[wildfly-dev] Embedding a WF instance in the CLI

Heiko Braun hbraun at redhat.com
Wed Feb 11 01:49:48 EST 2015 

What's again the rational behind this? 




> Am 10.02.2015 um 22:12 schrieb Brian Stansberry <brian.stansberry at redhat.com>:
> 
> I had some time over the holidays and on planes to progress quite a bit 
> on this. A standalone server protype is at [1]. A fairly in depth 
> description is on the WildFly Development wiki at [2].
> 
> I tried pretty hard to have clean commits on that branch, one per issue 
> I faced. So looking at the commits is worthwhile to get a better 
> understanding of particular aspects.
> 
> Some notes on what I did / issues to discuss:
> 
> 1) I semi-ported the "embedded" module from WildFly full to WildFly 
> Core. "Semi" in the sense that the code is now in both places, under 
> different maven GAVs and ending up in differently named modules in full. 
> We need to regularize this; decide if there's any point in a "full" 
> version of embedded, decide what to do about any APIs we don't want in 
> the core version. (There are some deprecated methods, and one method 
> "Context getContext()" that doesn't mean much in core, which has no JNDI.)
> 
> 2) The CLI's use of stdio needed to be tweaked a bit to make it possible 
> to control what the embedded server does with stdout. That's in the 
> "Remove direct use of System.out by most CLI code" commit at [1].
> 
> 3) I needed to deal with some general embedding issues in the server; 
> i.e. things that would probably pop up in any embedded use case:
> 
> a) controlling the LogContext so the embedded server logging can be 
> managed independent of the embedding app. See "Let apps that embed 
> WildFly control the LogContext" commit at [1].
> 
> I don't think this is real solid though. For example, I expect CLI-side 
> loggers that happen to get created after the embedded server starts will 
> end up using the server LogContext.
> 
> b) the server was calling System.exit in some places. See "[WFCORE-528] 
> Use SystemExiter, not System.exit" commit at [1].
> 
> c) the embedded server code didn't deal with reload, leaving behind a 
> broken ModelControllerClient. See "[WFCORE-511] Support reload in the 
> embedded server" commit at [1].
> 
> 4) The modular vs non-modular environment aspects discussed at "Modular 
> vs Non-Modular Classloading and JBOSS_HOME" in [2] are not ideal. I'm 
> not sure how far we can/should go in improving this though.
> 
> 5) This is painfully lacking in tests!
> 
> Comments and suggestions are welcome!
> 
> Cheers,
> Brian
> 
> [1] https://github.com/bstansberry/wildfly-core/commits/cli-embed-server
> 
> [2] https://developer.jboss.org/docs/DOC-53050
> 
>> On 5/14/14 9:53 AM, John Mazzitelli wrote:
>> How topical :) The RHQ installer could use this - just this very second I'm debugging and trying to figure out why the RHQ installer can't connect to the running app server instance to do its initial config setup - having to try to figure out what port its running on and why I can't connect is a pain.
>> 
>> ----- Original Message -----
>>> Moving a thread to the dev list.
>>> 
>>> This is about some prototyping I've been doing on weekends 'cause I'm
>>> bored with my regular tasks. I've been playing with direct local
>>> administration of a WF installation via the CLI without requiring a
>>> socket-based connection. The general use case is initial setup type
>>> activities where the user doesn't want to have to launch a WF server or
>>> HC process and potentially have it be visible on the network.
>>> https://issues.jboss.org/browse/WFLY-3288 is one use case; another is a
>>> desire some folks have expressed in being able to do configuration
>>> without first having to edit any xml to avoid port conflicts on 9990 or
>>> 9999.
>>> 
>>> This isn't a major initiative or big priority or anything at this point.
>>> Just something I find interesting and perhaps you will too.
>>> 
>>>> On 5/14/14, 8:54 AM, Alexey Loubyansky wrote:
>>>> Neat :) Yes, figuring out the module path is biting everywhere.
>>>> For file system path command line arguments there is a specialized
>>>> FileSystemPathArgument.
>>> 
>>> Thanks; I'll switch to that.
>>> 
>>>> 
>>>>> On 05/13/2014 10:54 PM, Brian Stansberry wrote:
>>>>> Copying Heiko Braun as he expressed some interest in the topic.
>>>>> 
>>>>> BTW, I played with this a bit more last weekend and was able to start an
>>>>> embedded server inside the CLI easily enough. See [1] for very raw
>>>>> prototype stuff. You can run bin/jboss-cli.sh (no -c) and then
>>>>> 
>>>>> [disconnected/] embed-server
>>>>> 
>>>>> There are a couple issues I see, besides the HC stuff I mentioned in my
>>>>> last message.
