Migrate to unified data storage and generation script

genconfig.py

@@ -0,0 +1,152 @@
+#!/usr/bin/env python
+
+import os
+from textwrap import dedent
+from optparse import OptionParser
+from socket import AF_INET, AF_INET6, inet_pton
+
+class Formatter(object):
+    """
+    Abstract class to define the interface for formatters.
+    """
+
+    def __init__(self):
+        """
+        Initialize formatter, maybe generate a preamble for the config
+        """
+        self.config = []
+        self.add_comment(dedent(
+            """
+            This file is automatically generated by the ffdns generator.
+            Don't edit it manually! Instead, send pull requests to
+            https://github.com/freifunkhamburg/ffdns
+            and re-generate it using the genconfig.py there!
+            """
+        ))
+
+    def add_comment(self, comment):
+        """
+        Add a comment to the config. Default is prefixed with #
+        """
+        self.config.append("# " + "\n# ".join(comment.split("\n")))
+
+    def add_data(self, domains, servers):
+        """
+        Add config directives so that every domain in domains is forwarded to
+        every server in servers.
+        """
+        raise NotImplementedError()
+
+    def finalize(self):
+        """
+        Finalize configuration and return it
+        """
+        return "\n".join(self.config)
+
+class DnsmasqFormatter(Formatter):
+    "Formatter for dnsmasq"
+    def add_data(self, domains, servers):
+        for domain in domains:
+            for server in servers:
+                self.config.append("server=/%s/%s" % (domain, server))
+
+class BindFormatter(Formatter):
+    "Formatter for bind9 (>=9.8) using type static-stub"
+    def add_data(self, domains, servers):
+        for domain in domains:
+            self.config.append(dedent("""
+                zone "%s" {
+                    type static-stub;
+                    server-addresses { %s; };
+                };
+            """ % (domain, "; ".join(servers))).lstrip())
+
+class BindForwardFormatter(Formatter):
+    "Formatter for bind9 using type forward"
+    def add_data(self, domains, servers):
+        for domain in domains:
+            self.config.append(dedent("""
+                zone "%s" {
+                    type forward;
+                    forwarders { %s; };
+                    forward only;
+                };
+            """ % (domain, "; ".join(servers))).lstrip())
+
+def create_config(srcdir, fmtclass, exclude=None, filters=[]):
+    """
+    Generates a configuration using all files in srcdir (non-recursively)
+    except those in the iterable exclude.
+
+    The files are read in lexicographic order to produce deterministic results.
+
+    Every option=value pair in the files is passed through all callables in the
+    iterable filters. Only if none return False, it is assumed valid.
+    """
+    COMMENT_CHAR = "#"
+    OPTION_CHAR = "="
+    formatter = fmtclass()
+    for fname in sorted(list(set(os.listdir(srcdir)) - set(exclude))):
+        fpath = os.path.join(srcdir, fname)
+        if os.path.isfile(fpath):
+            domains = []
+            servers = []
+
+            with file(fpath) as f:
+                formatter.add_comment("\n%s\n" % fname)
+                for line in f:
+                    if COMMENT_CHAR in line:
+                        line, comment = line.split(COMMENT_CHAR, 1)
+                        comment = comment.strip()
+                        if comment:
+                            formatter.add_comment(comment)
+                    if OPTION_CHAR in line:
+                        option, value = line.split(OPTION_CHAR, 1)
+                        option = option.strip()
+                        value = value.strip()
+                        if not all(filt(option, value) for filt in filters):
+                            continue
+                        if option == "server":
+                            servers.append(value)
+                        elif option == "domain":
+                            domains.append(value)
+                        else:
+                            raise RuntimeError("Unknown option '%s' in file '%s'" % (option, fpath))
+                    elif line.strip():
+                        raise RuntimeError("Unrecognized line '%s' in file '%s'" % (line, fpath))
+
+            if not domains:
+                formatter.add_comment("No valid domains found")
+            elif not servers:
+                formatter.add_comment("No valid servers found")
+            else:
+                formatter.add_data(domains, servers)
+
+    print(formatter.finalize())
+
+if __name__ == "__main__":
+    def try_inet_pton(af, ip):
+        try:
+            inet_pton(af, ip)
+            return True
+        except:
+            return False
+
+    formatters = {
+        "dnsmasq": DnsmasqFormatter,
+        "bind": BindFormatter,
+        "bind-forward": BindForwardFormatter,
+    }
+    filters = {
+        "v4": lambda option, value: option != "server" or try_inet_pton(AF_INET, value),
+        "v6": lambda option, value: option != "server" or try_inet_pton(AF_INET6, value),
+    }
+    parser = OptionParser()
+    parser.add_option("-f", "--format", dest="fmt", help="Create config in format FMT. Possible values: %s. Default: dnsmasq" % ", ".join(formatters.keys()), metavar="FMT", choices=formatters.keys(), default="dnsmasq")
+    parser.add_option("-s", "--sourcedir", dest="src", help="Use files in DIR as input files. Default: data/", metavar="DIR", default="data")
+    parser.add_option("-x", "--exclude", dest="exclude", help="Exclude the comma-separated list of FILES in the sourcedir from the generation", metavar="FILES", default="")
+    parser.add_option("--filter", dest="filter", help="Only include certain servers. Possible choices: %s" % ", ".join(filters.keys()), choices=filters.keys())
+
+    (options, args) = parser.parse_args()
+
+    create_config(options.src, formatters[options.fmt], options.exclude.split(","), [filters[options.filter]] if options.filter else [])