kerberos-client: remove kstart requirement on CentOS

All our AFS release roles use "kinit" for authentication.  The only
scripts using k5start are the mirror scripts, but since that doesn't
run on CentOS we don't need it there.

This avoids us having to use EPEL or, on 8, an unsupported build.
Anything needing to be portable should use kinit from now on.

Change-Id: I6323cb835cedf9974cf8d96faa7eb55b8aaafd9a

roles/kerberos-client/README.rst

@@ -1,5 +1,8 @@
 An ansible role to configure a kerberos client
 
+Note ```k5start`` is installed on Debuntu distributions, but is not
+part of RedHat distributions.
+
 **Role Variables**
 
 .. zuul:rolevar:: kerberos_realm

roles/kerberos-client/tasks/install-packages/CentOS.yaml

@@ -1,26 +0,0 @@
-- name: Ensure EPEL is pre-installed
-  package:
-    name:
-      - epel-release
-    state: present
-  become: yes
-
-# Until in EPEL8; see:
-#  https://bugzilla.redhat.com/show_bug.cgi?id=1791168
-- name: Install kstart copr repo for CentOS8
-  command: dnf copr enable -y iwienand/kstart
-  become: yes
-  when: ansible_distribution_major_version == '8'
-
-- name: Install kerberos client packages
-  yum:
-    name: '{{ kerberos_client_packages }}'
-    enablerepo: epel
-    state: present
-  become: yes
-
-- name: Remove kstart copr repo for CentOS8
-  command: dnf copr remove -y iwienand/kstart
-  become: yes
-  when: ansible_distribution_major_version == '8'
-

roles/kerberos-client/tasks/install-packages/default.yaml

@@ -1,5 +0,0 @@
-- name: Install kerberos client packages
-  package:
-    name: '{{ kerberos_client_packages }}'
-    state: present
-  become: yes

roles/kerberos-client/tasks/main.yaml

@@ -24,16 +24,8 @@
     src: etc/krb5.conf.j2
   become: yes
 
-# NOTE(ianw): urgh, we have to install with yum directly to enable
-# epel on CentOS for kstart, which is a pretty hard dependency for
-# useful automation.  If this ever changes, remove this and we can
-# just go back to generic package: installer.
-- name: Distro install kerberos client packages
-  include_tasks: "{{ lookup('first_found', params) }}"
-  vars:
-    params:
-      files:
-        - "{{ ansible_distribution }}.yaml"
-        - "default.yaml"
-      paths:
-        - install-packages
+- name: Install kerberos client packages
+  package:
+    name: '{{ kerberos_client_packages }}'
+    state: present
+  become: yes

roles/kerberos-client/vars/RedHat.yaml

@@ -1,3 +1,2 @@
 kerberos_client_packages:
   - krb5-workstation
-  - kstart