PluginManager: Installing non-existing plugin returns confusing error message

[spinscale]

If a plugin does not exist, then this is returned

bin/elasticsearch-plugin install nonexistentplugin
-> Downloading nonexistentplugin
Exception in thread "main" java.net.MalformedURLException: no protocol: nonexistentplugin
    at java.net.URL.<init>(URL.java:586)
    at java.net.URL.<init>(URL.java:483)
    at java.net.URL.<init>(URL.java:432)
    at org.elasticsearch.plugins.InstallPluginCommand.downloadZip(InstallPluginCommand.java:211)
    at org.elasticsearch.plugins.InstallPluginCommand.download(InstallPluginCommand.java:206)
    at org.elasticsearch.plugins.InstallPluginCommand.execute(InstallPluginCommand.java:174)
    at org.elasticsearch.plugins.InstallPluginCommand.execute(InstallPluginCommand.java:162)
    at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:88)
    at org.elasticsearch.cli.MultiCommand.execute(MultiCommand.java:69)
    at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:88)
    at org.elasticsearch.cli.Command.main(Command.java:53)
    at org.elasticsearch.plugins.PluginCli.main(PluginCli.java:57)

Also I cant seem to find out the URL which is actually requested for debugging purposes anymore, might be intended though?

[rjernst]

nonexistentplugin is the url the plugin cli is trying to resolve. The logic is simple (1) is it a known official plugin? (2) is it maven coordinates? (3) finally, try it as a url.

[rjernst]

If we want this to be "nicer" we could print a message in this final case on the usage info about what is supported (official plugin name, maven coordinates, or url).

[javanna]

If we want this to be "nicer" we could print a message in this final case on the usage info about what is supported (official plugin name, maven coordinates, or url).

++ that was the purpose of this issue I believe. The logic is clear to developers, but the current error is confusing to users.

[nik9000]

The logic is clear to developers, but the current error is confusing to users.

I suspect this mostly comes up in the "I misspelled kuromoji" kind of use case.

[rjernst]

Perhaps we should improve the usage information, and throw a UserError with USAGE here then. This way we don't have to repeat in this case, and in the general help.

[nikoncode]

I think need to show message like follows:

$elasticsearch-plugin install lipsum
Not found as core plugin.
Not found as maven artifact.
Not found as URL.
Usages:
install name
install groupId:artifactId:version
install file:///name.zip

Why github isn't supported now (5.x)?

[clintongormley]

Why github isn't supported now (5.x)?

Site plugins are no longer supported, only Java plugins. Site plugins should be reimplemented as Kibana plugins.

[clintongormley]

It's easy enough to figure out whether the argument looks like a protocol or not, and it would be much friendlier to say "unknown plugin" in this case than "no protocol: foo". Also, the current usage method doesn't mention that you can pass a URL or maven coordinates to install.

[rjernst]

I opened #18876 to give a nicer error message. It does not yet force listing out all the acceptable patterns for installing, but that is a broader issue I think we need to address with real usage lines.