Support services in different namespaces

Pass the service namespace to kubernetes-entrypoint in
order to support dependencies between namespaces.
Add documentation about endpoint/service namespaces.

Change-Id: I208c3240e9f2c8900323595f7b0e488bef5cb1fc
Implements: blueprint entrypoint-namespaces

doc/source/devref/endpoints.rst

@@ -98,3 +98,8 @@ Charts should not use hard coded values such as
 ``http://keystone-api:5000`` because these are not compatible with
 operator overrides and do not support spreading components out over
 various namespaces.
+
+By default, each endpoint is located in the same namespace as the current
+service's helm chart. To connect to a service which is running in a different
+kubernetes namespace, a ``namespace`` can be provided to each individual
+endpoint.

helm-toolkit/templates/endpoints/_service_name_endpoint_with_namespace_lookup.tpl

@@ -0,0 +1,34 @@
+{{/*
+Copyright 2017 The Openstack-Helm Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/}}
+
+# This function returns endpoint "<namespace>:<name>" pair from an endpoint
+# definition. This is used in kubernetes-entrypoint to support dependencies
+# between different services in different namespaces.
+# returns: the endpoint namespace and the service name, delimited by a colon
+
+{{- define "helm-toolkit.endpoints.service_name_endpoint_with_namespace_lookup" -}}
+{{- $type := index . 0 -}}
+{{- $endpoint := index . 1 -}}
+{{- $context := index . 2 -}}
+{{- $typeYamlSafe := $type | replace "-" "_" }}
+{{- $endpointMap := index $context.Values.endpoints $typeYamlSafe }}
+{{- with $endpointMap -}}
+{{- $endpointScheme := .scheme }}
+{{- $endpointName := index .hosts $endpoint | default .hosts.default}}
+{{- $endpointNamespace := .namespace | default $context.Release.Namespace }}
+{{- printf "%s:%s" $endpointNamespace $endpointName -}}
+{{- end -}}
+{{- end -}}

helm-toolkit/templates/snippets/_kubernetes_entrypoint_init_container.tpl

@@ -35,7 +35,7 @@ limitations under the License.
     - name: INTERFACE_NAME
       value: eth0
     - name: DEPENDENCY_SERVICE
-      value: "{{ tuple $deps.services $envAll | include "helm-toolkit.utils.comma_joined_hostname_list" }}"
+      value: "{{ tuple $deps.services $envAll | include "helm-toolkit.utils.comma_joined_service_list" }}"
     - name: DEPENDENCY_JOBS
       value: "{{  include "helm-toolkit.utils.joinListWithComma" $deps.jobs }}"
     - name: DEPENDENCY_DAEMONSET

helm-toolkit/templates/utils/_comma_joined_service_list.tpl

@@ -14,8 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */}}
 
-{{- define "helm-toolkit.utils.comma_joined_hostname_list" -}}
+{{- define "helm-toolkit.utils.comma_joined_service_list" -}}
 {{- $deps := index . 0 -}}
 {{- $envAll := index . 1 -}}
-{{- range $k, $v := $deps -}}{{- if $k -}},{{- end -}}{{ tuple $v.service $v.endpoint $envAll | include "helm-toolkit.endpoints.hostname_short_endpoint_lookup" }}{{- end -}}
+{{- range $k, $v := $deps -}}{{- if $k -}},{{- end -}}{{ tuple $v.service $v.endpoint $envAll | include "helm-toolkit.endpoints.service_name_endpoint_with_namespace_lookup" }}{{- end -}}
 {{- end -}}