>>>>> 
>>>>> 1) If the CLI is started in a non-modular environment via java -jar
>>>>> bin/client/jboss-cli-client.jar, we'd have to shade jboss-modules into
>>>>> the jar. And then the embed-server command would need params specifying
>>>>> the location of JBOSS_HOME, possibly module path etc. But it could embed
>>>>> a server installed in any accessible filesystem location.
>>>>> 
>>>>> But what I did at [1] is based on bin/jboss-cli.sh, where the CLI is
>>>>> running from a WF dist in a modular environment and the embedded server
>>>>> modules are coming from the CLI's own module path. It would be more
>>>>> effort to support embedding a server based on some other module path.
>>>>> Maybe it's no big deal; maybe it's really hard. :)
>>>>> 
>>>>> 2) The console logging from the embedded server goes to stdout mixed in
>>>>> with the CLI output. Maybe that's good, maybe it's bad.
>>>>> 
>>>>> [1] https://github.com/bstansberry/wildfly/tree/cli-embed
>>>>> 
>>>>>> On 4/28/14, 10:04 AM, Brian Stansberry wrote:
>>>>>> I was poking around at this for an hour or so over the weekend.
>>>>>> 
>>>>>> The standalone case seems pretty straightforward. Seems the existing
>>>>>> embedded server API could work readily enough. The
>>>>>> org.jboss.as.embedded.StandaloneServer interface already provides a
>>>>>> ModelControllerClient.
>>>>>> 
>>>>>> The domain case is much harder, as the CLI wants a HostController, not a
>>>>>> ProcessController. I'd really like this to use an in-VM client, not a
>>>>>> remote one, so I don't like having the CLI embed a PC and then the HC is
>>>>>> an external process. My thoughts of the morning are to allow inverting
>>>>>> the HC/PC relationship for this kind of usage. That is, remove
>>>>>> controlling the HC lifecycle from the charge of the PC component. CLI
>>>>>> launches HC, and then the HC creates an in-process PC-ish component (not
>>>>>> a separate process) to manage the server lifecycles. There could be all
>>>>>> sorts of problems with that; it's just the thought for the morning.
>>>>>> 
>>>>>>> On 4/25/14, 11:49 AM, Alexey Loubyansky wrote:
>>>>>>> Embedding the AS is the best starting point to achieve that! And more
>>>>>>> fun, I agree :)
>>>>>>> 
>>>>>>>> On 04/25/2014 06:28 PM, Darran Lofthouse wrote:
>>>>>>>> And to think my reason for opening the Jira was just for a common
>>>>>>>> way to
>>>>>>>> mask password inputs where java.io.Console is not available ;-)
>>>>>>>> 
>>>>>>>>> On 25/04/14 17:09, Brian Stansberry wrote:
>>>>>>>>>> On 4/25/14, 10:40 AM, Alexey Loubyansky wrote:
>>>>>>>>>> Wow! Indeed :)
>>>>>>>>>> 
>>>>>>>>>> There could be an embedded scope - true, i.e. commands available
>>>>>>>>>> only
>>>>>>>>>> this mode, like add-user, module mgmt related stuff, etc.
>>>>>>>>> 
>>>>>>>>> Those commands wouldn't need to be only in that mode though. The
>>>>>>>>> implementation of all of them would be based in the server; the
>>>>>>>>> "client"
>>>>>>>>> aspect of the CLI would just use the management interface. The
>>>>>>>>> difference between an embedded mode and what we have now would
>>>>>>>>> just be
>>>>>>>>> in how the "client" side gets its ModelControllerClient -- what we
>>>>>>>>> have
>>>>>>>>> now vs starting an embedded server and getting some sort of in-vm
>>>>>>>>> client.
>>>>>>>>> 
>>>>>>>>>> But it would still mean the server/controller would have to actually
>>>>>>>>>> provide implementations of that functionality and expose it to the
>>>>>>>>>> management tools like the CLI in the embedded mode.
>>>>>>>>> 
>>>>>>>>> Yep.
>>>>>>>>> 
>>>>>>>>>> I like this idea as a concept - direct local management. W/o any
>>>>>>>>>> remote
>>>>>>>>>> connect/re-connect/disconnect burden.
>>>>>>>>>> 
>>>>>>>>>> Extending the CLI with custom modules is on the list too. It's
>>>>>>>>>> probably
>>>>>>>>>> easier to implement at this point.
>>>>>>>>> 
>>>>>>>>> Likely so, but maybe less fun. ;) I copied you on a PRD-related
>>>>>>>>> thread
>>>>>>>>> where I briefly get into this general area too.
