I’m developing a DotNet Core hosted Blazor WebAssembly, as a frontend to my backend ASPNet Core API, running on Raspberry Pi’s, containerised in a Docker Swarm.
I’m developing on a MacBook Pro, using VSCode for Mac, and it’s really a great tool. I created the solution as “dotnet new blazorwasm —hosted” and got the solution created and build.
I have installed Docker Desktop, and created a Buildx builder for arm, which works great with all my other solutions (DotNet Core API, DotNet Background solutions), but with the hosted blazorwasm solution, I run into several problems, probably caused by my lacking knowledge on setting up build options.
So I installed Visual Studio 2019 (I have used VS on Windows for 20 years) and was actually surprised over the look and feel, a really great tool.
I created the hosted Blazor WebAssembly solution, which works great om Mac, and even the Docker desktop integration work without problems.
Building the Docker Image was easy, I just used my Buildx builder, and executed below command from the command line:
“docker buildx build --file ./SnakeConsole/Server/Dockerfile --platform linux/arm/v7 -t jagdriver/wavesnake:SnakeConsole3 --push .”
On the Raspberry Swarm, I then created the Stack/Container. The Stack installed but the container refused to start, and the log was:
standard_init_linux.go:211: exec user process caused “exec format error”.
I have seen this error before, and as far as I remember I added “-r ubuntu.19.10-arm” to the dotnet publish command to ensure that the code is generated for linux-arm.
So I tried to add “-r ubuntu.19.10-arm” to the dotnet publish command in below dockerfile, and execute the Docker buildx build command again, but then the Build Engine run into below error.
project.assets.json' doesn't have a target for '.NETCoreApp,Version=v5.0/browser-wasm'. Ensure that restore has run and that you have included 'net5.0' in the TargetFrameworks for your project. You may also need to include 'browser-wasm' in your project's RuntimeIdentifiers
Can anyone out the give me a helping hand on this, thanks in advance.
FACTS:
The solution I’m mentioning is the standard Hosted Blazor
WebAssembly template without any changes.
The target framework is .Net 5.0
Visual Studio for Mac community is version 8.7.2 (build 4)
Docker file from the default hosted Blazor WebAssembly template.
FROM mcr.microsoft.com/dotnet/aspnet:5.0-buster-slim AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443
FROM mcr.microsoft.com/dotnet/sdk:5.0-buster-slim AS build
WORKDIR /src
COPY SnakeConsole/Server/SnakeConsole.Server.csproj SnakeConsole/Server/
COPY SnakeConsole/Client/SnakeConsole.Client.csproj SnakeConsole/Client/
COPY SnakeConsole/Shared/SnakeConsole.Shared.csproj SnakeConsole/Shared/
RUN dotnet restore "SnakeConsole/Server/SnakeConsole.Server.csproj"
COPY . .
WORKDIR "/src/SnakeConsole/Server"
RUN dotnet build "SnakeConsole.Server.csproj" -c Release -o /app/build
FROM build AS publish
RUN dotnet publish "SnakeConsole.Server.csproj" -c Release -o /app/publish
FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "SnakeConsole.Server.dll"]
Have faced similar issue, documentation says:
Deploying a standalone Blazor WebAssembly app to Azure App Service for Linux isn't currently supported. A Linux server image to host the app isn't available at this time. Work is in progress to enable this scenario.
https://learn.microsoft.com/en-us/aspnet/core/blazor/host-and-deploy/webassembly?view=aspnetcore-5.0#standalone-deployment
Looks like this is a Docker OS compatibility and framework functionality issue. I would suggest to target your app to Server (Blazor Server Hosting model scenario).
Related
Apologies from the start but please bear with me, I am still rather novice at this so if you see any issues glaringly obvious, please forgive me.
I am working at a company where some devs are trying to have us deploy some .NET Core applications to containers in Azure Kubernetes Service (AKS). From my understanding, they have been written in .NET Core 3.1. The goal is to run this process using a CI/CD Azure Pipeline, using Azure Repos as repository, using a build pipeline to create the docker image, push image to our Azure Container Registry and create an artifact for the release pipeline to then deploy (using helm) contianers into the AKS.
File Structure is as follows:
Dockerfile
FROM mcr.microsoft.com/dotnet/aspnet:6.0 AS base
EXPOSE 80
FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
COPY ["AppFolder1\App.csproj", "."]
RUN dotnet restore "AppFolder1\App.csproj"
COPY . .
