Add button to delete hosts

- set cascade to all and delete-orphan to delete interfaces when
  deleting a host
- button added on the view host page to delete host (admin only)

JIRA INFRA-557 #action In Progress

app/models.py

@@ -899,7 +899,11 @@ class Host(CreatedMixin, db.Model):
     )
     ansible_vars = db.Column(postgresql.JSONB)
 
-    interfaces = db.relationship("Interface", backref="host")
+    # Set cascade to all (to add delete) and delete-orphan to delete all interfaces
+    # when deleting a host
+    interfaces = db.relationship(
+        "Interface", backref="host", cascade="all, delete-orphan"
+    )
     items = db.relationship("Item", backref="host")
     ansible_groups = db.relationship(
         "AnsibleGroup",

app/network/views.py

@@ -107,6 +107,19 @@ def create_host():
     return render_template("network/create_host.html", form=form)
 
 
+@bp.route("/hosts/delete", methods=["POST"])
+@login_groups_accepted("admin")
+def delete_host():
+    host = models.Host.query.get_or_404(request.form["host_id"])
+    # Deleting the host will also delete all
+    # associated interfaces due to the cascade delete option
+    # defined on the model
+    db.session.delete(host)
+    db.session.commit()
+    flash(f"Host {host.name} has been deleted", "success")
+    return redirect(url_for("network.list_hosts"))
+
+
 @bp.route("/hosts/view/<name>", methods=("GET", "POST"))
 @login_required
 def view_host(name):

app/templates/network/view_host.html

@@ -22,7 +22,22 @@
     <div class="col-sm-9">
       <dl class="row">
         <dt class="col-sm-3">Hostname</dt>
-        <dd class="col-sm-9">{{ host.fqdn }}</dd>
+        <dd class="col-sm-9">
+          <div class="row">
+            <div class="col-sm-10">
+              {{ host.fqdn }}
+            </div>
+            {% if current_user.is_admin %}
+            <div class="col-sm-2 text-right">
+              <form method="POST" action="/network/hosts/delete">
+                <input id="host_id" name="host_id" type="hidden" value="{{ host.id }}">
+                {{ delete_button_with_confirmation("Delete host", "deleteConfirmation-%s" | format(host.id),
+                   "Are you sure you want to delete the host %s?" | format(host.name)) }}
+              </form>
+            </div>
+            {% endif %}
+          </div>
+        </dd>
         <dt class="col-sm-3">Device Type</dt>
         <dd class="col-sm-9">{{ host.device_type }}</dd>
         {% if host.items %}

docs/network.rst

@@ -49,6 +49,23 @@ If you need more than one interface, you should go to the *Add interface* pane f
 
 .. image:: _static/add_interface.png
 
+
+Delete a host
+-------------
+
+Note that this is restricted to admin users.
+To delete a host, just click on the **trash** icon next to the hostname on the *View host* page.
+
+.. image:: _static/network/view_host_delete.png
+
+A confirmation window will be opened. You can confirm or cancel the action.
+
+.. image:: _static/network/delete_host_confirmation.png
+
+When deleting a host, all its interfaces are deleted as well.
+The host is only deleted from CSEntry. Virtual machines are not automatically deleted.
+
+
 DNS and DHCP update
 -------------------