This document discusses how Docker can help .NET developers by allowing them to containerize their .NET applications. It provides benefits like running applications across Windows and Linux containers, improving development workflows through features of Docker for Windows like Linux containers on Windows, and facilitating continuous integration and deployment of containerized applications through automation. The document provides examples of Dockerfiles for different types of .NET applications and demonstrates how to add Docker support and containerize existing applications using Visual Studio tools.

1. Docker for .NET
Developers
Michele Leroux
Bustamante
CIO / Cloud/Security Architect
Solliance
Microsoft Regional Director,
MVP Azure
Docker Captain
@michelebusta

2. • Microservices
architecture
• Faster releases
• Polyglot
• Improved
development
workflows
• Devops culture
• Better resiliency
Why Docker?

3. • Run .NET Framework applications in Windows containers
• Limited changes
• Encapsulate configuration and dependencies
• Refactor the monolith at your own pace
• Create new dotnetcore / aspnetcore applications
• Target Linux or Windows containers
• Familiar development experience / debugging
.NET Developer Benefits

5. IIS Dockerfile
Add windows features
Add windows features
Copy / run an existing
executable

6. ASP.NET 3.5 Dockerfile
Add required packages
Configure IIS requirements

7. ASP.NET 4.6.2 Dockerfile
Tailor added features by
specific platform

8. Container Images
https://store.docker.com

9. Docker for
Windows

10. Docker for Windows
Powershell
Developer Tools

11. Docker for Windows
provides a Linux VM for
local execution of
Docker containers.
Linux / Windows

12. Docker for Windows
provides a Linux VM for
local execution of
Docker containers.
Can verify mode.
Can swap between
modes from the task
tray.
Linux / Windows

13. Docker for Windows
provides a Linux VM for
local execution of
Docker containers.
Can verify mode.
Can swap between
modes from the task
tray.
Linux / Windows

14. Docker for Windows
Powershell
Visual Studio 2017
Developer Tools

15. Development Considerations
• Target environments and base image
• Debugging
• Access to logs
• Service dependencies and networking
• Environment variables
• CICD workflows

16. Project -> New
with Docker

17. FROM microsoft/aspnetcore:1.1
ARG source
WORKDIR /app
EXPOSE 80
COPY ${source:-obj/Docker/publish} .
ENTRYPOINT ["dotnet", “WebApi.dll"]
Demo Linux

18. FROM microsoft/aspnetcore:1.1-nanoserver
ARG source
WORKDIR /app
EXPOSE 80
COPY ${source:-obj/Docker/publish} .
ENTRYPOINT ["dotnet", “WebApi.dll"]
Demo Windows

19. Add Docker
Support

20. Add Docker to existing
dotnetcore or .NET
Framework projects.
Creates Dockerfile and
Docker project with
compose files ready for
debugging.
Add Docker

21. services:
webapp:
image: webapp
build:
context: ./src/WebApp
dockerfile: Dockerfile
webapi:
image: webapi
build:
context: ./src/WebApi
dockerfile: Dockerfile
DEMO Add Docker

22. services:
webapp:
image: webapp
build:
context: ./src/WebApp
dockerfile: Dockerfile
environment:
- "Api:BaseAddress=http://webapi"
DEMO Environment Variables

23. Migrating
Legacy Apps

24. FROM microsoft/aspnet
ARG source
WORKDIR /inetpub/wwwroot
COPY ${source:-obj/Docker/publish} .
DEMO Legacy Migration

25. services:
snapboard.web:
image: snapboard.web
…
depends_on:
mssql:
condition: service_healthy
mssql:
image: microsoft/mssql-server-windows-developer
…
DEMO Compose Up Developer Love

26. # Enable DNS resolution to work properly for all windows containers
# instead of caching (temporary fix)
SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop';"]
RUN set-itemproperty -path
'HKLM:SYSTEMCurrentControlSetServicesDnscacheParameters' -Name
ServerPriorityTimeLimit -Value 0 -Type Dword
# see music store sample
# https://github.com/docker/labs/blob/master/windows/windows-
containers/MultiContainerApp.md
DNS Resolution Reference

27. FROM microsoft/aspnet
ARG source
WORKDIR /inetpub/wwwroot
COPY ${source:-obj/Docker/publish} .
ENTRYPOINT ["powershell", "./bootstrap.ps1"]
Environment Variables and IIS

28. # copy process environment variables machine-wide
foreach($key in [System.Environment]::GetEnvironmentVariables('Process').Keys) {
if ([System.Environment]::GetEnvironmentVariable($key, 'Machine') -eq $null) {
$value = [System.Environment]::GetEnvironmentVariable($key, 'Process')
[System.Environment]::SetEnvironmentVariable($key, $value, 'Machine')
}
}
Bootstrap.ps1
REFERENCE: Elton Stoneman
https://github.com/sixeyed/nerd-dinner/blob/dockerize-part2/docker/web/bootstrap.ps1

29. CICD

30. Automating Image Builds (CI)
Git /
TFS
VSTS
Build
Definition
Registry
Build
Images
Pull
Latest
Push
Images
Service
Image
Repo
Latest
Version Info
Repository tags
Promotion tags
Commit / Checkin
VSTS
Service
Repo
Tagged
Images

31. Build Definition

32. Build Output

33. Azure Container Registry

34. Deployment (CD)
Git /
TFS
VSTS
Build
Definition
Registry
Build
Images
Pull
Latest
Push
Images
Service
Image
Repo
Latest
Version Info
Repository tags
Promotion tags
Commit / Checkin
VSTS
Service
Repo
Tagged
Images
Dev
Uat
Uat

35. Your investment
in .NET will pay
off.

37. Thank You!
@docker #dockercon