Wednesday, September 13, 2017

Wrote a post on Wiki Life at Official Blog of TechNet Wiki

Wrote a post in Wiki Ninjas - Official Blog of TechNet Wiki. The title of the post is TNWiki Article Spotlight – Getting started with Cognitive Services – Vision.
image
TNWiki Article Spotlight – Getting started with Cognitive Services – Vision

Happy Coding.

Regards,
Jaliya

Tuesday, August 29, 2017

Visual C# Technical Guru - July 2017

Another month as a judge in Microsoft TechNet Guru Awards under Visual C# category. The TechNet Guru Awards celebrate the technical articles on Microsoft TechNet.

Post in WikiNinjas Official Blog,
image
Visual C# Technical Guru - July 2017
Happy Coding.

Regards,
Jaliya

Thursday, August 17, 2017

Getting Started with ASP.NET Core 2.0 Razor Pages

With the release of ASP.NET Core 2.0, one of the new features that got introduced was Razor Pages. The easiest way to get yourself started on ASP.NET Core Razor Pages is with Visual Studio 2017 Update 15.3.

Once you have installed Visual Studio 2017 Update 15.3 and if you try to create a new ASP.NET Core Web Application,
image
New Project
You are presented with an improved dialog window. 
image
New ASP.NET Core Web Application
When you selected ASP.NET Core 2.0 from the ASP.NET Core version selection dropdown, you are presented with multiple application templates. From there, when you select your template as Web Application, you can see that it uses Razor Pages.

Let’s go ahead and create a Web Application. Once the project is created, if you have a look at Solution Explorer, you should be able to see something like below.
image
Pages Folder
When I first had a look at this, for me it was familiar MVC file names and Web Forms like file structure (HTML file and a code behind file).

Now if you run the application, you should be seeing the familiar template.
image
Running
Now to explore what ASP.NET Core Razor Pages really is, let’s open up About.cshtml and About.cshtml.cs (I am going ahead with About files as there are less static content there).

About.cshtml
image
About.cshtml
Here the highlighted @page directive is one of the most important things. It enables, razor file to link with it’s related PageModel.

About.cshtml.cs
image
About.cshtml.cs
If you prefer, to improve productivity in development, you can have the content in code behind in the razor file itself.

About.cshtml
@page
@model AboutModel
@using Microsoft.AspNetCore.Mvc.RazorPages
@{
    ViewData["Title"] = "About";
}
 
@functions{
    public class AboutModel : PageModel
    {
        public string Message { get; set; }
 
        public void OnGet()
        {
            Message = "Your application description page.";
        }
    }
}
 
<h2>@ViewData["Title"]</h2>
<h3>@Model.Message</h3>
 
<p>Use this area to provide additional information.</p>
While above will work fine, there is a advantage, above supports run-time compilation. That is pretty handy in development, you don't need to stop the debugger to do some change in PageModel class.

When the page is requested by http://localhost:xxxx/About, OnGet method will get called and when you want to post something, you can introduce OnPost method and it will get trigged upon POST requests. For async requests, you can name  the methods as OnGetAsync, OnPostAsync etc.

About.cshtml
@page
@model AboutModel
@using Microsoft.AspNetCore.Mvc.RazorPages
@{
    ViewData["Title"] = "About";
}
 
@functions{
    public class AboutModel : PageModel
    {
        public string Message { get; set; }
 
        public void OnGet()
        {
            Message = "Your application description page.";
        }
 
        public void OnPost()
        {
            Message = $"You just made a post on {DateTime.Now}.";
        }
    }
}
 
<h2>@ViewData["Title"]</h2>
<h3>@Model.Message</h3>
 
<p>Use this area to provide additional information.</p>
 
<form method="post">
    <input type="submit" value="Submit"/>
</form>
Hopefully, this will help you get started on ASP.NET Core Razor Pages.

More reads,

Happy Coding.

