[AOLSERVER] Application packages
We briefly discussed this some time ago, just wanted to bring it up again and maybe get some fresh ideas as it is still something I am interested in doing. And also ask a sanity check from those with better knowledge of the AOLserver core. The goal would be to have simple deployable application modules, quite like a WAR file in J2EE. Let's codename it AOLserver Application Package, or AAP for short. (yes, that is Dutch for monkey) This would give the advantage that it would be easy to deploy any open source applications written for AOLserver without having to copy loads of files into the right location or do much editing the global nsd.tcl. Just drop it in and go. You could even do it the Tomcat way; just drop the .aap file in the applications directory and it will unpack and bind it to a url automatically. In the simplest form this would look something like: /modules/tcl/ -- Tcl library files /pages/ -- adp, html, images, etc. /config.tcl -- application level config file You should then be able to deploy this application to a root, like /openacs, or simply /. (developers need to make sure they only use relative urls in their html!) Initialy I thought this was something that needed to go into the core, but now I am thinking a module could do it. You could load the ns_aap module in the server of choice with a section like ns/server/server1/aap listing the applications to be loaded and ns/server/server1/aap/my_aap can list config values for the AAP in question. Using functionality found in ns_rewrite (where did that disappear to?) we should be able to map anything under the designated root to the AAP's pages directory. Now for the hard parts: - Library loading: Could the module instruct the server to source the Tcl library files from the application? Ns_TclInitModule does something like it, but is limited to the server's modules/tcl directory. It also stores it by name in a Tcl list, so I guess the path expansion happens further down. That may need a core change after all. - Application protection: an application that is a good citizen could run in the normal shared interpreter pool, but applications not using their own namespaces or non-prefixed nsv keys need to be seperated. I know you can have different thread pools, but would it be possible to a) create these at runtime by the ns_aap module and b) load them with the application's Tcl lib, not the server global one? I do consider this to be an optional one, I could live without it; developers just have to follow the rules. - registered procedures and traces. The root should be taken into account when registering these in the the AAP's init.tcl. I guess the module could overwrite the appropriate procedures with wrapper that does just that before the application's Tcl lib is sourced. I'd love to hear back from the usual suspects (and others!) about their views on the implementation of this. Cheers, Bas. -- AOLserver - http://www.aolserver.com/ To Remove yourself from this list, simply send an email to [EMAIL PROTECTED] with the body of SIGNOFF AOLSERVER in the email message. You can leave the Subject: field of your email blank.
Re: [AOLSERVER] Application packages
Bas, Good ideas! I'm using a 'package' structure which does some of the things that you are talking about. In some ways the directory/file structure is modeled on the ACS4/OACS structure. The big difference is that it is entirely file based. That is configuration isn't in the database, you don't even need to use a database with this configuration. The main reason is so that you can quickly tar/gz up an application and move/replicate it somewhere else with minor changes, if any. In support of this effort, I also have a new configuration file setup. Every virtual server has a new directory called config: servers/server1/ modules/ tcl/ twt/ init.tcl (sourced to start) packages/ db/ tcl/ templates/ queries/ config/ server.tcl (all sections which have /$server/ ) nslog.tcl (referenced from /ns/$server/modules) nscgi.tcl .. mymodule.tcl (tcl or c module in modules sect) pages/ log/ /supervise/ run (multilog script) supervise/ run (startup file, serverlog = /dev/fd/1) Anyway, the packaging isn't to the point of dropping in and having the server automatically notice stuff, but each package/module has a separate set of configuation files, so it is much easier to add/remove stuff without editing a monolithic config file. To see how to set the local configuration of packages look at how things are sourced starting at: twt/init.tcl: http://rmadilo.com/m2/servers/rmadilo/modules/tcl/twt/ (somewhat out of date, I'll freshed up this today) I haven't settled on a standard way of 'mounting' a package, although the session package filters anything directed at /session/* and runs templates from the sessions/templates directory. I think this is how standard Tomcat packages work, based upon filters. On Monday 20 February 2006 06:52, Bas Scheffers wrote: Using functionality found in ns_rewrite (where did that disappear to?) we should be able to map anything under the designated root to the AAP's pages directory. Actually ns_rewriteurl only redirects under the set pageroot, so you can't use it for this purpose. What you can do is to write a simple filter which rewrites the url to some other place under pageroot which is blocked from direct access. You could, for instance, map a url /mypackage/* to /packages/mypackage/*, and just block direct access to /packages/*. http://rmadilo.com/files/nsrewrite/doc/nsrewriteurl.html Now for the hard parts: - Library loading: Could the module instruct the server to source the Tcl library files from the application? Ns_TclInitModule does something like it, but is limited to the server's modules/tcl directory. It also stores it by name in a Tcl list, so I guess the path expansion happens further down. That may need a core change after all. Loading C level modules using the AOLserver api will likely need to be done at the correct time, before tcl modules are sourced, so I don't see how to jump ahead and read a tcl configuration file to load an AOLserver C module. However, if it is just a Tcl .so module, you can do this easily right now. tom jackson -- AOLserver - http://www.aolserver.com/ To Remove yourself from this list, simply send an email to [EMAIL PROTECTED] with the body of SIGNOFF AOLSERVER in the email message. You can leave the Subject: field of your email blank.