RUN dotnet build "AppFolder1\App.csproj" -c Release -o /app/build
FROM build AS publish
RUN dotnet publish "AppFolder1\App.csproj" -c Release -o /app/publish
FROM base AS final
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "DotNet.Docker.dll"]
ERROR
Question: Could there be an issue with 6.0 sdk when trying to deploy app made with .net core 3.1?
running "kubectl get pods -n redacted-namespace"
a) retrieves two pods with CrashLoopBackOff Status showing 9 restarts
running "kubectl define pod -n redacted-namespace" retrieves information on pods
a) both pods show successful pod scheduling - Successfully assigned redacted-namespace/ to aks-nodepool1-02 AND aks-nodepool1-00
b) Both show multiple successful pull of image
c) Both show creation of container and start of container
d) End message:
Warning BackOff 58s (x117 over 26m) kubelet Back-off restarting failed container
--ATTEMPTS TO SOLVE--
It was suggested that the Dockerfile was to blame. Spent time creating and running pipeline with multiple iterations of dockerfile, including changing .net versioning to 3.1 from 6.0. No successful pipelines using these dockerfiles yet.
running kubectl logs <pod-name> -n redacted-namespace:
Could not execute because the application was not found or a compatible .NET SDK is not installed.
Possible reasons for this include:
* You intended to execute a .NET program:
The application 'DotNet.Docker.dll' does not exist.
* You intended to execute a .NET SDK command:
It was not possible to find any installed .NET SDKs.
Install a .NET SDK from:
https://aka.ms/dotnet-download
I had figured that the installation of the .NET SDK should have been handled by the dockerfile line 1, however it doesn't seem to be working properly. In the meantime, adding in pipeline release Agent Task Use .NET Core sdk 6.0 and deleting previous pods to try again.
Re-running pipeline release - No effect. Likely .NET Core SDK install agent task does not work inside of each pod and is therefore not available as an installed resource within pods and replicas.
Apparently there were TWO problems with the Dockerfile. The first and foremost, #Hans Kilian, you're absolutely right. Apparently they were using .NET 3.1. The other issue was the ENDPOINT I had set up was not pointing to the right .dll file. This I found by going to Solutions/App.sln and pulled the name from the Project line (something like Project("################################")= "Project_name"... Its working and running just fine now. Thank you!
I'm trying to run my dotnet 5 single file app with Alpine Linux docker image.
This is my Dockerfile
FROM mcr.microsoft.com/dotnet/aspnet:5.0-alpine
WORKDIR /app
COPY ["Service.Translations", "/app/Service.Translations"]
CMD ["./Service.Translations", "--urls", "http://0.0.0.0:5000"]
This was framework-dependent app. Also tried with self-contained and result is the same:
not found. Dotnet doesn't see my file and sh doesn't see too.
Is it problem because I built my app on Windows? All tutorials with alpine compile app inside image. If I change Alpine to Ubuntu or smth else - everything is ok.
UPDATE:
Ok, problem was with publish. I had to change --runtime to linux-musl-x64 instead of linux-x64
I found the problem. Alpine Linux uses musl c library and it makes standard dotnet build incompatible with this linux distro. Visual studio doesn't have all publish runtime options. Here https://learn.microsoft.com/en-us/dotnet/core/rid-catalog you can find all of them. So for alpine linux we have to use linux-musl-x64 runtime instead of linux-x64
My ASP.NET Core 2.1 webapp works perfectly on my dev setup. Now I want to test it in production.
The production server is Ubuntu 18. I followed the instructions. I don't want to setup nginx yet, just do some quick tests, and the instructions say:
"Either configuration—with or without a reverse proxy server—is a valid and supported hosting configuration for ASP.NET Core 2.0 or later apps".
So I built and published my project: dotnet publish --configuration Release.
Then on the server:
install the dotnet runtime
copied files to server (/var/www/myapp)
opened ports: sudo uwf allow 5000/tcp 80/tcp
run dotnet MyApp.dll (also tried sudo dotnet MyApp.dll)
It runs without errors/warnings, and says it's listening on http://localhost:5000.
On my local machine I tried http://serveripaddress (and http://serveripaddress:5000) but get nothing ("can't connect"). I can access that server with ssh, sftp, etc - only http isn't working.
