Update to python3

18 files changed, 109 insertions, 106 deletions

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 28c664c..f2e6051 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -2,12 +2,15 @@ image: debian:stretch
 
 before_script:
   - apt-get update -y
-  - apt-get install -y -qq python-dev python-pip
+  - apt-get install -y -qq python3-dev python3-pip
   # Deps for running tests
   - apt-get install -y -qq cmdtest curl git
   # Deps for lorry-controller
-  - apt-get install -y -qq python-bottle python-flup python-requests
-  - pip install yoyo-migrations
+  - apt-get install -y -qq python3-bottle python3-requests
+  - pip3 install flup
+  - pip3 install yoyo-migrations
+  - pip3 install pyyaml
+  - pip3 install https://gitlab.com/trovekube/cliapp/-/archive/cliapp-1.20180812.1/cliapp-cliapp-1.20180812.1.tar.gz
 run-check:
   script:
   - sh check
diff --git a/lorry-controller-minion b/lorry-controller-minion
index 459130e..6e2affd 100755
--- a/lorry-controller-minion
+++ b/lorry-controller-minion
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Copyright (C) 2014-2019  Codethink Limited
 #
@@ -17,7 +17,7 @@
 
 
 import fcntl
-import httplib
+import http.client
 import json
 import logging
 import os
@@ -28,7 +28,7 @@ import signal
 import subprocess
 import tempfile
 import time
-import urllib
+import urllib.parse
 
 import cliapp
 
@@ -115,7 +115,7 @@ class MINION(cliapp.Application):
 
         logging.debug('Requesting job from WEBAPP (%s:%s)', host, port)
 
-        params = urllib.urlencode({
+        params = urllib.parse.urlencode({
                 'host': platform.node(),
                 'pid': os.getpid(),
                 })
@@ -159,7 +159,7 @@ class MINION(cliapp.Application):
             job_spec['path'])
 
         fd, self.temp_lorry_filename = tempfile.mkstemp()
-        os.write(fd, job_spec['text'])
+        os.write(fd, job_spec['text'].encode('utf-8'))
         os.close(fd)
 
 
@@ -237,7 +237,7 @@ class MINION(cliapp.Application):
         else:
             disk_usage = self.get_lorry_disk_usage(job_spec)
 
-        params = urllib.urlencode({
+        params = urllib.parse.urlencode({
                 'job_id': job_spec['job_id'],
                 'exit': 'no' if exit is None else exit,
                 'stdout': stdout,
@@ -262,7 +262,7 @@ class MINION(cliapp.Application):
         host = self.settings['webapp-host']
         port = int(self.settings['webapp-port'])
         timeout = self.settings['webapp-timeout']
-        conn = httplib.HTTPConnection(host, port=port, timeout=timeout)
+        conn = http.client.HTTPConnection(host, port=port, timeout=timeout)
 
         headers = {}
         if body:
@@ -274,7 +274,7 @@ class MINION(cliapp.Application):
         response_body = response.read()
         conn.close()
 
-        if response.status != httplib.OK:
+        if response.status != http.client.OK:
             raise WEBAPPError(response.status, response.reason, response_body)
 
         return response_body
diff --git a/lorry-controller-remove-old-jobs b/lorry-controller-remove-old-jobs
index 2a54a30..fcd8b38 100755
--- a/lorry-controller-remove-old-jobs
+++ b/lorry-controller-remove-old-jobs
@@ -1,6 +1,6 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
-# Copyright (C) 2014  Codethink Limited
+# Copyright (C) 2014-2019  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -19,8 +19,7 @@
 import json
 import logging
 import time
-import urllib2
-import urlparse
+import urllib.request, urllib.error, urllib.parse
 import contextlib
 
 import cliapp
@@ -78,12 +77,12 @@ class OldJobRemover(cliapp.Application):
 
     def list_jobs(self):
         data = self.get('/1.0/list-jobs')
-        obj = json.loads(data)
+        obj = json.loads(data.decode('utf-8'))
         return obj['job_ids']
 
