Link together all the containers in the example app.

experimental/example/client/Dockerfile

@@ -1,6 +1,7 @@
 FROM gliderlabs/alpine
 MAINTAINER Weaveworks Inc <help@weave.works>
 WORKDIR /home/weave
+RUN apk add --update curl
 ADD ./client /home/weave/
 RUN chmod u+x /home/weave/client
 ENTRYPOINT ["/home/weave/client"]

experimental/example/client/client

@@ -1,3 +1,6 @@
 #!/bin/sh
 
-while true; do echo "foo" | nc qotd 4446; sleep 1; done
+while true; do
+	curl http://pyapp:5000/
+	sleep 1
+done

experimental/example/docker-compose.yml

@@ -2,21 +2,25 @@ client:
   build: client
   links:
     - qotd
+    - pyapp
+pyapp:
+  build: pyapp
+  ports:
+    - "5000"
+  links:
+    - qotd
+    - redis
+    - goapp
 qotd:
   build: qotd
   expose:
     - "4446"
-pyapp:
-  build: pyapp
-  ports:
-    - "5000:5000"
-  links:
-    - redis
-    - qotd
 redis:
   image: redis
 goapp:
   build: goapp
+  ports:
+    - "8080"
   links:
     - elasticsearch1
     - elasticsearch2

experimental/example/goapp/app.go

@@ -15,13 +15,11 @@ import (
 	"sync"
 	"sync/atomic"
 	"syscall"
-	"time"
 )
 
 func main() {
 	var (
 		addr = flag.String("addr", ":8080", "HTTP listen address")
-		rate = flag.Duration("rate", 3*time.Second, "request rate")
 	)
 	flag.Parse()
 
@@ -45,7 +43,9 @@ func main() {
 
 	var reads uint64
 
-	http.HandleFunc("/", func(w http.ResponseWriter, _ *http.Request) {
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		log.Printf("Handling %v", r)
+		read(targets, &reads)
 		fmt.Fprintf(w, "%s %d", hostname, atomic.LoadUint64(&reads))
 	})
 
@@ -56,31 +56,24 @@ func main() {
 		errc <- http.ListenAndServe(*addr, nil)
 	}()
 
-	go func() {
-		errc <- read(targets, *rate, &reads)
-	}()
-
 	go func() {
 		errc <- interrupt()
 	}()
 
-	log.Printf("%s", <-errc)
+	log.Printf("%v", <-errc)
 }
 
-func read(targets []string, rate time.Duration, reads *uint64) error {
-	for range time.Tick(rate) {
-		var wg sync.WaitGroup
-		wg.Add(len(targets))
-		for _, target := range targets {
-			go func(target string) {
-				get(target)
-				atomic.AddUint64(reads, 1)
-				wg.Done()
-			}(target)
-		}
-		wg.Wait()
+func read(targets []string, reads *uint64) {
+	var wg sync.WaitGroup
+	wg.Add(len(targets))
+	for _, target := range targets {
+		go func(target string) {
+			get(target)
+			atomic.AddUint64(reads, 1)
+			wg.Done()
+		}(target)
 	}
-	return nil
+	wg.Wait()
 }
 
 func get(target string) {

experimental/example/goapp/entrypoint.sh

@@ -1,2 +1,2 @@
 #!/bin/sh
-/home/weave/app elasticsearch1 elasticsearch2
+exec /home/weave/app elasticsearch1 elasticsearch2

experimental/example/pyapp/Dockerfile

@@ -1,6 +1,7 @@
 FROM python:2.7
 MAINTAINER Weaveworks Inc <help@weave.works>
-ADD . /home/weave
 WORKDIR /home/weave
+ADD requirements.txt /home/weave/
 RUN pip install -r /home/weave/requirements.txt
+ADD app.py /home/weave/
 ENTRYPOINT ["python", "/home/weave/app.py"]

experimental/example/pyapp/app.py

@@ -1,15 +1,41 @@
 import os
-
+import socket
+import requests
+from concurrent.futures import ThreadPoolExecutor
 from flask import Flask
 from redis import Redis
 
 app = Flask(__name__)
 redis = Redis(host='redis', port=6379)
+pool = ThreadPoolExecutor(max_workers=10)
+
+def do_redis():
+  redis.incr('hits')
+  return redis.get('hits')
+
+def do_qotd():
+  s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+  try:
+    s.connect(("qotd", 4446))
+    s.send("Hello")
+    return s.recv(1024)
+  finally:
+    s.close()
+
+def do_search():
+  r = requests.get('http://goapp:8080/')
+  return r.text
+
 
 @app.route('/')
 def hello():
-  redis.incr('hits')
-  return 'Hello World! I have been seen %s times.' % redis.get('hits')
+  counter_future = pool.submit(do_redis)
+  search_future = pool.submit(do_search)
+  qotd_future = pool.submit(do_qotd)
+  result = 'Hello World! I have been seen %s times.' % counter_future.result()
+  result += search_future.result()
+  result += qotd_future.result()
+  return result
 
 if __name__ == "__main__":
   app.run(host="0.0.0.0", debug=True)

experimental/example/pyapp/requirements.txt

@@ -2,4 +2,3 @@ flask
 redis
 requests
 futures
-requests-futures

experimental/example/qotd/qotd.c

@@ -14,11 +14,13 @@ void *thread_func(void *sock) {
 
   printf("I'm thread %d\n", syscall(SYS_gettid));
 
-  if (read(sockfd, buffer, sizeof(buffer), 0) < 0) {
+  if (read(sockfd, buffer, sizeof(buffer)) < 0) {
     perror("ERROR reading from socket");
     return;
   }
 
+  sleep(1);
+
   clientfd = socket(AF_INET, SOCK_STREAM, 0);
   if (clientfd < 0) {
     perror("ERROR opening socket");