notify-client-server 0.1.6

notification server/website with client functions

• website: https://arrizza.com/python-notify-client-server.html
• installation: see https://arrizza.com/setup-common.html

Summary

This project shows a client and server for notifications.

I have several PCs that are on my home network (a couple of Ubuntu, a Mac laptop and a Win11 laptop). These have backup scripts but those jobs are independent. To see if any of them ran or failed, I had to manually check the logs and files. That was a pain.

To fix it, a central server is needed and each of the PCs send a notification when a job passes or fails. Then using a browser I can see what happened at 2:00AM when the backup jobs ran.

Server

The server is started by running ./do_server.

It assumes that there is a directory "webhost" for a sqlite database to be created there.

Note that the server can be started as an Ubuntu service. See src/notify_client_server/template_notify_server.service for a starting point for your service.

Copy that template to ./webhost/notify_server.service

Configure it by changing the values in braces { }. Currently, these are:

• User={svc_user_name} : the userid the service should run under
• Group={svc_group_name}: the groupid the service should run under
• WorkingDirectory={svc_working_dir} : the working directory. Use the notify-client-server git repo directory
• ExecStart={svc_do_server_path} : the path to the ./do_server script. Normally this is the svc_working_dir above with /do_server
• use absolute full paths

For example:

<snip>
[Service]
User=my_userid
Group=my_userid
WorkingDirectory=/home/my_userid/projects/notify-client-server
ExecStart=/home/my_userid/projects/notify-client-server/do_server
<snip>

Configuration

See src/notify_client_server/template_cfg.json for configuration.

The configuration json is in three sections.

• is_local: if true, uses value from local_mode, otherwise uses values from remote_mode

local_mode

This section is used when your server is running on this local (Ubuntu) machine

• is_debug: is used for the flask server to be automatically restarted when it detects a change. Very handy during development!

• server_hostname: the hostname of your local PC

• server_port: the URL port to use. Currently 5004

• server_ip: you can use 127.0.0.1 or 0.0.0.0

• server_url: defaults to the current hostname and port

• server_sudo_pwd_path: holds your root pwd. Since the Ubuntu service is installed via root you'll to provide it. Currently, webhost/pf_pwd holds that. The "pf_" indicates it is a personal file and the .gitignore does not commit it.

• svc_name : the name of the service file. Currently notify_server.service

• svc_user_name: the userid to run the service under

• svc_group_name: the groupid to run the service under

• svc_working_dir: the location of the local notify-client-server directory

• svc_do_server_path: the location of the do_server script

• clients: the list of clients to use for do_admin push

remote_mode

These are the same as the values above, except for the remote server.

pc_info

Holds client information as needed by do_admin push

pc hostname: e.g. "pc1" to identify the hostname used by ssh to connect to that client

Each PC entry has to have the following fields:

• user_name: the userid used by ssh to connect to that client
• working_dir: the location of the notify-client-server directory

Admin

To install and interact with the server, you can use do_admin

That script assumes you have fully installed the notify-client-server:

./do_subm_update full
./do_install

ls -al webhost
-rw-r--r--  1 my_userid my_userid 8282 May  1 20:33 notify_server.db   <= will be created when the server is started
-rw-rw-r--  1 my_userid my_userid 3080 May  4 14:45 notify-server.json
-rw-rw-r--  1 my_userid my_userid  346 May  4 14:45 notify_server.service

./do_server
# fix any warnings, issues, etc.
# note this expects the configuration to be correctly set up, see above

• ./do_admin install : installs the Ubuntu service using the notify_server.service

• ./do_admin restart : starts or restarts the service

• ./do_admin status : shows the service's current status

• ./do_admin journal : shows the service log for any warnings etc.

• ./do_admin stop : stops the service

• ./do_admin uninstall : removes the service from Ubuntu services

• ./do_admin push : sends the .cfg file to all of your clients

• ./do_admin test : checks you can connect to your clients and run multiple commands.

Client(s)

The clients are kicked off using ./doit. See sample/app.py to see how a notification is sent.

It also shows how to send a "ping". This can be used to ensure communication is working before sending a notification.

Run

Running ./do_server, as typical output:

==== do_server: starting...
     gen: constants_version.py rc=0
16:24:21.076 ==== on 2025/05/04 
00:00:00.000 ==== server.main host=0.0.0.0, port=5004, debug=True
 * Serving Flask app 'server'
 * Debug mode: on
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
 * Running on all addresses (0.0.0.0)
 * Running on http://127.0.0.1:5004
 * Running on http://10.0.0.17:5004
Press CTRL+C to quit
 * Restarting with stat
16:24:21.155 ==== on 2025/05/04 
00:00:00.000 ==== server.main host=0.0.0.0, port=5004, debug=True
 * Debugger is active!
 * Debugger PIN: 926-003-063

Then open a browser to: http://localhost:5004/. There should be no notifications.

Run ./doiit

(venv)$ ./doit
OK   set_env: rc=0
OK   doit: out_dir: /home/myuserid/projects/notify-client-server/out
==== doit: starting...
16:26:29.954 INFO on 2025/05/04 
00:00:00.000 INFO App.init
00:00:00.000 INFO App.run
00:00:00.002 DBG  ping successful      POST 200 http://john26:5004
00:00:00.007 DBG  notify successful    POST 200 http://john26:5004
     doit: run_it rc=0
     doit: overall rc=0

The server should output some logging:

127.0.0.1 - - [04/May/2025 16:25:38] "GET / HTTP/1.1" 200 -
127.0.0.1 - - [04/May/2025 16:25:38] "GET /favicon.ico HTTP/1.1" 404 -
127.0.0.1 - - [04/May/2025 16:26:29] "POST /ping HTTP/1.1" 200 -
127.0.0.1 - - [04/May/2025 16:26:29] "POST /notify HTTP/1.1" 200 -
127.0.0.1 - - [04/May/2025 16:27:26] "GET / HTTP/1.1" 200 -

Refresh the browser page. There should be a sample notification:

Notifications
        date                 source event         status	description
Delete  2025/05/04 16:26:29	 john26	backup_nas x	ok	    running good 17
Pings: 1

The "Pings" should be 1. Run doit again and it should bump to 2, etc.

Click the Delete buttons to remove the notification on that row.

crontab

I have a python script that backs up the PC it's on to a NAS and at the end of that process it sends a notifications to notify_server:

def _notify(self, status, desc):
  tag = self._tag      <== indicates some information where the backup occurred e.g. crontab
  if len(sys.argv) > 1:
      tag = f'{self._tag} {sys.argv[1]}'  <== add info from the command line
  self._client.notify(tag, status, desc) 

The status is "ok", "fail" or "warn" depending on what happened during the backup:

status = 'ok'
if self._backups_warn > 0:      <== keeps track of any warnings logged
    status = 'warn'
if self._backups_failed > 0:    <== keeps track of any errors logged
    status = 'err'

The desc variable contains some useful info:

00:00:08 overallrc=0; done:0 warns:0 failed:0; needs commit: True;"
   ^-- time to complete the backup HH:MM:SS
           ^-- overall return code
                        ^-- number of directories backed up
                               ^-- number of warnings
                                      ^-- number of errors
                                                ^-- state of git the repo I use for this kind of maintenance  

crontab entry looks like this:

45  02  *   *   *     cd /jad; test_notify/doit "crontab" > /jad/test_notify/test.log
      ^-- runs every day at 2:45AM
                        ^-- enters my maintenance repo
                                     ^-- runs the backup and indicates its from a crontab entry instead of manual
                                                                ^-- saves the full log