What am I doing wrong?
the host default bind is 127.0.0.1 , so you can only access the app locally. if you want to access it from Network, please add --urls parameter. for example :
for development, you can run:
dotnet run --urls http://0.0.0.0:5000
and for deployed project, you can run:
dotnet MyApp.dll --urls http://0.0.0.0:5000
The dotnet core sdk I use is version 2.1.400.
Found the problem. I needed to use:
ASPNETCORE_URLS="http://0.0.0.0:5000" sudo dotnet MyApp.dll
Then it logs Now listening on: http://0.0.0.0:5000. And I can access that from a remote client.
When developing node.js projects I will normally use docker compose to bring up an entire stack of docker containers in order to develop on my local host. I mount volumes in and use nodemon to automatically update the running server. This works well. However, it does not seem to work quite the same way with asp.net core.
Is it possible to run a development container for an asp.net core application? I would like to have the server restart when there is a change on the host machine to a file. I know you can do this with the dotnet watch run command but I'm yet to see it working inside a running docker container. How can I get this working within a docker compose stack? What docker base image should I be using? Ideally this solution will work from the command line without using visual studio as I'm using Visual Studio code on a mac.
A little bit late to the party, but maybe it will help someone.
Here is the sample project setup that will leverage dotnet watch command
in a docker container, while source code is being edited on the host system.
As far as I know dotnet watch now is a global tool so you can use it with
different versions of .netcore.
Here is the documentation for
dotnet watch command.
Sample project overview
Here is a small example project for demo purposes, made with help of minimal api.
It has one endpoint /freshbread which returns "Baked bread".
Folder structure:
Bakery
│ Dockerfile
└───src
│───Bakery.csproj
└───Program.cs
Content of Program.cs:
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.MapGet("/freshbread", () => "Baked bread");
app.Run("http://*:80");
Content of Bakery.csproj
<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
<TargetFramework>net6.0</TargetFramework>
<Nullable>enable</Nullable>
<ImplicitUsings>enable</ImplicitUsings>
</PropertyGroup>
</Project>
Content of Dockerfile:
FROM mcr.microsoft.com/dotnet/sdk:6.0
WORKDIR /app
ENTRYPOINT ["dotnet", "watch"]
Based on a Microsoft .net core SDK image. It just defines an /app workdir and launches there dotnet watch command.
The "trick" here is to mount into /app folder your source code from the host machine and let container handle compilation
and server restart, so:
Build an image (from Bakery folder):
docker build -t dev-container .
Run a container:
docker run \
--rm \
--detach \
--volume /path/to/the/Bakery/src:/app \
--publish 5000:80
dev-container
Publish port outside, so api will be accessible from the host machine.
Now, container is watching files in mounted folder and whenever there are chages
it will perform hot-reload.
Demo
Here is a short demo of this setup, note that top and bottom-right splits are host machine terminals and bottom-left split is log of the container.
I want to publish my dotnet core app to IIS from mac. I use VS code for code writing and Dotnet Core 1.1 for publishing to local directory. (for example: bin/release/publish). There are compiled my files, ready to copy to IIS. On my IIS I currently have installed web deploy 3.6 and this is my VPS machine. Is there elegant way, how to copy files? The another way is using docker, but in this case I have the same problem. Generated docker file with docker publisher tool and I need to copy from mac os.
Thank you for your time.
From a terminal window navigate to the folder where your .csproj file is. From there run 'dotnet publish -c release'. A folder called publish will be created in bin/Release/netcoreappX.X. You can copy those files to the appropriate directory on your server. If you need help setting up IIS, follow the link below.
https://learn.microsoft.com/en-us/aspnet/core/publishing/iis
You can also run 'dotnet publish -h' to see all of the different arguments you can pass to the publish command.
Web Deploy (msdeploy.exe) seems to work in Mono, at least in WSL (Ubuntu 18.04). The tricky part is to extract the msi package somehow, which you can do easily on a Windows machine (you'll find the files in C:\Program Files\IIS\Microsoft Web Deploy V3).
Once you install Mono and obtain msdeploy.exe, just call the command, e.g.
mono msdeploy.exe -verb:sync -source:contentPath=/mnt/c/Data -dest:contentPath=test,ComputerName=https://example.com:8172/msdeploy.axd,UserName=WDeployAdmin,Password=PASSWORD,IncludeAcls=False,AuthType=Basic -enableRule:AppOffline -enableRule:DoNotDeleteRule -verbose -allowUntrusted:true
This lets you sync/copy the contents of /mnt/c/Data with the test web site in IIS on example.com with Web Deploy enabled.