[libvirt] Allow to generate dynamic config options

It may be required to use some dynamic options such as IP address
from interface where to bind service. This patch adds ability to
use dynamic logic in option detection and fill it in the configuration
file later.

Co-Authored-By: dbiletskiy <dbiletskiy@mirantis.com>

Change-Id: I8cc7da4935c11c50165a75b466d41f7d0da3e77c

libvirt/Chart.yaml

@@ -15,7 +15,7 @@ apiVersion: v1
 appVersion: v1.0.0
 description: OpenStack-Helm libvirt
 name: libvirt
-version: 0.1.35
+version: 0.1.36
 home: https://libvirt.org
 sources:
   - https://libvirt.org/git/?p=libvirt.git;a=summary

libvirt/templates/configmap-bin.yaml

@@ -37,4 +37,5 @@ data:
 {{ tuple "bin/_ceph-admin-keyring.sh.tpl" . | include "helm-toolkit.utils.template" | indent 4 }}
 {{- end }}
 {{- include "helm-toolkit.snippets.values_template_renderer" (dict "envAll" $envAll "template" .Values.conf.init_modules.script "key" "libvirt-init-modules.sh") | indent 2 }}
+{{- include "helm-toolkit.snippets.values_template_renderer" (dict "envAll" $envAll "template" .Values.conf.dynamic_options.script "key" "init-dynamic-options.sh") | indent 2 }}
 {{- end }}

libvirt/templates/configmap-etc.yaml

@@ -24,7 +24,6 @@ metadata:
   name: {{ $configMapName }}
 type: Opaque
 data:
-  libvirtd.conf: {{ include "libvirt.utils.to_libvirt_conf" .Values.conf.libvirt | b64enc }}
   qemu.conf: {{ include "libvirt.utils.to_libvirt_conf" .Values.conf.qemu | b64enc }}
 {{- end }}
 {{- end }}

libvirt/templates/daemonset-libvirt.yaml

@@ -100,6 +100,21 @@ spec:
               subPath: libvirt-init-modules.sh
               readOnly: true
 {{- end }}
+        - name: init-dynamic-options
+{{ tuple $envAll "libvirt" | include "helm-toolkit.snippets.image" | indent 10 }}
+{{ dict "envAll" $envAll "application" "libvirt" "container" "init_dynamic_options" | include "helm-toolkit.snippets.kubernetes_container_security_context" | indent 10 }}
+          terminationMessagePath: /var/log/termination-log
+          command:
+            - /tmp/init-dynamic-options.sh
+          volumeMounts:
+            - name: pod-tmp
+              mountPath: /tmp
+            - name: pod-shared
+              mountPath: /tmp/pod-shared
+            - name: libvirt-bin
+              mountPath: /tmp/init-dynamic-options.sh
+              subPath: init-dynamic-options.sh
+              readOnly: true
 {{- if eq .Values.conf.qemu.vnc_tls "1" }}
         - name: cert-init-vnc
 {{ tuple $envAll "kubectl" | include "helm-toolkit.snippets.image" | indent 10 }}
@@ -233,7 +248,7 @@ spec:
               mountPath: /tmp/libvirt.sh
               subPath: libvirt.sh
               readOnly: true
-            - name: libvirt-etc
+            - name: pod-shared
               mountPath: /etc/libvirt/libvirtd.conf
               subPath: libvirtd.conf
               readOnly: true
@@ -381,6 +396,8 @@ spec:
           hostPath:
             path: /
             type: Directory
+        - name: pod-shared
+          emptyDir: {}
 {{ dict "envAll" $envAll "component" "libvirt" "requireSys" true | include "helm-toolkit.snippets.kubernetes_apparmor_volumes" | indent 8 }}
 {{ if $mounts_libvirt.volumes }}{{ toYaml $mounts_libvirt.volumes | indent 8 }}{{ end }}
 {{- end }}

libvirt/values.yaml

@@ -112,9 +112,37 @@ conf:
     cert_file: "/etc/pki/libvirt/servercert.pem"
     key_file: "/etc/pki/libvirt/private/serverkey.pem"
     auth_unix_rw: "none"
-    listen_addr: 127.0.0.1
+    listen_addr: "${LISTEN_IP_ADDRESS}"
     log_level: "3"
     log_outputs: "1:file:/var/log/libvirt/libvirtd.log"
+  # Modifies the config in which value is specified as the name of a variable
+  # that is computed in the script.
+  dynamic_options:
+    libvirt:
+      listen_interface: null
+      listen_address: 127.0.0.1
+    script: |
+      #!/bin/bash
+      set -ex
+
+      LIBVIRT_CONF_PATH=/tmp/pod-shared/libvirtd.conf
+
+      {{- if .Values.conf.dynamic_options.libvirt.listen_interface }}
+
+      LISTEN_INTERFACE="{{ .Values.conf.dynamic_options.libvirt.listen_interface }}"
+      LISTEN_IP_ADDRESS=$(ip address show $LISTEN_INTERFACE | grep 'inet ' | awk '{print $2}' | awk -F "/" '{print $1}')
+      {{- else if .Values.conf.dynamic_options.libvirt.listen_address }}
+      LISTEN_IP_ADDRESS={{ .Values.conf.dynamic_options.libvirt.listen_address }}
+      {{- end }}
+
+      if [[ -z $LISTEN_IP_ADDRESS ]]; then
+          echo "LISTEN_IP_ADDRESS is not set."
+          exit 1
+      fi
+
+      tee > ${LIBVIRT_CONF_PATH} << EOF
+      {{ include "libvirt.utils.to_libvirt_conf" .Values.conf.libvirt }}
+      EOF
   qemu:
     vnc_tls: "0"
     vnc_tls_x509_verify: "0"
@@ -254,6 +282,14 @@ pod:
           capabilities:
             drop:
               - ALL
+        init_dynamic_options:
+          runAsUser: 65534
+          runAsNonRoot: true
+          readOnlyRootFilesystem: true
+          allowPrivilegeEscalation: false
+          capabilities:
+            drop:
+              - ALL
   sidecars:
     libvirt_exporter: false
 

releasenotes/notes/libvirt.yaml

@@ -36,4 +36,5 @@ libvirt:
   - 0.1.33 Handle cgroupv2 correctly
   - 0.1.34 Remove hugepages creation test
   - 0.1.35 Allow to initialize virtualization modules
+  - 0.1.36 Allow to generate dynamic config options
 ...