changed up

Dockerfile

@@ -3,20 +3,28 @@ FROM docker.io/gitea/act_runner:latest
 # Switch to root to install packages
 USER root
 
-# Update package lists and install prerequisites
-RUN apt-get update && apt-get install -y \
+# Update Alpine packages and install prerequisites
+RUN apk update && apk add --no-cache \
     wget \
-    apt-transport-https \
-    software-properties-common \
-    && rm -rf /var/lib/apt/lists/*
+    curl \
+    bash \
+    icu-libs \
+    ca-certificates \
+    && rm -rf /var/cache/apk/*
 
 # Add Microsoft package repository and install .NET SDK
-RUN wget https://packages.microsoft.com/config/ubuntu/22.04/packages-microsoft-prod.deb -O packages-microsoft-prod.deb \
-    && dpkg -i packages-microsoft-prod.deb \
-    && rm packages-microsoft-prod.deb \
-    && apt-get update \
-    && apt-get install -y dotnet-sdk-9.0 \
-    && rm -rf /var/lib/apt/lists/*
+# Microsoft doesn’t publish Alpine .NET SDK packages in apt repos,
+# so you need to install the official tarball instead
+RUN wget https://builds.dotnet.microsoft.com/dotnet/Sdk/9.0.305/dotnet-sdk-9.0.305-linux-musl-x64.tar.gz \
+    -O dotnet-sdk.tar.gz \
+    && mkdir -p /usr/share/dotnet \
+    && tar -zxf dotnet-sdk.tar.gz -C /usr/share/dotnet \
+    && rm dotnet-sdk.tar.gz
+
+
+# Set environment variables for .NET before verifying installation
+ENV DOTNET_ROOT=/usr/share/dotnet
+ENV PATH=$PATH:/usr/share/dotnet
 
 # Verify .NET installation
 RUN dotnet --version
@@ -25,9 +33,8 @@ RUN dotnet --version
 # Check what user the base image uses
 RUN id
 
-# Set environment variables for .NET
-ENV DOTNET_ROOT=/usr/share/dotnet
-ENV PATH=$PATH:/usr/share/dotnet
-
 # Keep the original entrypoint from act_runner
 # The base image will handle the act_runner functionality
+
+# Switch back to the original user
+USER runner