#1614 local cache fails to update with github file

[Jeremy Faden]

I notice that the HTTPFileSystem fails to update the local copy of a file from GitHub. See attached image where "Units" is mixed case on the local cache copy, and UNITS on GitHub.

[Jeremy Faden]

For some reason the WebFileSystem object for the GitHub immediately goes off-line, with a 400 error code.

The script:

from org.das2.util.filesystem import FileSystem
fs= FileSystem.recreate(URI('https://raw.githubusercontent.com/JSONheadedASCII/examples/master/'))
print fs.isOffline()

Prints:

== Executing Script ==
das2.filesystem.http SEVERE: 400: failed to connect to https://raw.githubusercontent.com/JSONheadedASCII/examples/master/
Bad Request
das2.filesystem.http INFO: remote filesystem is offline, allowing access to local cache.
das2.filesystem.http WARNING: filesystem is offline: https://raw.githubusercontent.com/JSONheadedASCII/examples/master/
console.stdout INFO: 1

[Jeremy Faden]

Note both wget and Firefox will show the "bad request" when retrieving:
https://raw.githubusercontent.com/JSONheadedASCII/examples/master/

I think this was the movitation for introducing a special FileSystem for github.

[Jeremy Faden]

So I think there's a way that Autoplot can load a single file from github, but then because it can't list the parent, the file will never be updated.

[Jeremy Faden]

Specialized support for GitHub sites was added in 2019. For example, vap+dat:https://github.com/JSONHeadedASCII/examples/20150331_LANL-01A_eph.txt?column=Rad now works because The FileSystem class recognizes that this is a GitHub site and uses a special filesystem type.

[Jeremy Faden]

See also https://sourceforge.net/p/autoplot/feature-requests/665/