dotnet-containers

Name: dotnet-containers
Author: wshaddix

65stars10forks

How to install dotnet-containers?

wshaddix/dotnet-skills/dotnet-containers

$npx -y skills add wshaddix/dotnet-skills --skill dotnet-containers

Installs into the current project.

Summary

Containerizing .NET apps. Multi-stage Dockerfiles, SDK container publish (.NET 8+), rootless.

Files · 1

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SKILL.md

1	# dotnet-containers
2
3	Best practices for containerizing .NET applications. Covers multi-stage Dockerfile patterns, the `dotnet publish` container image feature (.NET 8+), rootless container configuration, optimized layer caching, and container health checks.
4
5	Out of scope: DI container mechanics and service lifetimes -- see [skill:dotnet-csharp-dependency-injection]. Kubernetes deployment manifests and Docker Compose orchestration are covered in [skill:dotnet-container-deployment]. CI/CD pipeline integration for building and pushing images -- see [skill:dotnet-gha-publish] and [skill:dotnet-ado-publish]. Testing containerized applications -- see [skill:dotnet-integration-testing] for Testcontainers patterns.
6
7	Cross-references: [skill:dotnet-observability] for health check patterns, [skill:dotnet-container-deployment] for deploying containers to Kubernetes and local dev with Compose, [skill:dotnet-artifacts-output] for Dockerfile path adjustments when using centralized build output layout.
8
9	---
10
11	## Multi-Stage Dockerfiles
12
13	Multi-stage builds separate the build environment from the runtime environment, producing minimal final images.
14
15	### Standard Multi-Stage Pattern
16
17	```dockerfile
18	# Stage 1: Build
19	FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
20	WORKDIR /src
21
22	# Copy project files first for layer caching
23	COPY ["src/MyApi/MyApi.csproj", "src/MyApi/"]
24	COPY ["src/MyApi.Core/MyApi.Core.csproj", "src/MyApi.Core/"]
25	COPY ["Directory.Build.props", "."]
26	COPY ["Directory.Packages.props", "."]
27	RUN dotnet restore "src/MyApi/MyApi.csproj"
28
29	# Copy everything else and build
30	COPY . .
31	WORKDIR "/src/src/MyApi"
32	RUN dotnet publish -c Release -o /app/publish --no-restore
33
34	# Stage 2: Runtime
35	FROM mcr.microsoft.com/dotnet/aspnet:10.0 AS runtime
36	WORKDIR /app
37	EXPOSE 8080
38
39	COPY --from=build /app/publish .
40	ENTRYPOINT ["dotnet", "MyApi.dll"]
41	```
42
43	### Layer Caching Strategy
44
45	Order COPY instructions from least-frequently-changed to most-frequently-changed:
46
47	1. Project files and props -- change only when dependencies change
48	2. `dotnet restore` -- cached until project files change
49	3. Source code -- changes with every build
50	4. `dotnet publish` -- runs only when source or restore layer changes
51
52	```dockerfile
53	# Good: restore layer is cached when only source changes
54	COPY ["src/MyApi/MyApi.csproj", "src/MyApi/"]
55	RUN dotnet restore
56	COPY . .
57	RUN dotnet publish
58
59	# Bad: restore runs on every source change
60	COPY . .
61	RUN dotnet restore
62	RUN dotnet publish
63	```
64
65	### Solution-Level Restore
66
67	For multi-project solutions, copy all `.csproj` files and the solution file to enable a single restore:
68
69	```dockerfile
70	FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
71	WORKDIR /src
72
73	# Copy solution and all project files for restore caching
74	COPY ["MyApp.sln", "."]
75	COPY ["Directory.Build.props", "."]
76	COPY ["Directory.Packages.props", "."]
77	COPY ["src/MyApi/MyApi.csproj", "src/MyApi/"]
78	COPY ["src/MyApi.Core/MyApi.Core.csproj", "src/MyApi.Core/"]
79	COPY ["src/MyApi.Infrastructure/MyApi.Infrastructure.csproj", "src/MyApi.Infrastructure/"]
80	RUN dotnet restore
81
82	COPY . .
83	RUN dotnet publish "src/MyApi/MyApi.csproj" -c Release -o /app/publish --no-restore
84	```
85
86	---
87
88	## dotnet publish Container Images (.NET 8+)
89
90	Starting with .NET 8, `dotnet publish` can produce OCI container images directly without a Dockerfile. This uses the `Microsoft.NET.Build.Containers` SDK (included in the .NET SDK).
91
92	### Basic Usage
93
94	```bash
95	# Publish as a container image to local Docker daemon
96	dotnet publish --os linux --arch x64 /t:PublishContainer
97
98	# Publish to a remote registry
99	dotnet publish --os linux --arch x64 /t:PublishContainer \
100	-p:ContainerRegistry=ghcr.io \
101	-p:ContainerRepository=myorg/myapi
102	```
103
104	### MSBuild Configuration
105
106	Configure container properties in the `.csproj`:
107
108	```xml
109	<PropertyGroup>
110	<ContainerBaseImage>mcr.microsoft.com/dotnet/aspnet:10.0</ContainerBaseImage>
111	<ContainerImageName>myapi</ContainerImageName>
112	<ContainerImageTag>$(Version)</ContainerImageTag>
113	</PropertyGroup>
114
115	<ItemGroup>
116	<ContainerPort Include="8080" Type="tcp" />
117	</ItemGroup>
118	```
119
120	### Advanced Configuration
121
122	```xml
123	<PropertyGroup>
124	<!-- Use chiseled (distroless) base image for smaller attack surface -->
125	<ContainerBaseImage>mcr.microsoft.com/dotnet/aspnet:10.0-noble-chiseled</ContainerBaseImage>
126
127	<!-- Run as non-root user (default for chiseled images) -->
128	<ContainerUser>app</ContainerUser>
129	</PropertyGroup>
130
131	<ItemGroup>
132	<!-- Environment variables -->
133	<ContainerEnvironmentVariable Include="ASPNETCORE_URLS" Value="http://+:8080" />
134	<ContainerEnvironmentVariable Include="DOTNET_RUNNING_IN_CONTAINER" Value="true" />
135
136	<!-- Labels -->
137	<ContainerLabel Include="org.opencontainers.image.source" Value="https://github.com/myorg/myapi" />
138	</ItemGroup>
139	```
140
141	### When to Use dotnet publish vs Dockerfile
142
143	\| Scenario \| Recommendation \|
144	\|----------\|---------

