Converted into a docker container

Dockerfile

@@ -0,0 +1,21 @@
+FROM debian:8
+
+MAINTAINER Joachim Lusiardi
+
+RUN apt-get update;
+RUN apt-get install -y python3-pip
+RUN apt-get install -y nginx
+
+
+ADD nginx.conf /etc/nginx.conf
+ADD start.sh /start.sh
+RUN chmod +x /start.sh
+
+ADD nginx_proxy.py /nginx_proxy.py
+RUN chmod +x /nginx_proxy.py
+RUN pip3 install docker-py
+
+VOLUME ["/keys"]
+EXPOSE 80
+ENTRYPOINT /start.sh
+

nginx.conf

@@ -0,0 +1,18 @@
+worker_processes  1;
+
+events {
+	worker_connections  1024;
+}
+
+http {
+    sendfile        on;
+    keepalive_timeout  65;
+    log_format https_combined '$remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" HTTPS';
+    log_format http_combined '$remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" HTTP';
+
+    include /tmp/nginx/*;
+}
+
+daemon on;
+error_log /dev/stdout info;
+

nginx_proxy.py

@@ -1,27 +1,32 @@
 #!/usr/bin/python3.4
 
-import os
+from docker import Client
-import sys
+from docker.errors import APIError
-import http.client
-import json
-import signal
 from string import Template
+import json
+import datetime
+import signal
+import os
+import logging
+import sys
 
-target_path="/tmp/nginx"
+target_path="/tmp/nginx/"
-pid_file="/run/nginx.pid"
+pid_file="/var/run/nginx.pid"
-non_location_template = """server {
+non_location_template = """# proxy for container '$containername'
+server {
     listen $listen;
     server_name $name;
     location / {
         proxy_set_header X-Real-IP  $$remote_addr;
         proxy_set_header X-Forwarded-For $$remote_addr;
         proxy_set_header Host $$host;
-        proxy_pass http://$ip:$port/;      
+        proxy_pass http://$ip:$port/;
     }
 }
 """
 
-location_template="""server {
+location_template="""# proxy for container '$containername'
+server {
     listen $listen;
     server_name $name;
     location / {
@@ -31,116 +36,124 @@ location_template="""server {
         proxy_set_header X-Real-IP  $$remote_addr;
         proxy_set_header X-Forwarded-For $$remote_addr;
         proxy_set_header Host $$host;
-        proxy_pass http://$ip:$port/;      
+        proxy_pass http://$ip:$port/;
     }
 }
 """
 
-def get_pid():
+def print_json(data):
-    with open(pid_file, 'r') as file:
+    """Prints the given value in JSON to stdout. Use this for debugging only"""
-        return int(file.read())
+    print(json.dumps(data, sort_keys=True, indent=4))
 
-def get_container_data():
+def analyse_env_vars(inspect_data):
-    conn = http.client.HTTPConnection("localhost:2375")
+    """Extracts the environment variables from the given result of an 'inspect
-    conn.request("GET", "/containers/json")
+        container' call."""
-    response = conn.getresponse()
-    data = response.read().decode("UTF-8")
-    data = json.loads(data)
-#    print(json.dumps(data, sort_keys=True, indent=4))
-    conn.close()
-    return data
-
-def inspect_container(container_id):
-    conn = http.client.HTTPConnection("localhost:2375")
-    conn.request("GET", "/containers/"+str(container_id)+"/json")
-    response = conn.getresponse()
-    data = response.read().decode("UTF-8")
-    data = json.loads(data)
-#    print(json.dumps(data, sort_keys=True, indent=4))
-    conn.close()
-    return data
-
-def analyse_env_vars(data):
     env_data = {}
-    for env_var in data:
+    for env_var in inspect_data['Config']['Env']:
         t = env_var.split("=")
         env_data[t[0]] = t[1]
     return env_data
 
 def analyse_proxy_data(data):
+    """Extracts the data for the proxy configuration (envrionment variable
+        'PROXY_DATA' and converts it to a dictionary."""
     proxy_data = {}
-    for proxy_var in data.split(','):
+    for proxy_var in data['PROXY_DATA'].split(','):
         t = proxy_var.split(":",1)
         proxy_data[t[0]] = t[1]
     return proxy_data
 
-def handle_event(event):
+def extract_ip(inspect_data):
-    files = os.listdir(target_path)
+    """extracts the container's ip from the given inspect data"""
-    print('deleting files')
+    return inspect_data['NetworkSettings']['IPAddress']
-    for file in files:
-        if file.startswith('proxy_'):
-            os.remove(target_path+'/'+file)
-    event_data = json.loads(event)
-    containers_data = get_container_data()
-    for container_data in containers_data:
-        inspect_data = inspect_container(container_data['Id'])
-        env_data = analyse_env_vars(inspect_data['Config']['Env'])
-        if 'PROXY_DATA' in env_data:
-            container_id = container_data['Id']
-            ip = inspect_data['NetworkSettings']['IPAddress']
-            proxy_data = analyse_proxy_data(env_data['PROXY_DATA'])
 
