External task is defined by 3 things:
- location of the executable (launcher)
- task name
- task parameters
To define an external launcher in Firefly
Define executable in app.prop, using the following convention:
launchername.exe = @launchername.exe@
These are the implementation details that place certain requirements on the python launcher implementation:
1. Task parameters are passed via json file. The json input is coming directly from user: it's JSON.stringify from "taskParams" object below.
function onFireflyLoaded() {
var tableData= { "processor" : "TableFromExternalTask",
"launcher" : "python",
"task" : "TestTask",
"taskParams" :
{
"param1" : "str-1",
"param2" : 23456
}
};
firefly.showTable(tableData, "tableHere");
2. All other parameters as passed via key/value pairs or options. This way there is no danger that the order or extra parameters will affect the existing behavior.
This is the list of currently used options:
-d DIR, --work=DIR work directory
-i FILE, --in=FILE json file with task params
-n TASK, --name=TASK task name (no spaces)
-o DIR, --outdir=DIR directory for the final output file
In future (requested by Gregory):
-s STR, --sep=STR separator string, after which task status is written (default to "__TASK STATUS__")
3. A suggested output directory is provided rather than a suggested output file. It's up to the python launcher to create a unique file in this directory.
4. What is expected to be in standard error and standard output stream
- STDERR (Standard Error Stream) - whatever is coming from it is logged as warnings for now - we might come with a better idea later.
- STDOUT (Standard Output Stream) - can contain debugging info, the final output must be a line with the keyword, followed by JSON, which contains error message if any.
__TASK STATUS__
{
outfile: "/path/file.fits"
}
OR
__TASK STATUS__
{
error: "Description of the error"
}
5. External process exit status 0 means the execution was normal. Everything else means an error was encountered.
Story
External task is defined by 3 things:
To define an external launcher in Firefly
Define executable in app.prop, using the following convention:
launchername.exe = @launchername.exe@
These are the implementation details that place certain requirements on the python launcher implementation:
1. Task parameters are passed via json file. The json input is coming directly from user: it's JSON.stringify from "taskParams" object below.
function onFireflyLoaded() {
{ "param1" : "str-1", "param2" : 23456 }var tableData= { "processor" : "TableFromExternalTask",
"launcher" : "python",
"task" : "TestTask",
"taskParams" :
};
firefly.showTable(tableData, "tableHere");
2. All other parameters as passed via key/value pairs or options. This way there is no danger that the order or extra parameters will affect the existing behavior.
This is the list of currently used options:
-d DIR, --work=DIR work directory
-i FILE, --in=FILE json file with task params
-n TASK, --name=TASK task name (no spaces)
-o DIR, --outdir=DIR directory for the final output file
In future (requested by Gregory):
-s STR, --sep=STR separator string, after which task status is written (default to "__TASK STATUS__")
3. A suggested output directory is provided rather than a suggested output file. It's up to the python launcher to create a unique file in this directory.
4. What is expected to be in standard error and standard output stream
__TASK STATUS__
{ outfile: "/path/file.fits" }OR
__TASK STATUS__
{ error: "Description of the error" }5. External process exit status 0 means the execution was normal. Everything else means an error was encountered.