Fix a bug with "serialize_positional_argument" not correctly handling unicode values and fix unicode support in core.sendmail action

[Kami]

This pull request fixes a bug with serialize_positional_argument function not correctly handling unicode values.

This would prevent actions such as core.sendmail from working when a non-ascii (unicode) value was provided.

Reported by @johandahlberg.

Resolves StackStorm/st2contrib#597.

[johandahlberg]

I've tried this, and I can verify that the action works. However, the email that I get does look a little bit funky. Instead of the swedish letter "Å" I get the result below when I run: st2 run core.sendmail to='johan.dahlberg@medsci.uu.se' body='Test Åsa' subject='Test Åsa'

I'm unsure if this is directly related to the st2 action, or it might have something to do with the locale settings of the system. Any ideas?

[Kami]

I also confirmed that with those changes unicode characters are correctly passed to the script so it could indeed be something with the bash locale setting for stanley user.

If you run the following command:

st2 run core.sendmail to='johan.dahlberg@medsci.uu.se' body='Test Åsa' subject='Test Åsa'

The action runner process will run the following script (you can see the command in the action runner log file under DEBUG log level).

chmod +x /opt/stackstorm/packs/core/actions/send_mail/send_mail ; sudo -E -H -u stanley -- bash -c '/opt/stackstorm/packs/core/actions/send_mail/send_mail stanley johan.dahlberg@medsci.uu.se '"'"'Test Åsa'"'"' 1 text/html '"'"'Test Åsa'"'"' '"'"''"'"''

I would recommend you to test / play with this script directly. Locally I tried to modify it to modify it to print the values out directly instead of calling sendmail and it seems to work fine:

(virtualenv) vagrant@ubuntu-xenial:/data/stanley$ python st2client/st2client/shell.py run core.sendmail to='johan.dahlberg@medsci.uu.se' body='Test Åsa' subject='Test Åsa'
.
id: 5c595110076129037f50d54c
status: failed
parameters: 
  body: "Test Åsa"
  subject: "Test Åsa"
  to: johan.dahlberg@medsci.uu.se
result: 
  failed: true
  return_code: 1
  stderr: ''
  stdout: "johan.dahlberg@medsci.uu.se
Test Åsa
Test Åsa"
  succeeded: false

[Kami]

Discussed this with @johandahlberg on Slack and we managed to get it work end to end with one additional change / fix - 4784d94.

We now force utf8 charset for the email body.

In theory, we could also make this configurable as par of the action parameter (either as part of content_type one or by adding new one), but I think it's not worth the complexity - you would pretty much almost always want to default to utf8 anyway.

[johandahlberg]

I've added a PR into this branch here #4534 with some additional fixes. Feel free to close it if you don't think that the changes make sense.

[Kami]

While at it, I will also work on some unit tests since I don't think we have any right now.

[Kami]

I added some unit / integration tests in ded040f.

To be able to test the script better, I need to modify the action a bit. I added a new "sendmail_binary" argument which is set to cat by the tests. This way the whole raw email data is output to stdout instead of piped to the sendmail binary.

This allows us to test 90% of the original sendmail script code and works much better than alternative mock approaches or similar (in a lot of cases like that, people tend to mock too much of the original code / action and your tests end up mostly testing the mocks and not the actual code itself).

[arm4b]

Looks good 👍