initial setup

Dockerfile

@@ -0,0 +1,49 @@
+ARG CONFIG_DIRECTORY_ARG=/config
+ARG CERT_PASSWORD_FILE_ARG=$CONFIG_DIRECTORY_ARG/password
+FROM mcr.microsoft.com/dotnet/sdk:8.0-alpine-amd64 AS build-env
+ARG CERT_PASSWORD_FILE_ARG
+ENV CERT_PASSWORD_FILE=$CERT_PASSWORD_FILE_ARG
+ARG CONFIG_DIRECTORY_ARG
+ENV CONFIG_DIRECTORY=$CONFIG_DIRECTORY_ARG
+RUN mkdir $CONFIG_DIRECTORY \
+  && apk upgrade --update-cache --available \
+  && apk add openssl \
+  && rm -rf /var/cache/apk/* \
+  && openssl rand -base64 12 >> "$CERT_PASSWORD_FILE" \
+  && CERT_PASSWORD=$(cat $CERT_PASSWORD_FILE) \
+  && dotnet dev-certs https --export-path /config/aspnetapp.pem --password "$CERT_PASSWORD" --format PEM
+
+FROM mcr.microsoft.com/dotnet/aspnet:8.0-alpine-amd64
+ARG CERT_PASSWORD_FILE_ARG
+ENV CERT_PASSWORD_FILE=$CERT_PASSWORD_FILE_ARG
+ARG CONFIG_DIRECTORY_ARG
+ENV CONFIG_DIRECTORY=$CONFIG_DIRECTORY_ARG
+ENV DOTNET_CLI_TELEMETRY_OPTOUT=1
+ENV ASPNETCORE_ENVIRONMENT=Production
+ENV ASPNETCORE_URLS=http://+:80;https://+:443
+ENV CERTIFICATES_DIRECTORY=/usr/local/share/ca-certificates
+ENV ASPNETCORE_Kestrel__Certificates__Default__Path=$CERTIFICATES_DIRECTORY/aspnetapp.crt
+ENV ASPNETCORE_Kestrel__Certificates__Default__KeyPath=$CERTIFICATES_DIRECTORY/aspnetapp.key
+ENV TZ = Europe/Brussels
+RUN apk update \
+  && apk upgrade --available \
+  && apk add ca-certificates \
+  && apk add  tzdata \
+  && rm -rf /var/cache/apk/* \
+  && mkdir -p $CERTIFICATES_DIRECTORY \
+  && mkdir -p $CONFIG_DIRECTORY
+COPY --from=build-env $CONFIG_DIRECTORY $CONFIG_DIRECTORY
+RUN CERT_PASSWORD=$(cat $CERT_PASSWORD_FILE) \
+  && cp $CONFIG_DIRECTORY/aspnetapp.pem $ASPNETCORE_Kestrel__Certificates__Default__Path \
+  && cp $CONFIG_DIRECTORY/aspnetapp.key $ASPNETCORE_Kestrel__Certificates__Default__KeyPath \
+  && rm -rf $CONFIG_DIRECTORY \
+  && chmod 755 $ASPNETCORE_Kestrel__Certificates__Default__Path \
+  && chmod +x $ASPNETCORE_Kestrel__Certificates__Default__Path \
+  && cat $ASPNETCORE_Kestrel__Certificates__Default__Path >> /etc/ssl/certs/ca-certificates.crt \
+  && chmod 755 $ASPNETCORE_Kestrel__Certificates__Default__KeyPath \
+  && chmod +x $ASPNETCORE_Kestrel__Certificates__Default__KeyPath \
+  && update-ca-certificates
+ENV ASPNETCORE_Kestrel__Certificates__Default__Password=$CERT_PASSWORD
+
+EXPOSE 80 
+EXPOSE 443

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2025 david
+Copyright (c) 2025 David Claeys
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

README.md

@@ -1,3 +1,37 @@
 # net-base
 
-Base  docker file for .Net applications
+Base  docker file that allows you to deploy .NET wit ease.
+Microsoft makes some images available to deploy .NET applications in Docker.
+However in order to use them, there is need for some tweaking.
+
+This image is based on the *mcr.microsoft.com/dotnet/aspnet* image, but includes these tweaks.
+Among other things these tweaks are included :
+ - automatic generation of certificate for the web server
+ - disable telemetry
+ - inclusion of tzdata for time setup
+
+
+ ## Docker image
+
+### Environment Variables
+
+| Variable                                            | Description                                                             | Default                                                                                      |
+|-----------------------------------------------------|-------------------------------------------------------------------------|----------------------------------------------------------------------------------------------|
+| ASPNETCORE_Kestrel__Certificates__Default__Path     | The path containing the server certificate                              | /usr/local/share/ca-certificates/aspnetapp.crt                                               |
+| ASPNETCORE_Kestrel__Certificates__Default__KeyPath  | The path containing the key for the server certificate                  | /usr/local/share/ca-certificates/aspnetapp.key                                               |
+| ASPNETCORE_Kestrel__Certificates__Default__Password | The password for required for the server key                            | N/A (generated at build time)                                                                |
+| CERTIFICATES_DIRECTORY                              | The directory where the certificate files are stored for the web server | /usr/local/share/ca-certificates                                                             |
+| ASPNETCORE_URLS                                     | Specifies at which urls and ports the Kestrel server should listen      | http://+:80;https://+:443                                                                    |
+| DOTNET_CLI_TELEMETRY_OPTOUT                         | Disables telemetry                                                      | 1                                                                                            |
+| TZ                                                  | Time zone ([list](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List)) | Europe/Brussels |                                                                               |
+
+### Security implications
+
+This images uses the system provided by Microsoft to generate a development certificate and uses the [Kestrel](https://learn.microsoft.com/en-us/aspnet/core/fundamentals/servers/?view=aspnetcore-9.0&tabs=windows) webserver.
+In previous .NET versions it was not recommended to expose Kestrel directly to the internet. Now Microsoft claims you can do that.
+However you never should use the included development certificate if you want to do that.
+
+If you want to expose the Kestrel server you should use the *ASPNETCORE_Kestrel__Certificates__Default__Path*, *ASPNETCORE_Kestrel__Certificates__Default__KeyPath* and *ASPNETCORE_Kestrel__Certificates__Default__Password* variables to correclty setup a certificate. The _dotnet dev-certs_ command is not really suited for production environments.
+
+In practice it's much easier to expose the server through a proxy to the public (hence the recommended method). 
+And depending on your use-case you event might consider to use docker networking in order to accomplish proper isolation.