feat: first pass at implement resource limitation on a pre-process basis

plugins/resource/src/triggers/docker-args-process-deploy/docker-args-process-deploy.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
+
+	"github.com/dokku/dokku/plugins/common"
+)
+
+// outputs the process-specific docker options
+func main() {
+	stdin, err := ioutil.ReadAll(os.Stdin)
+	if err != nil {
+		common.LogFail(err.Error())
+	}
+
+	flag.Parse()
+	appName := flag.Arg(0)
+	procType := flag.Arg(3)
+
+	resources, err := common.PropertyGetAll("resource", appName)
+	if err != nil {
+		fmt.Print(string(stdin))
+		common.LogFail(err.Error())
+	}
+
+	limits := make(map[string]string)
+	reservations := make(map[string]string)
+
+	validLimits := map[string]bool{
+		"cpu":         true,
+		"memory":      true,
+		"memory-swap": true,
+	}
+	validReservations := map[string]bool{
+		"memory": true,
+	}
+	validPrefixes := []string{"_default_.", fmt.Sprintf("%s.", procType)}
+	for _, validPrefix := range validPrefixes {
+		for key, value := range resources {
+			if !strings.HasPrefix(key, validPrefix) {
+				continue
+			}
+			parts := strings.SplitN(strings.TrimPrefix(key, validPrefix), ".", 2)
+			if parts[0] == "limit" {
+				if !validLimits[parts[1]] {
+					continue
+				}
+
+				limits[parts[1]] = value
+			}
+			if parts[0] == "reserve" {
+				if !validReservations[parts[1]] {
+					continue
+				}
+
+				reservations[parts[1]] = value
+			}
+		}
+	}
+
+	for key, value := range limits {
+		fmt.Print(" --%s=%s ", key, value)
+	}
+
+	for key, value := range reservations {
+		fmt.Print(" --%s-reservation=%s ", key, value)
+	}
+
+	fmt.Print(string(stdin))
+}