Module: Capistrano::Configuration::Connections

Module | Capistrano::Configuration::Connections
In: | lib/capistrano/configuration/connections.rb lib/capistrano/configuration/connections.rb

### Methods

connect! connect! connection_factory connection_factory establish_connections_to establish_connections_to execute_on_servers execute_on_servers failed! failed! has_failed? has_failed? teardown_connections_to teardown_connections_to

### Attributes

sessions | [R] | A hash of the SSH sessions that are currently open and available. Because sessions are constructed lazily, this will only contain connections to those servers that have been the targets of one or more executed tasks.
sessions | [R] | A hash of the SSH sessions that are currently open and available. Because sessions are constructed lazily, this will only contain connections to those servers that have been the targets of one or more executed tasks.

### Public Instance methods

connect!(options={})

Used to force connections to be made to the current task‘s servers. Connections are normally made lazily in Capistrano—you can use this to force them open before performing some operation that might be time-sensitive.

[Source]

        # File lib/capistrano/configuration/connections.rb, line 78
    78:       def connect!(options={})
    79:         execute_on_servers(options) { }
    80:       end

connect!(options={})

Used to force connections to be made to the current task‘s servers. Connections are normally made lazily in Capistrano—you can use this to force them open before performing some operation that might be time-sensitive.

[Source]

        # File lib/capistrano/configuration/connections.rb, line 78
    78:       def connect!(options={})
    79:         execute_on_servers(options) { }
    80:       end

connection_factory()

Returns the object responsible for establishing new SSH connections. The factory will respond to connect_to, which can be used to establish connections to servers defined via ServerDefinition objects.

[Source]

        # File lib/capistrano/configuration/connections.rb, line 85
    85:       def connection_factory
    86:         @connection_factory ||= begin
    87:           if exists?(:gateway)
    88:             logger.debug "establishing connection to gateway `#{fetch(:gateway)}'"
    89:             GatewayConnectionFactory.new(fetch(:gateway), self)
    90:           else
    91:             DefaultConnectionFactory.new(self)
    92:           end
    93:         end
    94:       end

connection_factory()

Returns the object responsible for establishing new SSH connections. The factory will respond to connect_to, which can be used to establish connections to servers defined via ServerDefinition objects.

[Source]

        # File lib/capistrano/configuration/connections.rb, line 85
    85:       def connection_factory
    86:         @connection_factory ||= begin
    87:           if exists?(:gateway)
    88:             logger.debug "establishing connection to gateway `#{fetch(:gateway)}'"
    89:             GatewayConnectionFactory.new(fetch(:gateway), self)
    90:           else
    91:             DefaultConnectionFactory.new(self)
    92:           end
    93:         end
    94:       end

establish_connections_to(servers)

Ensures that there are active sessions for each server in the list.

[Source]

         # File lib/capistrano/configuration/connections.rb, line 97
     97:       def establish_connections_to(servers)
     98:         failed_servers = []
     99:
    100:         # force the connection factory to be instantiated synchronously,
    101:         # otherwise we wind up with multiple gateway instances, because
    102:         # each connection is done in parallel.
    103:         connection_factory
    104:
    105:         threads = Array(servers).map { |server| establish_connection_to(server, failed_servers) }
    106:         threads.each { |t| t.join }
    107:
    108:         if failed_servers.any?
    109:           errors = failed_servers.map { |h| "#{h[:server]} (#{h[:error].class}: #{h[:error].message})" }
    110:           error = ConnectionError.new("connection failed for: #{errors.join(', ')}")
    111:           error.hosts = failed_servers.map { |h| h[:server] }
    112:           raise error
    113:         end
    114:       end

establish_connections_to(servers)

Ensures that there are active sessions for each server in the list.

[Source]

         # File lib/capistrano/configuration/connections.rb, line 97
     97:       def establish_connections_to(servers)
     98:         failed_servers = []
     99:
    100:         # force the connection factory to be instantiated synchronously,
    101:         # otherwise we wind up with multiple gateway instances, because
    102:         # each connection is done in parallel.
    103:         connection_factory
    104:
    105:         threads = Array(servers).map { |server| establish_connection_to(server, failed_servers) }
    106:         threads.each { |t| t.join }
    107:
    108:         if failed_servers.any?
    109:           errors = failed_servers.map { |h| "#{h[:server]} (#{h[:error].class}: #{h[:error].message})" }
    110:           error = ConnectionError.new("connection failed for: #{errors.join(', ')}")
    111:           error.hosts = failed_servers.map { |h| h[:server] }
    112:           raise error
    113:         end
    114:       end

execute_on_servers(options={}) {|servers_slice| ...}

Determines the set of servers within the current task‘s scope and establishes connections to them, and then yields that list of servers.

