Add SELinux contexts for nova log directory

The log directory for nova has the default_t SELinux context and this
prevents rsyslog from accessing nova's logs. This patch ensures that
the file contexts are set properly for nova's logs.

This change also makes nova's log directory configurable using the
`nova_log_dir` variable.

Closes-Bug: 1748911
Change-Id: Iaac69c5807715f50386624602375c89adeeb48a1
(cherry picked from commit 10fc6d9035)

defaults/main.yml

@@ -60,6 +60,7 @@ nova_system_shell: /bin/bash
 nova_system_comment: nova system user
 nova_system_home_folder: "/var/lib/{{ nova_system_user_name }}"
 nova_libvirt_save_path: "{{ nova_system_home_folder }}/save"
+nova_log_dir: "/var/log/nova"
 
 nova_lock_path: "/var/lock/nova"
 

tasks/nova_pre_install.yml

@@ -77,9 +77,9 @@
 
 - name: Test for log directory or link
   shell: |
-    if [ -h "/var/log/nova"  ]; then
-      chown -h {{ nova_system_user_name }}:{{ nova_system_group_name }} "/var/log/nova"
-      chown -R {{ nova_system_user_name }}:{{ nova_system_group_name }} "$(readlink /var/log/nova)"
+    if [ -h "{{ nova_log_dir }}"  ]; then
+      chown -h {{ nova_system_user_name }}:{{ nova_system_group_name }} "{{ nova_log_dir }}"
+      chown -R {{ nova_system_user_name }}:{{ nova_system_group_name }} "$(readlink {{ nova_log_dir }})"
     else
       exit 1
     fi
@@ -92,7 +92,7 @@
 
 - name: Create nova log dir
   file:
-    path: "/var/log/nova"
+    path: "{{ nova_log_dir }}"
     state: directory
     owner: "{{ nova_system_user_name }}"
     group: "{{ nova_system_group_name }}"

tasks/nova_selinux.yml

@@ -43,6 +43,23 @@
   when:
     - selinux_equivalence | changed or selinux_file_context_ssh_keys | changed
 
+- name: Stat nova's log directory
+  stat:
+    path: "{{ nova_log_dir }}"
+  register: nova_log_dir_check
+
+- name: Set SELinux file contexts for nova's log directory
+  sefcontext:
+    target: "{{ (nova_log_dir_check.stat.islnk) | ternary(nova_log_dir_check.stat.lnk_target, nova_log_dir) }}(/.*)?"
+    setype: nova_log_t
+    state: present
+  register: selinux_file_context_log_files
+
+- name: Apply updated SELinux contexts on nova log directory
+  command: "restorecon -Rv {{ (nova_log_dir_check.stat.islnk) | ternary(nova_log_dir_check.stat.lnk_target, nova_log_dir) }}"
+  when:
+    - selinux_file_context_log_files | changed
+
 - name: Copy OSA SELinux policy
   copy:
     src: osa-nova.te

templates/nova.conf.j2

@@ -6,7 +6,7 @@ use_stderr = False
 # Logs / State
 debug = {{ debug }}
 fatal_deprecations = {{ nova_fatal_deprecations }}
-log_dir = /var/log/nova
+log_dir = {{ nova_log_dir }}
 state_path = {{ nova_system_home_folder }}
 rootwrap_config = /etc/nova/rootwrap.conf
 service_down_time = 120