Merge pull request #4260 from matrix-org/rav/python3

Notes on upgrading to python3, and README updates.

3 files changed, 82 insertions, 53 deletions

diff --git a/README.rst b/README.rst
index 8c55dd7894..664a0ea03f 100644
--- a/README.rst
+++ b/README.rst
@@ -86,7 +86,7 @@ Synapse is the reference Python/Twisted Matrix homeserver implementation.
 System requirements:
 
 - POSIX-compliant system (tested on Linux & OS X)
-- Python 2.7
+- Python 3.5, 3.6, or 2.7
 - At least 1GB of free RAM if you want to join large public rooms like #matrix:matrix.org
 
 Installing from source
@@ -101,13 +101,13 @@ header files for Python C extensions.
 
 Installing prerequisites on Ubuntu or Debian::
 
-    sudo apt-get install build-essential python2.7-dev libffi-dev \
+    sudo apt-get install build-essential python3-dev libffi-dev \
                          python-pip python-setuptools sqlite3 \
                          libssl-dev python-virtualenv libjpeg-dev libxslt1-dev
 
 Installing prerequisites on ArchLinux::
 
-    sudo pacman -S base-devel python2 python-pip \
+    sudo pacman -S base-devel python python-pip \
                    python-setuptools python-virtualenv sqlite3
 
 Installing prerequisites on CentOS 7 or Fedora 25::
@@ -126,12 +126,9 @@ Installing prerequisites on Mac OS X::
 
 Installing prerequisites on Raspbian::
 
-    sudo apt-get install build-essential python2.7-dev libffi-dev \
+    sudo apt-get install build-essential python3-dev libffi-dev \
                          python-pip python-setuptools sqlite3 \
                          libssl-dev python-virtualenv libjpeg-dev
-    sudo pip install --upgrade pip
-    sudo pip install --upgrade ndg-httpsclient
-    sudo pip install --upgrade virtualenv
 
 Installing prerequisites on openSUSE::
 
@@ -146,20 +143,21 @@ Installing prerequisites on OpenBSD::
 
 To install the Synapse homeserver run::
 
-    virtualenv -p python2.7 ~/.synapse
-    source ~/.synapse/bin/activate
+    mkdir -p ~/synapse
+    virtualenv -p python3 ~/synapse/env
+    source ~/synapse/env/bin/activate
     pip install --upgrade pip
     pip install --upgrade setuptools
     pip install matrix-synapse
 
 This installs Synapse, along with the libraries it uses, into a virtual
-environment under ``~/.synapse``.  Feel free to pick a different directory
+environment under ``~/synapse/env``.  Feel free to pick a different directory
 if you prefer.
 
 This Synapse installation can then be later upgraded by using pip again with the
 update flag::
 
-    source ~/.synapse/bin/activate
+    source ~/synapse/env/bin/activate
     pip install -U matrix-synapse
 
 In case of problems, please see the _`Troubleshooting` section below.
@@ -240,7 +238,7 @@ commandline script.
 
 To get started, it is easiest to use the command line to register new users::
 
-    $ source ~/.synapse/bin/activate
+    $ source ~/synapse/env/bin/activate
     $ synctl start # if not already running
     $ register_new_matrix_user -c homeserver.yaml https://localhost:8448
     New user localpart: erikj
@@ -266,13 +264,12 @@ Running Synapse
 ===============
 
 To actually run your new homeserver, pick a working directory for Synapse to
-run (e.g. ``~/.synapse``), and::
+run (e.g. ``~/synapse``), and::
 
-    cd ~/.synapse
-    source ./bin/activate
+    cd ~/synapse
+    source env/bin/activate
     synctl start
 
-
 Connecting to Synapse from a client
 ===================================
 
@@ -380,35 +377,17 @@ the generated config),
 https://www.archlinux.org/packages/community/any/python2-matrix-angular-sdk/ will also need to
 be installed.
 
-Alternatively, to install using pip a few changes may be needed as ArchLinux
-defaults to python 3, but synapse currently assumes python 2.7 by default:
-
 pip may be outdated (6.0.7-1 and needs to be upgraded to 6.0.8-1 )::
 
-    sudo pip2.7 install --upgrade pip
-
-You also may need to explicitly specify python 2.7 again during the install
-request::
-
-    pip2.7 install https://github.com/matrix-org/synapse/tarball/master
+    sudo pip install --upgrade pip
 
 If you encounter an error with lib bcrypt causing an Wrong ELF Class:
 ELFCLASS32 (x64 Systems), you may need to reinstall py-bcrypt to correctly
 compile it under the right architecture. (This should not be needed if
 installing under virtualenv)::
 
-    sudo pip2.7 uninstall py-bcrypt
-    sudo pip2.7 install py-bcrypt
-
-During setup of Synapse you need to call python2.7 directly again::
-
-    cd ~/.synapse
-    python2.7 -m synapse.app.homeserver \
-      --server-name machine.my.domain.name \
-      --config-path homeserver.yaml \
-      --generate-config
-
-...substituting your host and domain name as appropriate.
+    sudo pip uninstall py-bcrypt
+    sudo pip install py-bcrypt
 
 FreeBSD
 -------
@@ -475,7 +454,7 @@ You can fix this by manually upgrading pip and virtualenv::
 
     sudo pip install --upgrade virtualenv
 
-You can next rerun ``virtualenv -p python2.7 synapse`` to update the virtual env.
+You can next rerun ``virtualenv -p python3 synapse`` to update the virtual env.
 