>>>>>>>>> 
>>>>>>>>>> Alexey
>>>>>>>>>> 
>>>>>>>>>>> On 04/25/2014 05:00 PM, Brian Stansberry wrote:
>>>>>>>>>>> Hi Alexey,
>>>>>>>>>>> 
>>>>>>>>>>> Wanted to point the discussion on this JIRA out to you as it gets
>>>>>>>>>>> into
>>>>>>>>>>> some fairly fundamental brainstorming that you may find
>>>>>>>>>>> interesting.
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> -------- Original Message --------
>>>>>>>>>>> Subject: [JBoss JIRA] (WFLY-3288) Update add-user to use AESH or
>>>>>>>>>>> move it
>>>>>>>>>>> into the CLI
>>>>>>>>>>> Date: Fri, 25 Apr 2014 09:44:35 -0400 (EDT)
>>>>>>>>>>> From: Darran Lofthouse (JIRA) <issues at jboss.org>
>>>>>>>>>>> To: brian.stansberry at redhat.com
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>>      [
>>>>>>>>>>> https://issues.jboss.org/browse/WFLY-3288?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12963854#comment-12963854
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> ]
>>>>>>>>>>> 
>>>>>>>>>>> Darran Lofthouse commented on WFLY-3288:
>>>>>>>>>>> ----------------------------------------
>>>>>>>>>>> 
>>>>>>>>>>> That could be very interested, won't go into too much detail in
>>>>>>>>>>> this
>>>>>>>>>>> Jira as it is not directly related shortly I am switching to the
>>>>>>>>>>> SSL
>>>>>>>>>>> related tasks we have outstanding including the out of the box
>>>>>>>>>>> enablement we talked about in Brno - managing an embedded instance
>>>>>>>>>>> could
>>>>>>>>>>> be useful there as well to get it all op based.
>>>>>>>>>>> 
>>>>>>>>>>> I can see this task may end up coming back my way combined with the
>>>>>>>>>>> other stuff ;-)
>>>>>>>>>>> 
>>>>>>>>>>>> Update add-user to use AESH or move it into the CLI
>>>>>>>>>>>> ---------------------------------------------------
>>>>>>>>>>>> 
>>>>>>>>>>>>                 Key: WFLY-3288
>>>>>>>>>>>>                 URL: https://issues.jboss.org/browse/WFLY-3288
>>>>>>>>>>>>             Project: WildFly
>>>>>>>>>>>>          Issue Type: Feature Request
>>>>>>>>>>>>      Security Level: Public(Everyone can see)
>>>>>>>>>>>>          Components: Domain Management, Scripts
>>>>>>>>>>>>            Reporter: Darran Lofthouse
>>>>>>>>>>>>             Fix For: Awaiting Volunteers
>>>>>>>>>>>> 
>>>>>>>>>>>> 
>>>>>>>>>>>> Within the add-user utility it is difficult to handle situations
>>>>>>>>>>>> where
>>>>>>>>>>>> we do not have access to a java.io.Console which is the easiest
>>>>>>>>>>>> way to
>>>>>>>>>>>> handle password reading without an echo to the user e.g. in Cygwin
>>>>>>>>>>>> Switching to AESH would allow us to use the implementation
>>>>>>>>>>>> there to
>>>>>>>>>>>> handle this.
>>>>>>>>>>>> Alternatively it may actually make sense to make add-user a
>>>>>>>>>>>> special
>>>>>>>>>>>> mode of the CLI, we may at some point want to switch to runtime
>>>>>>>>>>>> operations being executed on the server so porting to the CLI
>>>>>>>>>>>> could be
>>>>>>>>>>>> the first step to make this possible.
>>>>>>>>>>>> Overall this is going to require further discussion so the
>>>>>>>>>>>> comments
>>>>>>>>>>>> here are just a starting point.
>>>>>>>>>>> 
>>>>>>>>>>> --
>>>>>>>>>>> This message is automatically generated by JIRA.
>>>>>>>>>>> If you think it was sent incorrectly, please contact your JIRA
>>>>>>>>>>> administrators
>>>>>>>>>>> For more information on JIRA, see:
>>>>>>>>>>> http://www.atlassian.com/software/jira
>>> 
>>> 
>>> --
>>> Brian Stansberry
>>> Senior Principal Software Engineer
>>> JBoss by Red Hat
>>> _______________________________________________
>>> wildfly-dev mailing list
>>> wildfly-dev at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/wildfly-dev
> 
> 
> -- 
> Brian Stansberry
> Senior Principal Software Engineer
> JBoss by Red Hat
> _______________________________________________
> wildfly-dev mailing list
> wildfly-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/wildfly-dev

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