Accessing Docker Swarm Secrets From Asp Net Core

The second day, this happened again and it was worse, the API with the memory leak was almost consuming 4GB. Which is up to 5 times more resources compared to other APIs. I will leave it to the official documentation to describe exactly how all this works but when you give a service access to the secret you essentially give it access to an in-memory file. This means your application needs to know how to read the secret from the file to be able to use the application.

You have to find the Network Security Group tab from the VM settings, then the Network Security Group tab then the Inbound Security Rules tab. I created an Ubuntu Server 14.04 VM (at the moment of writing this article, only Ubuntu 14.04 and 15.04 are supported by Docker Cloud). If you link the Docker Cloud account with your cloud subscription , you can create nodes and clusters directly from the Docker Cloud portal. And this is the entire ASP.NET Core application we will use for this article. There’s a lot more to learn about Serilog in ASP.NET Core 3. One option is using the Azure-based “party clusters” that Microsoft maintain so you can experiment with Service Fabric.

• So in my previous post, I had separated the different layers into separate projects, however, when deploying through VS2017 I encountered some limitations in the Visual Studio tooling for Entity Framework Core (1.0) migrations.
• Choose a Server Name and fill out the rest of the inputs, make sure you use strong credentials for your server configuration.
• So far we created a very simple ASP .NET Core application and we ran it locally inside Docker.We haven’t used the GitHub repo, Docker Hub, Docker Cloud or Azure just yet.
• It’s impossible to cover everything related to a well performing app, but this post will give you some guidance at least.
• I did not have metrics for everything here, but I tried one thing after another – inspecting that the application behaved good/better and continued.

You need to play detective to find out what might be wrong. Noticed that the project has two databases that will be deployed along with their respective Entity Framework Migrations. This is a nice feature because you can deploy multiple databases at the same time, such as an identity database and a product database. Once you have all the tools installed and the source code for your project, open up the solution for your API Project and conduct a Build in order to make sure everything is working as expected.

Visual Studio 2017 Installation Configuration

You can use this function anytime after the configuration has been loaded from other providers. You will likely call this function somewhere in your startup.cs but could be anywhere you have access to the Configuraiton object. Note that depending on your set-up you may want to tweak the function to not fall back on the Configuration object.

At this point, you can create additional service and start containers on this machine, provided you open ports on the VM with the procedure described above. This will be the part with the least focus in this article, since we have covered building ASP.NET Core applications for a while now and you can find a lot resources on this topic, including some on this site. Then, we will configure an Azure VM to be a node for Docker Cloud and Docker Cloud will automatically publish containers to that VM.

Creating A Service Based On The Image We Created

I did have a feeling that we were not going things right in our code, so I started to search for “pitfalls”. If you are like me – having an app runing inside Kubernetes – you might also have questions such as “is my app behaving well?”. It’s impossible to cover everything related to a well performing app, but this post will give you some guidance at least. We also tried various different ways to reproduce the problem in our development environment. Browse other questions tagged ubuntu docker memory asp.net-core .net-core or ask your own question.

It needs to be used to store coredump.1 The directory of the file is mounted to the container , Or yourself cp go in . [[email protected] Diagnostic_scenarios_sample_debug_target]# docker build -t dumptest . The example contains leaked memory 、 Deadlock thread 、CPU It’s taking too much of an interface , Easy to learn .

Ideally you should avoid adding this kind of run-time implementation detail as it undermines the portability of the service. Generate some deadlock threads and memory leaks through the interface provided in the example . During same period as above memory graph.We can see see that memory usage is now much better and well-suited to fit into k8s. The green line is average response times.This web application handles roughly 1k requests per minute, so that is very low compared to what ASP.NET Core is benchmarked against. On the other hand, it’s a web application that is very dependent on other API’s as it doesn’t have it’s own storage, so one request in results in 1-5 different outgoing dependency calls to other API’s.

There’s one more thing we had to look at in my case, since we made a lot external API calls and used the network a lot. I did not have metrics for everything here, but I tried one thing after another – inspecting that the application behaved good/better and continued. Unfortunately I don’t have updated graphs in-between each step I took.

Creating An Asp Net Core Configuration Provider

This ends up being a bad idea in a Docker containers because any one who can do an inspect can see the secrets. Docker Swarm introduced Secrets in version 1.13, which enables your share secrets across the cluster securely and only with the containers that need access to them. The secrets are encrypted during transit and at rest which makes them a great way to distribute connection strings, passwords, certs or any other sensitive information. Set Environment variables Set the edit environment variables and link your service to other existing services in Docker Cloud.

Once the service is running you can use rolling upgrades to push new versions without downtime, though be aware that upgrading requires you to change the version number on your container image tag. If you tag your images with “latest” then service fabric does not download them when you run an update. Kubernetes runs the applications in Docker images, and with Docker the container receives the memory limit through the –memory flag of the docker run command. So I was wondering that maybe Kubernetes is not passing in any memory limit, and the .NET process thinks that the machine has a lot of available memory. The fastest way to look into a memory leak is to create a dump file of the process in production. There’s no need to try to reproduce the problem because you can access all the data you need.

Be careful how you configure your dependency injection container. Make sure scoped services are scoped and singletons are singletons. Otherwise unnecessary objects might be created as your traffic increases.

