Show templating debug in updatecli manifest show --debug

[olblak]

Fix #954

This pullrequest shows a diff between the raw manifest and the templated manifest when running

updatecli manifest show --debug

Test

To test this pull request, you can run the following commands:

go build -o bin/updatecli
./bin/updatecli manifest show --debug

Successful templating

 ~/Pr/Updatecli/updatecli │ on @a20269f7 *141 !3  ./bin/updatecli manifest show --config /tmp/updatecli.yaml --values /tmp/scm.yaml --debug


+++++++++++
+ PREPARE +
+++++++++++

Loading Pipeline "/tmp/updatecli.yaml"
DEBUG: Golang templating change detected:
- - - raw manifest
+++ templated manifest

@@ -1,3 +1,8 @@
 scms:
   default:
-{{ .scms.default | toYaml | indent 4}}
+    kind: github
+    spec:
+        owner: updatecli
+        repository: updatecli
+        token: xxx
+        username: yyy


---

SCM repository retrieved: 1
DEBUG: stage: git-clone
...

On purpose failing templating

+++++++++++
+ PREPARE +
+++++++++++

Loading Pipeline "/tmp/updatecli.yaml"
DEBUG: Golang templating change detected:
--- raw manifest
+++ templated manifest
@@ -1,3 +1,8 @@
 scms:
   default:
-    {{ .scms.default | toYaml | indent 4}}
+        kind: github
+    spec:
+        owner: updatecli
+        repository: updatecli
+        token: xxx
+        username: yyy


---
ERROR: failed loading pipeline(s)
	* "/tmp/updatecli.yaml" - yaml: line 1: did not find expected key

0 pipeline(s) successfully loaded

Additional Information

Tradeoff

While thinking about this issue, I was concerned showing too much information like:

1. Raw manifest content
2. Post templating
3. Post YAML parser

The purpose of the command updatecli manifest show sounds the perfect fit to debug the manifest

My second concern was leaking credentials from a CI environment, and it is unlikely that we run updatecli manifest show from a CI

Potential improvement

Maybe the debug flag shouldn't be needed when running updatecli manifest show