Deploying .NET Core Applications

This section covers various strategies and considerations for deploying your .NET Core applications to different environments. Successful deployment ensures your application is accessible, performant, and secure for your users.

Deployment Strategies

Choosing the right deployment strategy depends on your application's needs, target environment, and team expertise. Common strategies include:

• Self-Contained Deployments: The .NET Core runtime and libraries are deployed with your application. This allows your application to run without a pre-installed .NET Core version on the target machine.
• Framework-Dependent Deployments: Your application depends on a shared .NET Core runtime installed on the target machine. This is more efficient in terms of disk space when deploying multiple applications.
• Containerization (Docker): Packaging your application and its dependencies into a container provides consistency across development, testing, and production environments.
• Cloud Deployment: Leveraging cloud platforms like Azure, AWS, or Google Cloud offers scalability, managed services, and simplified deployment pipelines.

Preparing for Deployment

Before deploying, ensure your application is ready:

Publishing Your Application

The .NET CLI provides powerful commands to publish your application. Use the dotnet publish command:

# Publish a framework-dependent executable
dotnet publish -c Release -f net6.0 --runtime linux-x64 --self-contained false

# Publish a self-contained executable
dotnet publish -c Release -f net6.0 --runtime win-x64 --self-contained true
            

Key flags:

• -c Release: Compiles in Release mode, optimizing for performance.
• -f <runtime-identifier>: Specifies the target runtime (e.g., net6.0 for .NET 6, linux-x64, win-x64).
• --self-contained <true|false>: Determines whether to include the .NET Core runtime.

Configuration Management

Application settings should be managed externally to avoid recompiling the application for configuration changes. .NET Core supports various configuration providers:

• JSON files (appsettings.json, appsettings.{Environment}.json)
• Environment variables
• Command-line arguments
• Azure Key Vault

Consider using the ASPNETCORE_ENVIRONMENT environment variable (e.g., Development, Staging, Production) to load environment-specific settings.

Deployment Targets

Windows Server

Deploying to Windows Server typically involves:

1. Installing the .NET Core Runtime (if using framework-dependent deployment) or ensuring the self-contained deployment is present.
2. Configuring IIS or another web server to host your application.
3. Setting up the application pool and virtual directory.

You can also use the .NET Core Hosting Bundle for IIS.

Linux

Common deployment methods for Linux include:

• Using Nginx or Apache as a reverse proxy to forward requests to your Kestrel web server.
• Running your application as a systemd service for process management.
• Publishing as a self-contained executable for easier deployment.

# Example using systemd on Linux
# Create a .service file in /etc/systemd/system/

[Unit]
Description=My .NET Core App

[Service]
WorkingDirectory=/path/to/your/app
ExecStart=/usr/bin/dotnet /path/to/your/app/YourApp.dll
Restart=always
# Other configurations...

[Install]
WantedBy=multi-user.target
            

Containerization with Docker

Docker simplifies deployment by packaging your application. A sample Dockerfile:

# Use an official .NET Core runtime as a parent image
FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
WORKDIR /app

# Copy the application and project files
COPY *.csproj ./
RUN dotnet restore

COPY . ./
RUN dotnet publish -c Release -o out

# Build runtime image
FROM mcr.microsoft.com/dotnet/aspnet:6.0 AS runtime
WORKDIR /app
COPY --from=build /app/out .

ENTRYPOINT ["dotnet", "YourApp.dll"]
            

Build and run your Docker image:

docker build -t my-dotnet-app .
docker run -p 8080:80 my-dotnet-app
            

Deployment Best Practices

• Automate Deployments: Use CI/CD pipelines (Azure DevOps, GitHub Actions, Jenkins) to automate the build, test, and deployment process.
• Monitor Your Application: Implement robust logging and monitoring (Application Insights, Prometheus, Grafana) to track performance and identify issues.
• Security First: Regularly update your .NET Core runtime and dependencies to patch security vulnerabilities. Secure your connection strings and sensitive configuration data.
• Environment Variables: Prefer environment variables for configuration in production environments for better security and flexibility.