Add ignore_permission_denied option

[aminalaee]

Closes #147

[codecov]

Codecov Report

Merging #224 (2f96cfa) into main (ea789d3) will increase coverage by 0.00%.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #224   +/-   ##
=======================================
  Coverage   99.50%   99.51%           
=======================================
  Files           6        6           
  Lines         403      411    +8     
  Branches       82       83    +1     
=======================================
+ Hits          401      409    +8     
  Misses          1        1           
  Partials        1        1           

Files Changed	Coverage Δ
watchfiles/run.py	100.00% <ø> (ø)
watchfiles/cli.py	100.00% <100.00%> (ø)
watchfiles/main.py	98.19% <100.00%> (+0.12%)	⬆️

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[samuelcolvin]

Looks like a great start.

The parameter should be called ignore_permission_denied, default false.

And it should cause only permission denied errors to be ignored.

[aminalaee]

Not sure why, but doing watchfiles --ignore-permission-denied / still fails with error locally, but the tests are passing.

[samuelcolvin]

I'll review properly soon, but would be good if we respected an env variable so it could be set when using watchfiles with uvicorn etc. - that's much more common than the command line usage.

[samuelcolvin]

and the env var I mentioned.

[aminalaee]

Thanks for the review

[samuelcolvin]

thanks so much.

[mshytikov]

Hi here, thank you for adding the --ignore-permission-denied

I just want to flag that I observed strange behaviour with it (Linux). Which might help other people to save some time.

It stops watching directories if permission-denied occurs on the first directory in the workdir.

Example you have a directory a, b, c:

• if a has permission-denied then workdir is watched but a,  b and c are not watched anymore - which is unexpected. I would expect b and c to still be watched. 
• if b has permission-denied then workdir, a, c  are watched and b is not - which is expected.

Directory setup

# LC_COLLATE="C.UTF-8"
# directories setup
mkdir tmp && cd tmp
mkdir a b c
touch a/test.txt b/test.txt c/test.txt

Example 1 (unexpected behaviour)

# set permissions on 'a' directory and make it unaccessible.
sudo chown -R root a b c  && sudo chmod -R go+rwx a b c 
sudo chmod go-rwx a 

# start watching files and send it to background 
watchfiles 'echo change' --ignore-permission-denied &

# change file in workdir and observe the change event 
echo '!' >> test.txt

# change files in 'b' and 'c', no change events observed.
echo '!' >> b/test.txt
echo '!' >> c/test.txt 

# stop watchfiles 
pkill watchfiles

Example 2 (expected behaviour)

# set permissions and make 'a' accessible and 'b' not. 
# change permissions on 'a' directory
sudo chown -R root a b c  && sudo chmod -R go+rwx a b c 
sudo chmod go-rwx b 

# start watching files and send it to background 
watchfiles 'echo change' --ignore-permission-denied &

# change in files in workdir, 'a' and 'c'  and observe all change event 
echo '!' >> test.txt
echo '!' >> a/test.txt
echo '!' >> c/test.txt 

# stop watchfiles 
pkill watchfiles

In uvicorn for example here is recommended to use env var (WATCHFILES_IGNORE_PERMISSION_DENIED) but it does not help because of above.
For my case the only way to avoid the issue while using uvicorn, is to set the --reload-dir, but this encode/uvicorn#2107 is not merged yet.