How do I get `print ` statements to show up in the web conso

Question

How do I get `print ` statements to show up in the web console at localhost 8080 Here s my example code that prints to the terminal but does not now up in the web console ```from prefect import task Flow task def simple func log stdout=True print simple print statement if name == main with Flow test logging as flow simple func flow register test log flow run ```

nicholas · Answer

Hi < jack> check out the I think those will give you everything you need for that but let me know if not slightly smiling face

jack · Answer

Thanks for the link That s where I started reading Then searched the slack archives and read a few examples Some people see to have simple logging working using the log stdout=True kwarg and others do not It s not working yet for me

jack · Answer

Not sure if I m supposed to set `log to cloud = true` in config toml or not

jack · Answer

Is there a `log to server` option I m using the server backend

jack · Answer

``` 2020 12 15 02 37 16+0000 CRITICAL CloudHandler | Failed to write log with error 400 Client Error Bad Request for url <http localhost 4200 graphql> The following error messages were provided by the GraphQL server INTERNAL SERVER ERROR Variable $input got invalid value null at input logs 0 flow run id Expected non nullable type UUID not to be null The GraphQL query was mutation $input write run logs input write run logs input $input success The passed variables were input logs flow run id null task run id null timestamp 2020 12 15T02 37 15 644721+00 00 name prefect FlowRunner message Beginning Flow run for test alteryx logging level INFO info msg Beginning Flow run for test alteryx logging levelno 20 pathname home vagrant p ts prefect 1 0 env lib64 python3 7 site packages prefect engine flow runner py filename flow runner py module flow runner exc info null exc text null stack info null lineno 224 funcName run msecs 644 721269607544 relativeCreated 2320 8816051483154 thread 140260445312832 threadName MainThread processName MainProcess process 14188 asctime 2020 12 15 02 37 15+0000 flow run id 9e720791 b7c1 406e a773 f3ff23e4cb01 task run id b2b390d0 bf27 42dc 9c50 2b076563fae6 timestamp 2020 12 15T02 37 15 929799+00 00 name prefect TaskRunner message Task simple func Starting task run level INFO info msg Task simple func Starting task run levelno 20 pathname home vagrant p ts prefect 1 0 env lib64 python3 7 site packages prefect engine task runner py filename task runner py module task runner exc info null exc text null stack info null lineno 237 funcName run msecs 929 7986030578613 relativeCreated 2605 958938598633 thread 140260445312832 threadName MainThread processName MainProcess process 14188 flow name test alteryx logging flow run id 9e720791 b7c1 406e a773 f3ff23e4cb01 task name simple func task slug simple func 1 task run id b2b390d0 bf27 42dc 9c50 2b076563fae6 asctime 2020 12 15 02 37 15+0000 flow run id 9e720791 b7c1 406e a773 f3ff23e4cb01 task run id b2b390d0 bf27 42dc 9c50 2b076563fae6 timestamp 2020 12 15T02 37 16 045748+00 00 name prefect TaskRunner message Task simple func Finished task run for task with final state Success level INFO info msg Task simple func Finished task run for task with final state Success levelno 20 pathname home vagrant p ts prefect 1 0 env lib64 python3 7 site packages prefect engine task runner py filename task runner py module task runner exc info null exc text null stack info null lineno 332 funcName run msecs 45 74751853942871 relativeCreated 2721 9078540802 thread 140260445312832 threadName MainThread processName MainProcess process 14188 flow name test alteryx logging flow run id 9e720791 b7c1 406e a773 f3ff23e4cb01 task name simple func task slug simple func 1 task run id b2b390d0 bf27 42dc 9c50 2b076563fae6 asctime 2020 12 15 02 37 16+0000 flow run id 9e720791 b7c1 406e a773 f3ff23e4cb01 task run id null timestamp 2020 12 15T02 37 16 048198+00 00 name prefect FlowRunner message Flow run SUCCESS all reference tasks succeeded level INFO info msg Flow run SUCCESS all reference tasks succeeded levelno 20 pathname home vagrant p ts prefect 1 0 env lib64 python3 7 site packages prefect engine flow runner py filename flow runner py module flow runner exc info null exc text null stack info null lineno 685 funcName determine final state msecs 48 19774627685547 relativeCreated 2724 358081817627 thread 140260445312832 threadName MainThread processName MainProcess process 14188 flow name test alteryx logging flow run id 9e720791 b7c1 406e a773 f3ff23e4cb01 asctime 2020 12 15 02 37 16+0000 2020 12 15 02 37 16+0000 CRITICAL CloudHandler | Unable to write logs to Prefect Cloud 2020 12 15 02 37 16+0000 CRITICAL CloudHandler | Unable to write logs to Prefect Cloud 2020 12 15 02 37 16+0000 CRITICAL CloudHandler | Unable to write logs to Prefect Cloud```

