Add capability to set node role

Presently the node role assignment is only automatic. Auto selection
makes the assumption every node is identical however in many deployments
a deployer may want to assign node roles to specific hardware thereby
optimizing resources and improving general performance. This change
adds and documents the ability to set the node roles within an ansible
inventory.

Change-Id: I22a2b636cb1441f17e575439b55ca64f9c7b0336
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>

elk_metrics_6x/README.rst

@@ -508,6 +508,56 @@ Overview of kibana custom dashboard
     :align: center
 
 
+Optional | Customize Elasticsearch cluster configuration
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Cluster configuration can be augmented using several variables which will force
+a node to use a given role.
+
+Available roles are *data*, *ingest*, and *master*.
+
+* ``elasticsearch_node_data``:  This variable will override the automatic node
+  determination and set a given node to be an "data" node.
+* ``elasticsearch_node_ingest``: This variable will override the automatic node
+   determination and set a given node to be an "ingest" node.
+* ``elasticsearch_node_master``: This variable will override the automatic node
+   determination and set a given node to be an "master" node.
+
+Example setting override options within inventory.
+
+.. code-block:: yaml
+
+    hosts:
+      children:
+        elastic-logstash:
+          hosts:
+            elk1:
+              ansible_host: 10.0.0.1
+              ansible_user: root
+              elasticsearch_node_master: true
+              elasticsearch_node_data: false
+              elasticsearch_node_ingest: false
+            elk2:
+              ansible_host: 10.0.0.2
+              ansible_user: root
+              elasticsearch_node_master: false
+              elasticsearch_node_data: true
+              elasticsearch_node_ingest: false
+            elk3:
+              ansible_host: 10.0.0.3
+              ansible_user: root
+              elasticsearch_node_master: false
+              elasticsearch_node_data: false
+              elasticsearch_node_ingest: true
+            elk4:
+              ansible_host: 10.0.0.4
+              ansible_user: root
+
+With the following inventory settings **elk1** would be a master node, **elk2**
+would be a data, **elk3** would be an ingest node, and **elk4** would auto
+select a role.
+
+
 Upgrading the cluster
 ---------------------
 

elk_metrics_6x/bootstrap-embedded-ansible.sh

@@ -52,7 +52,7 @@ if [[ ! -d "${ANSIBLE_EMBED_HOME}/repositories/ansible-config_template" ]]; then
   popd
 fi
 
-if [[ ! -d "${ANSIBLE_EMBED_HOME}/repositories/openstack_ansible_plugins" ]]; then
+if [[ ! -d "${ANSIBLE_EMBED_HOME}/repositories/openstack-ansible-plugins" ]]; then
   mkdir -p "${ANSIBLE_EMBED_HOME}/repositories"
   git clone https://git.openstack.org/openstack/openstack-ansible-plugins "${ANSIBLE_EMBED_HOME}/repositories/openstack-ansible-plugins"
   pushd "${ANSIBLE_EMBED_HOME}/repositories/openstack-ansible-plugins"

elk_metrics_6x/roles/elastic_data_hosts/vars/data-node-variables.yml

@@ -21,7 +21,7 @@ storage_node_count: "{{ groups['elastic-logstash'] | length }}"
 # 2 node clusters have 1 master-eligable nodes to avoid split-brain
 # 3 node clusters have 3 master-eligable nodes
 # >3 node clusters have (nodes // 2) eligable masters rounded up to the next odd number
-master_node_count: |-
+elastic_master_node_count: |-
   {% set masters = 0 %}
   {% if (storage_node_count | int) < 3 %}
   {%   set masters = 1 %}
@@ -36,10 +36,76 @@ master_node_count: |-
   {{ masters }}
 
