adding docker file

.github/workflows/build.yml

@@ -25,6 +25,24 @@ jobs:
         with:
           name: bindings.zip
           path: build/bindings.zip
+  build-linux-ubi8-gcc12:
+    runs-on: ubuntu-20.04
+    steps:
+      - run: sudo apt update
+      - run: sudo apt install -y uuid-dev
+      - uses: actions/checkout@v2
+        with:
+          submodules: true
+      - 
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      -
+        name: Build
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: ./Dockerfile
+          platforms: linux/amd64
   build-macos:
     runs-on: macos-latest
     steps:
@@ -41,7 +59,6 @@ jobs:
         with:
           name: lib3mf.dylib
           path: build/lib3mf.dylib
-
   codecoverage-macos:
     runs-on: macos-latest
     steps:

CI/Dockerfile

@@ -1,4 +1,18 @@
-FROM martinweismann/lib3mf_ppcbuilds:latest
+# Copy this to root folder of lib3mf then build and run this image. 
+FROM ubuntu:20.04
+
+RUN apt-get update && DEBIAN_FRONTEND=noninteractive TZ=Etc/UTC apt-get -y install build-essential uuid-dev wget
+
+RUN wget -qO- "https://cmake.org/files/v3.28/cmake-3.28.1-linux-x86_64.tar.gz" | tar --strip-components=1 -xz -C /usr/local
+
 ADD . lib3mf-repo
-ADD CI/script.sh script.sh
-ENTRYPOINT ["sh", "script.sh"]
+
+WORKDIR "/lib3mf-repo"
+
+RUN cmake/GenerateMake.sh
+
+WORKDIR "/lib3mf-repo/build"
+
+RUN cmake --build . 
+
+RUN ctest -V .