update for skopeo util (#20)

* update for skopeo

* update for automated test.

* skopeo_spec typo

* permissions error.

* modify exit code

* update for dockerfile format

Co-authored-by: Sony Francis <sony.p.francis@saic.com>

spec/skopeo_spec.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env shellspec
+
+Describe "printVersion()"
+  printVersion() {
+    skopeo -v | grep "${SKOPEO_VERSION}"
+  }
+
+  It "validates tool is installed by checking version"
+    When call printVersion
+    The output should include "${SKOPEO_VERSION}"
+    The status should eq 0
+  End
+End

src/docker/Dockerfile

@@ -136,6 +136,14 @@ RUN dnf -y install podman-${PODMAN_VERSION} \
   && rm -rf /var/cache/yum/ \
   && rm -rf /var/tmp/* /tmp/* /var/tmp/.???* /tmp/.???*
 
+# Install Skopeo. Get available versions by running the command `dnf list skopeo`
+ARG SKOPEO_VERSION="1.2.0"
+ENV SKOPEO_VERSION=${SKOPEO_VERSION}
+RUN dnf -y install skopeo-${SKOPEO_VERSION} \
+  && dnf clean all \
+  && rm -rf /var/cache/yum/ \
+  && rm -rf /var/tmp/* /tmp/* /var/tmp/.???* /tmp/.???*
+
 RUN useradd -ms /bin/bash anvil
 
 USER anvil