[Source]

         # File lib/capistrano/configuration/connections.rb, line 127
    127:       def execute_on_servers(options={})
    128:         raise ArgumentError, "expected a block" unless block_given?
    129:
    130:         if task = current_task
    131:           servers = find_servers_for_task(task, options)
    132:
    133:           if servers.empty?
    134:             if ENV['HOSTFILTER']
    135:               logger.info "skipping `#{task.fully_qualified_name}' because no servers matched"
    136:               return
    137:             else
    138:               raise Capistrano::NoMatchingServersError, "`#{task.fully_qualified_name}' is only run for servers matching #{task.options.inspect}, but no servers matched"
    139:             end
    140:           end
    141:
    142:           if task.continue_on_error?
    143:             servers.delete_if { |s| has_failed?(s) }
    144:             return if servers.empty?
    145:           end
    146:         else
    147:           servers = find_servers(options)
    148:           raise Capistrano::NoMatchingServersError, "no servers found to match #{options.inspect}" if servers.empty?
    149:         end
    150:
    151:         servers = [servers.first] if options[:once]
    152:         logger.trace "servers: #{servers.map { |s| s.host }.inspect}"
    153:
    154:         max_hosts = (options[:max_hosts] || (task && task.max_hosts) || servers.size).to_i
    155:         is_subset = max_hosts < servers.size
    156:
    157:         # establish connections to those servers in groups of max_hosts, as necessary
    158:         servers.each_slice(max_hosts) do |servers_slice|
    159:           begin
    160:             establish_connections_to(servers_slice)
    161:           rescue ConnectionError => error
    162:             raise error unless task && task.continue_on_error?
    163:             error.hosts.each do |h|
    164:               servers_slice.delete(h)
    165:               failed!(h)
    166:             end
    167:           end
    168:
    169:           begin
    170:             yield servers_slice
    171:           rescue RemoteError => error
    172:             raise error unless task && task.continue_on_error?
    173:             error.hosts.each { |h| failed!(h) }
    174:           end
    175:
    176:           # if dealing with a subset (e.g., :max_hosts is less than the
    177:           # number of servers available) teardown the subset of connections
    178:           # that were just made, so that we can make room for the next subset.
    179:           teardown_connections_to(servers_slice) if is_subset
    180:         end
    181:       end

execute_on_servers(options={}) {|servers_slice| ...}

Determines the set of servers within the current task‘s scope and establishes connections to them, and then yields that list of servers.

[Source]

         # File lib/capistrano/configuration/connections.rb, line 127
    127:       def execute_on_servers(options={})
    128:         raise ArgumentError, "expected a block" unless block_given?
    129:
    130:         if task = current_task
    131:           servers = find_servers_for_task(task, options)
    132:
    133:           if servers.empty?
    134:             if ENV['HOSTFILTER']
    135:               logger.info "skipping `#{task.fully_qualified_name}' because no servers matched"
    136:               return
    137:             else
    138:               raise Capistrano::NoMatchingServersError, "`#{task.fully_qualified_name}' is only run for servers matching #{task.options.inspect}, but no servers matched"
    139:             end
    140:           end
    141:
    142:           if task.continue_on_error?
    143:             servers.delete_if { |s| has_failed?(s) }
    144:             return if servers.empty?
    145:           end
    146:         else
    147:           servers = find_servers(options)
    148:           raise Capistrano::NoMatchingServersError, "no servers found to match #{options.inspect}" if servers.empty?
    149:         end
    150:
    151:         servers = [servers.first] if options[:once]
    152:         logger.trace "servers: #{servers.map { |s| s.host }.inspect}"
    153:
    154:         max_hosts = (options[:max_hosts] || (task && task.max_hosts) || servers.size).to_i
    155:         is_subset = max_hosts < servers.size
    156:
    157:         # establish connections to those servers in groups of max_hosts, as necessary
    158:         servers.each_slice(max_hosts) do |servers_slice|
    159:           begin
    160:             establish_connections_to(servers_slice)
    161:           rescue ConnectionError => error
    162:             raise error unless task && task.continue_on_error?
    163:             error.hosts.each do |h|
    164:               servers_slice.delete(h)
    165:               failed!(h)
    166:             end
    167:           end
    168:
    169:           begin
    170:             yield servers_slice
    171:           rescue RemoteError => error
    172:             raise error unless task && task.continue_on_error?
    173:             error.hosts.each { |h| failed!(h) }
    174:           end
    175:
    176:           # if dealing with a subset (e.g., :max_hosts is less than the
    177:           # number of servers available) teardown the subset of connections
    178:           # that were just made, so that we can make room for the next subset.
    179:           teardown_connections_to(servers_slice) if is_subset
    180:         end
    181:       end

failed!(server)

Indicate that the given server could not be connected to.

[Source]

        # File lib/capistrano/configuration/connections.rb, line 64
    64:       def failed!(server)
    65:         @failed_sessions << server
    66:       end

failed!(server)

Indicate that the given server could not be connected to.

[Source]

        # File lib/capistrano/configuration/connections.rb, line 64
    64:       def failed!(server)
    65:         @failed_sessions << server
    66:       end

has_failed?(server)

Query whether previous connection attempts to the given server have failed.

[Source]

        # File lib/capistrano/configuration/connections.rb, line 70
    70:       def has_failed?(server)
    71:         @failed_sessions.include?(server)
    72:       end

has_failed?(server)

Query whether previous connection attempts to the given server have failed.

[Source]

        # File lib/capistrano/configuration/connections.rb, line 70
    70:       def has_failed?(server)
    71:         @failed_sessions.include?(server)
    72:       end

teardown_connections_to(servers)

Destroys sessions for each server in the list.

[Source]

         # File lib/capistrano/configuration/connections.rb, line 117
    117:       def teardown_connections_to(servers)
    118:         servers.each do |server|
    119:            @sessions[server].close
    120:            @sessions.delete(server)
    121:          end
    122:       end

teardown_connections_to(servers)

Destroys sessions for each server in the list.

[Source]

         # File lib/capistrano/configuration/connections.rb, line 117
    117:       def teardown_connections_to(servers)
    118:         servers.each do |server|
    119:            @sessions[server].close
    120:            @sessions.delete(server)
    121:          end
    122:       end

[Validate]