RHEL8 spec update to require moby-engine or docker-ce (#7026)

* RHEL8 spec update to require moby-engine or docker-ce (#6972)

Co-authored-by: Andrew Smith <andsmi@microsoft.com>
Co-authored-by: Damon Barry <damonbarry@users.noreply.github.com>

edgelet/contrib/enterprise-linux/aziot-edge.spec

@@ -22,6 +22,7 @@ URL:            https://github.com/azure/iotedge
 %{?systemd_requires}
 BuildRequires:  systemd
 Requires(pre):  shadow-utils
+Requires:       (moby-engine or docker-ce)
 Requires:       aziot-identity-service = 1.4.4-1%{?dist}
 Source0:        aziot-edge-%{version}.tar.gz
 
@@ -62,19 +63,6 @@ make \
 rm -rf $RPM_BUILD_ROOT
 
 %pre
-# Check for container runtime
-if ! /usr/bin/getent group docker >/dev/null; then
-    echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
-    echo ""
-    echo " ERROR: No container runtime detected."
-    echo ""
-    echo " Please install a container runtime and run this install again."
-    echo ""
-    echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
-
-    exit 1
-fi
-
 # Create iotedge group
 if ! /usr/bin/getent group iotedge >/dev/null; then
     %{_sbindir}/groupadd -r %{iotedge_group}
@@ -85,16 +73,6 @@ if ! /usr/bin/getent passwd iotedge >/dev/null; then
     %{_sbindir}/useradd -r -g %{iotedge_group} -c "iotedge user" -s /sbin/nologin -d %{iotedge_home} %{iotedge_user}
 fi
 
-# Add iotedge user to moby-engine group
-if /usr/bin/getent group docker >/dev/null; then
-    %{_sbindir}/usermod -aG docker %{iotedge_user}
-fi
-
-# Add iotedge user to systemd-journal group so it can get system logs
-if /usr/bin/getent group systemd-journal >/dev/null; then
-    %{_sbindir}/usermod -aG systemd-journal %{iotedge_user}
-fi
-
 # Create an edgeagentuser and add it to iotedge group
 if ! /usr/bin/getent passwd %{iotedge_agent_user} >/dev/null; then
     %{_sbindir}/useradd -r -g %{iotedge_group} -c "edgeAgent user" -s /sbin/nologin -u %{iotedge_agent_uid} %{iotedge_agent_user} || true
@@ -116,8 +94,31 @@ if /usr/bin/getent group aziotid >/dev/null; then
     %{_sbindir}/usermod -aG aziotid %{iotedge_user}
 fi
 exit 0
-
 %post
+# Check for container runtime
+if ! /usr/bin/getent group docker >/dev/null; then
+    echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
+    echo ""
+    echo " ERROR: No container runtime detected."
+    echo ""
+    echo " Please install a container runtime and run this install again."
+    echo ""
+    echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
+
+    exit 1
+fi
+
+# Add iotedge user to moby-engine group
+if /usr/bin/getent group docker >/dev/null; then
+    %{_sbindir}/usermod -aG docker %{iotedge_user}
+fi
+
+# Add iotedge user to systemd-journal group so it can get system logs
+if /usr/bin/getent group systemd-journal >/dev/null; then
+    %{_sbindir}/usermod -aG systemd-journal %{iotedge_user}
+fi
+
+
 if [ ! -f '/etc/aziot/config.toml' ]; then
     echo "==============================================================================="
     echo ""