 # Assign node roles
-# the first 'master_node_count' hosts in groups['elastic-logstash'] become master-eligible nodes
+# the first 'elastic_master_node_count' hosts in groups['elastic-logstash'] become master-eligible nodes
-# the first 'master_node_count' and subsequent alternate hosts in groups['elastic-logstash'] becomes data nodes
+# the first 'elastic_master_node_count' and subsequent alternate hosts in groups['elastic-logstash'] becomes data nodes
-data_nodes: "{{ (groups['elastic-logstash'][:master_node_count | int] + groups['elastic-logstash'][master_node_count | int::2]) }}"
+## While the data node group is dynamically chosen the override
-master_nodes: "{{ groups['elastic-logstash'][:master_node_count | int] }}"
+## `elasticsearch_node_data` can be used to override the node type.
+## Dynamic node inclusion will still work for all other nodes in the group.
+_data_nodes: "{{ (groups['elastic-logstash'][:elastic_master_node_count | int] | union(groups['elastic-logstash'][elastic_master_node_count | int::2])) }}"
+data_nodes: |-
+  {% set nodes = [] %}
+  {% for node in groups['elastic-logstash'] %}
+  {%   if (hostvars[node]['elasticsearch_node_data'] is defined) and (hostvars[node]['elasticsearch_node_data'] | bool) %}
+  {%     set _ = nodes.append(node) %}
+  {%   elif (node in _data_nodes) %}
+  {%     set _ = nodes.append(node) %}
+  {%   endif %}
+  {% endfor %}
+  {{ nodes }}
+
+## While the logstash node group is dynamically chosen the override
+## `elasticsearch_node_ingest` can be used to override the node type.
+## Dynamic node inclusion will still work for all other nodes in the group.
+_logstash_nodes: "{{ data_nodes }}"
+logstash_nodes: |-
+  {% set nodes = [] %}
+  {% for node in groups['elastic-logstash'] %}
+  {%   if (hostvars[node]['elasticsearch_node_ingest'] is defined) and (hostvars[node]['elasticsearch_node_ingest'] | bool) %}
+  {%     set _ = nodes.append(node) %}
+  {%   elif (node in _logstash_nodes) %}
+  {%     set _ = nodes.append(node) %}
+  {%   endif %}
+  {% endfor %}
+  {{ nodes }}
+
+## While the logstash node group is dynamically chosen the override
+## `elasticsearch_node_ingest` can be used to override the node type.
+## Dynamic node inclusion will still work for all other nodes in the group.
+_ingest_nodes: "{{ data_nodes }}"
+ingest_nodes: |-
+  {% set nodes = [] %}
+  {% for node in groups['elastic-logstash'] %}
+  {%   if (hostvars[node]['elasticsearch_node_ingest'] is defined) and (hostvars[node]['elasticsearch_node_ingest'] | bool) %}
+  {%     set _ = nodes.append(node) %}
+  {%   elif (node in _ingest_nodes) %}
+  {%     set _ = nodes.append(node) %}
+  {%   endif %}
+  {% endfor %}
+  {{ nodes }}
+
+## While the master node group is dynamically chosen the override
+## `elasticsearch_node_master` can be used to override the node type.
+## Dynamic node inclusion will still work for all other nodes in the group.
+_master_nodes: "{{ groups['elastic-logstash'][:elastic_master_node_count | int] }}"
+master_nodes: |-
+  {% set nodes = [] %}
+  {% for node in groups['elastic-logstash'] %}
+  {%   if (nodes | length) <= (elastic_master_node_count | int) %}
+  {%     if (hostvars[node]['elasticsearch_node_master'] is defined) and (hostvars[node]['elasticsearch_node_master'] | bool) %}
+  {%       set _ = nodes.append(node) %}
+  {%     endif %}
+  {%   endif %}
+  {% endfor %}
+  {% for node in groups['elastic-logstash'] %}
+  {%   if (nodes | length) <= (elastic_master_node_count | int) %}
+  {%     if (node in _master_nodes) %}
+  {%       set _ = nodes.append(node) %}
+  {%     endif %}
+  {%   endif %}
+  {% endfor %}
+  {{ nodes }}
+master_node_count: "{{ master_nodes | length }}"
+
 coordination_nodes: >-
   {{
     (groups['kibana'] | map('extract', hostvars, 'ansible_host') | list)
@@ -90,7 +156,7 @@ elasticsearch_data_node_details: >-
   }}
 logstash_data_node_details: >-
   {{
-    (data_nodes | map('extract', hostvars, 'ansible_host') | list) | map('regex_replace', '(.*)' ,'\1:' ~ logstash_beat_input_port) | list
+    (logstash_nodes | map('extract', hostvars, 'ansible_host') | list) | map('regex_replace', '(.*)' ,'\1:' ~ logstash_beat_input_port) | list
   }}
 
