XML-RPC API Documentation

To use the XML-RPC interface, connect to supervisor’s HTTP port with any XML-RPC client library and run commands against it. An example of doing this using Python’s xmlrpclib client library is as follows.

import xmlrpclib
server = xmlrpclib.Server('http://localhost:9001/RPC2')

You may call methods against supervisord and its subprocesses by using the supervisor namespace. An example is provided below.

server.supervisor.getState()

You can get a list of methods supported by the supervisord XML-RPC interface by using the XML-RPC system.listMethods API:

server.system.listMethods()

You can see help on a method by using the system.methodHelp API against the method:

server.system.methodHelp('supervisor.shutdown')

The supervisord XML-RPC interface also supports the XML-RPC multicall API.

You can extend supervisord functionality with new XML-RPC API methods by adding new top-level RPC interfaces as necessary. See Configuring XML-RPC Interface Factories.

Status and Control

class supervisor.rpcinterface.SupervisorNamespaceRPCInterface(supervisord)

getAPIVersion()

Return the version of the RPC API used by supervisord

@return string version version id

This API is versioned separately from Supervisor itself. The API version returned by getAPIVersion only changes when the API changes. Its purpose is to help the client identify with which version of the Supervisor API it is communicating.

When writing software that communicates with this API, it is highly recommended that you first test the API version for compatibility before making method calls.

Note

The getAPIVersion method replaces getVersion found in Supervisor versions prior to 3.0a1. It is aliased for compatibility but getVersion() is deprecated and support will be dropped from Supervisor in a future version.

getSupervisorVersion()

Return the version of the supervisor package in use by supervisord

@return string version version id

getIdentification()

Return identifiying string of supervisord

@return string identifier identifying string

This method allows the client to identify with which Supervisor instance it is communicating in the case of environments where multiple Supervisors may be running.

The identification is a string that must be set in Supervisor’s configuration file. This method simply returns that value back to the client.

getState()

Return current state of supervisord as a struct

@return struct A struct with keys string statecode, int statename

This is an internal value maintained by Supervisor that determines what Supervisor believes to be its current operational state.

Some method calls can alter the current state of the Supervisor. For example, calling the method supervisor.shutdown() while the station is in the RUNNING state places the Supervisor in the SHUTDOWN state while it is shutting down.

The supervisor.getState() method provides a means for the client to check Supervisor’s state, both for informational purposes and to ensure that the methods it intends to call will be permitted.

The return value is a struct:

{'statecode': 1,
 'statename': 'RUNNING'}

The possible return values are:

statecode	statename	Description
2	FATAL	Supervisor has experienced a serious error.
1	RUNNING	Supervisor is working normally.
0	RESTARTING	Supervisor is in the process of restarting.
-1	SHUTDOWN	Supervisor is in the process of shutting down.

The FATAL state reports unrecoverable errors, such as internal errors inside Supervisor or system runaway conditions. Once set to FATAL, the Supervisor can never return to any other state without being restarted.

In the FATAL state, all future methods except supervisor.shutdown() and supervisor.restart() will automatically fail without being called and the fault FATAL_STATE will be raised.

In the SHUTDOWN or RESTARTING states, all method calls are ignored and their possible return values are undefined.

getPID()

Return the PID of supervisord

@return int PID

readLog(offset, length)

Read length bytes from the main log starting at offset

@param int offset offset to start reading from. @param int length number of bytes to read from the log. @return string result Bytes of log

It can either return the entire log, a number of characters from the tail of the log, or a slice of the log specified by the offset and length parameters:

Offset	Length	Behavior of readProcessLog
Negative	Not Zero	Bad arguments. This will raise the fault BAD_ARGUMENTS.
Negative	Zero	This will return the tail of the log, or offset number of characters from the end of the log. For example, if offset = -4 and length = 0, then the last four characters will be returned from the end of the log.
Zero or Positive	Negative	Bad arguments. This will raise the fault BAD_ARGUMENTS.
Zero or Positive	Zero	All characters will be returned from the offset specified.
Zero or Positive	Positive	A number of characters length will be returned from the offset.

