setup auto airprint avahi services generating when adding a new printer

Dockerfile

@@ -30,6 +30,8 @@ RUN apt-get update -qq  && apt-get upgrade -qqy \
     hp-ppd \
     hplip \
     avahi-daemon \
+    inotify-tools \
+    python3-cups \
     && apt-get clean \
     && rm -rf /var/lib/apt/lists/*
 
@@ -43,13 +45,15 @@ RUN sed -i 's/Listen localhost:631/Listen 0.0.0.0:631/' /etc/cups/cupsd.conf &&
     sed -i 's/<Location \/admin>/<Location \/admin>\n  Allow All\n  Require user @SYSTEM/' /etc/cups/cupsd.conf && \
     sed -i 's/<Location \/admin\/conf>/<Location \/admin\/conf>\n  Allow All/' /etc/cups/cupsd.conf && \
     echo "ServerAlias *" >> /etc/cups/cupsd.conf && \
-    echo "DefaultEncryption Never" >> /etc/cups/cupsd.conf
+    echo "DefaultEncryption Never" >> /etc/cups/cupsd.conf && \
+    sed -i 's/#enable-dbus=yes/enable-dbus=no/' /etc/avahi/avahi-daemon.conf
 
 # back up cups configs in case used does not add their own
 RUN cp -rp /etc/cups /etc/cups-bak
 VOLUME [ "/etc/cups" ]
+VOLUME [ "/etc/avahi/services" ]
 
-COPY entrypoint.sh /
-RUN chmod +x /entrypoint.sh
+COPY entrypoint.sh airprint-generate.py printer-update.sh /
+RUN chmod +x /entrypoint.sh /airprint-generate.py /printer-update.sh
 
 CMD ["/entrypoint.sh"]

