Fix dockerfile binary permissions (#279)

Author: astaninger

Dockerfile

@@ -13,11 +13,26 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# First stage: Use an image that includes shell and utilities
+FROM mcr.microsoft.com/cbl-mariner/base/core:2.0 AS builder
+
+# Set the working directory and copy the 'manager' binary
+WORKDIR /
+COPY bin/manager .
+
+# Set the executable permission on the 'manager' binary
+RUN chmod +x /manager
+
 # Use distroless as minimal base image to package the manager binary
 FROM  mcr.microsoft.com/cbl-mariner/distroless/debug:2.0
 WORKDIR /
 
-COPY bin/manager ./
+# Copy the 'manager' binary from the first stage with the correct permissions
+COPY --from=builder --chown=65532:65532 /manager .
+
+# Set the user ID for the container process to 65532 (nonroot user)
 USER 65532:65532
 
+# Specify the command to run when the container starts
+
 ENTRYPOINT ["/manager"]