gatus/controller/badge.go
2021-08-19 23:12:48 -04:00

121 lines
3.6 KiB
Go

package controller
import (
"fmt"
"net/http"
"strings"
"time"
"github.com/TwinProduction/gatus/storage"
"github.com/TwinProduction/gatus/storage/store/common"
"github.com/gorilla/mux"
)
// badgeHandler handles the automatic generation of badge based on the group name and service name passed.
//
// Valid values for {duration}: 7d, 24h, 1h
// Pattern for {identifier}: <KEY>.svg
func badgeHandler(writer http.ResponseWriter, request *http.Request) {
variables := mux.Vars(request)
duration := variables["duration"]
var from time.Time
switch duration {
case "7d":
from = time.Now().Add(-time.Hour * 24 * 7)
case "24h":
from = time.Now().Add(-time.Hour * 24)
case "1h":
from = time.Now().Add(-time.Hour)
default:
writer.WriteHeader(http.StatusBadRequest)
_, _ = writer.Write([]byte("Durations supported: 7d, 24h, 1h"))
return
}
identifier := variables["identifier"]
key := strings.TrimSuffix(identifier, ".svg")
uptime, err := storage.Get().GetUptimeByKey(key, from, time.Now())
if err != nil {
if err == common.ErrServiceNotFound {
writer.WriteHeader(http.StatusNotFound)
} else if err == common.ErrInvalidTimeRange {
writer.WriteHeader(http.StatusBadRequest)
} else {
writer.WriteHeader(http.StatusInternalServerError)
}
_, _ = writer.Write([]byte(err.Error()))
return
}
formattedDate := time.Now().Format(http.TimeFormat)
writer.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
writer.Header().Set("Date", formattedDate)
writer.Header().Set("Expires", formattedDate)
writer.Header().Set("Content-Type", "image/svg+xml")
_, _ = writer.Write(generateSVG(duration, uptime))
}
func generateSVG(duration string, uptime float64) []byte {
var labelWidth, valueWidth, valueWidthAdjustment int
switch duration {
case "7d":
labelWidth = 65
case "24h":
labelWidth = 70
case "1h":
labelWidth = 65
default:
}
color := getBadgeColorFromUptime(uptime)
sanitizedValue := strings.TrimRight(strings.TrimRight(fmt.Sprintf("%.2f", uptime*100), "0"), ".") + "%"
if strings.Contains(sanitizedValue, ".") {
valueWidthAdjustment = -10
}
valueWidth = (len(sanitizedValue) * 11) + valueWidthAdjustment
width := labelWidth + valueWidth
labelX := labelWidth / 2
valueX := labelWidth + (valueWidth / 2)
svg := []byte(fmt.Sprintf(`<svg xmlns="http://www.w3.org/2000/svg" width="%d" height="20">
<linearGradient id="b" x2="0" y2="100%%">
<stop offset="0" stop-color="#bbb" stop-opacity=".1"/>
<stop offset="1" stop-opacity=".1"/>
</linearGradient>
<mask id="a">
<rect width="%d" height="20" rx="3" fill="#fff"/>
</mask>
<g mask="url(#a)">
<path fill="#555" d="M0 0h%dv20H0z"/>
<path fill="%s" d="M%d 0h%dv20H%dz"/>
<path fill="url(#b)" d="M0 0h%dv20H0z"/>
</g>
<g fill="#fff" text-anchor="middle" font-family="DejaVu Sans,Verdana,Geneva,sans-serif" font-size="11">
<text x="%d" y="15" fill="#010101" fill-opacity=".3">
uptime %s
</text>
<text x="%d" y="14">
uptime %s
</text>
<text x="%d" y="15" fill="#010101" fill-opacity=".3">
%s
</text>
<text x="%d" y="14">
%s
</text>
</g>
</svg>`, width, width, labelWidth, color, labelWidth, valueWidth, labelWidth, width, labelX, duration, labelX, duration, valueX, sanitizedValue, valueX, sanitizedValue))
return svg
}
func getBadgeColorFromUptime(uptime float64) string {
if uptime >= 0.975 {
return "#40cc11"
} else if uptime >= 0.95 {
return "#94cc11"
} else if uptime >= 0.9 {
return "#ccc311"
} else if uptime >= 0.8 {
return "#ccb311"
} else if uptime >= 0.65 {
return "#cc8111"
}
return "#c7130a"
}