jack · Answer

If I do set `log to cloud` to true running the task throws an error

nicholas · Answer

`log to cloud` will send to either Server or Cloud whichever it s running against

nicholas · Answer

Hm that looks like a bug then let me take a quick look at that code

nicholas · Answer

Oh hold on are you trying to log to Server from a local run using `flow run `

jack · Answer

When I call `flow run ` I don t expect the log to show up in the browser But after registering the flow and then running it from the browser that s when I expect the log to show up in the browser But it doesn t

nicholas · Answer

Got it the log you posted above is from the local run right Trying to make sure I m looking in the right place

jack · Answer

Just found additional documentation for logging <https docs prefect io core idioms logging html>

jack · Answer

Yes the log posted above is from the local run

jack · Answer

Also tried restarting the server and the agent after changing config toml Not sure if that makes a difference or not

nicholas · Answer

< jack> it looks like you re passing the `log stdout` as a keyword to your task instead of to the task decorator your above code should be ``` task log stdout=True def simple func print simple print statement ```

jack · Answer

Oh silly me So I ve moved the log stdout kwarg to the task decorator Now the printed line shows up in the browser regardless of whether log to cloud is true or false So perhaps log to cloud is not being honored

nicholas · Answer

Is `log to cloud` still set to true in your config toml

jack · Answer

I ve run it with ``` logging log to cloud = true``` and with ``` logging log to cloud = false``` and with ``` logging log to cloud = true``` They are give the same result the log goes to the web browser

nicholas · Answer

If you modified the `log stdout` kwarg you ll need to reregister did you already do that

jack · Answer

I left the `log stdout` kwarg in place but just changed the config toml

jack · Answer

To be clear the print statement now shows up as a prefect log I just want to understand what `log to cloud` does so I can add it to the documentation And for me the logs are showing up regardless of the `log to cloud` setting

nicholas · Answer

Ah ok so then `log to cloud` will determine if any logs are sent to your Server however changes to that will require that you restart your agent

nicholas · Answer

It only impacts `log stdout` insofar as that uses the Prefect logger in general

jack · Answer

Here is my flow ```from prefect import task Flow task log stdout=True def simple func print simple print statement if name == main with Flow simple print statement as flow simple func flow register test log flow run ``` and here is my ~ prefect config toml ``` logging log to cloud = false extra loggers = clone special ``` and here is the log in the browser which probably isn t expected to be there

nicholas · Answer

Hm it looks like your agent isn t correctly picking up your config this could happen if it doesn t have access to the config wasn t restarted or there s an environment variable overriding it

jack · Answer

To test this out I ve removed the closing square bracket from ` logging ` in config toml Upon restarting the agent it raises an exception inside env lib64 python3 7 site packages toml decoder py So it appears to be loading the config file

nicholas · Answer

Is it possible you have a different agent picking up the run

jack · Answer

I stopped the agent in terminal two just to see what would happen Clicked Quick Run and waited about a minute still hasn t run

jack · Answer

Then I started the agent in terminal two with this environment variable ```PREFECT LOGGING LOG TO CLOUD=false prefect agent local start``` The flow ran about ten seconds after the agent was started and it still has the `simple print statement` in the logs in the browser

jack · Answer

I m going to reboot my computer to see if that changes anything

nicholas · Answer

Ok great that s helpful It seems like you ve done all you can here if after a restart you re still seeing those logs let s open a bug ticket

jack · Answer

Behavior remains the same after a reboot I ll file a bug ticket

nicholas · Answer

Ok feel free to link to this slack conversation in the ticket it might be helpful context you can also cc me znicholasbrown

jack · Answer

Here s the new issue <https github com PrefectHQ prefect issues 3844>

jack · Answer

Thanks for your help digging into this Now I know what it should be doing thumbsup

nicholas · Answer

Happy to help The Core team will have more insight there I ll follow along