Script Development / Built-in Variables

To help Scripts obtain relevant runtime status information during execution, DataFlux Func provides some directly usable built-in variables in the Script context.

Built-in Variable	Type	Scope	Description	Example Value
_DFF_IMAGE_INFO	dict	All	Current image info	See below
_DFF_TRACE_ID	str	All	Trace ID Trace inside Func	"TRACE-14E6D8D6-1F1A-4A5A-8280-854F6DD8CDB0"
_DFF_TASK_ID	str	All	Task ID	"task-2UHeFYPdb6Q7"
_DFF_ROOT_TASK_ID	str	All	Root task ID For the root task itself, fixed to "ROOT	"task-2UHeFYPdb6Q7"
_DFF_SCRIPT_SET_ID	str	All	Script Set ID	"demo"
_DFF_SCRIPT_SET_NAME	str	All	Script Set name Same as _DFF_SCRIPT_SET_ID	"demo"
_DFF_SCRIPT_SET_TITLE	str	All	Script Set title	"Example"
_DFF_SCRIPT_ID	str	All	Script ID	"demo__basic"
_DFF_SCRIPT_NAME	str	All	Script name i.e., the part excluding the Script Set ID	"basic"
_DFF_SCRIPT_TITLE	str	All	Script title	"Basic"
_DFF_FUNC_ID	str	All	Function ID	"demo__basic.hello_world"
_DFF_FUNC_NAME	str	All	Function name i.e., the part excluding the Script ID	"hello_world"
_DFF_FUNC_TITLE	str	All	Function title	"My Function"
_DFF_FUNC_CHAIN	list	All	Function call chain	[ "demo__basic.run", "demo__basic.hello_world" ]
_DFF_FUNC_CALL_KWARGS	dict	All	Function call parameters	{"x": 1, "y": 2}
_DFF_ORIGIN	str	All	Task source	"funcAPI"
_DFF_ORIGIN_ID	str	All	Source ID	"fapi-tDGC12Gdc5H6"
_DFF_TRIGGER_TIME	int	All	Scheduled start time (seconds)	1625651909
_DFF_TRIGGER_TIME_MS	int	All	Scheduled start time (milliseconds)	1625651909582
_DFF_START_TIME	int	All	Actual start time (seconds)	1625651910
_DFF_START_TIME_MS	int	All	Actual start time (milliseconds)	1625651910630
_DFF_QUEUE	int	All	Execution queue	2
_DFF_CRON_EXPR	str	Cron Job	Crontab expression	* * * * *
_DFF_HTTP_REQUEST	dict	Func API Function Page	Request body when the API is invoked	See below

Difference between _DFF_TRIGGER_TIME and _DFF_START_TIME

_DFF_START_TIME refers to the actual start time of the function, equivalent to executing int(time.time()) at the function entry, and may be delayed by factors such as queue congestion.

_DFF_TRIGGER_TIME, on the other hand, refers to the time when the function is triggered. It does not change due to queue congestion and can be considered the "scheduled start time". The values are as follows:

Function invocation method	Value
Execute function from UI	Time when the backend API service receives the HTTP request
Func API	Time when the backend API service receives the HTTP request
Cron Job	The exact time point corresponding to the Crontab expression

When using Cron Job to fetch time-series data at fixed intervals, use _DFF_TRIGGER_TIME and _DFF_TRIGGER_TIME_MS as the baseline, and do not use time.time() in your own code to get the current time

_DFF_IMAGE_INFO Data Structure

_DFF_IMAGE_INFO contains DataFlux Func image information, including the version number and other details.

Field	Description
EDITION	Edition; possible values are "original", "GSE", "TSE"
VERSION	Version number, e.g., "1.2.3"
ARCHITECTURE	Architecture; possible values are "x86_64", "aarch64"
RELEASE_TIMESTAMP	Release time (UNIX timestamp in seconds)

{
  "EDITION"          : "GSE",
  "VERSION"          : "7.3.6",
  "ARCHITECTURE"     : "x86_64",
  "RELEASE_TIMESTAMP": 1761298748
}

_DFF_HTTP_REQUEST Data Structure

_DFF_HTTP_REQUEST contains the request body details.

For example, given the following request:

curl \
    -X POST \
    -H "Content-Type: application/json" \
    -d '{"a":"b"}' \
    http://localhost:8088/api/v1/al/func-api-xxxxx/s?x=y

Then, the value of _DFF_HTTP_REQUEST is as follows:

{
    "method"     : "POST",
    "originalUrl": "/api/v1/al/func-api-xxxxx/s?x=y",
    "url"        : "/api/v1/al/func-api-xxxxx/s",
    "host"       : "localhost:8088",
    "hostname"   : "localhost",
    "protocol"   : "http",
    "headers": {
        "host"          : "localhost:8088",
        "user-agent"    : "curl/7.68.0",
        "accept"        : "*/*",
        "content-type"  : "application/json",
        "content-length": "9"
    },
    "query": {
        "x": "y"
    },
    "body": {
        "a": "b"
    },
    "ip" : "127.0.0.1",
    "ips": [],
    "xhr": false
}

In different versions of DataFlux Func, the fields contained in _DFF_HTTP_REQUEST may differ slightly; please refer to the actual version.

The headers field type is IgnoreCaseDict. IgnoreCaseDict inherits dict, so it is used basically the same way, except that key names are case-insensitive. For example, all the following lines of code can obtain the same value

_DFF_HTTP_REQUEST['headers']['user-agent']
_DFF_HTTP_REQUEST['headers']['User-Agent']
_DFF_HTTP_REQUEST['headers']['USER-AGENT']