Update Dockerfile to use opencontainers metadata and build-time labels.

Dockerfile

@@ -1,18 +1,11 @@
-ARG GIT_COMMIT=unspecified
-ARG GIT_REMOTE=unspecified
 ARG VERSION=unspecified
 
 FROM python:3.9-alpine
 
-ARG GIT_COMMIT
-ARG GIT_REMOTE
 ARG VERSION
 
-LABEL git_commit=${GIT_COMMIT}
-LABEL git_remote=${GIT_REMOTE}
-LABEL maintainer="[email protected]"
-LABEL vendor="Cyber and Infrastructure Security Agency"
-LABEL version=${VERSION}
+LABEL org.opencontainers.image.authors="[email protected]"
+LABEL org.opencontainers.image.vendor="Cyber and Infrastructure Security Agency"
 
 ARG CISA_UID=421
 ENV CISA_HOME="/home/cisa"

tests/container_test.py

@@ -89,5 +89,5 @@ def test_container_version_label_matches(version_container):
         exec(f.read(), pkg_vars)  # nosec
     project_version = pkg_vars["__version__"]
     assert (
-        version_container.labels["version"] == project_version
+        version_container.labels["org.opencontainers.image.version"] == project_version
     ), "Dockerfile version label does not match project version"