If the log is empty and the entire log is requested, an empty string is returned.

If either offset or length is out of range, the fault BAD_ARGUMENTS will be returned.

If the log cannot be read, this method will raise either the NO_FILE error if the file does not exist or the FAILED error if any other problem was encountered.

Note

The readLog() method replaces readMainLog() found in Supervisor versions prior to 2.1. It is aliased for compatibility but readMainLog() is deprecated and support will be dropped from Supervisor in a future version.

clearLog()

Clear the main log.

@return boolean result always returns True unless error

If the log cannot be cleared because the log file does not exist, the fault NO_FILE will be raised. If the log cannot be cleared for any other reason, the fault FAILED will be raised.

shutdown()

Shut down the supervisor process

@return boolean result always returns True unless error

This method shuts down the Supervisor daemon. If any processes are running, they are automatically killed without warning.

Unlike most other methods, if Supervisor is in the FATAL state, this method will still function.

restart()

Restart the supervisor process

@return boolean result always return True unless error

This method soft restarts the Supervisor daemon. If any processes are running, they are automatically killed without warning. Note that the actual UNIX process for Supervisor cannot restart; only Supervisor’s main program loop. This has the effect of resetting the internal states of Supervisor.

Unlike most other methods, if Supervisor is in the FATAL state, this method will still function.

Process Control

class supervisor.rpcinterface.SupervisorNamespaceRPCInterface(supervisord)

getProcessInfo(name)

Get info about a process named name

@param string name The name of the process (or ‘group:name’) @return struct result A structure containing data about the process

The return value is a struct:

{'name':           'process name',
 'group':          'group name',
 'start':          1200361776,
 'stop':           0,
 'now':            1200361812,
 'state':          1,
 'statename':      'RUNNING',
 'spawnerr':       '',
 'exitstatus':     0,
 'stdout_logfile': '/path/to/stdout-log',
 'stderr_logfile': '/path/to/stderr-log',
 'pid':            1}

name

Name of the process

group

Name of the process’ group

start

UNIX timestamp of when the process was started

stop

UNIX timestamp of when the process ended, or 0 if the process is still running.

now

UNIX timestamp of the current time, which can be used to calculate process up-time.

state

State code, see table below.

statename

String description of state, see table below.

stdout_logfile

Absolute path and filename to the STDOUT logfile

stderr_logfile

Absolute path and filename to the STDOUT logfile

spawnerr

Description of error that occurred during spawn, or empty string if none.

exitstatus

Exit status (errorlevel) of process, or 0 if the process is still running.

pid

UNIX process ID (PID) of the process, or 0 if the process is not running.

getAllProcessInfo()

Get info about all processes

@return array result An array of process status results

Each element contains a struct, and this struct contains the exact same elements as the struct returned by getProcess. If the process table is empty, an empty array is returned.

startProcess(name, wait=True)

Start a process

@param string name Process name (or ‘group:name’, or ‘group:*‘) @param boolean wait Wait for process to be fully started @return boolean result Always true unless error

startAllProcesses(wait=True)

Start all processes listed in the configuration file

@param boolean wait Wait for each process to be fully started @return struct result A structure containing start statuses

startProcessGroup(name, wait=True)

Start all processes in the group named ‘name’

@param string name The group name @param boolean wait Wait for each process to be fully started @return struct result A structure containing start statuses

stopProcessGroup(name, wait=True)

Stop all processes in the process group named ‘name’

@param string name The group name @param boolean wait Wait for each process to be fully stopped @return boolean result Always return true unless error.

sendProcessStdin(name, chars)

Send a string of chars to the stdin of the process name. If non-7-bit data is sent (unicode), it is encoded to utf-8 before being sent to the process’ stdin. If chars is not a string or is not unicode, raise INCORRECT_PARAMETERS. If the process is not running, raise NOT_RUNNING. If the process’ stdin cannot accept input (e.g. it was closed by the child process), raise NO_FILE.

