A little bit more insight into what I'm thinking of doing... since
some of you can't read minds to well :-P
I'd like to convert all of the assemblies to basically look like
what the assemblies/geronimo-jetty6-javaee5-gshell produces.
And then I'd like to start converting the other cli bits to gshell
command impls, like: deployer, client and shutdown.
And then (maybe around the same time or before the above), I'd
like to adapt the gshell of target jvm bits to load jars from the
repository, instead of using the lib/* bits.
A little background for those who haven't looked at assemblies/
geronimo-jetty6-javaee5-gshell and what it produces from a lib/*
perspective. Right now I've set up the assembly to produce:
geronimo-jetty6-javaee5-gshell-2.1-SNAPSHOT/lib
geronimo-jetty6-javaee5-gshell-2.1-SNAPSHOT/lib/boot
geronimo-jetty6-javaee5-gshell-2.1-SNAPSHOT/lib/endorsed
geronimo-jetty6-javaee5-gshell-2.1-SNAPSHOT/lib/gshell
Where the bits in lib/* and lib/endorsed/* are the same as they
were before. The bits in lib/boot/* and lib/gshell/* are specific
to gshell. And normally a gshell installation would have
everything I put into lib/gshell/* into lib/*, but I moved them to
a sub dir for now... since the bin/*.jar's load jars from the ../
lib/* dirs.
The lib/boot/* stuff is the very minimal gshell bootstrap classes,
which setup up the other happiness... and let you do things like:
java -jar ./geronimo-jetty6-javaee5-gshell-2.1-SNAPSHOT/lib/
boot/gshell-bootstrap.jar
And that will give you a nice shell... or
java -jar ./geronimo-jetty6-javaee5-gshell-2.1-SNAPSHOT/lib/
boot/gshell-bootstrap.jar start-server
That will launch the G server process using all of the right -
Djava.ext.dirs and whatever properties that we currently have
hacked into platform scripts.
Anyways, so the idea is to move all of the bits which are current
in the lib/* into the repository, and then configure the gshell
command impl to load put the correct dependency artifacts onto the
classpath of the target jvm that is booted up. This will augment
the existing kernel bootstrap from repo stuff, putting evertying
except what is needed from gshell into the repository...
And really, what I'd like to eventually get to is having the
bootstrap from the repository... so that everything except for
what is now it lib/boot/* and lib/endorsed/* can live in the
repository like happy little communistic jars should be :-P
* * *
And then there are longer term things for GShell...
Remote administration (via, telnet, ssh, or custom ssl protocol...
last is most likely to actually happen soonish)
Process management, which is great for clusters, or staging ->
production management. A full suite of command-line tools which
can manage the configuration of a server... easily. So, for
example, lets say you've got a configuration that is working
really well for you... but you want to play with something new...
So you might:
./bin/gsh backup-configuration before-mucking
./bin/gsh start-server
And then go and change a whole bunch of stuff... and it doesn't
work... yikes... so rollback...
./bin/gsh backup-configuration hosed-server
./bin/gsh restore-configuration before-mucking
./bin/gsh start-server
And then maybe you want to play with the "hosed-server"
configuration again...
./bin/gsh start-server --configuration hosed-server
Of course, all of these could have been run from a single ./bin/
gsh, but just for clarity, you can run them one off too.
Maybe list or mange the configurations
./bin/gsh list-configurations
./bin/gsh remove-configuration some-unwanted-config
./bin/gsh copy-configuration default some-new-config
The sky is the limit really... for what kind of management we can
do...
Lets say you wanted to do the above on a remote node?
./bin/gsh remote-shell someserver:9443
Connecting to someserver:9447...
Connected
username: system
password: **** (remember this is all jline, so we can mask
passwords like one woudl expect)
someserver:9447 > list-configurations
someserver:9447 > remove-configuration some-unwanted-config
someserver:9447 > copy-configuration default some-new-config
So, all of these operations would happen on the node named
"someserver" listening on 9443 (over ssl of course). Or how about
you want to reboot a server remotely?
someserver:9447 > restart-server now
Geronimo server shutting down...
....
Geronimo server shutdown.
Geronimo server starting...
...
Geronimo server started in ...
Since GShell manages the processes its really easy to perform a
full restart of a Server w/o needing magical platform scripting
muck. And it will just work the same on each platform too.
Once we have clustering, then we can do the same kinda thing for
an entire cluster of nodes...
someserver:9447 > restart-cluster now
Shutting down 2 nodes...
