Node on the local host.
%%% @see start/3
start(Node)->
start(gethostname(), Node).
%%%-----------------------------------------------------------------
%%% @spec start(Host, Node) -> Result
%%% Node = atom()
%%% Host = atom()
%%% Result = {ok, NodeName} |
%%% {error, already_started, NodeName} |
%%% {error, started_not_connected, NodeName} |
%%% {error, boot_timeout, NodeName} |
%%% {error, init_timeout, NodeName} |
%%% {error, startup_timeout, NodeName}
%%% NodeName = atom()
%%% @doc Starts an Erlang node with name Node on host
%%% Host with the default options.
%%% @see start/3
start(Host, Node)->
start(Host, Node, []).
%%%-----------------------------------------------------------------
%%% @spec start(Host, Node, Opts) -> Result
%%% Node = atom()
%%% Host = atom()
%%% Opts = [OptTuples]
%%% OptTuples = {username, Username} |
%%% {password, Password} |
%%% {boot_timeout, BootTimeout} | {init_timeout, InitTimeout} |
%%% {startup_timeout, StartupTimeout} |
%%% {startup_functions, StartupFunctions} |
%%% {monitor_master, Monitor} |
%%% {kill_if_fail, KillIfFail}
%%% Username = string()
%%% Password = string()
%%% BootTimeout = integer()
%%% InitTimeout = integer()
%%% StartupTimeout = integer()
%%% StartupFunctions = [StartupFunctionSpec]
%%% StartupFunctionSpec = {Module, Function, Arguments}
%%% Module = atom()
%%% Function = atom()
%%% Arguments = [term]
%%% Monitor = bool
%%% KillIfFail = bool
%%% Result = {ok, NodeName} | {error, already_started, NodeName} |
%%% {error, started_not_connected, NodeName} |
%%% {error, boot_timeout, NodeName} |
%%% {error, init_timeout, NodeName} |
%%% {error, startup_timeout, NodeName}
%%% NodeName = atom()
%%% @doc Starts an Erlang node with name Node on host
%%% Host as specified by the combination of options in
%%% Opts.
%%%
%%% Options Username and Password will be used
%%% to log in onto the remote host Host.
%%% Username, if omitted, defaults to the current user name,
%%% and password is empty by default.
A list of functions specified in the Startup option will be
%%% executed after startup of the node. Note that all used modules should be
%%% present in the code path on the Host.
The timeouts are applied as follows:
%%%
%%%
BootTimeout - time to start the Erlang node, in seconds.
%%% Defaults to 3 seconds. If node does not become pingable within this time,
%%% the result {error, boot_timeout, NodeName} is returned;
%%% InitTimeout - time to wait for the node until it calls the
%%% internal callback function informing master about successfull startup.
%%% Defaults to one second.
%%% In case of timed out message the result
%%% {error, init_timeout, NodeName} is returned;
%%% StartupTimeout - time to wait intil the node finishes to run
%%% the StartupFunctions. Defaults to one second.
%%% If this timeout occurs, the result
%%% {error, startup_timeout, NodeName} is returned.
%%%
Option monitor_master specifies, if the slave node should be
%%% stopped in case of master node stop. Defaults to false
Option kill_if_fail specifies, if the slave node should be
%%% killed in case of a timeout during initialization or startup.
%%% Defaults to true. Note that node also may be still alive it the boot
%%% timeout occurred, but it will not be killed in this case.
Special return values are:
%%%
%%%
{error, already_started, NodeName} - if the node with
%%% the given name is already started on a given host;{error, started_not_connected, NodeName} - if node is
%%% started, but not connected to the master node.
Node on
%%% the localhost.
stop(Node)->
stop(gethostname(), Node).
%%% @spec stop(Host, Node) -> Result
%%% Host = atom()
%%% Node = atom()
%%% Result = {ok, NodeName} |
%%% {error, not_started, NodeName} |
%%% {error, not_connected, NodeName} |
%%% {error, stop_timeout, NodeName}
%%% NodeName = atom()
%%% @doc Stops the running Erlang node with name Node on
%%% host Host.
stop(Host, Node)->
ENode = enodename(Host, Node),
case is_started(ENode) of
{true, connected}->
do_stop(ENode);
{true, not_connected}->
{error, not_connected, ENode};
false->
{error, not_started, ENode}
end.
%%% fetch an option value from the tagged tuple list with default
get_option_value(Key, OptionList, Default)->
case lists:keyfind(Key, 1, OptionList) of
false->
Default;
{Key, Value}->
Value
end.
%%% convert option list to the option record, fill all defaults
fetch_options(Options)->
UserName = get_option_value(username, Options, []),
Password = get_option_value(password, Options, []),
BootTimeout = get_option_value(boot_timeout, Options, 3),
InitTimeout = get_option_value(init_timeout, Options, 1),
StartupTimeout = get_option_value(startup_timeout, Options, 1),
StartupFunctions = get_option_value(startup_functions, Options, []),
Monitor = get_option_value(monitor_master, Options, false),
KillIfFail = get_option_value(kill_if_fail, Options, true),
#options{username=UserName, password=Password,
boot_timeout=BootTimeout, init_timeout=InitTimeout,
startup_timeout=StartupTimeout, startup_functions=StartupFunctions,
monitor_master=Monitor, kill_if_fail=KillIfFail}.
