Purpose

This Go binary performs basic network diagnostics on a set of hostnames, useful for checking connectivity to dependency containers.

Usage

1. Build:

   ./build.sh
   

2. Set Environment Variables:

   • HOSTNAMES: Comma-separated list of hostnames to check (e.g., database,redis-server,api.example.com)
   • FAIL_ON_ERROR (optional): Set to "true" to exit the program immediately upon the first ping failure.
   • COMMAND (optional): Set to "entrypoint.sh" to execute an additional script on each host.
   • ERROR_COMMAND (optional): A command to execute if a ping failure occurs, useful for automated error reporting (e.g., go-glitch report-error <hostname> 'Ping failed').

3. Run:

   ./host_check
   

Output

For each hostname:

• DNS Resolution: Success or failure, with resolved IPs if successful.
• Ping: Success or failure, with ping statistics if successful.
• Custom Script: Output of the entrypoint.sh script, if executed.
• Error Reporting: Output of the ERROR_COMMAND, if set and a ping failure occurs.

Example

To check connectivity to "db-container" and "webserver", execute an entrypoint.sh script, and report errors to go-glitch:

export HOSTNAMES="db-container,webserver"
export COMMAND="entrypoint.sh"
export ERROR_COMMAND="go-glitch report-error <hostname> 'Ping failed'"
./host_check 

Important:

• Make sure you have a build.sh script in your project directory to handle the Go compilation process.
• You'll need an entrypoint.sh script if you want to leverage the COMMAND functionality.

Let me know if you'd like any other adjustments to your README!