Skip Secrets, add some text to README.md about diff

README.md

@@ -34,6 +34,7 @@ k8s-handle is a helm alternative, but without package manager
      * [Sync mode](#sync-mode)
      * [Strict mode](#strict-mode)
   * [Destroy](#destroy)
+  * [Diff](#diff)
   * [Operating without config.yaml](#operating-without-configyaml)
      * [Render](#render)
      * [Apply](#apply)
@@ -535,7 +536,7 @@ You can specify number of tries before k8s-handle exit with non zero exit code a
 In some cases k8s-handle warn you about ambiguous situations and keep working. With `--strict` mode k8s-handle warn and exit 
 with non zero code. For example when some used environment variables is empty.
 ```bash
-$ k8s-handle-os deploy -s staging --use-kubeconfig --strict
+$ k8s-handle deploy -s staging --use-kubeconfig --strict
 ERROR:__main__:RuntimeError: Environment variable "IMAGE_VERSION" is not set
 $ echo $?
 1
@@ -546,6 +547,13 @@ support `destroy` subcommand for you. Just use `destroy` instead of `deploy`. k8
 call delete kubernetes api calls instead of create or replace. 
 > Sync mode is available for destroy as well.
 
+### Diff
+You can get diff between objects in Kubernetes API and local working copy of configuration.
+```bash
+$ k8s-handle diff -s <section> --use-kubeconfig
+```
+> Secrets are ignored by security reasons
+
 ## Operating without config.yaml
 The most common way for the most of use cases is to operate with k8s-handle via `config.yaml`, specifying
 connection parameters, targets (sections and tags) and variables in one file. The deploy command that runs after that, 

k8s_handle/k8s/diff.py

@@ -56,6 +56,9 @@ class Diff:
     @staticmethod
     def run(file_path):
         for template_body in get_template_contexts(file_path):
+            if template_body.get('kind') == 'Secret':
+                log.info(f'Skipping secret {template_body.get("metadata", {}).get("name")}')
+                continue
             kube_client = Adapter.get_instance(template_body)
             new = yaml.safe_dump(template_body)
             k8s_object = kube_client.get()