Return active pool members from log local0. in an irule?

Is it possible to list the active pool members for a specific pool using the log local0. logging command in an irule?

Yes.

Start with looking at: Pool Member Status HTML5 Page

Instead of creating HTML content, just log to local0.

e.g.

when HTTP_REQUEST {
    set thispool "my_http_pool"
    foreach { pmem } [members -list $thispool] {
      log local0. "$thispool - [getfield $pmem " " 1] [LB::status pool $thispool member [getfield $pmem " " 1] [getfield $pmem " " 2]]"
    }
}

I hope this helps.

So this is how my irule now looks. I have added in the above and am hoping I did it correctly. I was hoping someone could look it over and point out any issues they see (if any)? I'm not 100% certain I inserted the above logging statement for the pool members accurately. My irule is based on one Kevin Stewart helped me here: https://devcentral.f5.com/questions?pid=61854.

when HTTP_REQUEST {
    switch -glob [string tolower [HTTP::uri]] {
      "/place/portal" -
      "/place/portal/" -
      "/" { 
        HTTP::respond 301 "Location" "https://www.my-website.com/portal/my-website-com" 
       }
      "/redirect.nsf*" { 

 This section prints the active members in the SuperServers_pool to the logs
 if this section of the irule is invoked.

      set thispool "SuperServers_pool"
      foreach { pmem } [members -list $thispool] {
        log local0. "$thispool - [getfield $pmem " " 1] [LB::status pool $thispool member [getfield $pmem " " 1] [getfield $pmem " " 2]]"
       }
 
 This next section states that if there are more than 0 pool members are active in the SuperServers_pool 
 then the user is redirected there, else they are presented a Maintenance Page.

          if { [active_members SuperServers_pool] > 0 } {
          log local0. "Sending to the SuperServers_pool."
              pool SuperServers_pool 
          } else {
          log local0. "Sending to MX Page for the SuperServers_pool."
              HTTP::respond 503 content [ifile get "/external/my-website_MaintenancePage_ifile"] noserver "Content-Type" "text/html" "Cache-Control" "no-cache, must-revalidate"
              return
          }
      }
      "*/hrp/*" { 

 This section prints the active members in the PDFServers_Pool to the logs
 if this section of the irule is invoked.

      set thispool "PDFServers_Pool"
      foreach { pmem } [members -list $thispool] {
        log local0. "$thispool - [getfield $pmem " " 1] [LB::status pool $thispool member [getfield $pmem " " 1] [getfield $pmem " " 2]]"
       }
 
 This next section states that if there are more than 0 pool members are active in the PDFServers_Pool 
 then the user is redirected there, else they are presented a Maintenance Page.

          if { [active_members PDFServers_Pool] > 0 } {
          log local0. "Sending to the PDFServers_Pool."
              pool PDFServers_Pool 
          } else {
          log local0. "Sending to MX Page for the PDFServers_Pool."
              HTTP::respond 503 content [ifile get "/external/my-website_MaintenancePage_ifile"] noserver "Content-Type" "text/html" "Cache-Control" "no-cache, must-revalidate"
              return
          }
       }
      default { 

 This section prints the active members in the my-website.com_pool to the logs
 if this section of the irule is invoked.

      set thispool "my-website.com_pool"
      foreach { pmem } [members -list $thispool] {
        log local0. "$thispool - [getfield $pmem " " 1] [LB::status pool $thispool member [getfield $pmem " " 1] [getfield $pmem " " 2]]"
       }
 
 This next section states that if there are more than 0 pool members are active in the my-website.com_pool 
 then the user is redirected there, else they are presented a Maintenance Page.

          if { [active_members my-website.com_pool] > 0 } {
          log local0. "Sending to the my-website.com_pool."
              pool my-website.com_pool 
          } else {
          log local0. "Sending to MX Page for the my-website.com_pool."
              HTTP::respond 503 content [ifile get "/external/my-website_MaintenancePage_ifile"] noserver "Content-Type" "text/html" "Cache-Control" "no-cache, must-revalidate"
              return
          }
      }
    }

  log local0. "Inserting HttpsIndicatorHeader Value"
    HTTP::header insert HttpsIndicatorHeader True
}