Of course at a first glance this might sound very bad, but I was pretty confident the app still did “the right thing”, I just wanted to use the right lifetime for each service. By creating a dump file of the process, we have a way to look into the process. All of the information that we need is already there, it just needs to be collected and analyzed.

You’ll notice in the snippet above, the URL of the Seq server is hard-coded. URLs, API keys, etc. will commonly vary between your local development environment, and your app’s staging or production environments. If you usually have bursts of traffic at different times you might want to increase the miniumum amount of threads the ThreadPool can create on demand. By default the ThreadPool will only create Environment.ProcessorCount number of threads on demand. These things are essential to know when trying to understand memory usage and “wellbeing” of you application, so I thought i’ll mention them.

We noticed that the process of a new API was consuming more memory compared to other processes. At first, we didn’t think much of it and we assumed it was normal because this API receives a lot of requests. At the end of the day, the API almost tripled its memory consumption and at this time we started thinking that we had a memory leak.

This makes it possible to prototype applications and write tests without having to set up a local or external database. When you’re ready to switch to using a real database, you can simply swap in your actual provider. You can host containers in Service Fabric, but it is first and foremost an application server.

How Do I Reduce Memory Usage For Net Core Docker Containers?

I am a London-based technical architect who has spent more than twenty five years leading development across start-ups, digital agencies, software houses and corporates. Over the years I have built a lot of stuff including web sites and services, systems integrations, data platforms, and middleware. My current focus is on providing architectural leadership asp net usage in agile environments. Perhaps Service Fabric’s support for containers could be seen in the context of supporting a longer-term migration strategy. If you’ve already made a significant investment in Service Fabric, then you can start to migrate towards a more “cloud native” style of service without having to replace your runtime infrastructure.

After you click Save and Build the image building will start on the machine you provided. After the command above successfully executed and you refreshed your Docker Cloud tab, you should see your newly created node. After the deployment succeeds, we will need to open some ports on that VM so the Docker Cloud self discovery service can work.

In this tutorial you use the dotnet commands, dotnet trace, dotnet counters, and dotnet dump to find and troubleshoot process. This article will walk through the basics of reading that file from an ASP.NET Core application. The basic steps would be the same for ASP.NET 4.6 or any other language. I’ve used the InMemory provider to rapidly prototype APIs and test ideas, and my favorite part is the ability to switch one line of code to connect to a live database like SQL Server.

Using Dotnet Dump To Analyze The Memory Leak Of Docker Container

It’s also useful for building integration tests that need to exercise your data access layer or data-related business code. Instead of standing up a database for testing, you can run these integration tests entirely in memory. Basically, the Dockerfile is like a recipe for building container images. It is a script composed of multiple commands executed successively to create images based on other images. — It’s easy enough to use if() and environment variables to choose between pre-configured sinks in code, if you’re in a situation where this is required. Before diving into how to deploy the application, it would be good to know just a little bit on how things are setup in my test sample project.

You can provision a Service Fabric cluster in Azure but be aware that you will be charged by the hour for all the VMs, storage and network resources that you use. The cheapest test cluster will still require three VMs to be running in a virtual machine scale set. De-allocating the set of VMs stops the clock ticking on VM billing but it effectively resets the clusters , forcing you to redeploy everything when it comes back up. This has the effect of embedded configuration detail about the orchestrator into your service code.

Setting The Container Image And Registry

In this article you can see the detailed process on how to open ports for Azure VMs. In this case we will normally create a VM from the Azure Portal (or from any other cloud provider or on-premise) and install the Docker Cloud agent. The main part of a CI/CD workflow like this is the application itself. It can be however complicated, but in this case I want to emphasize the workflow itself and will only build a very simple application with ASP.NET Core. So far, we’ve seen WriteTo.Console() and WriteTo.File(), both of which are available through the Serilog.AspNetCore package. Other log outputs like Seq are distributed via NuGet in additional packages.

Your Job Is Not To Write Code

These are all decisions that the runtime will take no matter what; and to improve them we must first understand them. We have an ASP.NET Core 3.1 web application in k8s running with 3 pods in total. Normally each pod have had a memory limit for 300MB which have been working well for two months, and all of a sudden we saw spikes in CPU usage and response times . The memory usage didn’t increase infinitely any more , but it capped at around 600MB, and this number seemed to be pretty consistent between different container instances and restarts.

Updating The Application

We automatically thought that our APIs had memory leaks, and spent quite a lot of time investigating the issue, checking the allocations with Visual Studio, creating memory dumps, but couldn’t find anything. After the users and posts are asynchronously retrieved from the database, the array is projected into a response model that includes only the fields you need in the response. It is not production ready, as it does not have any testing workflow put in place and the application is rather simple. So far we created a very simple ASP .NET Core application and we ran it locally inside Docker.We haven’t used the GitHub repo, Docker Hub, Docker Cloud or Azure just yet. This command started our container, so Docker must have executed dotnet run inside the container , so the application should have started. In the folder that was just created from cloning the repository, execute dotnet new in order to create a new .NET Core application.

Every container is built upon an image, that is composed of the application itself and its dependencies. If you already have a repo with an application you want to use you can do that. However, I will create a new repo and clone it on my computer. The resulting logs are much quieter, and because important properties like the request path, response status code, and timing information are on the same event, it’s much easier to do log analysis. We’ll be a bit tactical about where we add Serilog into the pipeline.