airprint-generate.py

@@ -0,0 +1,279 @@
+#!/usr/bin/env python3
+
+"""
+Copyright (c) 2010 Timothy J Fontaine <tjfontaine@atxconsulting.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+"""
+
+import cups, os, optparse, re
+import urllib.parse as urlparse
+import os.path
+from io import StringIO
+
+from xml.dom.minidom import parseString
+from xml.dom import minidom
+
+import sys
+
+try:
+    import lxml.etree as etree
+    from lxml.etree import Element, ElementTree, tostring
+except:
+    try:
+        from xml.etree.ElementTree import Element, ElementTree, tostring
+        etree = None
+    except:
+        try:
+            from elementtree import Element, ElementTree, tostring
+            etree = None
+        except:
+            print('Failed to find python libxml or elementtree, please install one of those or use python >= 2.5')
+            raise
+
+XML_TEMPLATE = """<!DOCTYPE service-group SYSTEM "avahi-service.dtd">
+<service-group>
+<name replace-wildcards="yes"></name>
+<service>
+	<type>_ipp._tcp</type>
+	<subtype>_universal._sub._ipp._tcp</subtype>
+	<port>631</port>
+	<txt-record>txtvers=1</txt-record>
+	<txt-record>qtotal=1</txt-record>
+	<txt-record>Transparent=T</txt-record>
+	<txt-record>URF=none</txt-record>
+</service>
+</service-group>"""
+
+#TODO XXX FIXME
+#<txt-record>ty=AirPrint Ricoh Aficio MP 6000</txt-record>
+#<txt-record>Binary=T</txt-record>
+#<txt-record>Duplex=T</txt-record>
+#<txt-record>Copies=T</txt-record>
+
+
+DOCUMENT_TYPES = {
+    # These content-types will be at the front of the list
+    'application/pdf': True,
+    'application/postscript': True,
+    'application/vnd.cups-raster': True,
+    'application/octet-stream': True,
+    'image/urf': True,
+    'image/png': True,
+    'image/tiff': True,
+    'image/png': True,
+    'image/jpeg': True,
+    'image/gif': True,
+    'text/plain': True,
+    'text/html': True,
+
+    # These content-types will never be reported
+    'image/x-xwindowdump': False,
+    'image/x-xpixmap': False,
+    'image/x-xbitmap': False,
+    'image/x-sun-raster': False,
+    'image/x-sgi-rgb': False,
+    'image/x-portable-pixmap': False,
+    'image/x-portable-graymap': False,
+    'image/x-portable-bitmap': False,
+    'image/x-portable-anymap': False,
+    'application/x-shell': False,
+    'application/x-perl': False,
+    'application/x-csource': False,
+    'application/x-cshell': False,
+}
+
+class AirPrintGenerate(object):
+    def __init__(self, host=None, user=None, port=None, verbose=False,
+        directory=None, prefix='AirPrint-', adminurl=False):
+        self.host = host
+        self.user = user
+        self.port = port
+        self.verbose = verbose
+        self.directory = directory
+        self.prefix = prefix
+        self.adminurl = adminurl
+
+        if self.user:
+            cups.setUser(self.user)
+
+    def generate(self):
+        if not self.host:
+            conn = cups.Connection()
+        else:
+            if not self.port:
+                self.port = 631
+            conn = cups.Connection(self.host, self.port)
+
+        printers = conn.getPrinters()
+
+        for p, v in list(printers.items()):
+            if v['printer-is-shared']:
+                attrs = conn.getPrinterAttributes(p)
+                uri = urlparse.urlparse(v['printer-uri-supported'])
+
+                tree = ElementTree()
+                tree.parse(StringIO(XML_TEMPLATE.replace('\n', '').replace('\r', '').replace('\t', '')))
+
+                name = tree.find('name')
+                name.text = 'AirPrint %s @ %%h' % (p)
+
+                service = tree.find('service')
+
+                port = service.find('port')
+                port_no = None
+                if hasattr(uri, 'port'):
+                  port_no = uri.port
+                if not port_no:
+                    port_no = self.port
+                if not port_no:
+                    port_no = cups.getPort()
+                port.text = '%d' % port_no
+
+                if hasattr(uri, 'path'):
+                  rp = uri.path
+                else:
+                  rp = uri[2]
+
+                re_match = re.match(r'^//(.*):(\d+)(/.*)', rp)
+                if re_match:
+                  rp = re_match.group(3)
+
+                #Remove leading slashes from path
+                #TODO XXX FIXME I'm worried this will match broken urlparse
+                #results as well (for instance if they don't include a port)
+                #the xml would be malform'd either way
+                rp = re.sub(r'^/+', '', rp)
+
+                path = Element('txt-record')
+                path.text = 'rp=%s' % (rp)
+                service.append(path)
+
+                desc = Element('txt-record')
+                desc.text = 'note=%s' % (v['printer-info'])
+                service.append(desc)
+
+                product = Element('txt-record')
+                product.text = 'product=(GPL Ghostscript)'
+                service.append(product)
+
+                state = Element('txt-record')
+                state.text = 'printer-state=%s' % (v['printer-state'])
+                service.append(state)
+
+                ptype = Element('txt-record')
+                ptype.text = 'printer-type=%s' % (hex(v['printer-type']))
+                service.append(ptype)
+
+                pdl = Element('txt-record')
+                fmts = []
+                defer = []
+
+                for a in attrs['document-format-supported']:
+                    if a in DOCUMENT_TYPES:
+                        if DOCUMENT_TYPES[a]:
+                            fmts.append(a)
+                    else:
+                        defer.append(a)
+
+                if 'image/urf' not in fmts:
+                    sys.stderr.write('image/urf is not in mime types, %s may not be available on ios6 (see https://github.com/tjfontaine/airprint-generate/issues/5)%s' % (p, os.linesep))
+
+                fmts = ','.join(fmts+defer)
+
+                dropped = []
+
+                # TODO XXX FIXME all fields should be checked for 255 limit
+                while len('pdl=%s' % (fmts)) >= 255:
+                    (fmts, drop) = fmts.rsplit(',', 1)
+                    dropped.append(drop)
+
+                if len(dropped) and self.verbose:
+                    sys.stderr.write('%s Losing support for: %s%s' % (p, ','.join(dropped), os.linesep))
+
+                pdl.text = 'pdl=%s' % (fmts)
+                service.append(pdl)
+
+                if self.adminurl:
+                    admin = Element('txt-record')
+                    admin.text = 'adminurl=%s' % (v['printer-uri-supported'])
+                    service.append(admin)
+
+                fname = '%s%s.service' % (self.prefix, p)
+
+                if self.directory:
+                    fname = os.path.join(self.directory, fname)
+
+                f = open(fname, 'w')
+
+                if etree:
+                    tree.write(f, pretty_print=True, xml_declaration=True, encoding="UTF-8")
+                else:
+                    xmlstr = tostring(tree.getroot())
+                    doc = parseString(xmlstr)
+                    dt= minidom.getDOMImplementation('').createDocumentType('service-group', None, 'avahi-service.dtd')
+                    doc.insertBefore(dt, doc.documentElement)
+                    doc.writexml(f)
+                f.close()
+
+                if self.verbose:
+                    sys.stderr.write('Created: %s%s' % (fname, os.linesep))
+
+if __name__ == '__main__':
+    parser = optparse.OptionParser()
+    parser.add_option('-H', '--host', action="store", type="string",
+        dest='hostname', help='Hostname of CUPS server (optional)', metavar='HOSTNAME')
+    parser.add_option('-P', '--port', action="store", type="int",
+        dest='port', help='Port number of CUPS server', metavar='PORT')
+    parser.add_option('-u', '--user', action="store", type="string",
+        dest='username', help='Username to authenticate with against CUPS',
+        metavar='USER')
+    parser.add_option('-d', '--directory', action="store", type="string",
+        dest='directory', help='Directory to create service files',
+        metavar='DIRECTORY')
+    parser.add_option('-v', '--verbose', action="store_true", dest="verbose",
+        help="Print debugging information to STDERR")
+    parser.add_option('-p', '--prefix', action="store", type="string",
+        dest='prefix', help='Prefix all files with this string', metavar='PREFIX',
+        default='AirPrint-')
+    parser.add_option('-a', '--admin', action="store_true", dest="adminurl",
+        help="Include the printer specified uri as the adminurl")
+
+    (options, args) = parser.parse_args()
+
+    # TODO XXX FIXME -- if cups login required, need to add
+    # air=username,password
+    from getpass import getpass
+    cups.setPasswordCB(getpass)
+
+    if options.directory:
+        if not os.path.exists(options.directory):
+            os.mkdir(options.directory)
+
+    apg = AirPrintGenerate(
+        user=options.username,
+        host=options.hostname,
+        port=options.port,
+        verbose=options.verbose,
+        directory=options.directory,
+        prefix=options.prefix,
+        adminurl=options.adminurl,
+    )
+
+    apg.generate()

entrypoint.sh

@@ -16,4 +16,7 @@ if [ ! -f /etc/cups/cupsd.conf ]; then
     cp -rpn /etc/cups-bak/* /etc/cups/
 fi
 
+/printer-update.sh &
+avahi-daemon &
 exec /usr/sbin/cupsd -f
+

printer-update.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+inotifywait -m -e close_write,moved_to,create /etc/cups | 
+while read -r directory events filename; do
+	if [ "$filename" = "printers.conf" ]; then
+		rm -rf /etc/avahi/services/AirPrint-*.service
+		/airprint-generate.py -d /etc/avahi/services
+		cp /etc/cups/printers.conf /config/printers.conf
+	fi
+done