     def get(self, path):
         url = self.make_url(path)
-        with contextlib.closing(urllib2.urlopen(url)) as f:
+        with urllib.request.urlopen(url) as f:
             return f.read()
 
     def make_url(self, path):
@@ -93,14 +92,14 @@ class OldJobRemover(cliapp.Application):
         query = None
         fragment = None
         parts = (scheme, netloc, path, query, fragment)
-        return urlparse.urlunsplit(parts)
+        return urllib.parse.urlunsplit(parts)
 
     def get_job_infos(self, job_ids):
         job_infos = []
         for job_id in job_ids:
             try:
                 job_infos.append(self.get_job_info(job_id))
-            except urllib2.HTTPError as e:
+            except urllib.error.HTTPError as e:
                 logging.warning(
                     'Trouble getting job info for job %s: %s' %
                     (job_id, str(e)))
@@ -108,7 +107,7 @@ class OldJobRemover(cliapp.Application):
 
     def get_job_info(self, job_id):
         data = self.get('/1.0/job/%s' % job_id)
-        obj = json.loads(data)
+        obj = json.loads(data.decode('utf-8'))
         exit_code = obj['exit']
         if obj['job_ended']:
             exit_timestamp = self.parse_timestamp(obj['job_ended'])
@@ -144,9 +143,8 @@ class OldJobRemover(cliapp.Application):
 
     def post(self, path, data):
         url = self.make_url(path)
-        f = urllib2.urlopen(url, data)
-        result = f.read()
-        f.close()
+        with urllib.request.urlopen(url, data.encode('utf-8')) as f:
+            result = f.read()
 
 
 OldJobRemover().run()
diff --git a/lorry-controller-webapp b/lorry-controller-webapp
index 18b28a9..c73333a 100755
--- a/lorry-controller-webapp
+++ b/lorry-controller-webapp
@@ -1,6 +1,6 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
-# Copyright (C) 2014-2017  Codethink Limited
+# Copyright (C) 2014-2019  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -235,7 +235,8 @@ class WEBAPP(cliapp.Application):
 
             '''
 
-            def __init__(self, (host, port), *args, **kwargs):
+            def __init__(self, server_address, *args, **kwargs):
+                (host, port) = server_address
                 wsgiref.simple_server.WSGIServer.__init__(
                     self, (host, 0), *args, **kwargs)
                 with open(server_port_file, 'w') as f:
diff --git a/lorrycontroller/__init__.py b/lorrycontroller/__init__.py
index 72696fa..c5bf0ad 100644
--- a/lorrycontroller/__init__.py
+++ b/lorrycontroller/__init__.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2014-2016  Codethink Limited
+# Copyright (C) 2014-2019  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -14,38 +14,38 @@
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
 
