diff --git a/.github/workflows/docker_ci_main.yml b/.github/workflows/docker_ci_main.yml
new file mode 100644
index 0000000..5910fec
--- /dev/null
+++ b/.github/workflows/docker_ci_main.yml
@@ -0,0 +1,16 @@
+
+name: CI - Main
+on:
+  pull_request:
+    branches:
+    - main
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    
+    steps:
+    - uses: actions/checkout@v1
+    - name: Build and test with Docker
+      run: |
+        docker build -t example_python_package_image .
+        docker run --rm example_python_package_image /bin/bash -c "bash run_tests.sh"
\ No newline at end of file
diff --git a/Dockerfile b/Dockerfile
index 4bdd877..fca0e3a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,7 +1,7 @@
 
 FROM continuumio/miniconda3:4.9.2
 
-ARG compile_cores=6
+ARG compile_cores=1
 
 RUN apt-get --yes update && apt-get --yes upgrade
 
@@ -15,4 +15,13 @@ RUN conda install -c conda-forge -c python python=3.8 && \
     pip install jupyter-cadquery==2.1.0 && \
     # change to clone repo and pip install locally
     pip install paramak && \
-    conda clean -afy
\ No newline at end of file
+    conda clean -afy
+
+COPY run_tests.sh run_tests.sh
+COPY tests tests/
+
+COPY README.md README.md
+COPY example_python_package example_python_package/
+COPY setup.py setup.py
+
+RUN python setup.py install
\ No newline at end of file
diff --git a/run_tests.sh b/run_tests.sh
new file mode 100644
index 0000000..82a1260
--- /dev/null
+++ b/run_tests.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+pytest tests/test_multiplication.py
\ No newline at end of file
diff --git a/tests/test_multiplication.py b/tests/test_multiplication.py
index b928bda..2492a21 100644
--- a/tests/test_multiplication.py
+++ b/tests/test_multiplication.py
@@ -7,4 +7,4 @@ def test_multiplication_small_numbers():
 
 def test_multiplication_large_numbers():
     result = multiply_two_numbers(100, 300)
-    assert result == 30000
\ No newline at end of file
+    assert result == None
\ No newline at end of file