-            server_name = ''
+def extract_name(inspect_data):
-            if 'server_name' in proxy_data:
+    """extracts the container's name from the given inspect data"""
-                server_name = proxy_data['server_name']
+    return inspect_data['Name']
-            
-            port = 0
-            if 'port' in proxy_data:
-                port = proxy_data['port']
 
-            location = ''
+def get_if_available(dict, key, defValue):
-            if 'location' in proxy_data:
+    if key in dict:
-                location = proxy_data['location']
+        return dict[key]
+    else:
+        return defValue
 
-            listen ='*:80'
+def handle_container(id):
-            if 'ip' in proxy_data:
+    """This function take a container's id and collects all data required
-                listen = proxy_data['ip']+':80'
+        to create a proper proxy configuration. The configuration is then
+        written to the directory of temporary nginx files"""
+    inspect_data = client.inspect_container(id)
+    env_vars = analyse_env_vars(inspect_data)
+    if 'PROXY_DATA' in env_vars:
+        proxy_data = analyse_proxy_data(env_vars)
+        substitutes = {
+            'containername': extract_name(inspect_data),
+            'ip': extract_ip(inspect_data),
+            'location': get_if_available(proxy_data, 'location', ''),
+            'name': get_if_available(proxy_data, 'server_name', ''),
+            'port': get_if_available(proxy_data, 'port', 80),
+            'listen': get_if_available(proxy_data, 'ip', '*') + ':80'
+        }
+        logging.info('writing to %sproxy_%s', target_path, id)
+        with open(target_path + '/proxy_'+id, 'w') as file:
+            if substitutes['location'] == '':
+                del substitutes['location']
+                file.write(Template(non_location_template).substitute(substitutes))
+            else:
+                file.write(Template(location_template).substitute(substitutes))
 
-            print('writing /tmp/nginx/proxy_'+container_id)
+def reload_nginx_configuration():
-            with open('/tmp/nginx/proxy_'+container_id, 'w') as file:
+    logging.info('HUPing nginx')
-                if location == '':
+    os.kill(pid, signal.SIGHUP)
-                    s = Template(non_location_template)                
-                    file.write(s.substitute(name=server_name,ip=ip,port=port,listen=listen))
-                else:
-                    s = Template(location_template)            
-                    file.write(s.substitute(name=server_name,ip=ip,port=port,listen=listen,location=location))
-            print('HUPing nginx')
-            os.kill(pid, signal.SIGHUP)
 
-if not os.path.exists(target_path):
+def get_pid():
-    os.mkdir(target_path)
+    """This function reads the process id from the given file."""
+    with open(pid_file, 'r') as file:
+        return int(file.read())
 
-pid = get_pid()
+def setup_logging():
+    logging.basicConfig(format='%(asctime)s [%(levelname)s]: %(message)s', level=logging.INFO)
 
-conn = http.client.HTTPConnection("localhost:2375")
+if __name__ == '__main__':
-try:
+    setup_logging()
-	conn.request("GET", "/events")
-except ConnectionRefusedError:
-	print('Docker does not expose events on its REST-API. Perhaps it is not running?')
-	sys.exit(-1)
 
-response = conn.getresponse()
+    # prepare required stuff
+    pid = get_pid()
+    logging.info('nginx pid: %s', str(pid))
+    if not os.path.exists(target_path):
+        logging.info('creating target path: %s', target_path)
+        os.mkdir(target_path)
+
+    client = Client(base_url='unix://var/run/docker.sock', version='1.15')
+
+    # handle all running containers existing at startup of this container
+    container_ids = client.containers(quiet=True)
+    for container_id in container_ids:
+        handle_container(container_id['Id'])
+    reload_nginx_configuration()
+
+    # hook to the events
+    for line in client.events():
+        line_str = line.decode("utf-8")
+        event = json.loads(line_str)
+
+        container_id = event['id']
+        try:
+            inspect_data = client.inspect_container(container_id)
+            ip = extract_ip(inspect_data)
+        except APIError:
+            ip = ''
+
+#        logging.info(event['status'] + " " + ip)
+        if ip == '':
+            logging.info('removing %sproxy_%s', target_path, container_id)
+            if os.path.exists(target_path + 'proxy_' + container_id):
+                os.remove(target_path + 'proxy_' + container_id)
+        else:
+            handle_container(container_id)
+
+        reload_nginx_configuration()
+
+#        event['timestamp'] = datetime.datetime.fromtimestamp(event['time']).strftime('%Y-%m-%d %H:%M:%S');
+#        print_json(event)
 
-events = ""
-while not response.closed:
-    data = response.read(80)
-    if len(data) != 0:
-        events += data.decode("UTF-8")
-        if events.find("{") != -1:
-            open_pos = events.index("{")
-            if events.find("}", open_pos) != -1:
-                close_pos = events.index("}", open_pos)+1
-                handle_event(events[open_pos:close_pos])
-                events = events[close_pos:]
-            
 

start.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+nginx -c /etc/nginx.conf
+/nginx_proxy.py