Module: Enscalator::Plugins::Elasticache

Includes:
Helpers
Defined in:
lib/enscalator/plugins/elasticache.rb

Overview

Collection of methods to work with ElastiCache (Redis)

Instance Method Summary collapse

Methods included from Helpers

#cfn_call_script, #create_ssh_key, #find_ami, #flatten_hash, #gen_ssh_key_name, #init_assets_dir, #init_aws_config, #read_user_data, #run_cmd

Methods included from Helpers::Dns

#get_dns_records, #upsert_dns_record

Methods included from Helpers::Stack

#cfn_create_stack, #generate_parameters, #get_resource, #get_resources, #wait_stack

Methods included from Helpers::Wrappers

#cfn_client, #cfn_resource, #ec2_client, #route53_client

Instance Method Details

#elasticache_cluster_init(app_name, cache_node_type: 'cache.m1.small', num_cache_nodes: 1) ⇒ Object

Create ElastiCache cluster

Parameters:

  • app_name (String) —

    application name

  • cache_node_type (String) (defaults to: 'cache.m1.small') —

    instance node type

  • num_cache_nodes (Integer) (defaults to: 1) —

    number of nodes to create



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# File 'lib/enscalator/plugins/elasticache.rb', line 89

def elasticache_cluster_init(app_name, cache_node_type: 'cache.m1.small', num_cache_nodes: 1)
  cluster_resources = init_cluster_resources(app_name, cache_node_type)

  resource_name = "#{app_name}RedisCluster"
  resource resource_name,
           Type: 'AWS::ElastiCache::CacheCluster',
           Properties: {
             Engine: 'redis',
             NumCacheNodes: "#{num_cache_nodes}",
             CacheNodeType: cache_node_type,
             CacheSubnetGroupName: ref("#{app_name}ElasticacheSubnetGroup"),
             CacheParameterGroupName: ref(cluster_resources[:parameter_group]),
             VpcSecurityGroupIds: [get_att("#{app_name}RedisSecurityGroup", 'GroupId')]
           }
  resource_name

  # Unable to get created resource endpoint and port with Fn::GetAtt for engine == redis
  # For more details see here:
  # http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-elasticache-cache-cluster.html
end

#elasticache_repl_group_init(app_name, cache_node_type: 'cache.t2.small', num_cache_clusters: 2, seed: nil, **properties) ⇒ Object

Create ElastiCache replication group

Parameters:

  • app_name (String) —

    application name

  • cache_node_type (String) (defaults to: 'cache.t2.small') —

    instance node type



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# File 'lib/enscalator/plugins/elasticache.rb', line 113

def elasticache_repl_group_init(app_name, cache_node_type: 'cache.t2.small',
                                num_cache_clusters: 2, seed: nil, **properties)
  if %w(t1).map { |t| cache_node_type.include?(t) }.include?(true)
    fail "T1 instance types are not supported, got '#{cache_node_type}'"
  end

  cluster_properties =
    !properties.nil? && properties.key?(:cluster_properties) ? properties[:cluster_properties] : {}

  cluster_resources = init_cluster_resources(app_name,
                                             cache_node_type,
                                             param_group_seed: seed,
                                             parameter_group_properties: cluster_properties)

  resource_name = "#{app_name}RedisReplicationGroup"
  resource resource_name,
           Type: 'AWS::ElastiCache::ReplicationGroup',
           Properties: {
             Engine: 'redis',
             ReplicationGroupDescription: "Redis Replication group for #{app_name}",
             AutomaticFailoverEnabled: num_cache_clusters > 1 ? 'true' : 'false',
             NumCacheClusters: num_cache_clusters,
             CacheNodeType: cache_node_type,
             CacheSubnetGroupName: ref("#{app_name}ElasticacheSubnetGroup"),
             CacheParameterGroupName: ref(cluster_resources[:parameter_group]),
             SecurityGroupIds: [
               get_att("#{app_name}RedisSecurityGroup", 'GroupId'),
               ref_private_security_group
             ]
           }.merge(properties.reject { |k, _v| k == :cluster_properties })