 Installing may fail during installing virtualenv with ``InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.``
 You can fix this  by manually installing ndg-httpsclient::
@@ -524,16 +503,6 @@ log lines and looking for any 'Processed request' lines which take more than
 a few seconds to execute.  Please let us know at #matrix-dev:matrix.org if
 you see this failure mode so we can help debug it, however.
 
-ArchLinux
-~~~~~~~~~
-
-If running `$ synctl start` fails with 'returned non-zero exit status 1',
-you will need to explicitly call Python2.7 - either running as::
-
-    python2.7 -m synapse.app.homeserver --daemonize -c homeserver.yaml
-
-...or by editing synctl with the correct python executable.
-
 
 Upgrading an existing Synapse
 =============================
@@ -731,7 +700,7 @@ port:
 
 * Until v0.33.3, Synapse did not support SNI on the federation port
   (`bug #1491 <https://github.com/matrix-org/synapse/issues/1491>`_). This bug
-  is now fixed, but means that federating with older servers can be unreliable 
+  is now fixed, but means that federating with older servers can be unreliable
   when using name-based virtual hosting.
 
 Furthermore, a number of the normal reasons for using a reverse-proxy do not
diff --git a/UPGRADE.rst b/UPGRADE.rst
index aa5473ec62..9d68a64058 100644
--- a/UPGRADE.rst
+++ b/UPGRADE.rst
@@ -51,11 +51,70 @@ returned by the Client-Server API:
 Upgrading to v0.34.0
 ====================
 
-This release removes the ``riot.im`` from the default list of trusted identity servers.
+1. This release is the first to fully support Python 3. We recommend switching
+   to Python 3, as it has been shown to give performance improvements.
+
+   For users who have installed Synapse into a virtualenv, we recommend doing
+   this by creating a new virtualenv. For example::
+
+       virtualenv -p python3 ~/synapse/env3
+       source ~/synapse/env3/bin/activate
+       pip install matrix-synapse
+
+   You can then start synapse as normal, having activated the new virtualenv::
+
+       cd ~/synapse
+       source env3/bin/activate
+       synctl start
+
+   Users who have installed from distribution packages should see the relevant
+   package documentation.
+
+   * When upgrading to Python 3, you **must** make sure that your log files are
+     configured as UTF-8, by adding ``encoding: utf8`` to the
+     ``RotatingFileHandler`` configuration (if you have one) in your
+     ``<server>.log.config`` file. For example, if your ``log.config`` file
+     contains::
+
+       handlers:
+         file:
+           class: logging.handlers.RotatingFileHandler
+           formatter: precise
+           filename: homeserver.log
+           maxBytes: 104857600
+           backupCount: 10
+           filters: [context]
+         console:
+           class: logging.StreamHandler
+           formatter: precise
+           filters: [context]
+
+     Then you should update this to be::
+
+       handlers:
+         file:
+           class: logging.handlers.RotatingFileHandler
+           formatter: precise
+           filename: homeserver.log
+           maxBytes: 104857600
+           backupCount: 10
+           filters: [context]
+           encoding: utf8
+         console:
+           class: logging.StreamHandler
+           formatter: precise
+           filters: [context]
+
+     There is no need to revert this change if downgrading to Python 2.
+
+2. This release removes the ``riot.im`` from the default list of trusted
+   identity servers.
+
+   If ``riot.im`` is in your homeserver's list of
+   ``trusted_third_party_id_servers``, you should remove it. It was added in
+   case a hypothetical future identity server was put there. If you don't
+   remove it, users may be unable to deactivate their accounts.
 
-If ``riot.im`` is in your homeserver's list of ``trusted_third_party_id_servers``,
-you should remove it. It was added in case a hypothetical future identity server was
-put there. If you don't remove it, users may be unable to deactivate their accounts.
 
 Upgrading to v0.33.7
 ====================
diff --git a/changelog.d/4260.misc b/changelog.d/4260.misc
new file mode 100644
index 0000000000..0f7c4faf28
--- /dev/null
+++ b/changelog.d/4260.misc
@@ -0,0 +1 @@
+Update README.rst and UPGRADE.rst for Python 3.