-from statedb import (
+from .statedb import (
     StateDB,
     LorryNotFoundError,
     WrongNumberLorriesRunningJob,
     TroveNotFoundError)
-from route import LorryControllerRoute
-from readconf import ReadConfiguration
-from status import Status, StatusHTML, StatusRenderer
-from listqueue import ListQueue
-from showlorry import ShowLorry, ShowLorryHTML
-from startstopqueue import StartQueue, StopQueue
-from givemejob import GiveMeJob
-from jobupdate import JobUpdate
-from listrunningjobs import ListRunningJobs
-from movetopbottom import MoveToTop, MoveToBottom
-from stopjob import StopJob
-from listjobs import ListAllJobs, ListAllJobsHTML
-from showjob import ShowJob, ShowJobHTML, JobShower
-from removeghostjobs import RemoveGhostJobs
-from removejob import RemoveJob
-from lstroves import LsTroves, ForceLsTrove
-from pretendtime import PretendTime
-from maxjobs import GetMaxJobs, SetMaxJobs
-from gitano import (
+from .route import LorryControllerRoute
+from .readconf import ReadConfiguration
+from .status import Status, StatusHTML, StatusRenderer
+from .listqueue import ListQueue
+from .showlorry import ShowLorry, ShowLorryHTML
+from .startstopqueue import StartQueue, StopQueue
+from .givemejob import GiveMeJob
+from .jobupdate import JobUpdate
+from .listrunningjobs import ListRunningJobs
+from .movetopbottom import MoveToTop, MoveToBottom
+from .stopjob import StopJob
+from .listjobs import ListAllJobs, ListAllJobsHTML
+from .showjob import ShowJob, ShowJobHTML, JobShower
+from .removeghostjobs import RemoveGhostJobs
+from .removejob import RemoveJob
+from .lstroves import LsTroves, ForceLsTrove
+from .pretendtime import PretendTime
+from .maxjobs import GetMaxJobs, SetMaxJobs
+from .gitano import (
     GitanoCommand,
     LocalTroveGitanoCommand,
     GitanoCommandFailure,
     new_gitano_command)
-from static import StaticFile
-from proxy import setup_proxy
-from gerrit import Gerrit
-from gitlab import Gitlab
+from .static import StaticFile
+from .proxy import setup_proxy
+from .gerrit import Gerrit
+from .gitlab import Gitlab
 
 
 __all__ = locals()
diff --git a/lorrycontroller/gitano.py b/lorrycontroller/gitano.py
index c0cca05..d0d1a0c 100644
--- a/lorrycontroller/gitano.py
+++ b/lorrycontroller/gitano.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2014  Codethink Limited
+# Copyright (C) 2014-2019  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -17,8 +17,8 @@
 import collections
 import logging
 import re
-import urllib2
-import urlparse
+import urllib.request, urllib.error, urllib.parse
+import urllib.parse
 
 import cliapp
 import requests
@@ -104,8 +104,8 @@ class GitanoCommand(object):
         return stdout
 
     def _http_command(self, gitano_args):
-        quoted_args = urllib2.quote(' '.join(gitano_args))
-        url = urlparse.urlunsplit((
+        quoted_args = urllib.parse.quote(' '.join(gitano_args))
+        url = urllib.parse.urlunsplit((
             self.protocol,
             self.trovehost,
             '/gitano-command.cgi',
diff --git a/lorrycontroller/gitlab.py b/lorrycontroller/gitlab.py
index a426b0d..6938cae 100644
--- a/lorrycontroller/gitlab.py
+++ b/lorrycontroller/gitlab.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2016  Codethink Limited
+# Copyright (C) 2016-2019  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -13,9 +13,9 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
-from __future__ import absolute_import
+
 import re
-import urlparse
+import urllib.parse
 import itertools
 try:
     import gitlab
@@ -46,7 +46,7 @@ class Gitlab(object):
                 '\tpython-gitlab is required with GitLab as the git server')
 
     def first(self, predicate, iterable):
-        return next(itertools.ifilter(predicate, iterable))
+        return next(filter(predicate, iterable))
 
     def split_and_unslashify_path(self, path):
         group, project = path.split('/', 1)
@@ -137,6 +137,6 @@ class Gitlab(object):
         if protocol == 'ssh':
             return project.ssh_url_to_repo
         elif protocol in ('http', 'https'):
-            split = urlparse.urlsplit(project.http_url_to_repo)
-            return urlparse.urlunsplit((
+            split = urllib.parse.urlsplit(project.http_url_to_repo)
+            return urllib.parse.urlunsplit((
                 protocol, split.netloc, split.path, '', ''))
diff --git a/lorrycontroller/lstroves.py b/lorrycontroller/lstroves.py
index 456359c..34648cb 100644
--- a/lorrycontroller/lstroves.py
+++ b/lorrycontroller/lstroves.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2014-2016  Codethink Limited
+# Copyright (C) 2014-2019  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -126,7 +126,7 @@ class TroveRepositoryLister(object):
 