<node1> Geronimo server shutting down...
<node1>....
<node2> Geronimo server shutting down...
<node2>....
<node1>Geronimo server shutdown.
<node2>Geronimo server shutdown.
Starting up 2 nodes...
<node1>Geronimo server starting...
<node1>..
<node2>Geronimo server starting...
<node2>..
<node1>Geronimo server started in ...
<node2>Geronimo server started in ...
Started up 2 nodes.
And well, if you had some kinda script file which controlled say a
logical grouping of nodes you could easily invoke that script (ya
even on a remote system) and it will go and do it:
someserver:9447 > script -l groovy local:file://restart-
universe.groovy qa-universe
The local: bit of the uri siginals the local URL handler to be
used, which will cause the file://restart-universe.groovy to be
loaded from the gsh instance where you are actually logged into
(and ran the remote-shell gshell command) and will pipe its
contents securely to the remote shell running on someserver:9447
and pass it to the script command to execute.
The restart-universe.groovy might look something like this:
<snip>
import universe.Lookup
assert args.size == 1 : 'Missing universe name'
def universe = args[0]
// Look up a list of nodes (for now say they are basically
hostname:port)
def nodes = Lookup.lookup(universe)
log.info("Stopping universe ${universe}...")
nodes.each { host ->
shell.execute("remove-shell $host stop-server")
}
log.info("Universe ${universe} stopped")
log.info("Starting universe ${universe}...")
nodes.each { host ->
shell.execute("remove-shell $host start-server")
}
log.info("Universe ${universe} started")
</snip>
Its kinda crude script, but I think you get the general point...
* * *
Anyways... I see... well, *HUGE* potential for this stuff...
And really, a lot of what I just described above isn't that far
into fantasy, its all relatively easy to implement on top of
GShell... as it is now (or really as it was a year+ ago when I
wrote it). Its really a matter of do others see the same value...
and do others see the vision of using GShell as the core process
launcher to allow things like "restart-server", or a "stop-server;
copy-configuration default known-good; copy-configuration default
testing; start-server", or that uber-fancy remote-shell muck.
So, I'm gonna give y'all a few days to grok (or try to) what I've
just spit out... please ask questions or comment, as I like to
know I'm not just talking to myself here.
And then maybe later next week, we might vote or come to some
other consensus that this is the right direction for Geronimo, and
well... then I'll make it become reality.
Aighty, and now I'll shut up :-P
--jason
On Sep 8, 2007, at 11:53 AM, Jason Dillon wrote:
Aighty, well... I've done some long awaited re-factoring, and
while its still not _perfect_ its a whole lot better now IMO I
think from a framework perspective that its probably mature
enough to take on the task of being the server bootloader.
I'm going to continue to refactor the guts of GShell over time,
of course... but I think that what is there now is highly usable
for a simple platform independent launcher, as well as for
porting over the other cli bits we have.
I've done a lot of work in the past week, incase you didn't see
the storm of scm messages... pulled out pico, plopped in plexus,
pulled out commons-logging and commons-lang, which are suck and
boated (in that order). I've gotten the basic framework and
supported classes to use GShell down to ~ 1mb (a wee bit
under)... though when I started to add the layout.xml abstraction
stuff, I had to pull in xstream which bloated her back up to
~1.4m. I may eventually fix that... or not, cause xstream is
soooo very handy for xml -> object stuff.
I've fallen in love with annotations... they are *ucking great.
They work really well for handling the cli option and argument
muck which most every command needs to do. And striping out the
insano-sucking commons-cli really simplified command
implementations dramatically IMO.
Anyways... I've make a heck of a lot of progress on cleaning up
the GShell framework... and more is to come I'm sure... But for
now, I think its probably ready for use primetime as the Geronimo
Server's bootloader.
I think this provides a some significant value...
1) Platform scripts become consistent and relatively simple,
easy to maintain
2) Everyone will now have a consist way of launching the server,
even if you like a .sh, .bat, or java -jar, then end process that
is launched will be the same for everyone.
3) Opens up the door for some really nice and fancy fancy
management muck (like restarting the server from the web console,
or cloning a server instance or backing up a server instance...)
4) Lays the ground work for future features, like cluster
management, remote administration and scripting...
* * *
So, I think its time to decide... are we a go or no go for GShell
as the core CLI for Geronimo thingys and even more important, are
we go or no go for using GShell to boot up the server process?
--jason
