Merge branch 'master' of code.nerd2nerd.org:n0ob/docker_nginx_auto_proxy

Dockerfile

@@ -0,0 +1,18 @@
+FROM debian8_python3
+
+MAINTAINER Joachim Lusiardi
+
+RUN apt-get update; \
+    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
+
+EXPOSE 80
+ENTRYPOINT /start.sh
+

README.md

@@ -1,8 +1,22 @@
 # Automated Nginx reverse Proxy for Docker Webservices
+This image attaches to the docker event queue and creates/removes proxy settings in the contained nginx.
 
-## Requirements
+## Starting the container
+The container is started as:
 
-1. installed nginx
+`docker run --name auto_proxy -d -v /var/run/docker.sock:/var/run/docker.sock -p 80:80 docker_nginx_auto_proxy`
-2. adapted nginx configuration
+
-3. docker daemon must be configured to listen to TCP port
+The socket must be handed in so the container can get the events.
-4. existing /tmp/nginx to store proxy files
+
+## How it works
+Containers that should be proxied neet meta information in the environment variable *PROXY_DATA* available.
+This variable must be of the following format:
+
+`PROXY_DATA=server_name:test.com,port:80`
+
+The following options are possible:
+
+* **server_name**(required) the name of the virtual host
+* **port**(optional, defaults to 80) the port on the target container
+* **ip**(optional, defaults to listen on all IPs) the IP on which the proxy should listen. 
+* **location**(optional) if the proxied web application is not running on the /-path

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

@@ -1,15 +1,17 @@
 #!/usr/bin/python3.4
 
-import os
+from docker import Client
-import sys
+from docker.errors import APIError
-import http.client
+from string import Template
 import json
 import signal
-from string import Template
+import os
+import logging
 
-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 / {
@@ -21,7 +23,8 @@ non_location_template = """server {
 }
 """
 
-location_template="""server {
+location_template="""# proxy for container '$containername'
+server {
     listen $listen;
     server_name $name;
     location / {
@@ -36,111 +39,114 @@ location_template="""server {
 }
 """
 
-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
+def get_if_available(dict, key, defValue):
-            if 'port' in proxy_data:
+    if key in dict:
-                port = proxy_data['port']
+        return dict[key]
-
-            location = ''
-            if 'location' in proxy_data:
-                location = proxy_data['location']
-
-            listen ='*:80'
-            if 'ip' in proxy_data:
-                listen = proxy_data['ip']+':80'
-
-            print('writing /tmp/nginx/proxy_'+container_id)
-            with open('/tmp/nginx/proxy_'+container_id, 'w') as file:
-                if location == '':
-                    s = Template(non_location_template)                
-                    file.write(s.substitute(name=server_name,ip=ip,port=port,listen=listen))
     else:
-                    s = Template(location_template)            
+        return defValue
-                    file.write(s.substitute(name=server_name,ip=ip,port=port,listen=listen,location=location))
+
-            print('HUPing nginx')
+def handle_container(id):
+    """This function take a container's id and collects all data required
+        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))
+
+def reload_nginx_configuration():
+    logging.info('HUPing nginx')
     os.kill(pid, signal.SIGHUP)
 
+def get_pid():
+    """This function reads the process id from the given file."""
+    with open(pid_file, 'r') as file:
+        return int(file.read())
+
+def setup_logging():
+    logging.basicConfig(format='%(asctime)s [%(levelname)s]: %(message)s', level=logging.INFO)
+
+if __name__ == '__main__':
+    setup_logging()
+
+    # 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)
 
-pid = get_pid()
+    client = Client(base_url='unix://var/run/docker.sock', version='1.15')
 
-conn = http.client.HTTPConnection("localhost:2375")
+    # 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:
-	conn.request("GET", "/events")
+            inspect_data = client.inspect_container(container_id)
-except ConnectionRefusedError:
+            ip = extract_ip(inspect_data)
-	print('Docker does not expose events on its REST-API. Perhaps it is not running?')
+        except APIError:
-	sys.exit(-1)
+            ip = ''
 
-response = conn.getresponse()
+        if ip == '':
-
+            logging.info('removing %sproxy_%s', target_path, container_id)
-events = ""
+            if os.path.exists(target_path + 'proxy_' + container_id):
-while not response.closed:
+                os.remove(target_path + 'proxy_' + container_id)
-    data = response.read(80)
+        else:
-    if len(data) != 0:
+            handle_container(container_id)
-        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:]
 
+        reload_nginx_configuration()
 

start.sh

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