     def update_lorries_for_trove(self, statedb, trove_info, repo_map):
         trovehost = trove_info['trovehost']
-        for remote_path, local_path in repo_map.items():
+        for remote_path, local_path in list(repo_map.items()):
             lorry = self.construct_lorry(trove_info, local_path, remote_path)
             statedb.add_to_lorries(
                 path=local_path,
diff --git a/lorrycontroller/proxy.py b/lorrycontroller/proxy.py
index b9e75b8..5eea4f1 100644
--- a/lorrycontroller/proxy.py
+++ b/lorrycontroller/proxy.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2014  Codethink Limited
+# Copyright (C) 2014-2019  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -16,13 +16,13 @@
 
 import json
 import os
-import urllib
+import urllib.request, urllib.parse, urllib.error
 
 
 def build_proxy_url(protocol, proxy_config):
     """Build a proxy URL from data in our proxy configuration format."""
 
-    hostname = urllib.quote(proxy_config['hostname'])
+    hostname = urllib.parse.quote(proxy_config['hostname'])
     url = '%s:%s' % (hostname, proxy_config['port'])
 
     if 'username' not in proxy_config:
diff --git a/lorrycontroller/readconf.py b/lorrycontroller/readconf.py
index 162e116..a8949c1 100644
--- a/lorrycontroller/readconf.py
+++ b/lorrycontroller/readconf.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2014-2016  Codethink Limited
+# Copyright (C) 2014-2019  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -394,7 +394,7 @@ class LorryControllerConfValidator(object):
     def _check_is_list_of_strings(self, section, field):
         obj = section[field]
         if not isinstance(obj, list) or not all(
-                isinstance(s, basestring) for s in obj):
+                isinstance(s, str) for s in obj):
             raise ValidationError(
                 '%s field in %r must be a list of strings' %
                 (field, section))
diff --git a/lorrycontroller/showlorry.py b/lorrycontroller/showlorry.py
index d54073a..b553b9c 100644
--- a/lorrycontroller/showlorry.py
+++ b/lorrycontroller/showlorry.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2014  Codethink Limited
+# Copyright (C) 2014-2019  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -17,7 +17,7 @@
 import json
 import logging
 import time
-import urlparse
+import urllib.parse
 
 import bottle
 
@@ -65,7 +65,7 @@ class ShowLorryHTML(ShowLorryBase, lorrycontroller.LorryControllerRoute):
         renderer = lorrycontroller.StatusRenderer()
         shower = lorrycontroller.JobShower()
 
-        lorry_obj = json.loads(lorry_info['text']).values()[0]
+        lorry_obj = list(json.loads(lorry_info['text']).values())[0]
         lorry_info['url'] = lorry_obj['url']
 
         lorry_info['interval_nice'] = renderer.format_secs_nicely(
@@ -85,9 +85,9 @@ class ShowLorryHTML(ShowLorryBase, lorrycontroller.LorryControllerRoute):
 
         timestamp = time.strftime('%Y-%m-%d %H:%M:%S UTC', time.gmtime(now))
 
-        parts = urlparse.urlparse(bottle.request.url)
+        parts = urllib.parse.urlparse(bottle.request.url)
         host, port = parts.netloc.split(':', 1)
-        http_server_root = urlparse.urlunparse(
+        http_server_root = urllib.parse.urlunparse(
             (parts.scheme, host, '', '', '', ''))
 
         return bottle.template(
diff --git a/lorrycontroller/status.py b/lorrycontroller/status.py
index 9d65c4e..2e6334d 100644
--- a/lorrycontroller/status.py
+++ b/lorrycontroller/status.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2014-2017  Codethink Limited
+# Copyright (C) 2014-2019  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -61,7 +61,7 @@ class StatusRenderer(object):
 
         try:
             temp_filename = self.temp_filename_in_same_dir_as(filename)
-            with open(temp_filename, 'w') as f:
+            with open(temp_filename, 'wb') as f:
                 f.write(html.encode("UTF-8"))
             os.rename(temp_filename, filename)
 