% send a message when slave node is started
% @hidden
slave_started(ENode, MasterPid)->
MasterPid ! {node_started, ENode},
ok.
% send a message when slave node has finished startup
% @hidden
slave_ready(ENode, MasterPid)->
MasterPid ! {node_ready, ENode},
ok.
% start monitoring of the master node
% @hidden
monitor_master(MasterNode)->
spawn(fun()->monitor_master_int(MasterNode) end).
% code of the masterdeath-waiter process
monitor_master_int(MasterNode)->
erlang:monitor_node(MasterNode, true),
receive
{nodedown, MasterNode}->
init:stop()
end.
% check if node is listed in the nodes()
is_connected(ENode)->
[N||N<-nodes(), N==ENode] == [ENode].
% check if node is alive (ping and disconnect if pingable)
is_started(ENode)->
case is_connected(ENode) of
true->
{true, connected};
false->
case net_adm:ping(ENode) of
pang->
false;
pong->
erlang:disconnect_node(ENode),
{true, not_connected}
end
end.
% make a Erlang node name from name and hostname
enodename(Host, Node)->
list_to_atom(atom_to_list(Node)++"@"++atom_to_list(Host)).
% performs actual start of the "slave" node
do_start(Host, Node, Options)->
ENode = enodename(Host, Node),
Functions =
lists:concat([[{ct_slave, slave_started, [ENode, self()]}],
Options#options.startup_functions,
[{ct_slave, slave_ready, [ENode, self()]}]]),
Functions2 = if
Options#options.monitor_master->
[{ct_slave, monitor_master, [node()]}|Functions];
true->
Functions
end,
MasterHost = gethostname(),
if
MasterHost == Host ->
spawn_local_node(Node);
true->
spawn_remote_node(Host, Node, Options)
end,
BootTimeout = Options#options.boot_timeout,
InitTimeout = Options#options.init_timeout,
StartupTimeout = Options#options.startup_timeout,
Result = case wait_for_node_alive(ENode, BootTimeout) of
pong->
call_functions(ENode, Functions2),
receive
{node_started, ENode}->
receive
{node_ready, ENode}->
{ok, ENode}
after StartupTimeout*1000->
{error, startup_timeout, ENode}
end
after InitTimeout*1000 ->
{error, init_timeout, ENode}
end;
pang->
{error, boot_timeout, ENode}
end,
case Result of
{ok, ENode}->
ok;
{error, Timeout, ENode}
when ((Timeout==init_timeout) or (Timeout==startup_timeout)) and
Options#options.kill_if_fail->
do_stop(ENode);
_-> ok
end,
Result.
% are we using fully qualified hostnames
long_or_short()->
case net_kernel:longnames() of
true->
"-name";
false->
"-sname"
end.
% get the localhost's name, depending on the using name policy
gethostname()->
Hostname = case net_kernel:longnames() of
true->
net_adm:localhost();
_->
{ok, Name}=inet:gethostname(),
Name
end,
list_to_atom(Hostname).
% get cmd for starting Erlang
get_cmd(Node)->
"erl -detached -noinput "++ long_or_short() ++ " " ++ atom_to_list(Node).
% spawn node locally
spawn_local_node(Node)->
Cmd = get_cmd(Node),
%io:format("Running cmd: ~p~n", [Cmd]),
open_port({spawn, Cmd}, [stream]).
% start crypto and ssh if not yet started
check_for_ssh_running()->
case application:get_application(crypto) of
undefined->
application:start(crypto),
case application:get_application(ssh) of
undefined->
application:start(ssh);
{ok, ssh}->
ok
end;
{ok, crypto}->
ok
end.
% spawn node remotely
spawn_remote_node(Host, Node, Options)->
Username = Options#options.username,
Password = Options#options.password,
SSHOptions = case {Username, Password} of
{[], []}->
[];
{_, []}->
[{user, Username}];
{_, _}->
[{user, Username}, {password, Password}]
end ++ [{silently_accept_hosts, true}],
check_for_ssh_running(),
{ok, SSHConnRef} = ssh:connect(atom_to_list(Host), 22, SSHOptions),
{ok, SSHChannelId} = ssh_connection:session_channel(SSHConnRef, infinity),
ssh_connection:exec(SSHConnRef, SSHChannelId, get_cmd(Node), infinity).
% call functions on a remote Erlang node
call_functions(_Node, [])->
ok;
call_functions(Node, [{M, F, A}|Functions])->
rpc:call(Node, M, F, A),
call_functions(Node, Functions).
% wait N seconds until node is pingable
wait_for_node_alive(_Node, 0)->
pang;
wait_for_node_alive(Node, N)->
timer:sleep(1000),
case net_adm:ping(Node) of
pong->
pong;
pang->
wait_for_node_alive(Node, N-1)
end.
% call init:stop on a remote node
do_stop(ENode)->
spawn(ENode, init, stop, []),
wait_for_node_dead(ENode, 5).
% wait N seconds until node is disconnected
wait_for_node_dead(Node, 0)->
{error, stop_timeout, Node};
wait_for_node_dead(Node, N)->
timer:sleep(1000),
case lists:member(Node, nodes()) of
true->
wait_for_node_dead(Node, N-1);
false->
{ok, Node}
end.