Re: [AOLSERVER] Application packages
Tom Jackson wrote: Actually ns_rewriteurl only redirects under the set pageroot, so you can't use it for this purpose. Ah, I see, Ns_ConnRedirect it must be. I looked into the source and it goes very deep just by URL, before expanding it to a path, so not very useful indeed. What you can do is to write a simple filter which rewrites the url to some other place under pageroot which is blocked from direct access. You could, Sound like that would be harder (config wise) for the users, not optimal. Hmmm, I think I just hit the jackpot, Ns_UrlToFileProc in the NsServer-fastpath struct. There even is an example on how to use it: http://www.aolserver.com/docs/devel/c/c-examples.html (example 2: Alias) Looks like that does what I want it to do. That makes it even simpler than I thought it would be, I was afraid I might have to do a lot of this stuff manually. (ie: Ns_ConnReturnFile and the like) Loading C level modules using the AOLserver api will likely need to be done at the correct time, before tcl modules are sourced, so I don't see how to jump ahead and read a tcl configuration file to load an AOLserver C module. However, if it is just a Tcl .so module, you can do this easily right now. Reading http://www.aolserver.com/docs/devel/c/api/c-ch393.htm, it sounds like any of your own C modules load before nsd starts sourcing the Tcl libraries (modules/tcl), so you should be able to tell it to go look somewhere else for them too. I'll keep looking. One down, one to go. Cheers, Bas. -- AOLserver - http://www.aolserver.com/ To Remove yourself from this list, simply send an email to [EMAIL PROTECTED] with the body of SIGNOFF AOLSERVER in the email message. You can leave the Subject: field of your email blank.
Re: [AOLSERVER] Application packages
On Monday 20 February 2006 09:45, Bas Scheffers wrote: Tom Jackson wrote: What you can do is to write a simple filter which rewrites the url to some other place under pageroot which is blocked from direct access. You could, Sound like that would be harder (config wise) for the users, not optimal. Check out my package-name-init.tcl files, this is where you put filters so that they load with the package. My session package has the best example of this, and also even uses ns_rewriteurl for urls which contain an embeded session id. (SID). I think it is a mistake to put all files under the package, outside of pageroot, or at least to force this to be the case. It essentially means that every file must be served by a filter. You can still put your package page files under pageroot and then include a filter to just rewrite the url, which will let AOLserver take over. Loading C level modules using the AOLserver api will likely need to be done at the correct time, before tcl modules are sourced, so I don't see how to jump ahead and read a tcl configuration file to load an AOLserver C module. However, if it is just a Tcl .so module, you can do this easily right now. Reading http://www.aolserver.com/docs/devel/c/api/c-ch393.htm, it sounds like any of your own C modules load before nsd starts sourcing the Tcl libraries (modules/tcl), so you should be able to tell it to go look somewhere else for them too. I'll keep looking. One down, one to go. Every C module is listed in /ns/server/$server/modules and has an exact path to the shared library file. Tcl modules contain only the name of the directory under the private tcl directory to look for an init.tcl file. ns_section ns/server/$server/modules ns_param my_c_module /path/to/my_c_module.so ns_param my_tcl_module tcl so /path/to... could anywhere on the machine. my_tcl_module must be located under $private_tcl_lib/my_tcl_module. In my case all my packages are part of a tcl module twt, so I never have to add anything to the server.tcl file when I change the configuration of my packages. tom jackson -- AOLserver - http://www.aolserver.com/ To Remove yourself from this list, simply send an email to [EMAIL PROTECTED] with the body of SIGNOFF AOLSERVER in the email message. You can leave the Subject: field of your email blank.
Re: [AOLSERVER] Application packages
On Mon, 20 Feb 2006 14:52:12 +, Bas Scheffers [EMAIL PROTECTED] wrote: The goal would be to have simple deployable application modules, quite like a WAR file in J2EE. Let's codename it AOLserver Application Package, or AAP for short. (yes, that is Dutch for monkey) This would give the advantage that it would be easy to deploy any open source applications written for AOLserver without having to copy loads of files into the right location or do much editing the global nsd.tcl. Just drop it in and go. You could even do it the Tomcat way; just drop the .aap file in the applications directory and it will unpack and bind it to a url automatically. Could AOLServer use tcl's vfs layer to directly mount say, a zipfile or a tclkit file? This would make for a very nice deployment method and works well elsewhere. Since the configuration file is a tcl program, it could include configuration from other files. Maybe an AAP package could include a file that is to be inserted into the main config.tcl at server startup to load whatever modules and database pools it needs. The big downside is it would need a server restart to load a new package. Whatever you come up with, please don't have the configuration in a few dozen xml files ala tomcat. Just because everyone else does it that way doesn't mean it's a good way to do it. -J -- AOLserver - http://www.aolserver.com/ To Remove yourself from this list, simply send an email to [EMAIL PROTECTED] with the body of SIGNOFF AOLSERVER in the email message. You can leave the Subject: field of your email blank.