Regards,
Jaliya

Thursday, August 10, 2017

Session : Docker for .NET Developers at Sri Lanka .NET Forum

Delivered an hour long session at Sri Lanka .NET Forum today.

There was no session slides, I was totally focusing on showing the participants Docker in action. I have demoed how we can run a containerized ASP.NET Core application in a Linux container using only docker command. Then I have showed what Visual Studio 2017 has introduced to improve the productivity in building containerized applications and the use of docker-compose command.

For more information,
   Meetup Event

Happy Coding.

Regards,
Jaliya

Tuesday, July 25, 2017

Visual C# Technical Guru - June 2017

Another month as a judge in Microsoft TechNet Guru Awards under Visual C# category. The TechNet Guru Awards celebrate the technical articles on Microsoft TechNet.

Post in WikiNinjas Official Blog,
image
Visual C# Technical Guru - June 2017
Happy Coding.

Regards,
Jaliya

Tuesday, July 4, 2017

Session : ASP.NET MVC 5 and SignalR 2

Delivered a 2-hour long session today about ASP.NET MVC 5 and SignalR 2 for a Microsoft partnered company in Sri Lanka.

There I went through the following set of topics in the context of ASP.NET MVC 5 and SignalR 2.
  • What is SignalR
  • Transports
  • Supported Platforms
  • Connections and Hubs
  • Hubs API Guide
    • Server (C#)
    • Client (JavaScript)
  • Understanding Lifetime Events
  • Security
  • Performance
  • What’s Next: ASP.NET Core SignalR


And a demo application was created during the session from scratch for a better understanding of the concepts.
Happy Coding.

Regards,
Jaliya

Friday, June 23, 2017

Visual C# Technical Guru - May 2017

Another month as a judge in Microsoft TechNet Guru Awards under Visual C# category. The TechNet Guru Awards celebrate the technical articles on Microsoft TechNet.

Post in WikiNinjas Official Blog,
image
Visual C# Technical Guru - May 2017
Happy Coding.

Regards,
Jaliya

Wednesday, June 21, 2017

Wrote a post on Wiki Life at Official Blog of TechNet Wiki

Wrote a post in Wiki Ninjas - Official Blog of TechNet Wiki. The title of the post is Wiki Life: TechNet Guru Competition – How far we have come.
image
Wiki Life: TechNet Guru Competition – How far we have come

Happy Coding.

Regards,
Jaliya

Tuesday, June 20, 2017

Creating a Docker Container Running ASP.NET Core Web Application Powered by React and Redux

This is likely going to be a quick post. I wanted to have a Docker Container running ASP.NET Core Web Application powered by React and Redux. Luckily there are nice SPA templates introduced by Microsoft, and there we have React, Redux template.
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MVC ASP.NET Core with React.js and Redux
I created the application and did a publish. Then I have added a Dockerfile with following configs.

Dockerfile
FROM microsoft/aspnetcore:1.1.2
LABEL Name=ReactReduxApp Version=0.0.0
ARG source
WORKDIR /app
EXPOSE 30000
COPY ${source:-bin/Release/netcoreapp1.1/publish} .
RUN apt-get update
# Installing npm
RUN apt-get install -y npm
# Installing Node.js
RUN npm install -g n; n stable
ENTRYPOINT dotnet ReactReduxApp.dll    
Next I have build the image. This will install all npm and Node.js to my base Image. Once that is done, I have started the Container and all is good.
image
docker run
image
MVC ASP.NET Core with React.js and Redux Running in Docker
If you want to learn how to create a ASP.NET Core MVC Application running inside a Docker Linux Container this post should help.

Complete source code is available on GitHub.
https://github.com/jaliyaudagedara/Blog-Post-Samples/tree/master/ReactReduxApp

Happy Coding.