@@ -85,7 +85,7 @@ class StatusRenderer(object):
     def temp_filename_in_same_dir_as(self, filename):
         dirname = os.path.dirname(filename)
         fd, temp_filename = tempfile.mkstemp(dir=dirname)
-        os.fchmod(fd, 0644)
+        os.fchmod(fd, 0o644)
         os.close(fd)
         return temp_filename
 
diff --git a/setup.py b/setup.py
index f5b7838..a7de1e8 100644
--- a/setup.py
+++ b/setup.py
@@ -1,6 +1,6 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 #
-# Copyright (C) 2012-2016  Codethink Limited
+# Copyright (C) 2012-2019  Codethink Limited
 
 
 from distutils.core import setup
diff --git a/templates/status.tpl b/templates/status.tpl
index 939f77d..46fe034 100644
--- a/templates/status.tpl
+++ b/templates/status.tpl
@@ -110,7 +110,7 @@
 </tr>
 % for i, spec in enumerate(run_queue):
 %   obj = json.loads(spec['text'])
-%   name = obj.keys()[0]
+%   name = list(obj)[0]
 %   fields = obj[name]
 <tr>
 <td>{{i+1}}</td>
diff --git a/test-wait-for-port b/test-wait-for-port
index 22e07be..9f6a726 100755
--- a/test-wait-for-port
+++ b/test-wait-for-port
@@ -1,6 +1,6 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
-# Copyright (C) 2014  Codethink Limited
+# Copyright (C) 2014-2019  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -28,7 +28,7 @@ host = sys.argv[1]
 port = int(sys.argv[2])
 
 while True:
-    print "Trying %s port %s" % (host, port)
+    print("Trying %s port %s" % (host, port))
     s = socket.socket()
     try:
         s.connect((host, port))
diff --git a/yarns.webapp/900-implementations.yarn b/yarns.webapp/900-implementations.yarn
index 06411a7..245cd73 100644
--- a/yarns.webapp/900-implementations.yarn
+++ b/yarns.webapp/900-implementations.yarn
@@ -86,7 +86,7 @@ most of the configuration.
 
     IMPLEMENTS GIVEN (\S+) in (\S+) adds lorries (\S+) using prefix (\S+)
     cd "$SRCDIR"/yarns.webapp
-    python -c '
+    python3 -c '
     import os
     import yarnlib
 
@@ -112,7 +112,7 @@ most of the configuration.
 
     IMPLEMENTS GIVEN (\S+) in (\S+) adds trove (\S+)
     cd "$SRCDIR"/yarns.webapp
-    python -c '
+    python3 -c '
     import os
     import yarnlib
 
@@ -138,7 +138,7 @@ file.
 
     IMPLEMENTS GIVEN (\S+) in (\S+) has (\S+) set to (.+) for everything
     cd "$SRCDIR"/yarns.webapp
-    python -c '
+    python3 -c '
     import os
     import json
     import yarnlib
@@ -159,7 +159,7 @@ Set a specific field for a `troves` section.
 
     IMPLEMENTS GIVEN (\S+) in (\S+) sets (\S+) to (.+) for trove (\S+)
     cd "$SRCDIR"/yarns.webapp
-    python -c '
+    python3 -c '
     import os
     import json
     import yarnlib
@@ -182,7 +182,7 @@ Remove a specified field for a `troves` section
 
     IMPLEMENTS GIVEN (\S+) in (\S+) removes field (\S+) from trove (\S+)
     cd "$SRCDIR"/yarns.webapp
-    python -c '
+    python3 -c '
     import os
     import yarnlib
 
@@ -204,7 +204,7 @@ file. Note that the Trove must already be in the configuration file.
 
