Class: Consul::Client::LocalService

Inherits:
Object
  • Object
show all
Defined in:
lib/consul/client/local_service.rb

Overview

Provides operations on services running on the local machine. Do not instantiate this class directly, instead use the appropriate factory methods.

See Also:

Instance Method Summary collapse

Constructor Details

#initialize(name, http:, logger:) ⇒ LocalService

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of LocalService.



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# File 'lib/consul/client/local_service.rb', line 10

def initialize(name, http:, logger:)
  @name   = name
  @consul = http
  @consul.logger = logger
end

Instance Method Details

#coordinated_shutdown!(min_nodes: 1, grace_period: 3, &block) ⇒ Object

Coordinate the shutdown of this node with the rest of the cluster so that a minimum number of nodes is always healthy. Blocks until a shutdown lock has been obtained and the cluster is healthy before yielding, in which callers should mark the service unhealthy (but continue to accept traffic). After the unhealthy state of the service has propagated and ‘grace_period` seconds has passed, this method returns and the caller should stop accepting new connections, finish existing work, then terminate.

Parameters:

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

    minimum require nodes for cluster to be considered healthy.

  • grace_period (Integer) (defaults to: 3) —

    number of seconds to sleep after service has been marked unhealthy in the cluster. This is important so that any in-flight requests are still able to be handled.



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# File 'lib/consul/client/local_service.rb', line 30

def coordinated_shutdown!(min_nodes: 1, grace_period: 3, &block)
  cluster = Consul::Client.v1.service(name, consul: consul)

  cluster.lock("shutdown") do
    cluster.wait_until_healthy!(min_nodes: min_nodes)
    block.()
    wait_until_unhealthy!

    # Release lock here and perform shutdown in our own time, since we
    # know the consistent view of nodes does not include this one and so
    # is safe for other nodes to try restarting.
  end

  # Grace period for any in-flight connections on their way already
  # before health check failure propagated.
  #
  # No way to avoid a sleep here.
  Kernel.sleep grace_period
end

#wait_until_unhealthy! ⇒ Object

Waits until the propagated health of this node is unhealthy so it is not receiving new traffic.



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# File 'lib/consul/client/local_service.rb', line 52

def wait_until_unhealthy!
  agent = consul.get("/agent/self")["Member"]["Name"]
  consul.get_while("/health/node/#{agent}") do |data|
    status = data.detect {|x| x["CheckID"] == "service:#{name}" }["Status"]
    status == 'passing'
  end
end