Regards,
Jaliya

Thursday, June 1, 2017

Creating a Release Build of an ASP.NET Core Project using Docker ASP.NET Core Build Image

In one of my previous posts I wrote about Creating and Debugging Docker Enabled .NET Core Project in Visual Studio 2017 and in this post let’s see how we can create a release build of an ASP.NET Core Project using official Docker ASP.NET Core Build Image.

Right now I have a Docker support enabled ASP.NET Core MVC Application created (If you don't know how, you can read my above mentioned previous post).

Note: I have created the solution using Visual Studio 2017, but you don't need to have Visual Studio 2017 to create this solution. dotnet SDK and Visual Studio Code should be more than enough. For the next steps, we only need dotnet SDK and cmd/PowerShell.

Let's proceed. I have a clean solution, no obj/bin folders present yet.
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No obj/bin folders
I have a PowerShell window opened on the root folder level.
PS C:\Users\Jaliya\Desktop\DockerComposeWebApp>
Next to do a Release build what I would do is do a dotnet restore and a publish like below.
# Restore packages
dotnet restore .\DockerComposeWebApp\DockerComposeWebApp.csproj
 
# Publish on Release mode
dotnet publish -c Release .\DockerComposeWebApp\DockerComposeWebApp.csproj
But in that case the build would be done on my local machine, instead here I want to use a Docker Container to do the building.

Now let’s open up the docker-compose.ci.build.yml in my local folder. Remember I did not write this file myself, Visual Studio 2017 created this for me when I have enabled Docker Support for my project (if you want to know how to get these docker-compose.xxxxx.yml files created when using Visual Studio Code, you can read this previous post of mine Running ASP.NET Core MVC Application inside a Docker Linux Container from Windows).

docker-compose.ci.build.yml
version: '2'
services:
  ci-build:
    image: microsoft/aspnetcore-build:1.0-1.1
    volumes:
      - .:/src
    working_dir: /src    
    command: /bin/bash -c "dotnet restore ./DockerComposeWebApp.sln && dotnet publish ./DockerComposeWebApp.sln -c Release -o ./obj/Docker/publish"
Here you can see that we have a service named ci-build which uses microsoft/aspnetcore-build Image and that is the official Image for building ASP.NET Core applications (version will be changed time to time). Then my current folder is getting mapped to src folder in the ci-build Container (which is not yet created). After Container is created and running, it’s working directory will get changed to src and the given command will get executed. And basically what the command does is a dotnet restore and a dotnet publish (here output path is set to .\obj\Docker\publish).

Now from PowerShell let’s run the following command.
# docker-compose up: Builds, (re)creates, starts, and attaches to containers for a service.
PS C:\Users\Jaliya\Desktop\DockerComposeWebApp> docker-compose -f .\docker-compose.ci.build.yml up
image
docker-compose up
(Note: since I already had microsoft/aspnetcore-build Image locally, it didn't get downloaded again. If not, downloading status of the image will be displayed here.)

Now if we examine the \DockerComposeWebApp project folder, we can see obj/bin folders has been created and if we go to .\obj\Docker\publish folder, build contents are there.
image
Published Folder
Now we have a Release build created using a Docker Container (remember we didn’t do the build on our local machine).

For a further step, to make sure all is good, let’s package this content into a another Docker Container and see whether it works.

docker-compose.yml
version: '2'
services:
  dockercomposewebapp:
    image: dockercomposewebapp    
    build:
      context: ./DockerComposeWebApp      
      dockerfile: Dockerfile
Dockerfile
FROM microsoft/aspnetcore:1.1
ARG source
WORKDIR /app
EXPOSE 80
COPY ${source:-obj/Docker/publish} .
ENTRYPOINT ["dotnet", "DockerComposeWebApp.dll"]
docker-compose.override.yml
version: '2'
services:
  dockercomposewebapp:
    environment:
      - ASPNETCORE_ENVIRONMENT=Development    
    ports:
      - "80"
PS C:\Users\Jaliya\Desktop\DockerComposeWebApp> docker-compose -f .\docker-compose.yml -f .\docker-compose.override.yml up
image
docker-compose up
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docker images & docker ps
:latest Image of a build has been created and a Container is running which got instantiated from that Image.

