[kong] handle DB-backed stream listen issue

#295 requires a workaround that
behaves differently depending on whether a DB-backed instance has or
does not have stream listens configured.

At the end of wait-for-db, this workaround removes the problem socket
file if it exists, or does nothing if it does not.

test5-values.yaml is a new DB-backed test that does not include stream
listens, as the only existing DB-backed test did include stream listens.

charts/kong/ci/test2-values.yaml

@@ -1,5 +1,6 @@
 # This tests the following unrelated aspects of Ingress Controller
 # - ingressController deploys with a database
+# - stream listens work
 ingressController:
   enabled: true
   installCRDs: false

charts/kong/ci/test5-values.yaml

@@ -0,0 +1,43 @@
+# This tests the following unrelated aspects of Ingress Controller
+# - ingressController deploys with a database
+# - TODO database-backed proxy works _without_ stream listens
+#   This test is a duplicate of test2-values.yaml to handle the https://github.com/Kong/charts/issues/295
+#   workaround when the socket file is _not_ created
+ingressController:
+  enabled: true
+  installCRDs: false
+  env:
+    anonymous_reports: "false"
+postgresql:
+  enabled: true
+  postgresqlUsername: kong
+  postgresqlDatabase: kong
+  service:
+    port: 5432
+env:
+  anonymous_reports: "off"
+  database: "postgres"
+# - ingress resources are created without hosts
+admin:
+  type: NodePort
+  ingress:
+    enabled: true
+    hosts: []
+    path: /
+proxy:
+  type: NodePort
+  ingress:
+    enabled: true
+    hostname: proxy.kong.example
+    annotations: {}
+    path: /
+
+# - PDB is enabled
+podDisruptionBudget:
+  enabled: true
+# update strategy
+updateStrategy:
+  type: "RollingUpdate"
+  rollingUpdate:
+    maxSurge: 1
+    maxUnavailable: 0

charts/kong/templates/_helpers.tpl

@@ -489,14 +489,15 @@ The name of the service used for the ingress controller's validation webhook
 {{- end -}}
 
 {{- define "kong.wait-for-db" -}}
+{{ $sockFile := (printf "%s/stream_rpc.sock" (default "/usr/local/kong" .Values.env.prefix)) }}
 - name: wait-for-db
   image: {{ include "kong.getRepoTag" .Values.image }}
   imagePullPolicy: {{ .Values.image.pullPolicy }}
   env:
   {{- include "kong.env" . | nindent 2 }}
-{{/* TODO: the rm command here is a workaround for https://github.com/Kong/kong/issues/6827
+{{/* TODO: the rm command here is a workaround for https://github.com/Kong/charts/issues/295
      It should be removed once that's fixed */}}
-  command: [ "/bin/sh", "-c", "until kong start; do echo 'waiting for db'; sleep 1; done; kong stop; rm {{ .Values.env.prefix | default "/usr/local/kong" }}/stream_rpc.sock" ]
+  command: [ "/bin/sh", "-c", "until kong start; do echo 'waiting for db'; sleep 1; done; kong stop; if [ -f {{ $sockFile }} ]; then rm {{ $sockFile }}; else true; fi"]
   volumeMounts:
   {{- include "kong.volumeMounts" . | nindent 4 }}
   resources: