stack/erp5: socat wrapper to get haproxy stats

haproxy can be controlled with this socket, so it might be useful
to "expose" it - it's not really expose because we only use a
UNIX socket.

component/socat/buildout.cfg

@@ -7,6 +7,7 @@ parts =
 
 [socat]
 recipe = slapos.recipe.cmmi
+shared = true
 url = http://www.dest-unreach.org/socat/download/socat-${:version}.tar.gz
 version = 1.7.3.2
 md5sum = aec3154f7854580cfab0c2d81e910519

software/erp5/test/test/test_balancer.py

@@ -375,6 +375,25 @@ class TestBalancer(BalancerTestCase):
         requests.get(self.default_balancer_url, verify=False, cookies=cookies).text,
         'backend_web_server1')
 
+  def test_balancer_stats_socket(self):
+    # real time statistics can be obtained by using the stats socket and there
+    # is a wrapper which makes this a bit easier.
+    socat_process = subprocess.Popen(
+        [self.computer_partition_root_path + '/bin/haproxy-socat-stats'],
+        stdin=subprocess.PIPE,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT
+    )
+    try:
+      output, _ = socat_process.communicate("show stat\n")
+    except:
+      socat_process.kill()
+      socat_process.wait()
+      raise
+    self.assertEqual(socat_process.poll(), 0)
+    # output is a csv
+    self.assertIn('family_default,FRONTEND,', output)
+
 
 class TestHTTP(BalancerTestCase):
   """Check HTTP protocol with a HTTP/1.1 backend

stack/erp5/buildout.cfg

@@ -11,6 +11,7 @@ extends =
   ../../component/gzip/buildout.cfg
   ../../component/xz-utils/buildout.cfg
   ../../component/haproxy/buildout.cfg
+  ../../component/socat/buildout.cfg
   ../../component/rsyslogd/buildout.cfg
   ../../component/findutils/buildout.cfg
   ../../component/librsvg/buildout.cfg
@@ -179,6 +180,7 @@ context =
     key gzip_location gzip:location
     key xz_utils_location xz-utils:location
     key haproxy_location haproxy:location
+    key socat_location socat:location
     key rsyslogd_location rsyslogd:location
     key instance_common_cfg instance-common:rendered
     key jsl_location jsl:location

stack/erp5/buildout.hash.cfg

@@ -70,7 +70,7 @@ md5sum = cc19560b9400cecbd23064d55c501eec
 
 [template]
 filename = instance.cfg.in
-md5sum = 3a0b3cbee2ed83fba32410bac15914fb
+md5sum = 960c7591b7744aab05a178d1489dacc3
 
 [monitor-template-dummy]
 filename = dummy.cfg
@@ -90,7 +90,7 @@ md5sum = 2f3ddd328ac1c375e483ecb2ef5ffb57
 
 [template-balancer]
 filename = instance-balancer.cfg.in
-md5sum = 05c3c35d0aadad566de992a13c9fd2d2
+md5sum = d5b26109702fb6502e9b1342b4f35160
 
 [template-haproxy-cfg]
 filename = haproxy.cfg.in

stack/erp5/instance-balancer.cfg.in

@@ -256,6 +256,15 @@ wrapper-path = ${directory:services-on-watch}/haproxy
 command-line = "{{ parameter_dict['haproxy'] }}/sbin/haproxy" -f "${haproxy-cfg:rendered}"
 hash-files = ${haproxy-cfg:rendered}
 
+[{{ section('haproxy-socat-stats')}}]
+recipe = collective.recipe.template
+output = ${directory:bin}/${:_buildout_section_name_}
+mode = 700
+input =
+  inline:
+  #!/bin/sh
+  "{{ parameter_dict['socat'] }}/bin/socat" unix-connect:${haproxy-cfg-parameter-dict:stats-socket} stdio
+
 [rsyslogd-cfg-parameter-dict]
 log-socket = ${directory:run}/log.sock
 access-log-file = ${directory:log}/apache-access.log

stack/erp5/instance.cfg.in

@@ -59,6 +59,7 @@ openssl-location = {{ openssl_location }}
 openssl = {{ openssl_location }}
 haproxy = {{ haproxy_location }}
 rsyslogd = {{ rsyslogd_location }}
+socat = {{ socat_location }}
 apachedex-location = {{ bin_directory }}/apachedex
 run-apachedex-location = {{ bin_directory }}/runApacheDex
 promise-check-apachedex-result = {{ bin_directory }}/check-apachedex-result

[Julien Muchembled]

Isn't slapos.cookbook:wrapper better ? In any case, let's avoid recipes for which we have forks.

[Jérome Perrin]

slapos.cookbook:wrapper usually tries to be too clever and usually escape too much, so I always avoid using it, but here it would be OK to use it.

I copied from existing section that was already collective.recipe.template, but probably we can use some slapos recipe for this and other sections. I'll review the recipes** used here, thanks.

[Jérome Perrin]

I changed this one to slapos.cookbook:wrapper others are using collective.recipe.template because it supports inline: input and does not escape. There are ~50 cases of collective.recipe.template so I don't start changing this now.

[Julien Muchembled]

I don't understand "too clever" and "escape too much". Can detail / give an example ?

[Jérome Perrin]

In the past I had troubles using this recipe to generate "simple scripts" ( thinks like kill $(cat pidfile) or PATH=${something:location}/bin/:$PATH command ), but for such a case were we only generate a wrapper it's actually fine.

[Julien Muchembled]

Yes, slapos.cookbook:wrapper can't be used to write (ba)sh code.