Host monitor

ICMP monitoring and notification tool (Gmail OAuth)


Download the latest version


./host-monitor -ip ip/range -mail [email protected] [-i interval] [-t timeout] [-debug] [-mailTest]


        Debug logging
        Show help tooltips
  -i int
        Interval in seconds between each check (default 60)
  -ip value
        IP range (CIDR or single IP) to monitor - e.g. or (can be repeated to specify multiple ip/ranges)
  -mail string
        Mail to notify
        Do not send any mail, only try to connect and trigger notifications.
  -t int
        Timeout in milliseconds for ICMP (default 1000ms)

First steps

Generate credentials for Google OAuth

  1. Access Google API Console
  2. Create a new project (or select an existing one)
  3. Go to OAuth Consent Screen and add a new user using your email
  4. Go to Credentials and create a new OAuth client ID:
    • Application type: Web application
    • Authorized Javascript Origins: http://IP:9090
    • Authorized Redirect URIs: http://IP:9090/callback-gl
    • Use the IP of the system that will launch the tool. It can be localhost if the system has a graphical browser (required to login the first time)
  5. Save the credential and download its JSON as credentials.json
  6. Put credentials.json in the same folder as its executable

First launch

When launching the tool for the first time, it will output a URL that will need to be opened in a browser. It can be opened in another computer if the credential was created with an IP instead of localhost

The URL redirects to Google Auth. After login into the corresponding account and authorizing the app, it will create a token.json and start the app.

Afterwards, the token will be refreshed automatically.


Token.json was removed or any other issues with token verification

If the token is removed, the authorization process will not set up automatic token refresh. To enable it again, the authorization needs to be revoked.

In case of any other errors regarding google auth, the same process applies.

  1. Access Google Account Security
  2. Go to Third Party apps -> Manage third-party access
  3. Remove access to the app
  4. Repeat the First launch process


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