Hi Thomas, Thanks for the detailed info! RGW lua scripting was never tested in a cephadm deployment :-( Opened a tracker: https://tracker.ceph.com/issues/59574 to make sure this would work out of the box. Yuval On Tue, Apr 25, 2023 at 10:25 PM Thomas Bennett <thomas@tsolo.io> wrote:
Hi ceph users,
I've been trying out the lua scripting for the rados gateway (thanks Yuval).
As in my previous email I mentioned that there is an error when trying to load the luasocket module. However, I thought it was a good time to report on my progress.
My 'hello world' example below is called *test.lua* below includes the following checks:
1. Can I write to the debug log? 2. Can I use the lua socket package to do something stupid but intersting, like connect to a webservice?
Before you continue reading this, you might need to know that I run all ceph processes in a *CentOS Stream release 8 *container deployed using ceph orchestrator running *Ceph v17.2.5*, so please view the information below in that context.
For anyone looking for a reference, I suggest going to the ceph lua rados gateway documentation at radosgw/lua-scripting <https://docs.ceph.com/en/quincy/radosgw/lua-scripting/>.
There are two new switches you need to know about in the radosgw-admin:
- *script* -> loading your lua script - *script-package* -> loading supporting packages for your script - e.i. luasocket in this case.
For a basic setup, you'll need to have a few dependencies in your containers:
- cephadm container: requires luarocks (I've checked the code - it runs a luarocks search command) - radosgw container: requires luarocks, gcc, make, m4, wget (wget just in case).
To achieve the above, I updated the container image for our running system. I needed to do this because I needed to redeploy the rados gateway container to inject the lua script packages into the radosgw runtime process. This will start with a fresh container based on the global config *container_image* setting on your running system.
For us this is currently captured in *quay.io/tsolo/ceph:v17.2.5-3 <http://quay.io/tsolo/ceph:v17.2.5-3>* and included the following exta steps (including installing the lua dev from an rpm because there is no centos package in yum): yum install luarocks gcc make wget m4 rpm -i
https://rpmfind.net/linux/centos/8-stream/PowerTools/x86_64/os/Packages/lua-...
You will notice that I've included a compiler and compiler support into the image. This is because luarocks on the radosgw to compile luasocket (the package I want to install). This will happen at start time when the radosgw is restarted from ceph orch.
In the cephadm container I still need to update our cephadm shell so I need to install luarocks by hand: yum install luarocks
Then set thew updated image to use: ceph config set global container_image quay.io/tsolo/ceph:v17.2.5-3
I now create a file called: *test.lua* in the cephadm container. This contains the following lines to write to the log and then do a get request to google. This is not practical in production, but it serves the purpose of testing the infrastructure:
RGWDebugLog("Tsolo start lua script") local LuaSocket = require("socket") client = LuaSocket.connect("google.com", 80) client:send("GET / HTTP/1.0\r\nHost: google.com\r\n\r\n") while true do s, status, partial = client:receive('*a') RGWDebugLog(s or partial) if status == "closed" then break end end client:close() RGWDebugLog("Tsolo stop lua")
Next I run: radosgw-admin script-package add --package=luasocket --allow-compilation
And then list the added package to make sure it is there: radosgw-admin script-package list
Note - at this point the radosgw has not been modified, it must first be restarted.
Then I put the *test.lua *script into the pre request context: radosgw-admin script put --infile=test.lua --context=preRequest
You also need to raise the debug log level on the running rados gateway: ceph daemon /var/run/ceph/ceph-client.rgw.xxx.xxx-cms1.xxxxx.x.xxxxxxxxxxxxxx.asok config set debug_rgw 20
Inside the radosgw container I apply my fix (as per previous email): cp -ru /tmp/luarocks/client.rgw.xxxxxx.xxx-xxxx-xxxx.pcoulb/lib64/* /tmp/luarocks/client.rgw.xxxxxx.xxx-xxxx-xxxx.pcoulb/lib/
Outside on the host running the radosgw-admin container I follow the journalctl for the radosgw container (to get the logs): journalctl -fu ceph-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx@rgw. xxx.xxx-cms1.xxxxx.x.xxxxxxxxxxxxxx.service
Then I run an s3cmd to put data in via the rados gateway and check the journalctl logs and see: Apr 25 20:54:47 brp-ceph-cms1 radosgw[60901]: Lua INFO: Tsolo start lua Apr 25 20:54:47 brp-ceph-cms1 radosgw[60901]: Lua INFO: HTTP/1.0 301 Moved Permanently Apr 25 20:54:47 brp-ceph-cms1 radosgw[60901]: Lua INFO: Apr 25 20:54:47 brp-ceph-cms1 radosgw[60901]: Lua INFO: Tsolo stop lua Apr 25 20:54:47 brp-ceph-cms1 radosgw[60901]: Lua INFO: Tsolo start lua Apr 25 20:54:48 brp-ceph-cms1 radosgw[60901]: Lua INFO: HTTP/1.0 301 Moved Permanently Apr 25 20:54:48 brp-ceph-cms1 radosgw[60901]: Lua INFO: Apr 25 20:54:48 brp-ceph-cms1 radosgw[60901]: Lua INFO: Tsolo stop lua
So the script worked :)
If you want to see where the luarocks libraries have been installed, look in the /tmp/ directory of the radosgw container after you redeploy it and you will find the content in /tmp/luarocks.
Conclusions: There was a bit to figure out to get this working, but now that I've got this simple test working I think there is a lot more to look into and discover and use w.r.t. this powerful tool.
Cheers, Tom _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io