Run docker containers - Part 1.1

Posted on October 18, 2020 in DevOps
Updated: November 09, 2020

This blog is part of a serie:

In this blog (Part 1.1) I'll do basic execution of Docker images as preparation for the next blog (Part 1.2).
Part 1 is about developing C# docker containers and hosting them in k8s.

It is partly inspired by eBook Using .NET Core, Docker, and Kubernetes Succinctly and partly from documents from Microsoft.
So I'll be reusing chapter numbers from the eBook, when they fit into the context.

Chapters from eBook Using .NET Core, Docker, and Kubernetes

Chapter 1 ASP.NET and Docker Together

Chapter 1.1 Execute .NET Core application with Docker

Install and start Docker.
Then open a shell. 

# Verify docker CLI is installed
docker --version
# Docker version 19.03.13, build 4484c46d9d

# View docker images cached on your machine
docker image ls
# or
docker images
# REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

Now we'll run a console app.

# pull specific images into your cache
docker pull microsoft/dotnet-samples # this is a console app
docker images
# REPOSITORY                 TAG                 IMAGE ID            CREATED             SIZE
# microsoft/dotnet-samples   latest              70e25069fca7        20 months ago       181MB

# start an image
docker run --name consoleapp 70e25069fca7
#    Hello from .NET Core!

# Which containers are running?
docker ps
# CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
# none - the above one fineshed and exited

# show all containers
docker ps -a
# CONTAINER ID        IMAGE                  COMMAND                  CREATED             STATUS                     PORTS                       NAMES
# a51691a1650f        70e25069fca7           "dotnet dotnetapp.dll"   3 minutes ago       Exited (0) 3 minutes ago                               consoleapp

# run again - to avoid creating more images
docker start consoleapp # runs in background by default, so you won't see print here - instead do
docker start consoleapp -i # interactive mode

# remove the image
docker rm consoleapp # by name
# or
docker rm a51691a1650f # by id

Next we'll run a web app. 

# Terminal 1:
# pull a web app
docker pull microsoft/dotnet-samples:aspnetapp # this is a web app
docker images
# REPOSITORY                 TAG                 IMAGE ID            CREATED             SIZE
# microsoft/dotnet-samples   aspnetapp           575d85b4a69b        20 months ago       263MB
# microsoft/dotnet-samples   latest              70e25069fca7        20 months ago       181MB

# start a new image
docker run --name mvcapp 575d85b4a69b # you can add -d to run in damon/background mode, which gives you the prompt back, but you then won't see its outputs
# Hosting environment: Production
# Content root path: /app
# Now listening on: http://[::]:80
# Application started. Press Ctrl+C to shut down.

# Terminal 2:
docker ps
# CONTAINER ID        IMAGE                  COMMAND                  CREATED             STATUS                   PORTS                       NAMES
# 82225a6f9672        575d85b4a69b           "dotnet aspnetapp.dll"   36 seconds ago      Up 34 seconds                                        mvcapp

But you can't access it on http://[::]:80 ... You have to redirect an outer port into its port 80.

# Terminal 1:
# stop the image
docker stop mvcapp # notice - stopping by name
# remove image
docker rm mvcapp

# start the image with access from port 8080 
docker run -p 8080:80 --name mvcapp 575d85b4a69b  # notice - starting by name, so we don't add yet an image
#or
docker create -p 8080:80 --name mvcapp 575d85b4a69b
docker start mvcapp # runs in background by default - use -i to see its outputs

# Terminal 2:
# open browser
start http://localhost:8080
docker ps
# CONTAINER ID        IMAGE                  COMMAND                  CREATED             STATUS                   PORTS                       NAMES
# bab98369a976        575d85b4a69b           "dotnet aspnetapp.dll"   45 seconds ago      Up 43 seconds            0.0.0.0:8080->80/tcp        mvcapp

# Terminal 1:
# stop the image
docker stop mvcapp # notice - stopping by name
# remove image
docker rm mvcapp

Chapter 2 Create Your Application with Docker

See Part 1.2: Develop .NET docker images

The End

#docker