  output "#{app_name}RedisReplicationGroup",
         Description: "Redis ReplicationGroup #{app_name}",
         Value: ref("#{app_name}RedisReplicationGroup")

  output "#{app_name}RedisPrimaryEndpointAddress",
         Description: "Redis Primary Endpoint Address #{app_name}",
         Value: get_att(resource_name, 'PrimaryEndPoint.Address')

  output "#{app_name}RedisPrimaryEndpointPort",
         Description: "Redis Primary Endpoint Port #{app_name}",
         Value: get_att(resource_name, 'PrimaryEndPoint.Port')

  output "#{app_name}RedisReadOnlyEndpointAddresses",
         Description: "Redis ReadOnly Endpoint Addresses #{app_name}",
         Value: get_att(resource_name, 'ReadEndPoint.Addresses')

  output "#{app_name}RedisReadOnlyEndpointPorts",
         Description: "Redis ReadOnly Endpoint Ports #{app_name}",
         Value: get_att(resource_name, 'ReadEndPoint.Ports')

  resource_name
end

#init_cluster_resources(app_name, cache_node_type, param_group_seed: nil, **properties) ⇒ Object

Initialize resources common for all ElastiCache instances

Parameters:

  • app_name (Object) —

    application stack name

  • cache_node_type (Object) —

    node type



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# File 'lib/enscalator/plugins/elasticache.rb', line 26

def init_cluster_resources(app_name, cache_node_type, param_group_seed: nil, **properties)
  subnet_group_name = "#{app_name}ElasticacheSubnetGroup"
  resource subnet_group_name,
           Type: 'AWS::ElastiCache::SubnetGroup',
           Properties: {
             Description: 'SubnetGroup for elasticache',
             SubnetIds: ref_resource_subnets
           }

  security_group_name =
    security_group_vpc "#{app_name}RedisSecurityGroup",
                       "Redis Security Group for #{app_name}",
                       ref_vpc_id,
                       security_group_ingress: [
                         {
                           IpProtocol: 'tcp',
                           FromPort: '6379',
                           ToPort: '6389',
                           SourceSecurityGroupId: ref_application_security_group
                         }
                       ],
                       tags: {
                         Name: join('-', aws_stack_name, 'res', 'sg'),
                         Application: aws_stack_name
                       }

  parameter_group_required_props = {
    'reserved-memory': Core::InstanceType.elasticache_instance_type.max_memory(cache_node_type) / 2
  }

  parameter_group_props = (
  if !properties.nil? && properties.key?(:parameter_group_properties)
    properties[:parameter_group_properties]
  else
    {}
  end).merge(parameter_group_required_props)

  # TODO: remove this workaround when related template gets fixed
  parameter_group_name = if param_group_seed
                           "#{app_name}RedisParameterGroup#{param_group_seed}"
                         else
                           "#{app_name}RedisParameterGroup#{magic_number(parameter_group_props)}"
                         end

  resource parameter_group_name,
           Type: 'AWS::ElastiCache::ParameterGroup',
           Properties: {
             Description: "#{app_name} redis parameter group",
             CacheParameterGroupFamily: 'redis3.2',
             Properties: parameter_group_props
           }

  {
    subnet_group: subnet_group_name,
    security_group: security_group_name,
    parameter_group: parameter_group_name
  }
end

#magic_number(input) ⇒ String

Generates magic number (sha256 hex digest) from given Hash

Parameters:

  • input (Object) —

    used for digest generation

Returns:

  • (String) 


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# File 'lib/enscalator/plugins/elasticache.rb', line 10

def magic_number(input)
  str = if input.is_a?(String)
          input
        elsif input.is_a?(Array)
          input.flatten.map(&:to_s).sort.join('&')
        elsif input.is_a?(Hash)
          flatten_hash(input).map { |k, v| "#{k}=#{v}" }.sort.join('&')
        else
          fail("Not supported input format: #{input.class}")
        end
  Digest::SHA256.hexdigest(str)
end