I have recently started working on twisted not much familiar with its functions.I have a problem related to "deferToThread" method...my code is here to use this method
from twisted.internet.threads import deferToThread
from twisted.internet import reactor
results=[]
class Tool(object):
def exectool(self,tool):
# print "Test Class Exec tool running..........."
exec tool
return
def getResult(self,tool):
return results.append(deferToThread(self.exectool, tool))
to=Tool()
to.getResult(tools)
f=open(temp).read()
obj_tool=compile(f, 'a_filename', 'exec')
[ at 0x8ce7020, file "a_filename", line 1>, at 0x8cd4e30, file "a_filename", line 2>]
I am passing tools one by one in getResults() method it executs successfully & prints the results what script written in the file objects.
I have to store the result of tools executing in some variable so that I can save it in database.How to achieve this cause when i call re=to.getResult(tools) and print "re" it prints none.
I HAVE TO STORE ITS RESULTS IN DATABASE? IS THERE SOMETHING I CAN DO?
thanx in advance
There are two problems here.
First, deferToThread will not work if you never start the reactor. Hopefully this code snippet was actually extracted from a larger Twisted-using application where the reactor is running, so that won't be an actual problem for you. But you shouldn't expect this snippet to work unless you add a reactor.run() call to it.
Second, deferToThread returns a Deferred. The Deferred fires with the result of the callable you passed in. This is covered in the API documentation. Many APIs in Twisted return a Deferred, so you might want to read the documentation covering them. Once you understand how they work and how to use them, lots of things should be quite a bit easier.
Related
Is there a way to make the logged user (on superset) to make the queries on impala?
I tried to enable the "Impersonate the logged on user" option on Databases but with no success because all the queries run on impala with superset user.
I'm trying to achieve the same! This will not completely answer this question since it does not still work but I want to share my research in order to maybe help another soul that is trying to use this instrument outside very basic use cases.
I went deep in the code and I found out that impersonation is not implemented for Impala. So you cannot achieve this from the UI. I found out this PR https://github.com/apache/superset/pull/4699 that for whatever reason was never merged into the codebase and tried to copy&paste code in my Superset version (1.1.0) but it didn't work. Adding some logs I can see that the configuration with the impersonation is updated, but then the actual Impala query is with the user I used to start the process.
As you can imagine, I am a complete noob at this. However I found out that the impersonation thing happens when you create a cursor and there is a constructor parameter in which you can pass the impersonation configuration.
I managed to correctly (at least to my understanding) implement impersonation for the SQL lab part.
In the sql_lab.py class you have to add in the execute_sql_statements method the following lines
with closing(engine.raw_connection()) as conn:
# closing the connection closes the cursor as well
cursor = conn.cursor(**database.cursor_kwargs)
where cursor_kwargs is defined in db_engine_specs/impala.py as the following
#classmethod
def get_configuration_for_impersonation(cls, uri, impersonate_user, username):
logger.info(
'Passing Impala execution_options.cursor_configuration for impersonation')
return {'execution_options': {
'cursor_configuration': {'impala.doas.user': username}}}
#classmethod
def get_cursor_configuration_for_impersonation(cls, uri, impersonate_user,
username):
logger.debug('Passing Impala cursor configuration for impersonation')
return {'configuration': {'impala.doas.user': username}}
Finally, in models/core.py you have to add the following bit in the get_sqla_engine def
params = extra.get("engine_params", {}) # that was already there just for you to find out the line
self.cursor_kwargs = self.db_engine_spec.get_cursor_configuration_for_impersonation(
str(url), self.impersonate_user, effective_username) # this is the line I added
...
params.update(self.get_encrypted_extra()) # already there
#new stuff
configuration = {}
configuration.update(
self.db_engine_spec.get_configuration_for_impersonation(
str(url),
self.impersonate_user,
effective_username))
if configuration:
params.update(configuration)
As you can see I just shamelessy pasted the code from the PR. However this kind of works only for the SQL lab as I already said. For the dashboards there is an entirely different way of querying Impala that I did not still find out.
This means that queries for the dashboards are handled in a different way and there isn't something like this
with closing(engine.raw_connection()) as conn:
# closing the connection closes the cursor as well
cursor = conn.cursor(**database.cursor_kwargs)
My gut (and debugging) feeling is that you need to first understand the sqlalchemy part and extend a new ImpalaEngine class that uses a custom cursor with the impersonation conf. Or something like that, however it is not simple (if we want to call this simple) as the sql_lab part. So, the trick is to find out where the query is executed and create a cursor with the impersonation configuration. Easy, isnt'it ?
I hope that this could shed some light to you and the others that have this issue. Let me know if you did find out another way to solve this issue, or if this comment was useful.
Update: something really useful
A colleague of mine succesfully implemented impersonation with impala without touching any superset related, but instead working directly with the impyla lib. A PR was open with the code to change. You can apply the patch directly in the impyla src used by superset. You have to edit both dbapi.py and hiveserver2.py.
As a reminder: we are still testing this and we do not know if it works with different accounts using the same superset instance.
