fix: ensure datadog is in good state, fix swap file path check (#465)

salt/datadog/init.sls

@@ -31,12 +31,25 @@ datadog_repo:
     - source: salt://datadog/files
 
 {% if 'datadog_api_key' in pillar %}
+check_datadog_installation:
+  cmd.run:
+    - name: |
+        if ! dpkg-query -W datadog-agent || ! test -f /etc/datadog-agent/datadog.yaml; then
+          dpkg --remove --force-remove-reinstreq datadog-agent || true
+          apt-get -y --fix-broken install
+          apt-get update
+        fi
+    - hide_output: True
+
 datadog-agent:
   pkg:
     - installed
     - require:
       - pkgrepo: datadog_repo
-      - mount: {% if swap_path %}{{ swap_path }}{% endif %}
+        {% if swap_path %}
+      - mount: {{ swap_path }}
+        {% endif %}
+      - cmd: check_datadog_installation
   service:
     - running
     - enable: True