Add Elasticsearch Curator Docker image

Kolla provides log aggregation, but no solution to set retention periods
for aggregated logs. It therefore accumulates log data indefinitely unless
a user manually intervenes. This change adds Elasticsearch Curator which
provides a mechanism for automating such retention periods [1].

[1] https://www.elastic.co/guide/en/elasticsearch/client/curator/current/about.html

The container contains cron to support running Curator periodically.

Change-Id: Ief2c554a64ef6cc971635d7e2a718f63c310fbf6

docker/elasticsearch/elasticsearch-curator/Dockerfile.j2

@@ -0,0 +1,40 @@
+FROM {{ namespace }}/{{ image_prefix }}base:{{ tag }}
+LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build_date }}"
+
+{% block elasticsearch_curator_header %}{% endblock %}
+
+{% import "macros.j2" as macros with context %}
+
+{% if base_package_type == 'rpm' %}
+    {% set elasticsearch_curator_packages = [
+        'cronie',
+        'python3-pip',
+    ] %}
+{% elif base_package_type == 'deb' %}
+    {% set elasticsearch_curator_packages = [
+        'cron',
+        'python3-pip',
+        'python3-setuptools'
+    ] %}
+{% endif %}
+
+{{ macros.install_packages(elasticsearch_curator_packages | customizable("packages")) }}
+
+{{ macros.configure_user(name='elasticsearch') }}
+
+{% set elasticsearch_curator_pip_packages = [
+    'elasticsearch-curator'
+] %}
+
+RUN {{ macros.install_pip(elasticsearch_curator_pip_packages | customizable("pip_packages"), constraints=false, pip_version="pip3") }} \
+    && mkdir -p /etc/elasticsearch-curator \
+    && chown -R elasticsearch: /etc/elasticsearch-curator
+
+COPY extend_start.sh /usr/local/bin/kolla_extend_start
+RUN chmod 755 /usr/local/bin/kolla_extend_start
+
+{% block elasticsearch_curator_base_footer %}{% endblock %}
+{% block footer %}{% endblock %}
+
+# NOTE(dszumski): Cron runs as root but should be configured to launch Curator
+# by the elasticsearch user.

docker/elasticsearch/elasticsearch-curator/extend_start.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+# NOTE(dszumski): Cron runs as root but should be configured to launch Curator
+# by the elasticsearch user. Therefore this directory needs to be owned by
+# the elasticsearch user.
+if [[ ! -d "/var/log/kolla/elasticsearch" ]]; then
+    install -d -m 0755 -o elasticsearch -g elasticsearch /var/log/kolla/elasticsearch
+fi

releasenotes/notes/add-elasticsearch-curator-88089d04f7ccd549.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    Adds Elasticsearch Curator for managing aggregated log data.