 # based on the assignment of roles to hosts, set per host booleans
@@ -105,16 +171,14 @@ elastic_thread_pool_size: "{{ ((ansible_processor_count | int) >= 24) | ternary(
 # ingest nodes.
 elasticsearch_number_of_replicas: "{{ ((data_nodes | length) > 2) | ternary('2', ((data_nodes | length) > 1) | ternary('1', '0')) }}"
 elasticsearch_data_hosts: |-
-  {% set nodes = elasticsearch_data_node_details %}
+  {% set data_hosts = elasticsearch_data_node_details | shuffle(seed=inventory_hostname) %}
-  {% set data_hosts = nodes | shuffle(seed=inventory_hostname) %}
   {% if inventory_hostname in data_nodes %}
-  {%   set _ = nodes.insert(0, '127.0.0.1:' ~ elastic_port) %}
+  {%   set _ = data_hosts.insert(0, '127.0.0.1:' ~ elastic_port) %}
   {% endif %}
   {{ data_hosts }}
 logstash_data_hosts: |-
-  {% set nodes = logstash_data_node_details %}
+  {% set data_hosts = logstash_data_node_details | shuffle(seed=inventory_hostname) %}
-  {% set data_hosts = nodes | shuffle(seed=inventory_hostname) %}
   {% if inventory_hostname in data_nodes %}
-  {%   set _ = nodes.insert(0, '127.0.0.1:' ~ logstash_beat_input_port) %}
+  {%   set _ = data_hosts.insert(0, '127.0.0.1:' ~ logstash_beat_input_port) %}
   {% endif %}
   {{ data_hosts }}

elk_metrics_6x/roles/elastic_dependencies/templates/jvm.options.j2

@@ -8,7 +8,8 @@
 -Xms{{ heap_size }}m
 # Xmx represents the maximum size of total heap space
 -Xmx{{ heap_size }}m
-
+# Sets the thread stack size
+-Xss1m
 
 ################################################################
 ## Expert settings

elk_metrics_6x/roles/elastic_logstash/handlers/main.yml

@@ -17,7 +17,7 @@
   systemd:
     name: "logstash"
     enabled: true
-    state: restarted
+    state: "{{ (inventory_hostname in logstash_nodes) | ternary('restarted', 'stopped') }}"
     daemon_reload: true
   when:
     - ansible_service_mgr == 'systemd'
@@ -26,7 +26,7 @@
 - name: Enable and restart logstash (upstart)
   service:
     name: "logstash"
-    state: restarted
+    state: "{{ (inventory_hostname in logstash_nodes) | ternary('restarted', 'stopped') }}"
     enabled: yes
   when:
     - ansible_service_mgr == 'upstart'

elk_metrics_6x/roles/elastic_logstash/templates/logstash.yml.j2

@@ -231,14 +231,14 @@ path.logs: /var/log/logstash
 xpack.monitoring.enabled: true
 #xpack.monitoring.elasticsearch.username: logstash_system
 #xpack.monitoring.elasticsearch.password: password
-#xpack.monitoring.elasticsearch.url: ["https://es1:9200", "https://es2:9200"]
+xpack.monitoring.elasticsearch.url: ["127.0.0.1:9200"]
 #xpack.monitoring.elasticsearch.ssl.ca: [ "/path/to/ca.crt" ]
 #xpack.monitoring.elasticsearch.ssl.truststore.path: path/to/file
 #xpack.monitoring.elasticsearch.ssl.truststore.password: password
 #xpack.monitoring.elasticsearch.ssl.keystore.path: /path/to/file
 #xpack.monitoring.elasticsearch.ssl.keystore.password: password
 #xpack.monitoring.elasticsearch.ssl.verification_mode: certificate
-#xpack.monitoring.elasticsearch.sniffing: false
+xpack.monitoring.elasticsearch.sniffing: false
 xpack.monitoring.collection.interval: 30s
 xpack.monitoring.collection.pipeline.details.enabled: true
 #

elk_metrics_6x/roles/elasticsearch/templates/systemd.elasticsearch-overrides.conf.j2

@@ -11,4 +11,4 @@ LimitMEMLOCK=infinity
 {% endif %}
 
 # Number of File Descriptors
-LimitNOFILE=131070
+LimitNOFILE=65536