Now let’s just browse the running port. And yes, it is working.
image
Site Running inside a Docker Container
Happy Coding.

Regards,
Jaliya

Wednesday, May 31, 2017

Creating and Debugging Docker Enabled .NET Core Project in Visual Studio 2017

In this post let’s see how you can use Visual Studio 2017 to develop .NET Core application with Docker support enabled and see what happens when you build/debug.

Let’s start off by creating a ASP.NET Core Web Application (.NET Core) and I am naming it as DockerComposeWebApp.
image
ASP.NET Core Web Application (.NET Core)
Once you clicked on OK from above, you are prompted to select application type (of course, I am sure you have done this hundred times, if not thousands).
image
Enable Docker Support
And there is a new check box presented in the dialog window, that is Enable Docker Support. You can either enable Docker support from there, or as mentioned, you can enable it later.

And I am not enabling it right now, I am clicking on OK and the solution gets created. And to enable Docker support now, you can right click on the Project, select Add and then click on Docker Support (well, you should be able to right click on any root item, and do Add –> Docker Support, but not on Solution level nor file level).
image
Enable Docker Support
Once you enabled Docker support, a Dockerfile has been added to DockerComposeWebApp project and you can see a new project that is added to the solution named docker-compose with some files.

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

image
Files View - Visual Studio
If you examine the files in the File Explorer, it looks like this.
image
Files View - File Explorer
Let’s just open up the docker-compose.dcproj file.
<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="15.0" Sdk="Microsoft.Docker.Sdk">
  <PropertyGroup Label="Globals">
    <ProjectGuid>00832628-12a5-4b9b-b434-fcabd17c57b8</ProjectGuid>
    <DockerLaunchBrowser>True</DockerLaunchBrowser>
    <DockerServiceUrl>http://localhost:{ServicePort}</DockerServiceUrl>
    <DockerServiceName>dockercomposewebapp</DockerServiceName>
  </PropertyGroup>
  <ItemGroup>
    <None Include="docker-compose.ci.build.yml" />
    <None Include="docker-compose.override.yml">
      <DependentUpon>docker-compose.yml</DependentUpon>
    </None>
    <None Include="docker-compose.vs.debug.yml">
      <DependentUpon>docker-compose.yml</DependentUpon>
    </None>
    <None Include="docker-compose.vs.release.yml">
      <DependentUpon>docker-compose.yml</DependentUpon>
    </None>
    <None Include="docker-compose.yml" />
  </ItemGroup>
</Project>
And if you have a look at the ItemGroup, that is what it gives Visual Studio the nested view in docker-compose project items. So basically there is two main docker-compose files, one is docker-compose.ci.build.yml and the other is docker-compose.yml.

Now let’s see what happens when you debug the application. Since our main interest here is in Docker side of things, let’s set the docker-compose project as the startup project. Same time you can see that the Debug target is changed to Docker (if you debug the solution having the Web App project as the startup project it will not be debugging on Docker).

Before hitting F5, let’s see is there any Docker Containers running.
image
docker images & docker ps -a
Nothing specific to our current project (DockerComposeWebApp).

