naming update, more configurable with env vars

Dockerfile

@@ -1,14 +1,11 @@
 from golang:alpine3.14
-WORKDIR /go/src/app
-COPY ./sandman.go .
-RUN go build sandman.go
+WORKDIR /root/
+COPY ./lazytainer.go .
+RUN go build lazytainer.go
 
 FROM alpine:latest
 RUN apk --no-cache add docker-cli
 WORKDIR /root/
-COPY --from=0 /go/src/app/sandman ./
-ENV TIMEOUT=30
-ENV LABEL=sandman
+COPY --from=0 /root/lazytainer ./
 
-
-CMD ["./sandman"]
+CMD ["./lazytainer"]

README.md

@@ -1,7 +1,7 @@
-# Sandman
+# Lazytainer
 Putting your containers to sleep  
 
-*man me a sand*
+*I don't really wanna do the work today*
 
 ---
 
@@ -13,15 +13,14 @@ if it looks like you're trying to access a stopped container, it starts
 
 ### Want to test it?
 ```
-$ git clone https://github.com/vmorganp/sandman
-$ cd sandman
-$ docker-compose up -d --build
+$ git clone https://github.com/vmorganp/Lazytainer
+$ cd Lazytainer
+$ docker-compose up 
 ```
 
 ## TODO
 - support multiple ports
 - test on common services
-- better time adjustment
 - docker security probably? this really shouldn't be getting exposed except to forward traffic so idk probably firewall all non listed ports?
 - improve logging
 - inevitable bugfixes

docker-compose.yaml

@@ -1,11 +1,11 @@
 version: "3"
 services:
-  sandman:
-    container_name: sandman
+  lazytainer:
+    container_name: lazytainer
     build: .
     environment:
       - PORT=81 # TODO make this work with more than one port
-      - LABEL=sandman # sandman checks
+      - LABEL=lazytainer # value of com.lazytainer.marker for other containers that lazytainer checks
       - TIMEOUT=30 # number of seconds to let container idle
     ports:
       - 81:81
@@ -16,10 +16,10 @@ services:
     container_name: whoami2
     image: containous/whoami
     command: --port 81
-    network_mode: service:sandman
+    network_mode: service:lazytainer
     depends_on: 
-      - sandman
+      - lazytainer
     # ports:
     # - 80:80
     labels:
-      - "com.sandman.marker=sandman"
+      - "com.lazytainer.marker=lazytainer"

lazytainer.go

@@ -11,12 +11,37 @@ import (
 
 func main() {
 	inactive_seconds := 0
-	// label := os.Getenv("LABEL")
+	// check if all of the necessary env vars are set, otherwise, use defaults
+	// how long a container is allowed to have no traffic before being stopped
 	inactive_timeout, err := strconv.Atoi(os.Getenv("TIMEOUT"))
-	check(err)
-	// tx
-	// port := os.Getenv("PORT")
-	rx_history := []int{0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+	if check_env_fetch_recoverable(err) {
+		fmt.Println("using default because env variable TIMEOUT not set ")
+		inactive_timeout = 30
+	}
+
+	// how many polls to keep around
+	rx_history_length, err := strconv.Atoi(os.Getenv("RXHISTLENGTH"))
+	if check_env_fetch_recoverable(err) {
+		fmt.Println("using default because env variable RXHISTLENGTH not set ")
+		rx_history_length = 10
+	}
+
+	// number of packets required between first and last poll to keep container alive
+	min_packet_threshhold, err := strconv.Atoi(os.Getenv("MINPACKETTHRESH"))
+	if check_env_fetch_recoverable(err) {
+		fmt.Println("using default because env variable MINPACKETTHRESH not set ")
+		min_packet_threshhold = 10
+	}
+
+	// how many seconds to wait in between polls
+	poll_rate, err := strconv.Atoi(os.Getenv("POLLRATE"))
+	if check_env_fetch_recoverable(err) {
+		fmt.Println("using default because env variable POLLRATE not set ")
+		poll_rate = 1
+	}
+
+	rx_history := make([]int, rx_history_length)
+
 	for {
 		// check if container is on
 		container_state_on := is_container_on()
@@ -27,6 +52,7 @@ func main() {
 		rx_packets, err := strconv.Atoi(strings.TrimSpace(string(rx)))
 		check(err)
 		rx_history = append(rx_history[1:], rx_packets)
+		fmt.Println(rx_packets, "rx packets")
 
 		// if the container is running, see if it needs to be stopped
 		if container_state_on {
@@ -37,27 +63,29 @@ func main() {
 			check(err)
 
 			// log out the results
-			println(active_clients, "active clients")
-			println(rx_packets, "rx packets")
-			fmt.Printf("%v rx history\n\n", rx_history)
+			fmt.Println(active_clients, "active clients")
+			// println(rx_packets, "rx packets")
+			// fmt.Printf("%v rx history", rx_history)
 
-			if active_clients == 0 && rx_history[0]+10 > rx_history[9] {
+			if active_clients == 0 && rx_history[0]+min_packet_threshhold > rx_history[len(rx_history)-1] {
 				// count up if we have no active clients
 				// if no clients are active and less than 10 packets recieved in the last 10 seconds
 				inactive_seconds++
-				println(inactive_seconds, "seconds without an active client")
+				fmt.Println(inactive_seconds, "seconds without an active client")
 				if inactive_seconds > inactive_timeout {
 					stop_containers()
 				}
 			}
 		} else {
 			// if more than 10 rx in last 10 seconds, start the container
-			if rx_history[0]+10 < rx_history[9] {
+			if rx_history[0]+min_packet_threshhold < rx_history[len(rx_history)-1] {
 				start_containers()
 			}
 		}
-
-		time.Sleep(time.Second)
+		fmt.Println("//////////////////////////////////////////////////////////////////////////////////")
+		for i := 0; i < poll_rate; i++ {
+			time.Sleep(time.Second)
+		}
 	}
 }
 
@@ -74,7 +102,7 @@ func newContainer(id string, state string) *container {
 
 func get_containers() []container {
 	containers := []container{}
-	out, err := exec.Command("/bin/sh", "-c", "docker ps -a --no-trunc --filter label=\"com.sandman.marker=$LABEL\" --format \"{{.ID}} {{.State}}\"").Output() // todo make this handle multiple ports?
+	out, err := exec.Command("/bin/sh", "-c", "docker ps -a --no-trunc --filter label=\"com.lazytainer.marker=$LABEL\" --format \"{{.ID}} {{.State}}\"").Output() // todo make this handle multiple ports?
 	check(err)
 	fmt.Println(string(out))
 	if strings.TrimSpace(string(out)) == "" {
@@ -98,7 +126,7 @@ func is_container_on() bool {
 }
 
 func stop_containers() {
-	println("stopping container(s)")
+	fmt.Println("stopping container(s)")
 	containers := get_containers()
 	idString := ""
 	for _, c := range containers {
@@ -111,7 +139,7 @@ func stop_containers() {
 }
 
 func start_containers() {
-	println("starting container(s)")
+	fmt.Println("starting container(s)")
 	containers := get_containers()
 	idString := ""
 	for _, c := range containers {
@@ -125,6 +153,17 @@ func start_containers() {
 
 func check(err error) {
 	if err != nil {
-		panic(err)
+		fmt.Println(err)
+		// panic(err)
 	}
 }
+
+func check_env_fetch_recoverable(err error) bool {
+	if err != nil {
+		if strings.Contains(err.Error(), "strconv.Atoi: parsing \"\": invalid syntax") {
+			return true
+		}
+		panic(err)
+	}
+	return false
+}