Allow underscores in kerberos principal names

[nightkr]

Description

Fixes #562

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

# Author
- [X] Helm chart can be installed and deployed operator works
- [X] Integration tests passed (for non trivial changes)

# Reviewer
- [ ] Code contains useful comments
- [ ] Code contains useful logging statements
- [ ] (Integration-)Test cases added
- [ ] Documentation added or updated. Follows the [style guide](https://docs.stackable.tech/home/nightly/contributor/docs/style-guide).
- [ ] Changelog updated
- [x] Cargo.toml only contains references to git tags (not specific commits or branches)

# Acceptance
- [ ] Feature Tracker has been updated
- [ ] Proper release label has been added
- [ ] [Roadmap](https://github.com/orgs/stackabletech/projects/25/views/1) has been updated

[nightkr]

Tested against krb5 by applying this:

diff --git a/tests/templates/kuttl/kerberos/01-install-kdc.yaml.j2 b/tests/templates/kuttl/kerberos/01-install-kdc.yaml.j2
index ade1705..51e0d64 100644
--- a/tests/templates/kuttl/kerberos/01-install-kdc.yaml.j2
+++ b/tests/templates/kuttl/kerberos/01-install-kdc.yaml.j2
@@ -33,7 +33,7 @@ spec:
               test -e /var/kerberos/krb5kdc/principal || kdb5_util create -s -P asdf
               kadmin.local get_principal -terse root/admin || kadmin.local add_principal -pw asdf root/admin
               # stackable-secret-operator principal must match the keytab specified in the SecretClass
-              kadmin.local get_principal -terse stackable-secret-operator || kadmin.local add_principal -e aes256-cts-hmac-sha384-192:normal -pw asdf stackable-secret-operator
+              kadmin.local get_principal -terse stackable-secret_operator || kadmin.local add_principal -e aes256-cts-hmac-sha384-192:normal -pw asdf stackable-secret_operator
           env:
             - name: KRB5_CONFIG
               value: /stackable/config/krb5.conf
@@ -143,11 +143,11 @@ data:
     cluster.local = CLUSTER.LOCAL
   kadm5.acl: |
     root/admin *e
-    stackable-secret-operator *e
+    stackable-secret_operator *e
 ---
 apiVersion: v1
 kind: Secret
 metadata:
   name: secret-operator-keytab
 data:
-  keytab: BQIAAABdAAEADUNMVVNURVIuTE9DQUwAGXN0YWNrYWJsZS1zZWNyZXQtb3BlcmF0b3IAAAABZAYWIgEAFAAgm8MCZ8B//XF1tH92GciD6/usWUNAmBTZnZQxLua2TkgAAAAB
+  keytab: BQIAAABdAAEADUNMVVNURVIuTE9DQUwAGXN0YWNrYWJsZS1zZWNyZXRfb3BlcmF0b3IAAAABZ6xjwgEAFAAgz8mI9b8YpFWDN8PWHkuVeX5GZq/wVu5KDSvxh7v9Bw8AAAAB
diff --git a/tests/templates/kuttl/kerberos/secretclass.yaml b/tests/templates/kuttl/kerberos/secretclass.yaml
index 33a003f..f508177 100644
--- a/tests/templates/kuttl/kerberos/secretclass.yaml
+++ b/tests/templates/kuttl/kerberos/secretclass.yaml
@@ -15,4 +15,4 @@ spec:
       adminKeytabSecret:
         name: secret-operator-keytab
         namespace: $NAMESPACE
-      adminPrincipal: stackable-secret-operator
+      adminPrincipal: stackable-secret_operator

Tested against AD by applying this to https://github.com/stackabletech/ad-init:

diff --git a/roles/ad-dc/tasks/main.yaml b/roles/ad-dc/tasks/main.yaml
index fdde98d..ff04912 100644
--- a/roles/ad-dc/tasks/main.yaml
+++ b/roles/ad-dc/tasks/main.yaml
@@ -16,7 +16,7 @@
 
 - name: Name Secret-Operator User
   set_fact:
-    secret_operator_principal: stackable-secret-operator@{{ ansible_facts.domain | upper }}
+    secret_operator_principal: stackable_secret_operator@{{ ansible_facts.domain | upper }}
 - name: Create Secret-Operator User
   microsoft.ad.user:
     name: stackable-secret-operator

[sbernauer]

Awesome and quick work!
Can you please add a changelog entry?

[nightkr]

Right, knew there was something I forgot

[sbernauer]

Thanks!

[sbernauer]

good old changelog conflicts 🙃

[nightkr]

Yuuuhp