README
¶
GO_Watcher
Lets you monitor the CPU- and Memory Usage of your System. Additonally added the number of Goroutines. Offers a webservice, for remote access, with updates regularly via websockets.. Compiled binary is <10mb in size and has a small memory/cpu footprint.
Uses
- Websockets
- Flags
- Goolge Charts
- Github Actions
Added Dockerfile for the funsies
Build image with:
docker build --tag go_watcher .
Run container with:
docker run --rm -p 8080:8080 go_watcher
Input
- -addr :8080 -> Changes to Port and Address of the Server
- -period 1s -> Changes the Update Speed of the Graph/Websocket
Todo
- Tests!
- More Infos
- Change Chart to Running
- Add better Timestamp
- ...
Documentation
¶
Index ¶
- Variables
- func GetCPULoad(Stats *PC_stats, interval time.Duration)
- func GetGoroutines(Stats *PC_stats, interval time.Duration)
- func GetMemLoad(Stats *PC_stats, interval time.Duration)
- func MessageReceiver(ctx context.Context, conn *websocket.Conn, close chan bool)
- func MessageWriter(ctx context.Context, conn *websocket.Conn, poll *time.Ticker, ...)
- func SendTemplate(w http.ResponseWriter, r *http.Request)
- func SendUpdates(w http.ResponseWriter, r *http.Request)
- func Start(pollPeriod time.Duration) error
- type PC_stats
Constants ¶
This section is empty.
Variables ¶
var HomeTemplate = template.Must(template.New("").Parse(`
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<link rel="icon" href="data:,">
</head>
<body>
<div id="chart_div"></div>
<div id="chart_mem"></div>
<div id="chart_go"></div>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script>
var data;
var chart;
var ws_data;
var index = 0;
var mem_data;
var mem_chart;
var mem_ws_data;
var mem_index = 0;
var go_data;
var go_chart;
var go_ws_data;
var go_index = 0;
// create options object with titles, colors, etc.
let options = {
title: "CPU Usage",
hAxis: {
title: "Time"
},
vAxis: {
title: "Usage"
}
};
// create options object with titles, colors, etc.
let mem_options = {
title: "Memory Usage",
hAxis: {
title: "Time"
},
vAxis: {
title: "Usage"
}
};
// create options object with titles, colors, etc.
let go_options = {
title: "Num Goroutines",
hAxis: {
title: "Time"
},
vAxis: {
title: "Usage"
}
};
// Das hier weils wichtig ist ob https oder nicht.
// Browser erlauben KEIN downgrad also https zu ws!
if (location.protocol === 'https:'){
ws = new WebSocket("wss://" + document.location.host + document.location.pathname + "echo");
} else {
ws = new WebSocket("ws://" + document.location.host + document.location.pathname + "echo");
}
ws.onopen = function(evt) {
console.log("OPEN");
}
ws.onclose = function(evt) {
document.getElementById("Load").innerText = "Closed by Server"
console.log("CLOSE");
}
// Listen for messages
ws.addEventListener('message', function (event) {
console.log('Message from server ', JSON.parse(event.data));
ws_data = JSON.parse(event.data)
data.addRow([index, ws_data.cpu_load]);
chart.draw(data, options);
index++;
mem_data.addRow([mem_index, ws_data.mem_load]);
mem_chart.draw(mem_data, mem_options);
mem_index++;
go_data.addRow([go_index, ws_data.goroutines]);
go_chart.draw(go_data, go_options);
go_index++;
});
ws.onerror = function(evt) {
document.getElementById("Load").innerText = "Erro occured"
console.log("ERROR: " + evt);
}
// load current chart package
google.charts.load("current", {
packages: ["corechart", "line"]
});
// set callback function when api loaded
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
// create data object with default value
data = google.visualization.arrayToDataTable([
["Year", "CPU Usage"],
[0, 0]
]);
// create data object with default value
mem_data = google.visualization.arrayToDataTable([
["Year", "Mem Usage"],
[0, 100]
]);
// create data object with default value
go_data = google.visualization.arrayToDataTable([
["Year", "Goroutines"],
[0, 25]
]);
chart = new google.visualization.LineChart(
document.getElementById("chart_div")
);
chart.draw(data, options);
mem_chart = new google.visualization.LineChart(
document.getElementById("chart_mem")
);
mem_chart.draw(mem_data, options);
go_chart = new google.visualization.LineChart(
document.getElementById("chart_go")
);
go_chart.draw(mem_data, options);
}
</script>
</body>
</html>
`))
var PollPeriod time.Duration
Functions ¶
func GetCPULoad ¶
GetCPULoad changes PC_StatsCPU_Load each interval.
func GetGoroutines ¶
GetCPULoad changes PC_StatsCPU_Load each interval.
func GetMemLoad ¶
GetMemLoad changes PC_Stats.Mem_Load each interval.
This goroutine also writes the Timestamp to PC_Stats.
func MessageReceiver ¶
MessageReceiver is needed to listen on the Closes from the Client side.
If you don´t listen to those messages, the Programm will try to write, on a dead connection and fail.
func MessageWriter ¶
MessageWriter writes to the Connection, at specified interval.
If the connection is closed on the client side, the goroutine is notified via the C_close Channel and returns. Additionally it regularly writes a PingMessage to the connection.
func SendTemplate ¶
func SendTemplate(w http.ResponseWriter, r *http.Request)
SendTemplate sends a HMTL which creates a Websocket Connection an updates Graphs. To function the SendUpdate function needs to added as *"echo"* and located relativ to this Path. For example:
http.HandleFunc("/echo", SendUpdates)
http.HandleFunc("/", SendTemplate)
func SendUpdates ¶
func SendUpdates(w http.ResponseWriter, r *http.Request)
SendStatusUpdates implements to Websocket Logik. So far I could not come up with an Idea how to stop MessageReceiver. Dont know how if thats bad...
Source Files