emacs-local.el

(defun remote-shell-fav-hosts-get ()
  "My hook to the remote-shell processes in order to connect to
    my OpenStack controller, and create a hashtable of host names as
    the keys, and IP addresses as the values."
  (interactive)

  ;; Run nova list command remotely on this host system, and put the
  ;; results in a temp buffer:
  (let* ((undercloud-controller "10.98.1.145")
         (default-directory    (format "/ssh:%s:" undercloud-controller))
         (tmp-buffer           "host-list"))

    (shell-command "source ./openrc; nova --os-password 'oh-bugger' list" tmp-buffer)

    (with-current-buffer tmp-buffer
      ;; Assuming we get here, let's invalidate the cache
      (clrhash remote-shell-fav-hosts)
      (puthash "undercloud-controller" undercloud-controller remote-shell-fav-hosts)

      (goto-char (point-min))
      (while (re-search-forward (concat "^| "  ;; Look for the UUID
                                        "[0-9a-fA-F]\\{8\\}-"
                                        "[0-9a-fA-F]\\{4\\}-"
                                        "[0-9a-fA-F]\\{4\\}-"
                                        "[0-9a-fA-F]\\{4\\}-"
                                        "[0-9a-fA-F]\\{12\\} *| *")
                                nil t)
        (let* ((name-s (point))
               (name-e (progn (re-search-forward " ")
                              (1- (match-end 0))))
               (name (buffer-substring-no-properties name-s name-e))

               (addr-s (progn (re-search-forward "cedev.*=")
                              (match-end 0)))
               (addr-e (progn (re-search-forward " ")
                              (1- (match-end 0))))
               (addr (buffer-substring-no-properties addr-s addr-e)))
          (puthash name addr remote-shell-fav-hosts))))))