Firefox tabs analysis with Prometheus and Grafana

#!/usr/bin/python3

# https://alexandre.deverteuil.net/posts/firefox-tabs-analysis/

## root crontab:
# * * * * * /home/alex/Programs/count-tabs.py | sponge /usr/local/lib/node_exporter/firefox-tabs.prom
## `sponge` comes from the moreutils package.

import glob
import json
import os
import os.path
import sys

import lz4.block  # sudo dnf install python3-lz4


# https://unix.stackexchange.com/questions/385023/firefox-reading-out-urls-of-opened-tabs-from-the-command-line
def count_tabs_and_windows():
    userdir = os.path.expanduser("~alex")
    pattern = ".mozilla/firefox*/*.default*/sessionstore-backups/recovery.jsonlz4"
    matches = glob.glob(userdir + "/" + pattern)
    if len(matches) == 0:
        print_metrics(0, 0, 0, 0)
        sys.exit()
    else:
        sessionstore = matches[0]
        with open(sessionstore, "rb") as f:
            magic = f.read(8)
            session_data = json.loads(lz4.block.decompress(f.read()).decode("utf-8"))

    # Uncomment to dump the uncompressed JSON in sessions.json.
    #with open("sessions.json", "w") as f:
    #    f.write(json.dumps(jdata))

    group_tabs_count = 0
    active_tabs_count = 0
    inactive_tabs_count = 0
    windows_count = 0

    for win in session_data["windows"]:
        windows_count += 1
        for tab in win["tabs"]:
            i = int(tab["index"]) - 1
            url = tab["entries"][i]["url"]
            title = tab["entries"][i]["title"]
            if (url.find("grouptab/index.html") > 0 or
                url.find("grouptab-personal/index.html") > 0 or
                url.find("grouptab%2Findex.html") > 0 or
                url.find("grouptab-personal%2Findex.html") > 0
                ):
                group_tabs_count += 1
                #print("GROUP", title)
            elif url.startswith("moz-extension://"):
                inactive_tabs_count += 1
                #print("INACTIVE", title, url)
            else:
                active_tabs_count += 1
                #print("ACTIVE", title)

    metric_fmt = "firefox_session_open_tabs{{type=\"{type}\"}} {value}"
    print("# HELP firefox_session_open_tabs number of open tabs from Firefox")
    print("# TYPE firefox_session_open_tabs gauge")
    print(metric_fmt.format(type="grouptab", value=group_tabs_count))
    print(metric_fmt.format(type="active", value=active_tabs_count))
    print(metric_fmt.format(type="inactive", value=inactive_tabs_count))
    print("# HELP firefox_session_open_windows number of open Firefox windows")
    print("# TYPE firefox_session_open_windows gauge")
    print("firefox_session_open_windows", windows_count)


def count_saved_sessions():
    userdir = os.path.expanduser("~alex")
    pattern = "Downloads/TabSessionManager - Backup/User Save/*.json"
    session_files = glob.glob(userdir + "/" + pattern)
    sessions = {}

    for session_file in session_files:
        with open(session_file) as f:
            session_data = json.loads(f.read())[0]
        name = session_data['name']
        if session_data['tag']:
            tag = session_data['tag'][0]
        else:
            tag = "untagged"
        group_tabs_count = 0
        regular_tabs_count = 0
        for window in session_data['windows']:
            for tab in session_data['windows'][window]:
                url = session_data['windows'][window][tab]['url']
                if (url.find("grouptab/index.html") > 0 or
                    url.find("grouptab-personal/index.html") > 0
                    ):
                    group_tabs_count += 1
                else:
                    regular_tabs_count += 1
        sessions[name] = {
            'name': name,
            'tag': tag,
            'group_tabs_count': group_tabs_count,
            'regular_tabs_count': regular_tabs_count
        }

    print("# HELP firefox_saved_session_tabs number of tabs from Firefox saved session")
    print("# TYPE firefox_saved_session_tabs gauge")
    metric_fmt = "firefox_saved_session_tabs{{tag=\"{tag}\",session_name=\"{name}\",type=\"{type}\"}} {value}"
    for name in sessions:
        print(metric_fmt.format(name=name, tag=sessions[name]['tag'], type="grouptab", value=sessions[name]['group_tabs_count']))
        print(metric_fmt.format(name=name, tag=sessions[name]['tag'], type="regular", value=sessions[name]['regular_tabs_count']))


count_tabs_and_windows()
count_saved_sessions()

# HELP firefox_session_open_tabs number of open tabs from Firefox
# TYPE firefox_session_open_tabs gauge
firefox_session_open_tabs{type="grouptab"} 25
firefox_session_open_tabs{type="active"} 22
firefox_session_open_tabs{type="inactive"} 73

# HELP firefox_session_open_windows number of open Firefox windows
# TYPE firefox_session_open_windows gauge
firefox_session_open_windows 6

# HELP firefox_saved_session_tabs number of tabs from Firefox saved session
# TYPE firefox_saved_session_tabs gauge
firefox_saved_session_tabs{tag="client",session_name="xxxxx",type="grouptab"} 3
firefox_saved_session_tabs{tag="client",session_name="xxxxx",type="regular"} 14
firefox_saved_session_tabs{tag="client",session_name="yyyyyyyyyyy",type="grouptab"} 1
firefox_saved_session_tabs{tag="client",session_name="yyyyyyyyyyy",type="regular"} 3
firefox_saved_session_tabs{tag="Grafana",session_name="Grafana: main",type="grouptab"} 1
firefox_saved_session_tabs{tag="Grafana",session_name="Grafana: main",type="regular"} 6