wshaddixPublisher · 77 listings

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wshaddix/dotnet-skills

# dotnet-containers

Best practices for containerizing .NET applications. Covers multi-stage Dockerfile patterns, the `dotnet publish` container image feature (.NET 8+), rootless co

**Out of scope:** DI container mechanics and service lifetimes -- see [skill:dotnet-csharp-dependency-injection]. Kubernetes deployment manifests and Docker Com

Cross-references: [skill:dotnet-observability] for health check patterns, [skill:dotnet-container-deployment] for deploying containers to Kubernetes and local d

Repowshaddix/dotnet-skills

License—

TypeSkills

CategoryInfrastructure

UpdatedFeb 2026

Repo stars65

First seenJul 22, 2026

People who liked this also viewed

6 picks

Type

dotnet-containers

65stars10forks

View on GitHub

How to install dotnet-containers?

wshaddix/dotnet-skills/dotnet-containers

$npx -y skills add wshaddix/dotnet-skills --skill dotnet-containers

Installs into the current project.

Summary

Containerizing .NET apps. Multi-stage Dockerfiles, SDK container publish (.NET 8+), rootless.

Files · 1

View on GitHub

SKILL.md

1	# dotnet-containers
2
3	Best practices for containerizing .NET applications. Covers multi-stage Dockerfile patterns, the `dotnet publish` container image feature (.NET 8+), rootless container configuration, optimized layer caching, and container health checks.
4
5	Out of scope: DI container mechanics and service lifetimes -- see [skill:dotnet-csharp-dependency-injection]. Kubernetes deployment manifests and Docker Compose orchestration are covered in [skill:dotnet-container-deployment]. CI/CD pipeline integration for building and pushing images -- see [skill:dotnet-gha-publish] and [skill:dotnet-ado-publish]. Testing containerized applications -- see [skill:dotnet-integration-testing] for Testcontainers patterns.
6
7	Cross-references: [skill:dotnet-observability] for health check patterns, [skill:dotnet-container-deployment] for deploying containers to Kubernetes and local dev with Compose, [skill:dotnet-artifacts-output] for Dockerfile path adjustments when using centralized build output layout.
8
9	---
10
11	## Multi-Stage Dockerfiles
12
13	Multi-stage builds separate the build environment from the runtime environment, producing minimal final images.
14
15	### Standard Multi-Stage Pattern
16
17	```dockerfile
18	# Stage 1: Build
19	FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
20	WORKDIR /src
21
22	# Copy project files first for layer caching
23	COPY ["src/MyApi/MyApi.csproj", "src/MyApi/"]
24	COPY ["src/MyApi.Core/MyApi.Core.csproj", "src/MyApi.Core/"]
25	COPY ["Directory.Build.props", "."]
26	COPY ["Directory.Packages.props", "."]
27	RUN dotnet restore "src/MyApi/MyApi.csproj"
28
29	# Copy everything else and build
30	COPY . .
31	WORKDIR "/src/src/MyApi"
32	RUN dotnet publish -c Release -o /app/publish --no-restore
33
34	# Stage 2: Runtime
35	FROM mcr.microsoft.com/dotnet/aspnet:10.0 AS runtime
36	WORKDIR /app
37	EXPOSE 8080
38
39	COPY --from=build /app/publish .
40	ENTRYPOINT ["dotnet", "MyApi.dll"]
41	```
42
43	### Layer Caching Strategy
44
45	Order COPY instructions from least-frequently-changed to most-frequently-changed:
46
47	1. Project files and props -- change only when dependencies change
48	2. `dotnet restore` -- cached until project files change
49	3. Source code -- changes with every build
50	4. `dotnet publish` -- runs only when source or restore layer changes
51
52	```dockerfile
53	# Good: restore layer is cached when only source changes
