":" in program_name and strftime of log stream name cause errors

[SilentEroder]

Problem 1 program_name

Windows contains ":" in program_name of log stream name.
For example, C:\

log stream name should not have ":" and "*". In regex, [^:*]
So, sys.argv[0] causes an error in Windows.

Solution 1 program_name

Remove all ":" in sys.argv[0]

program_name=sys.argv[0],  # before
program_name=sys.argv[0].replace(":", ""),  # after

#207

Problem 2 strftime

strftime of log stream name contains ":" because datetime.datetime.now() contains ":"
For example, 11:22:35

log stream name should not have ":" and "*". In regex, [^:*]
So, datetime.datetime.now() causes an error in Windows.

Solution 2-1 strftime

Remove all ":" in datetime.datetime.now()

from datetime import datetime, timezone

strftime=datetime.now(timezone.utc),  # before
strftime=str(datetime.now(timezone.utc)).replace(":", "-"),  # after

However, you can't use {strftime:%Y-%m-%d %H-%M-%S} with editing.

Solution 2-2 strftime

You can use {strftime:%Y-%m-%d %H-%M-%S} without editing.

[dougfultz]

Confirming Problem 2

On Linux, Using "{machine_name}/{logger_name}/{process_id}/{thread_name}/{strftime}" results in the following error:

WatchtowerWarning: Failed to deliver logs: An error occurred (InvalidParameterException) when calling the PutLogEvents operation: 1 validation error detected:
 Value 'myhostname.local/path.to.module/12345/MainThread/2024-12-17 22:32:57.097146' at 'logStreamName' failed to satisfy constraint: Member must satisfy regular expression pattern: [^:*]*

Confirming Solution 2-2

Using "{machine_name}/{logger_name}/{process_id}/{thread_name}/{strftime:%Y-%m-%d %H-%M-%S}" appears to resolve the error and produces log streams with format:

"myhostname.local/path.to.module/12345/MainThread/2024-12-18 16-18-40"

Note

Using highly unique log stream names will likely result in throttling by CloudWatch when creating the new log streams. A good balance may be to use {strftime:%Y-%m-%d} or {strftime:%Y-%m-%d-%H}.

[kislyuk]

Windows is unfortunately not directly supported by this library (WSL is supported). You can work around the issue with Windows program_name by not using program_name in your placeholder string.

The strftime behavior is expected. Yes, CloudWatch does not allow colons in the log stream name, and the Watchtower documentation correspondingly advises one to use a strftime format string with the strftime placeholder. I edited the documentation to more directly point out that using the default format string will result in an error.