Scalable system to check other systems

• Scalable - multiple instances of frontend and backend can run simultaneously to split the load
• Runs "checks", e.g. check if google.com responds within 2000ms and the response contains the word "Google"
• Different types of checks
  • HTTP Check with optional authentication
  • Database Check
  • Ping Check
• Sub-checks, e.g. check if response contains 'Hello' or SQL result is greater than 5
• Schedules using cron expressions, e.g. run every weekday every hour between 6am-8pm
• Notifications, e.g. if check fails for 5 minutes send slack message to #failures
• Different notification types
  • Slack
  • Email
  • SMS
• Dashboard
  • Shows a summary of all checks with pie charts on which are succeeding/failing/warning
  • Easily filterable by clicking on the pie chart or by using the filters on the table
  • Can goto the results view by clicking on it, or press the edit/copy/run buttons
• Results view ("details")
  • Shows in a graph all of the results for a particular check between configurable data ranges
  • Easily filterable to show only successes/warnings/failures by clicking on the legend
  • Can be zoomed by using the bar along the bottom
• Manual UI run
  • Allows any check to be run manually from the UI from the dashboard, results or edit pages
  • Shows a detailed log on exactly how the check is running
  • Useful for debugging the check itself or seeing what is going wrong to fix it in your system
• User configuration
  • Optional Windows Authentication within a certain Active Directory group
  • Basic username/password users (you'll be asked to create one if there aren't any for initial setup)
  • Configurable API keys (per user)
• Settings
  • Global settings
    • SMTP settings for email notifications
    • Clickatell API settings for SMS notifications
    • Slack token for slack notifications
    • Windows Authentication group for automatic login
    • Schedules and settings for automatic data cleanup/aggregation
    • Login expiration setting
    • Time zone setting for the schedules, UTC by default
  • Logins, used by HTTP Check type to authenticate with a website
  • Connection Strings, used by Database Check type to login to a SQL Server
  • Environments, used to split up checks on the dashboard, e.g. Production/Test
  • Contacts, used by email/SMS notifications to choose who to send to
  • Check groups, used to group up checks into system e.g. MySystem - Front Page

Environment variables:

• ConnectionStrings__SystemChecker
  • Example: Database=SystemChecker;Data Source=sql.yoursite.com;User Id=systemchecker;Password=test
  • Used for database connectivity
• AppSettings__Url
  • Example: https://systemchecker.yoursite.com
  • Used by notifications to include a link back to the check
• RedisUrl
  • Example: redis:6379 or localhost:6379
  • Used for communication between backend (service) and frontend (web), must be the same between everything
• ASPNETCORE_URLS
  • Example: localhost:5000
  • Used by ASP.NET Core to bind the frontend site to
• UseHttps
  • Boolean, defaults to false
  • If enabled, redirects all http traffic to https

Before first start, create a new empty database and create a user with read/write permissions and configure the ConnectionStrings__SystemChecker environment variable accordingly.

Make sure a redis server is running and configure the RedisUrl environment variable accordingly.

Finally, make sure the AppSettings__Url is set to the reachable address of where you plan to host the site.

On first-start or when upgrading, run the migrations tool with an appropriate ConnectionStrings__SystemChecker environment variable with enough permissions to modify the database schema or the migrations will fail.

Start the program with the appropriate ConnectionStrings__SystemChecker, AppSettings__Url, RedisUrl, ASPNETCORE_URLS and optionally UseHttps environment variables, depending on your deployment you may have a Windows executable or you may need to call dotnet SystemChecker.Web.dll

Start the program with the appropriate ConnectionStrings__SystemChecker, AppSettings__Url and RedisUrl environment variables, as above you may have a Windows executable or you may need to call dotnet SystemChecker.Service.dll

A command line option -s|--service is available which tells the program to run as a Windows service, useful for Windows-based deployments

A help command line option -?|-h|--help is also available.