ZEO: Factor it to separate component

We already patch ZEO4 with TCP_NODELAY patch (see 5cf4cf1f "ERP5:
enable TCP_NODELAY for ZEO") and we will need to backport more patches
to ZEO4 branch for wendelin.core 2 to work correctly.

It's not only software/neoppod which uses ZEO, and it is not convenient for
all other software-releases to inherit from neoppod to use correct
version and build of ZEO egg. For this reason factor out details of ZEO
egg building into component/ZEO and let users use ${ZEO:egg} where ZEO
is needed. This way ZEO will be correctly installed for all users.

This patch should be a non-functional change. We switch to
ZEO@5114f909 revision which corresponds to ZEO 4.3.1 +
TCP_NODELAY.patch

Adding other patches to ZEO4 needed by wendelin.core 2 will be done as a
separate step.

component/ZEO/buildout.cfg

+# SlapOS component for ZEO.
+# https://zeo.readthedocs.io/
+
+[buildout]
+extends =
+    ../git/buildout.cfg
+
+parts = ZEO/scripts
+
+
+# ZEO allows to use either ZEO4 or ZEO5
+# To select which version to use users should do:
+#
+#   [ZEO]
+#   egg = ${ZEO<version>:egg}
+#
+# By default ZEO4 is used.
+[ZEO]
+recipe  = zc.recipe.egg:eggs
+egg     = ${ZEO4:egg}
+eggs    = ${:egg}
+
+
+# ZEO/scripts installs scripts from ZEO
+[ZEO/scripts]
+recipe  = zc.recipe.egg:scripts
+eggs    = ${ZEO:egg}
+
+
+# ZEO4: we maintain our own 4-nxd branch with patches
+[ZEO4]
+recipe  = zc.recipe.egg:develop
+setup   = ${ZEO4-repository:location}
+egg     = ZEO
+
+[ZEO4-repository]
+recipe  = slapos.recipe.build:gitclone
+repository = https://lab.nexedi.com/nexedi/ZEO.git
+branch  = 4-nxd
+revision= 5114f909e5a5
+location = ${buildout:parts-directory}/ZEO4
+git-executable = ${git:location}/bin/git
+
+
+# ZEO5 is plain upstream egg
+[ZEO5]
+recipe  = zc.recipe.egg:eggs
+egg     = ZEO
+eggs    = ${:egg}
+
+
+[versions]
+# Required by:
+# ZEO==4.3.1
+zdaemon = 4.2.0

component/egg-patch/ZEO4/TCP_NODELAY.patch

-From 8b31ccec54584a287cc61501948283d7d6ee7073 Mon Sep 17 00:00:00 2001
-From: Julien Muchembled <jm@nexedi.com>
-Date: Mon, 26 Mar 2018 20:39:07 +0200
-Subject: [PATCH] Enable TCP_NODELAY for inet(6) sockets
-
-See commit 3d886d426243655b9f5a2528636e42b5c7662c19.
----
- src/ZEO/zrpc/client.py | 2 ++
- src/ZEO/zrpc/server.py | 1 +
- 2 files changed, 3 insertions(+)
-
-diff --git a/src/ZEO/zrpc/client.py b/src/ZEO/zrpc/client.py
-index 32a7a877..669f5962 100644
---- a/src/ZEO/zrpc/client.py
-+++ b/src/ZEO/zrpc/client.py
-@@ -568,6 +568,8 @@ def __init__(self, domain, addr, mgr, client):
-             self.close()
-             return
-         self.sock.setblocking(0)
-+        if domain in (socket.AF_INET, socket.AF_INET6):
-+            self.sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
-         self.state = "opened"
- 
-     def connect_procedure(self):
-diff --git a/src/ZEO/zrpc/server.py b/src/ZEO/zrpc/server.py
-index b83cc004..af91e3e4 100644
---- a/src/ZEO/zrpc/server.py
-+++ b/src/ZEO/zrpc/server.py
-@@ -66,6 +66,7 @@ def _open_socket(self):
-                         socket.IPPROTO_IPV6, socket.IPV6_V6ONLY, True)
-             else:
-                 self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
-+            self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
-         else:
-             self.create_socket(socket.AF_UNIX, socket.SOCK_STREAM)
-         self.set_reuse_addr()
--- 
-2.14.1
-

software/neoppod/software-common.cfg

@@ -15,10 +15,10 @@ extends =
     ../../component/lxml-python/buildout.cfg
 #END LXML
     ../../component/msgpack-python/buildout.cfg
-    ../../component/patch/buildout.cfg
     ../../component/python-mysqlclient/buildout.cfg
     ../../component/python-cryptography/buildout.cfg
     ../../component/pycurl/buildout.cfg
+    ../../component/ZEO/buildout.cfg
 
 parts =
 # keep neoppod first so that ZODB is built correctly,
@@ -54,10 +54,7 @@ eggs = neoppod[admin, ctl, master]
   coverage
   setproctitle
 adapter-egg = ${python-mysqlclient:egg}
-patch-binary = ${patch:location}/bin/patch
-ZEO-patch-options = -p1
-ZEO-patches =
-  ${:_profile_base_location_}/../../component/egg-patch/ZEO4/TCP_NODELAY.patch#b07288522d5c6857738240d948321df6
+depends = ${ZEO:egg}
 
 # XXX: buildout fails to install properly eggs with setup_requires
 [BTrees]
@@ -160,15 +157,6 @@ python-dateutil = 2.7.3
 # zodbtools==0.0.0dev4
 zodburi = 2.3.0
 
-# Required by:
-# zodburi==2.0
-# ZEO 5 requires transaction >= 2
-ZEO = 4.3.1+SlapOSPatched001
-
-# Required by:
-# ZEO==4.3.1
-zdaemon = 4.2.0
-
 # Required by:
 # mock = 3.0.5
 funcsigs = 1.0.2

software/neoppod/software-zodb5.cfg

@@ -3,7 +3,9 @@ extends = software.cfg
 
 [neoppod]
 eggs += mock
-ZEO-patches =
+
+[ZEO]
+egg = ${ZEO5:egg}
 
 [versions]
 ZODB = 5.6.0

software/neotest/software.cfg

@@ -103,7 +103,7 @@ eggs    =
 # to install not only wendelin.core modules but also scripts
     wendelin.core
 # for ZEO scripts (runzeo)
-    ZEO
+    ${ZEO:egg}
 # for nxd/runTestSuite
     erp5.util
 # for e.g. tcpu.py

stack/erp5/buildout.cfg

@@ -455,7 +455,7 @@ eggs = ${neoppod:eggs}
 # Zope acquisition patch
   Acquisition
 # for runzeo
-  ZEO
+  ${ZEO:egg}
 
 # Other Zope 2 packages
   Products.PluggableAuthService