     IMPLEMENTS GIVEN (\S+) in (\S+) has prefixmap (\S+):(\S+) for (\S+)
     cd "$SRCDIR"/yarns.webapp
-    python -c '
+    python3 -c '
     import os
     import yarnlib
 
@@ -242,7 +242,7 @@ Control the ls listing of a remote Trove.
         echo "{}" > "$filename"
     fi
     cat "$filename"
-    python -c '
+    python3 -c '
     import json, os, sys
     MATCH_2 = os.environ["MATCH_2"]
     filename = sys.argv[1]
@@ -262,7 +262,7 @@ Remove a repository from the fake remote Trove.
         echo "{}" > "$filename"
     fi
     cat "$filename"
-    python -c '
+    python3 -c '
     import json, os, sys
     MATCH_2 = os.environ["MATCH_2"]
     filename = sys.argv[1]
@@ -334,7 +334,7 @@ value is expresssed as a JSON value in the step.
 
     IMPLEMENTS THEN response has (\S+) set to (.+)
     cat "$DATADIR/response.body"
-    python -c '
+    python3 -c '
     import json, os, sys
     data = json.load(sys.stdin)
     key = os.environ["MATCH_1"]
@@ -353,22 +353,22 @@ we may need to look at a list of dicts, as below.
 
     IMPLEMENTS THEN response has (\S+) item (\d+) field (\S+) set to (\S+)
     cat "$DATADIR/response.body"
-    python -c '
+    python3 -c '
     import json, os, sys
     data = json.load(sys.stdin)
-    print "data:", repr(data)
+    print("data:", repr(data))
     items = os.environ["MATCH_1"]
-    print "items:", repr(items)
+    print("items:", repr(items))
     item = int(os.environ["MATCH_2"])
-    print "item:", repr(item)
+    print("item:", repr(item))
     field = os.environ["MATCH_3"]
-    print "field:", repr(field)
-    print "match3:", repr(os.environ["MATCH_4"])
+    print("field:", repr(field))
+    print("match3:", repr(os.environ["MATCH_4"]))
     expected = json.loads(os.environ["MATCH_4"])
-    print "expected:", repr(expected)
-    print "data[items]:", repr(data[items])
-    print "data[items][item]:", repr(data[items][item])
-    print "data[items][item][field]:", repr(data[items][item][field])
+    print("expected:", repr(expected))
+    print("data[items]:", repr(data[items]))
+    print("data[items][item]:", repr(data[items][item]))
+    print("data[items][item][field]:", repr(data[items][item][field]))
     value = data[items][item][field]
     if value != expected:
         sys.stderr.write(
@@ -384,7 +384,7 @@ value, but we do care that it is there.
 
     IMPLEMENTS THEN response has (\S+) set
     cat "$DATADIR/response.body"
-    python -c '
+    python3 -c '
     import json, os, sys
     data = json.load(sys.stdin)
     key = os.environ["MATCH_1"]
diff --git a/yarns.webapp/yarn.sh b/yarns.webapp/yarn.sh
index 2a9081d..260fd74 100644
--- a/yarns.webapp/yarn.sh
+++ b/yarns.webapp/yarn.sh
@@ -1,4 +1,4 @@
-# Copyright (C) 2014  Codethink Limited
+# Copyright (C) 2014-2019  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -40,6 +40,7 @@ add_to_config_file()
     then
         printf '[config]\n' > "$1"
     fi
+    sed -i "/^$2/d" "$1"
     printf '%s = %s\n' "$2" "$3" >> "$1"
 }
 
diff --git a/yarns.webapp/yarnlib.py b/yarns.webapp/yarnlib.py
index 89f87d9..4582649 100644
--- a/yarns.webapp/yarnlib.py
+++ b/yarns.webapp/yarnlib.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2015 Codethink Limited
+# Copyright (C) 2015-2019 Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -25,7 +25,7 @@ def matches():
     matches = {}
     prefix = "MATCH_"
 
-    for key, value in os.environ.iteritems():
+    for key, value in os.environ.items():
         if key.startswith(prefix):
             stripped_key = key[len(prefix):]
             if stripped_key.isdigit() and stripped_key != "0":