The simple-node-health tool is a versatile Go-based utility designed to monitor the health of Linux systems by providing an easy-to-use HTTP server and command-line interface. It performs essential checks, such as monitoring EXT4 file systems for read-only status, conducting DNS queries, and reporting the overall status of the node. This tool is best utilized when coupled with monitoring tools like Uptime Kuma or other systems that can monitor states via web calls, allowing users to integrate these health checks into their broader monitoring setups and ensure real-time visibility into server performance and stability in production environments.
The web routes are protected with an OAUTH bearer issued via form:client_id form:client_secret token method.
- Golang 1.22
$> ./simple-node-health --help
A simple tool to check hardware EXT4 devices and run DNS queries
Usage:
simple-node-health [flags]
simple-node-health [command]
Available Commands:
check Run various checks
completion Generate the autocompletion script for the specified shell
create-client Create a new client_id and client_secret and append them to the config file
help Help about any command
settings Print the current configuration settings
show-routes Show all registered HTTP routes
version
Flags:
-d, --domain string Domain to query with dig (default "cloudflare.com")
-h, --help help for simple-node-health
-p, --port int Port for the web server (default 8080)
--verbose verbose output
Use "simple-node-health [command] --help" for more information about a command.snh-config.yaml: Example secure configuration for OAUTH2 web use.
authtokensecret: change-my-s3cr3t-auth
clients:
- client_id: 0ea7386e827d0a33
client_secret: f72029251b56cf0b730e989f1af77c03
domain: cloudflare.com
port: 8080
verbose: falsesnh-config.yaml: Example insecure configuration with no webusers.
insecure: true
domain: cloudflare.com
port: 8080
verbose: falseInspect its default settings
./simple-node-health settings
domain: cloudflare.com
verbose: false
port: 8080Run the DNS example
./simple-node-health check dns
{
"response": [
"104.16.133.229",
"104.16.132.229"
]
}The /ready endpoint can be used to check for liveliness of the web application. (It does not need authentication)
$> curl http://localhost:8080/ready
{"status":"ok"}This web application is designed to be used with OAUTH2 tokens. It has a built-in token request endpoint and a token check endpoint. The /token request endpoint can be used to request a token with a client_id and client_secret.
Use the CLI to create new clients
$> simple-node-health create-client
New client_id and client_secret added:
client_id: 0ea7386e827d0a33
client_secret: f72029251b56cf0b730e989f1af77c03The token /check endpoint can be used to check the validity of the token. Use the header Authorization: Bearer <access_token> when make calls to any of the secured endpoints.
$> curl -X POST -d "client_id=81573e4c363622a6&client_secret=85e26051190016e5f3edb9d15c9803a9" http://localhost:8080/token{"access_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJjbGllbnRfaWQiOiI4MTU3M2U0YzM2MzYyMmE2IiwiZXhwIjoxNzI1Mzg3MTQ1fQ.f0OVB8ehLvDgak4-JcrHI-vblrkV9YLJpnmnJKFQSJY", "token_type": "Bearer", "expires_in": 3600} $> curl -H "Authorization: Bearer not-a-real-token" http://localhost:8080/check
Unauthorized: Invalid token$> curl -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJjbGllbnRfaWQiOiI4MTU3M2U0YzM2MzYyMmE2IiwiZXhwIjoxNzI1Mzg3MTQ1fQ.f0OVB8ehLvDgak4-JcrHI-vblrkV9YLJpnmnJKFQSJY" http://localhost:8080/check{"status":"ok"}Self document the URL routes that are available
$> ./simple-node-health show-routes
./build/simple-node-health_darwin_amd64 show-routes
2024/09/04 16:32:26 Clients size from Config: 5
{
"routes": [
"/",
"/check",
"/check/disks",
"/check/dns",
"/ready",
"/token"
]
}Product Version 2.0.0
Checking Build Dependencies ---->
Cleaning Build ---->
rm -f -rf pkg/*
rm -f -rf build/*
rm -f -rf tmp/*
rm -f -rf support/usr/local/bin/*
Building ---->
env GOOS=linux GOARCH=amd64 go build -ldflags "-X github.com/shadowbq/simple-node-health/cmd.Version=2.0.0 " -o build/simple-node-health_linux_amd64 main.go
env GOOS=darwin GOARCH=amd64 go build -ldflags "-X github.com/shadowbq/simple-node-health/cmd.Version=2.0.0 " -o build/simple-node-health_darwin_amd64 main.go
Packaging ---->
cp build/simple-node-health_linux_amd64 support/usr/local/bin/simple-node-health
# Replace {{VERSION}} in the control template with the actual version
sed 's/{{VERSION}}/2.0.0/g' support/DEBIAN/control.tpl > support/DEBIAN/control
chmod 0644 support/DEBIAN/control
# Build the .deb package
dpkg-deb --build support
dpkg-deb: building package 'simple-node-health' in 'support.deb'.
mv support.deb build/simple-node-health_2.0.0_amd64.debLightWeight Checking by default
-
Environment=GOMAXPROCS=1: Sets the Maximum Processes to only 1. This is ensure this stays a lightweight process on the endpoint. -
Nice=19: Sets the CPU scheduling priority of the service to the lowest level, meaning the process will have the least CPU priority compared to other processes. -
IOSchedulingClass=2: Sets the I/O scheduling class tobest-effort. -
IOSchedulingPriority=7: Sets the I/O priority within thebest-effortclass to the lowest level.
Copy the build/simple-node-health_linux_amd64 to /usr/local/bin/
Change the file perms chmod +x /usr/local/bin/simple-node-health
Next, create a systemd service unit file for your Go application. Systemd service files are typically located in the /etc/systemd/system/ directory.
Copy the support/snh.service to /etc/systemd/system
Using a file viewer: less /etc/systemd/system/snh.service
Reload the systemd manager configuration to read the new service file:
sudo systemctl daemon-reload
Enable the service to start on boot:
sudo systemctl enable snh.service
Start your new service:
sudo systemctl start snh.service
Check the status of the service to ensure it is running correctly:
sudo systemctl status snh.service
If you have a firewall enabled (such as ufw on Ubuntu), allow traffic on the port your service is using (in this example, port 8080):
sudo ufw allow 8080