54	COPY ["src/MyApi/MyApi.csproj", "src/MyApi/"]
55	RUN dotnet restore
56	COPY . .
57	RUN dotnet publish
58
59	# Bad: restore runs on every source change
60	COPY . .
61	RUN dotnet restore
62	RUN dotnet publish
63	```
64
65	### Solution-Level Restore
66
67	For multi-project solutions, copy all `.csproj` files and the solution file to enable a single restore:
68
69	```dockerfile
70	FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
71	WORKDIR /src
72
73	# Copy solution and all project files for restore caching
74	COPY ["MyApp.sln", "."]
75	COPY ["Directory.Build.props", "."]
76	COPY ["Directory.Packages.props", "."]
77	COPY ["src/MyApi/MyApi.csproj", "src/MyApi/"]
78	COPY ["src/MyApi.Core/MyApi.Core.csproj", "src/MyApi.Core/"]
79	COPY ["src/MyApi.Infrastructure/MyApi.Infrastructure.csproj", "src/MyApi.Infrastructure/"]
80	RUN dotnet restore
81
82	COPY . .
83	RUN dotnet publish "src/MyApi/MyApi.csproj" -c Release -o /app/publish --no-restore
84	```
85
86	---
87
88	## dotnet publish Container Images (.NET 8+)
89
90	Starting with .NET 8, `dotnet publish` can produce OCI container images directly without a Dockerfile. This uses the `Microsoft.NET.Build.Containers` SDK (included in the .NET SDK).
91
92	### Basic Usage
93
94	```bash
95	# Publish as a container image to local Docker daemon
96	dotnet publish --os linux --arch x64 /t:PublishContainer
97
98	# Publish to a remote registry
99	dotnet publish --os linux --arch x64 /t:PublishContainer \
100	-p:ContainerRegistry=ghcr.io \
101	-p:ContainerRepository=myorg/myapi
102	```
103
104	### MSBuild Configuration
105
106	Configure container properties in the `.csproj`:
107
108	```xml
109	<PropertyGroup>
110	<ContainerBaseImage>mcr.microsoft.com/dotnet/aspnet:10.0</ContainerBaseImage>
111	<ContainerImageName>myapi</ContainerImageName>
112	<ContainerImageTag>$(Version)</ContainerImageTag>
113	</PropertyGroup>
114
115	<ItemGroup>
116	<ContainerPort Include="8080" Type="tcp" />
117	</ItemGroup>
118	```
119
120	### Advanced Configuration
121
122	```xml
123	<PropertyGroup>
124	<!-- Use chiseled (distroless) base image for smaller attack surface -->
125	<ContainerBaseImage>mcr.microsoft.com/dotnet/aspnet:10.0-noble-chiseled</ContainerBaseImage>
126
127	<!-- Run as non-root user (default for chiseled images) -->
128	<ContainerUser>app</ContainerUser>
129	</PropertyGroup>
130
131	<ItemGroup>
132	<!-- Environment variables -->
133	<ContainerEnvironmentVariable Include="ASPNETCORE_URLS" Value="http://+:8080" />
134	<ContainerEnvironmentVariable Include="DOTNET_RUNNING_IN_CONTAINER" Value="true" />
135
136	<!-- Labels -->
137	<ContainerLabel Include="org.opencontainers.image.source" Value="https://github.com/myorg/myapi" />
138	</ItemGroup>
139	```
140
141	### When to Use dotnet publish vs Dockerfile
142
143	\| Scenario \| Recommendation \|
144	\|----------\|---------

wshaddixPublisher · 77 listings

Preview

wshaddix/dotnet-skills

# dotnet-containers

Best practices for containerizing .NET applications. Covers multi-stage Dockerfile patterns, the `dotnet publish` container image feature (.NET 8+), rootless co

**Out of scope:** DI container mechanics and service lifetimes -- see [skill:dotnet-csharp-dependency-injection]. Kubernetes deployment manifests and Docker Com

Cross-references: [skill:dotnet-observability] for health check patterns, [skill:dotnet-container-deployment] for deploying containers to Kubernetes and local d

Repowshaddix/dotnet-skills

License—

TypeSkills

CategoryInfrastructure

UpdatedFeb 2026

Repo stars65

First seenJul 22, 2026

People who liked this also viewed

6 picks

Type