Now let’s debug. After couple of seconds, the site is working (well, it should) and what we need to focus is the Build output in Visual Studio.
------ Build started: Project: docker-compose, Configuration: Debug Any CPU ------
docker-compose -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.yml" 
               -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.override.yml" 
               -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.vs.debug.yml" 
               -p dockercompose1628124139 
               config
First VS is issuing docker-compose config command to validate and view the compose file and it shows the output as below.
networks: {}
services:
  dockercomposewebapp:
    build:
      args:
        source: obj/Docker/empty/
      context: C:\Users\Jaliya\Desktop\DockerComposeWebApp\DockerComposeWebApp
      dockerfile: Dockerfile
    entrypoint: tail -f /dev/null
    environment:
      ASPNETCORE_ENVIRONMENT: Development
      DOTNET_USE_POLLING_FILE_WATCHER: '1'
    image: dockercomposewebapp:dev
    labels:
      com.microsoft.visualstudio.targetoperatingsystem: linux
    ports:
    - '80'
    volumes:
    - C:\Users\Jaliya\Desktop\DockerComposeWebApp\DockerComposeWebApp:/app:rw
    - C:\Users\Jaliya\clrdbg:/clrdbg:ro
    - C:\Users\Jaliya\.nuget\packages:/root/.nuget/packages:ro
version: '2.0'
volumes: {}
Basically this is a consolidation of docker-compose.yml, docker-compose.override.yml and docker-compose.vs.debug.yml files.

Next Visual Studio is executing docker ps command setting up some filter options to see if there is already a Container related to our project.
docker  ps --filter "status=running" --filter "name=dockercompose1628124139_dockercomposewebapp_" --format {{.ID}} -n 1
And there is no output. But still above command follows couple of docker-compose kill and docker-compose down commands using docker-compose release and debug yml files.
docker-compose -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.yml" 
               -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.override.yml" 
               -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.vs.release.yml" 
               -p dockercompose1628124139 
                kill
 
docker-compose -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.yml" 
               -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.override.yml" 
               -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.vs.release.yml" 
               -p dockercompose1628124139 
               down 
               --rmi local 
               --remove-orphans
 
Removing network dockercompose1628124139_default
Network dockercompose1628124139_default not found.
 
docker-compose -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.yml" 
               -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.override.yml" 
               -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.vs.debug.yml" 
               -p dockercompose1628124139 
               kill
 
docker-compose -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.yml" 
               -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.override.yml" 
               -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.vs.debug.yml" 
               -p dockercompose1628124139 
               down 
               --rmi local 
               --remove-orphans
 
Removing network dockercompose1628124139_default
Network dockercompose1628124139_default not found.
And finally docker-compose up command with build argument is being executed.
docker-compose -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.yml" 
               -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.override.yml" 
               -f "C:\Users\Jaliya\Desktop\DockerComposeWebApp\docker-compose.vs.debug.yml" 
               -p dockercompose1628124139 
               up 
               -d 
               --build
 
Creating network "dockercompose1628124139_default" with the default driver
Building dockercomposewebapp
Step 1/6 : FROM microsoft/aspnetcore:1.1
 ---> e57f6d3fac0a
Step 2/6 : ARG source
 ---> Running in 1d44520ba0ff
 ---> 3b1eab823df1
Removing intermediate container 1d44520ba0ff
Step 3/6 : WORKDIR /app
 ---> 2f8078c67f8b
Removing intermediate container 8e3775dc753a
Step 4/6 : EXPOSE 80
 ---> Running in ee30aa3b3287
 ---> 38ea46a28cd0
Removing intermediate container ee30aa3b3287
Step 5/6 : COPY ${source:-obj/Docker/publish} .
 ---> 441f4a61d8ee
Removing intermediate container 7426260a8476
Step 6/6 : ENTRYPOINT dotnet DockerComposeWebApp.dll
 ---> Running in 471fb962159c
 ---> e756ed44b5f7
Removing intermediate container 471fb962159c
Successfully built e756ed44b5f7
Creating dockercompose1628124139_dockercomposewebapp_1
========== Build: 1 succeeded or up-to-date, 0 failed, 0 skipped ==========
And now if I examine Images and currently running Containers, I can see an Image is created and a Container is running related to our project.
image
docker images & docker ps
And that’s it for this post. You definitely will like to see what happens/what commands gets executed if we stop the Debugger and start back. And I will leave it with you to find it out.

Note: I have not gone through all the theoretical things related to Docker Compose as Docker maintains a rich documentation over those.

Happy Coding.

