ensure OS packages are up to date when creating a new image (#339)

Author: ddsharpe

imagetool/src/main/resources/docker-files/package-managers.mustache

@@ -5,17 +5,20 @@
 #
 # Ensure necessary OS packages are installed
 {{#useYum}}
-    RUN yum -y --downloaddir={{{tempDir}}} install gzip tar unzip libaio jq findutils diffutils {{#osPackages}}{{{.}}} {{/osPackages}}\
+    RUN yum -y update \
+    && yum -y --downloaddir={{{tempDir}}} install gzip tar unzip libaio jq findutils diffutils {{#osPackages}}{{{.}}} {{/osPackages}}\
     && yum -y --downloaddir={{{tempDir}}} clean all \
     && rm -rf /var/cache/yum/* \
     && rm -rf {{{tempDir}}}
 {{/useYum}}
 {{#useDnf}}
-    RUN dnf -y install gzip tar unzip libaio jq findutils diffutils {{#osPackages}}{{{.}}} {{/osPackages}}\
+    RUN dnf -y update \
+    && dnf -y install gzip tar unzip libaio jq findutils diffutils {{#osPackages}}{{{.}}} {{/osPackages}}\
     && dnf clean all
 {{/useDnf}}
 {{#useMicroDnf}}
-    RUN microdnf install gzip tar unzip libaio jq findutils diffutils shadow-utils {{#osPackages}}{{{.}}} {{/osPackages}}\
+    RUN microdnf update \
+    && microdnf install gzip tar unzip libaio jq findutils diffutils shadow-utils {{#osPackages}}{{{.}}} {{/osPackages}}\
     && microdnf clean all
 {{/useMicroDnf}}
 {{#useAptGet}}