Set up Docker

• Windows 7, Windows 10 Home—Docker Toolbox for Windows
  This version of Docker installs VirtualBox on your system so you can run your choice of host operating system for the container.
• Windows 10 Pro, Enterprise, or Education—Docker Desktop for Windows 10
  This version lets you choose whether to use Windows as the container OS or Linux.
• Mac OS 10.12 or newer—Docker Desktop for Mac OS
  This version only supports containers that use Linux as the OS.
• Linux—Packages are available for all major distributions

Deploy a Web App in a Container

On your development machine:

1. Publish your web app to a folder. Use your Azure database connection string. Verify that the web app runs from the folder you published it to by executing this command:
   dotnet yourwebappname.dll
   
   
2. Create a file named Dockerfile in your web app solution folder (the same folder as your .sln file). Example:
   # download the ASP.NET Core runtime
FROM mcr.microsoft.com/dotnet/core/aspnet:3.1

   
   • FROM—downloads an image from the Microsoft Docker image repository, initializes a new build stage, and sets the Base Image for the remaining instructions.
   
   
3. Build the image and give it a name, following the -t (The tag is optional and could be given in the ‘name:tag’ format.) The dot means that the Dockerfile is in the current folder. Execute this command in the folder containing the Dockerfile:
   
   

   docker build -t yourwebappname . 
   

4. To see the images currently installed, type:
   docker images
   
   
5. Add commands to the Dockerfile to copy the web app into the container and set an entry-point for the web app. This will create new image layers.# Copy files from the dev machine to the container.
COPY GoodBookNook/bin/Release/netcoreapp3.1/publish/ app/

# Change directories, we need to run the app from the app directory.
WORKDIR app/

# Start the web app when the container runs.
ENTRYPOINT ["dotnet", "GoodBookNook.dll", "--environment=Production"]


1. COPY—copies new files or directories from the source path and adds them to the destination container filesystem.
1. ENTRYPOINT—specifies the command to run when the container starts, dotnet, and any arguments.
   
   
6. Build your images again as you did in step 3 and view them again too.
7. Create a container using the image you just created:
   docker create yourwebappname
   The output of the command shows the ID of your new container. To see a list of all containers, type:
   docker ps -a
   You'll notice that each container has a name that was assigned automatically.
   
   
8. Start the container using it's name:
   docker start some_name
   FYI, you can use the docker stop command to stop the container.
   
   
9. Run the app
   

   docker run --rm -p 5001:8080 yourwebappname

   Notes:
   • I set the port option to map port 5001 inside the container to 8080 outside the container since my web app is configured for HTTPS on port 5001.
   • If you are specifying a port in appsettings.json, be sure you don't specify localhost. Use + to represent any domain, like this:  "http://+:5001"
10. Upload the image to Docker Hub or any other container registry.

On the server:

1. Blah blah

Troubleshooting

You can connect a terminal to your container in order to see what's going on inside.

1. Start the container using it's name:
   docker start container_name
   Notes:
   
• You can stop your container using the command: docker stop
  
• You can get the names of your containers using the command: docker ps -a
  
2. Use the docker attach command.
   docker attach --sig-proxy=false container_name
   Notes:
   The CTRL + C keystroke is used to detach from the running container. This keystroke may actually end the process in the container, which will stop the container. The --sig-proxy=false parameter ensures that CTRL + C won't stop the process in the container.
   

Notes

Docker Toolbox for Windows

• Start by running the Docker Quickstart Terminal, this will open a console on a Linux VM. It's uname is MINGW64.
• The Windows Users folder is mounted in the Docker Linux VM at /c/Users.
  You can mount other Windows folders via the VirtualBox settings--see the Docker Toolbox documentation.
• Build the Docker image in step 2 above by first navigating to the web app's project folder, for example:
  

  cd c/Users/Student/Documents/GitHub/CS296N-BookInfo-Core-2/BookInfo

  Be sure to use forward slashes.
• After building your image, you may get this warning:
  

  SECURITY WARNING: You are building a
  dows Docker host. All files and dire
  wxr-xr-x' permissions. It is recomme
  or sensitive files and directories.

  This is because the files you copied from Windows to the Linux VM have permissions that are considered a security risk. You should change the permissions to improve security, but the image will still work even if you don't.