Add lua script for Slurm job_submit/lua interface

Routes user job submissions to the nodes they are allowed to run on.

etc/slurm/job_submit.lua

+--[[
+
+ Example lua script demonstrating the Slurm job_submit/lua interface.
+ This is only an example, not meant for use in its current form.
+
+ For use, this script should be copied into a file name "job_submit.lua"
+ in the same directory as the Slurm configuration file, slurm.conf.
+
+--]]
+function dump(o)
+   if type(o) == 'table' then
+      local s = '{ '
+      for k,v in pairs(o) do
+         if type(k) ~= 'number' then k = '"'..k..'"' end
+         s = s .. '['..k..'] = ' .. dump(v) .. ','
+      end
+      return s .. '} '
+   else
+      return tostring(o)
+   end
+end
+-- Load necessary library
+local pwd = require("posix").pwd
+local grp = require("posix").grp
+
+function slurm_job_submit(job_desc, part_list, submit_uid)
+
+	local target_group = "gpfs5"
+        local username = pwd.getpwuid(submit_uid).pw_name
+	local group_member = grp.getgrnam(target_group).gr_mem
+	local found = false
+
+	slurm.log_info("username:" .. username)
+        slurm.log_info("job_desc:" .. dump(job_desc) .. type(job_desc))
+        slurm.log_info("job_desc.features:" .. dump(job_desc.features))
+        slurm.log_info("part_list:" .. dump(part_list) .. type(part_list))
+        slurm.log_info("submit_uid:" .. dump(submit_uid) .. type(submit_uid))
+
+        -- Checking if the user is in the target_group
+        -- By compare group member and the username
+	for i,member in ipairs(group_member) do
+        	if member == username then
+			found = true
+			job_desc.features = "gpfs5"
+			break
+		end
+	end
+        if found != true then
+                job_desc.features = "gpfs4"
+	end
+
+	slurm.log_info("found:" .. dump(found))
+        slurm.log_info("job_desc.features:" .. dump(job_desc.features))
+        --slurm.log_user("job_desc.features: " .. dump(job_desc.features))
+
+	return slurm.SUCCESS
+end
+
+function slurm_job_modify(job_desc, job_rec, part_list, modify_uid)
+	if job_desc.comment == nil then
+		local comment = "***TEST_COMMENT***"
+		slurm.log_info("slurm_job_modify: for job %u from uid %u, setting default comment value: %s",
+				job_rec.job_id, modify_uid, comment)
+		job_desc.comment = comment
+	end
+
+	return slurm.SUCCESS
+end
+
+slurm.log_info("initialized")
+return slurm.SUCCESS
+