Enhancements: Upgraded Actions, Improved Logging, Restructured Project (#1)

* update python project use setup tools, and upgrade github action version

* add manual run trigger

* add check not found check

* remove TODO as not possible

* Update doc and add default value of non required config

---------

Co-authored-by: Snigdhajyoti Ghosh <snigdhasjg@users.noreply.github.com>

docker_nsupdate_ddns/default.config.env

@@ -0,0 +1,7 @@
+DOCKER_SOCKET=/var/run/docker.sock
+HOSTNAME_LABEL=nl.mtak.docker-nsupdate-ddns.hostname
+IGNORE_LABEL=nl.mtak.docker-nsupdate-ddns.ignore
+DNS_RECORD_TTL=60
+REFRESH_INTERVAL=60
+ONE_SHOT=False
+DEFAULT_NETWORK=None

docker_nsupdate_ddns/lib/__init__.py

@@ -0,0 +1 @@
+__all__ = ["container", "nsupdate"]

docker_nsupdate_ddns/lib/container.py

@@ -0,0 +1,66 @@
+import logging
+
+import docker
+
+config = {}
+
+LOG = logging.getLogger(__name__)
+
+
+def get_container_name(container):
+    """
+    Get name of container, try in the following order:
+      - Check if hostname_label is set
+      - Fall back to container Name
+    """
+    x = container.attrs['Name'][1:]
+
+    if config['HOSTNAME_LABEL'] in container.attrs['Config']['Labels']:
+        x = container.attrs['Config']['Labels'][config['HOSTNAME_LABEL']]
+
+    x = x.replace("_", "-")  # Be compliant with RFC1035
+    return x
+
+
+def get_container_ip(container):
+    """
+    Get IP of container. Try in the following order
+     - default_network
+     - First found network
+     - Fall back to ['NetworkSettings']['IPAddress']
+    """
+    x = container.attrs['NetworkSettings']['IPAddress']
+
+    if next(iter(container.attrs['NetworkSettings']['Networks'])):
+        network_name = next(
+            iter(container.attrs['NetworkSettings']['Networks']))
+        x = container.attrs['NetworkSettings']['Networks'][network_name]['IPAddress']
+
+    if config['DEFAULT_NETWORK'] in container.attrs['NetworkSettings']['Networks']:
+        x = container.attrs['NetworkSettings']['Networks'][config['DEFAULT_NETWORK']]['IPAddress']
+
+    return x
+
+
+def generate_container_list():
+    client = docker.from_env()
+
+    container_list = client.containers.list()
+    ipam4 = {}
+
+    for container in container_list:
+        if config['IGNORE_LABEL'] in container.attrs['Config']['Labels']:
+            LOG.debug(f"Ignoring container {container.attrs['Name']} as ignore label present")
+            continue
+
+        container_name = get_container_name(container)
+        container_ip = get_container_ip(container)
+        if container_ip:
+            ipam4[container_name] = container_ip
+
+    return ipam4
+
+
+def init(_config):
+    global config
+    config = _config

docker_nsupdate_ddns/lib/nsupdate.py

@@ -0,0 +1,44 @@
+import logging
+
+import dns.update
+import dns.query
+import dns.tsigkeyring
+import ipaddress
+
+config = {}
+
+LOG = logging.getLogger(__name__)
+
+
+def add_records(records):
+    keyring = dns.tsigkeyring.from_text({config['TSIG_NAME']: config['TSIG_KEY']})
+
+    for hostname, ip in records.items():
+        LOG.info(f"Adding record for {hostname}({ip})")
+
+        rrtype = "A"
+        address = ipaddress.ip_address(ip)
+        if isinstance(address, ipaddress.IPv4Address):
+            rrtype = "A"
+        if isinstance(address, ipaddress.IPv6Address):
+            rrtype = "AAAA"
+
+        update = dns.update.Update(config['DOMAIN'], keyring=keyring)
+        update.add(hostname, int(config['DNS_RECORD_TTL']), rrtype, ip)
+        dns.query.tcp(update, config['NAMESERVER'], timeout=2)
+
+
+def delete_records(records):
+    keyring = dns.tsigkeyring.from_text({config['TSIG_NAME']: config['TSIG_KEY']})
+
+    for hostname, ip in records.items():
+        LOG.info(f"Deleting record for {hostname}({ip})")
+
+        update = dns.update.Update(config['DOMAIN'], keyring=keyring)
+        update.delete(hostname)
+        dns.query.tcp(update, config['NAMESERVER'], timeout=2)
+
+
+def init(_config):
+    global config
+    config = _config

