
blessed.cont
--link apache.blessed.cont:
nginx.apache.cont
-p 6080:80
-p 6443:443

50. Benefits?
Configuration & Isolation

51. Docker Advantages
Configuration
NGiNX Apache

52. Docker Advantages
Configuration
NGiNX
location /git/ {
proxy_pass
https://nginx.apache.cont:8543/git/;
}
location /hgit/ {
proxy_pass
https://nginx.apache.cont:8553/hgit/;
}
Apache

53. Docker Advantages
Configuration
NGiNX
location /git/ {
proxy_pass
https://nginx.apache.cont:8543/git/;
}
location /hgit/ {
proxy_pass
https://nginx.apache.cont:8553/hgit/;
}
nginx.apache.cont:8543
nginx.apache.cont:8553
Apache

54. Docker Advantages
Configuration
NGiNX
location /git/ {
proxy_pass
https://nginx.apache.cont:8543/git/;
}
location /hgit/ {
proxy_pass
https://nginx.apache.cont:8553/hgit/;
}
nginx.apache.cont:8543
nginx.apache.cont:8543
Apache
EXPOSE 8543
EXPOSE 8553

55. Docker Advantages
Configuration
NGiNX
location /git/ {
proxy_pass
https://nginx.apache.cont:8543/git/;
}
location /hgit/ {
proxy_pass
https://nginx.apache.cont:8553/hgit/;
}
nginx.apache.cont:8543
nginx.apache.cont:8543
Apache
EXPOSE 8543
EXPOSE 8553
docker run --name=nginx.repos.
blessed.cont
--link apache.blessed.cont:
nginx.apache.cont

56. Docker Advantages
Isolation (services)
NGiNX Apache LDAP
MCron
SSHD
Data
HooksGit
repos

57. Docker Advantages
Isolation (services)
From outside: NGiNX Apache

58. Docker Advantages
Isolation (services)
From inside:
MCronData
HooksGit
repos

59. Docker Advantages
Isolation (services)
MCron
SSHD
Data
HooksGit
repos

60. Docker Advantages
Isolation (services)
SSHD
Data

61. Docker Advantages
Isolation (ports/names)
NGiNX Apache LDAP
Data MCron
SSHD

62. Docker Advantages
Isolation (ports/names)
NGiNX Apache LDAP
EXPOSE 8543
EXPOSE 8553
EXPOSE 80
EXPOSE 443
EXPOSE 369
Data MCron
SSHD
EXPOSE 2200

63. Docker Advantages
Isolation (ports/names)
NGiNX Apache LDAP
port 6080
port 6443
EXPOSE 8543
EXPOSE 8553
EXPOSE 80
EXPOSE 443
EXPOSE 369
port 6043
port 6053
Data MCron
SSHD
EXPOSE 2200port 2200

64. Conclusion
CaaS: Container as a Service

65. End result
● 21 containers,
in 3 sets,
one for each
environment.
● service vs.
data
● Extensible
without
downtime.
NGiNX Apache LDAP
Gpg2
Gitolite
HooksGit
repos
MCronData
SSHD
Blessed Staging ExternalFrom:
To:

66. End result: CaaS

67. End result: CaaS