Regards,
Jaliya

Friday, May 19, 2017

Running and Exploring a Docker Linux Container

Sometimes the best way to troubleshoot and understand how a Docker Container works, is by exploring the Container. While I believe there are couple of ways to explore, one of the ways I really found useful is docker exec. Basically docker exec let’s you run commands inside a Container, and for a Linux Container we can use docker exec to bash in and run shell commands.

But to bash in of course, you need to have the Container in running state. Here in this post, I have explained how you can setup your own Container, specifically a Linux Container with ASP.NET Core MVC Application running inside.

So let’s proceed.

Currently I have no Containers running.
image
docker ps -a
And I have following set of Images.
image
docker images
Here the dockerwebapp is the Image that I am planning of creating and running a Container from. I can run the Container by issuing  docker run.
# Runs in the foreground
# Even if pressed Ctrl+C, Container is still running
PS C:\WINDOWS\system32> docker run dockerwebapp
 
# Runs in the background/detached
PS C:\WINDOWS\system32> docker run -d dockerwebapp
 
# Runs in the foreground
# If pressed Ctrl+C, Container will stop running
# Container will be displayed in docker ps -a
PS C:\WINDOWS\system32> docker run -it dockerwebapp
 
# Runs in the foreground
# If pressed Ctrl+C, Container will stop running and will get deleted
PS C:\WINDOWS\system32> docker run -it –-rm dockerwebapp
In this case, I am going to run docker run –d dockerwebapp as I want the Container to be running in the background, so for next docker commands, I don’t want to open up another PowerShell window.
image
docker run -d dockerwebapp
Now I can see that my container is running, it’s time to explore the image.
PS C:\WINDOWS\system32> docker exec -i -t blissful_roentgen /bin/bash
 
# -i -t can be use together like follows
PS C:\WINDOWS\system32> docker exec -it blissful_roentgen /bin/bash
image
docker exec
You can see that I am now in a Linux shell and I can use shell commands to explore the image. For instance to see the file system.
image
ls
Hope this helps.

Happy Coding.

Regards,
Jaliya

Thursday, May 18, 2017

Running ASP.NET Core MVC Application inside a Docker Linux Container from Windows

I have been having some quality time with Docker recently and wanted to get an ASP.NET Core application running in a Docker Linux Container which will run inside my Windows machine. Was having some hard time getting it to work initially, but with some great help and guidance from a fellow MVP, Alex Thissen (@alexthissen), managed to get it up and running.

Here in this post, I assume you have some basic knowledge on Docker, Docker Images/Containers. And for some of the commands, I might not be explaining what each arguments of the command does, hoping you will do --help on those.

So let’s start.

So on my machine, I have Docker for Windows installed, and there under settings, I have my local C:\ drive shared with Containers.
image
Shared Drives
Now let’s create a folder (I am creating on my Desktop, make sure the drive you are creating the folder in, is shared like above) and I am naming it as a DockerWebApp.

Open up a PowerShell window and change the directory to DockerWebApp folder.
PS C:\Users\Jaliya\Desktop\DockerWebApp> dotnet new mvc
PS C:\Users\Jaliya\Desktop\DockerWebApp> dotnet restore
PS C:\Users\Jaliya\Desktop\DockerWebApp> code .
Now the project will get opened in Visual Studio Code. I have Docker extension for VS Code installed. If you haven’t installed, I suggest you do so, so we can create Docker related files pretty easily. So using the extension, I am creating a Dockerfile as follows.
Dockerfile
Docker for VS Code - Adding Dockerfile
So my Dockerfile looks like this.
FROM microsoft/aspnetcore:1.0.1
LABEL Name=dockerwebapp Version=0.0.1
ARG source=.
WORKDIR /app
EXPOSE 30000
COPY $source .
ENTRYPOINT dotnet dockerwebapp.dll
For now, I am not going to do any changes here, but I am going to delete the other Docker files which got created inside the project which are docker-compose.debug.yml and docker-compose.yml to make things not confusing.

