component/caddy: Disable telemetry fully

Copied part of gowork.install:command to activate GO111MODULES and also the
[caddy] section is minimised, as the whole build happnes in proper place.

component/caddy/buildout.cfg

 [buildout]
 extends =
   ../../component/golang/buildout.cfg
+  gowork.cfg
 
 parts =
+  gowork
   caddy
 
+[gowork.goinstall]
+command = bash -c ". ${gowork:env.sh} && cd ${go_github.com_caddyserver_caddy:location} && GO111MODULE=on go install -v $(echo -n '${gowork:install}' |tr '\n' ' ')"
+
 [gowork]
-# Caddy 1.x+ uses go modules, for which gowork does not work yet
 golang  = ${golang1.12:location}
 install =
-
-[gowork.goinstall]
-command = :
-depends =
-  ${caddy:recipe}
+  github.com/caddyserver/caddy/...
 
 [caddy]
-# revision and repository can be used to control which caddy version is used
-revision = v1.0.3
-repository = github.com/caddyserver/caddy/caddy
-
-recipe  = plone.recipe.command
+recipe = plone.recipe.command
+command = exit 0
 update-command = ${:command}
-stop-on-error = True
-# GO111MODULE=on enables go modules support
-# the chmod is needed as modules are fetched with u-w
-command =
-  . ${gowork:env.sh} &&
-  cd ${gowork:directory} &&
-  export GO111MODULE=on &&
-  go get ${:repository}@${:revision} &&
-  chmod -R u+w .
 output = ${gowork:bin}/caddy
 location = ${:output}

component/caddy/gowork.cfg

+# Code generated by gowork-snapshot; DO NOT EDIT.
+
+# list of go git repositories to fetch
+[gowork.goinstall]
+depends_gitfetch  =
+    ${go_github.com_caddyserver_caddy:recipe}
+
+[go_github.com_caddyserver_caddy]
+<= go-git-package
+go.importpath = github.com/caddyserver/caddy
+repository    = https://lab.nexedi.com/nexedi/caddy.git
+revision      = nxd-v1.0.3-1-g2c11cedc

software/caddy-frontend/test/test.py

@@ -1682,6 +1682,15 @@ class TestSlave(SlaveHttpFrontendTestCase, TestDataMixin):
       proto
     )
 
+  def test_telemetry_disabled(self):
+    # here we trust that telemetry not present in error log means it was
+    # really disabled
+    error_log_file = glob.glob(
+      os.path.join(
+       self.instance_path, '*', 'var', 'log', 'frontend-error.log'))[0]
+    with open(error_log_file) as fh:
+      self.assertNotIn('Sending telemetry', fh.read(), 'Telemetry enabled')
+
   def test_url(self):
     parameter_dict = self.assertSlaveBase('Url')