docker_nsupdate_ddns/main.py

@@ -0,0 +1,105 @@
+import os
+import stat
+import sys
+from dotenv import dotenv_values
+import time
+
+from docker_nsupdate_ddns.lib import *
+import logging
+
+config = {}
+ipam4_old = {}
+
+logging.basicConfig(level=logging.INFO, format='%(asctime)s %(name)s [%(levelname)s] %(message)s')
+LOG = logging.getLogger(__name__)
+
+
+def main():
+    global config
+    config = get_config()
+    check_required_vars(config)
+
+    if not eval(config['ONE_SHOT']):
+        while True:
+            loop()
+            time.sleep(int(config['REFRESH_INTERVAL']))
+
+    loop()
+    LOG.info("Ending the process as ONE_SHOT is True")
+
+
+def check_required_vars(_config):
+    # Check for all required config
+    required_vars = [
+        'DOMAIN',
+        'NAMESERVER',
+        'TSIG_NAME',
+        'DOCKER_SOCKET',
+        'HOSTNAME_LABEL',
+        'IGNORE_LABEL',
+        'DNS_RECORD_TTL',
+        'DEFAULT_NETWORK',
+        'REFRESH_INTERVAL',
+        'ONE_SHOT'
+    ]
+    missing_vars = []
+    for item in required_vars:
+        if item in _config:
+            LOG.info(f"Detected config value: {item}={_config[item]}")
+        else:
+            missing_vars.append(item)
+    if 'TSIG_KEY' not in _config:
+        # Don't log it as it's a secret
+        missing_vars.append('TSIG_KEY')
+    if len(missing_vars) > 1:
+        LOG.error(f"Missing required config: {', '.join(missing_vars)}")
+        exit(1)
+
+    # Check if docker socket is correct
+    try:
+        if not stat.S_ISSOCK(os.stat(_config['DOCKER_SOCKET']).st_mode):
+            LOG.error(f"{_config['DOCKER_SOCKET']} not a docker socket file, exiting...")
+            exit(1)
+    except Exception as e:
+        LOG.error(f"Docker socket {_config['DOCKER_SOCKET']} not found.", e)
+        raise e
+
+
+def loop():
+    container.init(config)
+    ipam4 = container.generate_container_list()
+    global ipam4_old
+
+    additions4 = determine_additions(ipam4, ipam4_old)
+    deletions4 = determine_deletions(ipam4, ipam4_old)
+
+    nsupdate.init(config)
+    nsupdate.delete_records(deletions4)
+    nsupdate.add_records(additions4)
+
+    ipam4_old = ipam4
+
+
+def get_config():
+    config_file = sys.argv[1] if len(sys.argv) >= 2 else 'config.env'
+
+    x = {
+        **dotenv_values(os.path.join(os.path.dirname(__file__), 'default.config.env')),
+        **dotenv_values(os.path.join(os.getcwd(), config_file)),
+        **os.environ
+    }
+
+    return x
+
+
+def determine_additions(ipam, ipam_old):
+    return {k: v for k, v in ipam.items() if k not in ipam_old}
+
+
+def determine_deletions(ipam, ipam_old):
+    return {k: v for k, v in ipam_old.items() if k not in ipam}
+    pass
+
+
+if __name__ == "__main__":
+    main()