Now let’s publish our application.
PS C:\Users\Jaliya\Desktop\DockerWebApp> dotnet publish -c Release
And since I haven’t specify any specific output path, application will get published to bin\Release\netcoreapp1.1\publish folder.
image
Publish folder
Now let’s move to back to our Dockerfile and do following changes.
FROM microsoft/aspnetcore:1.0.1
LABEL Name=dockerwebapp Version=0.0.1
ARG source
WORKDIR /app
EXPOSE 30000
COPY ${source:-bin/Release/netcoreapp1.1/publish} .
ENTRYPOINT dotnet DockerWebApp.dll
Here first what I have done is, I don’t want to copy the whole project folder to my Image, I am just copying the publish folder. Then I have renamed the dll name in the ENTRYPOINT as in the file name in the publish folder (well I have spent quite sometime figuring out an issue because of this name mismatch).

Now let’s build the Docker Image, so I can create a Container out of it.

For that I am running the following command.
PS C:\Users\Jaliya\Desktop\DockerWebApp> docker build -t dockerwebapp .
I am seeing the following output.
image
docker build -t dockerwebapp .
All seem to be good, there is a warning at the end, we can basically ignore that for now for the sake of this demo. Now let’s run the following command to confirm whether our image is created.
PS C:\Users\Jaliya\Desktop\DockerWebApp> docker images
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docker images
Yes, it is created, now let’s try to run it.
PS C:\Users\Jaliya\Desktop\DockerWebApp> docker run dockerwebapp
Now I am getting an error “The specified framework 'Microsoft.NETCore.App', version '1.1.2' was not found.”.
image
docker run dockerwebapp
Of course, I have been using an older aspnetcore image, I am changing the Dockerfile as follows.
FROM microsoft/aspnetcore:1.1.2
LABEL Name=dockerwebapp Version=0.0.1
ARG source
WORKDIR /app
EXPOSE 30000
COPY ${source:-bin/Release/netcoreapp1.1/publish} .
ENTRYPOINT dotnet DockerWebApp.dll
Here is the link where you can find the list ASP.NET Core Docker image information.
https://hub.docker.com/r/microsoft/aspnetcore/

Now let’s run a docker build again.
PS C:\Users\Jaliya\Desktop\DockerWebApp> docker build -t dockerwebapp .
image
docker build -t dockerwebapp .
Now let’s run the image again.
image
docker run dockerwebapp
Yes, it seem to be working. Let’s run the following command in a new PowerShell Window to see the status of all the running Containers.
PS C:\Users\Jaliya> docker ps
Here note that I am running the command from another directory. You can run docker ps from sitting inside any directory.
image
docker ps -a
Now from let’s try to access to site http://localhost:30000 from a browser.
image
Site can't be reached
That’s because I haven’t mapped Container ports and host machines ports. I can easily to fix it by running docker run specifying port mappings.
PS C:\Users\Jaliya\Desktop\DockerWebApp> docker run -p 30000:80 dockerwebapp
image
docker run -p 30000:80 dockerwebapp
And now if I check for running Containers, I can see the ports are mapped.
image
docker ps
Now let’s browse to http://localhost:30000 back again. And this time, it works!
image
Site is running
In this post, I have used following commands in the background.
# List running containers
docker ps
 
# List all containers
docker ps -a
 
# List all images
docker images
 
# Stop given container
docker stop {container_name}
 
# Delete given container
docker rm {container_name}
 
# Delete given image
docker rmi {image_id}
 
# Delete all containers
docker rm $(docker ps -a -q)
 
# Delete all images
docker rmi $(docker images -q)
Hope you find this post helpful.

Again huge thanks goes out to Alex Thissen (@alexthissen) for all his help.

More reads,
Running and Exploring a Docker Linux Container

Happy Coding.

Regards,
Jaliya