I´m currently writing tests for my application and therefore, I have to test some click.group commands I defined:
Let´s say I defined them like:
#click.group(cls=MyGroup)
#click.pass_context
def myapp(ctx):
init_stuff()
#myapp.command()
#click.option('--myOption')
def foo(myOption: str) -> None:
do_stuff() # change some files, print, create other files
I know that I could use the CliRunner from click.testing. However, I just want to make sure, that the command is called, but I DONT WANT it to execute any code (for example by applying the CliRunner.invoke()).
How could this be done?
I couldn´t come up with a solution using mocking with foo for example. Or do I have to execute code lets say using the isolated_filesystem() which CliRunner provides?
So the question is: What would be the most efficient way to test my commands when defined like shown above?
Many thanks in advance
You could add a --dry-run flag to your group or some commands, and save it it inside the context, and if the flag is enabled, do not execute any code. Then you can use CliRunner.invoke() with the --dry-run flag enabled and just check your invocations have happened, without actually executing the code.
Refer the following code:
def parse(height_id):
driver2=webdriver.Firefox()
driver2.get(height_id)
block_details_web_element=driver2.find_element_by_xpath('//*[#id="__next"]/div[3]/div/div[3]/div[1]/div/div')
print (block_details_web_element)
print(block_details_web_element.text)
print(" --- BLOCK PARSED SUCCESSFULLY! ---\n")
driver2.quit()
#the following parts are outside the function:
p = Pool(4)
records = p.map(parse, height_list_on_each_page2) #height_list_on_each_page2 is a list of URLs.
p.terminate()
p.join()
(Eg. of a typical URL: https://www.blockchain.com/btc/block/000000000000000000028e473f1c95060a63100c9861525105b1f5ced81a7fa0 )
Now, this works fine, but takes huge time. So, I planned to put the statement driver2=webdriver.Firefox() outside the parse function, so that I don't re-create the instance of WebDriver each time I'm calling the function. [And I also removed the statement driver2.quit() from this function]. This is saving time, however, almost half of the times the print statment print (block_details_web_element) is returning None as output.
I doubt that the find_elements_by_xpath method is not working correctly. Is this because of multi-processing that I am using?
Any insight, why this is happening? Please suggest a solution.
EDIT : (this is the error)
(https://www.dropbox.com/s/1yvknbdg9wefuwy/selenium.jpeg?dl=0)
I'm using Jmeter to design a test that requires data to be randomly read from text files. To save memory, I have set up a "setUp Thread Group" with a BeanShell PreProcessor with the following:
//Imports
import org.apache.commons.io.FileUtils;
//Read data files
List items = FileUtils.readLines(new File(vars.get("DataFolder") + "/items.txt"));
//Store for future use
props.put("items", items);
I then attempt to read this in my other thread groups and am trying to access a random line in my text files with something like this:
(props.get("items")).get(new Random().nextInt((props.get("items")).size()))
However, this throws a "Typed variable declaration" error and I think it's because the get() method returns an object and I'm trying to invoke size() on it, since it's really a List. I'm not sure what to do here. My ultimate goal is to define some lists of data once to be used globally in my test so my tests don't have to store this data themselves.
Does anyone have any thoughts as to what might be wrong?
EDIT
I've also tried defining the variables in the setUp thread group as follows:
bsh.shared.items = items;
And then using them as this:
(bsh.shared.items).get(new Random().nextInt((bsh.shared.items).size()))
But that fails with the error "Method size() not found in class'bsh.Primitive'".
You were very close, just add casting to List so the interpreter will know what's the expected object:
log.info(((List)props.get("items")).get(new Random().nextInt((props.get("items")).size())));
Be aware that since JMeter 3.1 it is recommended to use Groovy for any form of scripting as:
Groovy performance is much better
Groovy supports more modern Java features while with Beanshell you're stuck at Java 5 level
Groovy has a plenty of JDK enhancements, i.e. File.readLines() function
So kindly find Groovy solution below:
In the first Thread Group:
props.put('items', new File(vars.get('DataFolder') + '/items.txt').readLines()
In the second Thread Group:
def items = props.get('items')
def randomLine = items.get(new Random().nextInt(items.size))
I have written a code in twisted .I need to write the log information in when we have call
d.addErrback(on_failure).
from twisted.python import log
log.startLogging(open('/home/crytek.etl/foo.log', 'w'))
def on_failure(failure):
log.msg(failure)
d.addErrback(on_failure)
Is this the correct way of implementing this.I don't get any values written to the file.Can someone suggest on how this can be implemented
You probably want to consider opening your log file in append mode. Otherwise, every time your application starts you'll wipe out all your old logs. This could make it appear as though the log messages you're expecting to see aren't being logged.
from twisted.python import log
log.startLogging(open('/home/crytek.etl/foo.log', 'a'))
You should also log failures using log.err instead of log.msg
def on_failure(failure):
log.err(failure)
And you can do this more easily since on_failure has exactly the same signature as log.err. Just write:
d.addErrback(log.err)
Also, I liked, log.err doesn't have exactly the same signature as on_failure. It is better, it accepts a 2nd argument which is used to present a header for the failure in the log file. You can use it like this:
d.addErrback(log.err, "Frobbing the widget failed")
This will present "Frobbing the widget failed" together with the failure in the log file.