@param string name The process name to send to (or ‘group:name’) @param string chars The character data to send to the process @return boolean result Always return True unless error

sendRemoteCommEvent(type, data)

Send an event that will be received by event listener subprocesses subscribing to the RemoteCommunicationEvent.

@param string type String for the “type” key in the event header @param string data Data for the event body @return boolean Always return True unless error

addProcessGroup(name)

Update the config for a running process from config file.

@param string name name of process group to add @return boolean result true if successful

removeProcessGroup(name)

Remove a stopped process from the active configuration.

@param string name name of process group to remove @return boolean result Indicates wether the removal was successful

Process Logging

class supervisor.rpcinterface.SupervisorNamespaceRPCInterface(supervisord)

readProcessStdoutLog(name, offset, length)

Read length bytes from name’s stdout log starting at offset

@param string name the name of the process (or ‘group:name’) @param int offset offset to start reading from. @param int length number of bytes to read from the log. @return string result Bytes of log

readProcessStderrLog(name, offset, length)

Read length bytes from name’s stderr log starting at offset

@param string name the name of the process (or ‘group:name’) @param int offset offset to start reading from. @param int length number of bytes to read from the log. @return string result Bytes of log

tailProcessStdoutLog(name, offset, length)

Provides a more efficient way to tail the (stdout) log than readProcessStdoutLog(). Use readProcessStdoutLog() to read chunks and tailProcessStdoutLog() to tail.

Requests (length) bytes from the (name)’s log, starting at (offset). If the total log size is greater than (offset + length), the overflow flag is set and the (offset) is automatically increased to position the buffer at the end of the log. If less than (length) bytes are available, the maximum number of available bytes will be returned. (offset) returned is always the last offset in the log +1.

@param string name the name of the process (or ‘group:name’) @param int offset offset to start reading from @param int length maximum number of bytes to return @return array result [string bytes, int offset, bool overflow]

tailProcessStderrLog(name, offset, length)

Provides a more efficient way to tail the (stderr) log than readProcessStderrLog(). Use readProcessStderrLog() to read chunks and tailProcessStderrLog() to tail.

Requests (length) bytes from the (name)’s log, starting at (offset). If the total log size is greater than (offset + length), the overflow flag is set and the (offset) is automatically increased to position the buffer at the end of the log. If less than (length) bytes are available, the maximum number of available bytes will be returned. (offset) returned is always the last offset in the log +1.

@param string name the name of the process (or ‘group:name’) @param int offset offset to start reading from @param int length maximum number of bytes to return @return array result [string bytes, int offset, bool overflow]

clearProcessLogs(name)

Clear the stdout and stderr logs for the named process and reopen them.

@param string name The name of the process (or ‘group:name’) @return boolean result Always True unless error

clearAllProcessLogs()

Clear all process log files

@return boolean result Always return true

System Methods

class supervisor.xmlrpc.SystemNamespaceRPCInterface(namespaces)

listMethods()

Return an array listing the available method names

@return array result An array of method names available (strings).

methodHelp(name)

Return a string showing the method’s documentation

@param string name The name of the method. @return string result The documentation for the method name.

methodSignature(name)

Return an array describing the method signature in the form [rtype, ptype, ptype...] where rtype is the return data type of the method, and ptypes are the parameter data types that the method accepts in method argument order.

@param string name The name of the method. @return array result The result.

multicall(calls)

Process an array of calls, and return an array of results. Calls should be structs of the form {‘methodName’: string, ‘params’: array}. Each result will either be a single-item array containg the result value, or a struct of the form {‘faultCode’: int, ‘faultString’: string}. This is useful when you need to make lots of small calls without lots of round trips.

@param array calls An array of call requests @return array result An array of results