testcases (everything scripted / headless):
1. download war
2. start webserver
3. cli command install-plugin active-directory (which plugin does not matter)

1. download war
2. start webserver
3. wget -O /dev/null http://<JENKINS>/pluginManager/checkUpdates
4. cli command install-plugin active-directory (which plugin does not matter)

e.g.
$ java -jar /tmp/intelligence/jenkins-cli.jar -s http://localhost:8080/jenkins install-plugin active-directory
active-directory is neither a valid file, URL, nor a plugin artifact name in the update center
No update center data is retrieved yet from: http://updates.jenkins-ci.org/update-center.json
active-directory looks like a short plugin name. Did you mean 'null'?

— pieces of chat log —
[14:25] <damien___> hello
[14:26] <damien___> does anyone know what url triggers the webserver to fetch the update center json file?
[14:27] <damien___> I'm trying to have a script that from a war file 1. starts it, 2. install plugins from a list
[14:27] <damien___> list has short names
[14:35] <mrobinet> damien___ http://<JENKINS>/pluginManager/checkUpdates
[14:41] <damien___> mrobinet: doesn't seem to work in 1.417
[14:41] <damien___> i'm using CLI only
[14:41] <mrobinet> hmm
[14:42] <mrobinet> You can't just curl that URL?
[14:42] <damien___> i did
[14:42] <damien___> it doesn't seem to do the right thing
[14:43] <mrobinet> Ahh, nm, it requires auth
[14:43] <mrobinet> Not sure if/how you can do it from CLI
[14:43] <damien___> my instance is pristine, no auth
[14:44] <mrobinet> I'm at a loss then. That is the URL I see posted to when I examine the net traffic when asking it to update
[14:44] <damien___> hitting that url gives me html content that seems legit
[14:45] <damien___> but the server doesn't go and download the json file
[14:46] <damien___> oh my... I think I found the quirk
[14:47] <damien___> the /pluginManager/checkUpdates page has javascript
[14:47] <damien___> this goes and download the json file using YUI
[14:48] <damien___> then this sends an http POST with stuff to /updateCenter/byId/default/postBack
[14:49] <mrobinet> Yeah, that is what I see too, but I'm not sure what is missing
[14:52] <damien___> erh, curl doesn't exec the javascript
[14:52] <damien___> so the json doesn't get downloaded
[14:52] <damien___> and doesn't get POST'd to jenkins instance
[14:54] <mrobinet> I think there is a CLI to exec a custom groovy script. You might be able to use that to force the update
[14:57] <damien___> I wonder why that code is on the user side rather than server side?
[14:58] <damien___> mrobinet: thanks