[helm] Remove default dss image value to force user to set it manually

deploy/services/helm-charts/dss/README.md

@@ -8,8 +8,7 @@ Requirements and instructions to create a new Kubernetes cluster can be found [h
 3. Install [Helm](https://helm.sh/) version 3.11.3 or higher
 
 ## Usage
-1. Copy `values.example.yaml` to `values.dev.yaml` and edit it. See `values.schema.json` for schema definition. (Note that the key `cockroachdb` supports all values supported by the [`cockroachdb` Chart](https://github.com/cockroachdb/helm-charts/tree/master/cockroachdb#configuration)).
-Note that values.yaml contains the default values and are always passed to helm.
+1. Copy `values.example.yaml` to `values.dev.yaml` and edit it. In particular, the key `dss.image` must be set manually. See `values.schema.json` for schema definition. The root key `cockroachdb` supports all values supported by the [`cockroachdb` Chart](https://github.com/cockroachdb/helm-charts/tree/master/cockroachdb#configuration)). Note that values.yaml contains the default values and are always passed to helm.
 2. Validate the configuration: `helm lint -f values.dev.yaml .`
 3. Set a RELEASE_NAME to `dss`: `export RELEASE_NAME=dss`
 It is temporarily the only release name possible.

deploy/services/helm-charts/dss/values.example.yaml

@@ -1,5 +1,15 @@
 # See values.schema.json for schema description
 
+dss:
+  image: docker.io/interuss/dss:v0.15.0 # See https://hub.docker.com/r/interuss/dss/tags for official image releases.
+  conf:
+    pubKeys:
+      - /test-certs/auth2.pem
+    jwksEndpoint: ''
+    jwksKeyIds: []
+    hostname: dss.example.com
+    enableScd: true
+
 cockroachdb:
   # See https://github.com/cockroachdb/helm-charts/blob/master/cockroachdb/values.yaml
   fullnameOverride: dss-cockroachdb
@@ -32,14 +42,5 @@ loadBalancers:
 #    subnet: subnet-xxx # for aws only
 #    certName: arn:xxxx # for aws only
 
-dss:
-  conf:
-    pubKeys:
-      - /test-certs/auth2.pem
-    jwksEndpoint: ''
-    jwksKeyIds: []
-    hostname: dss.example.com
-    enableScd: true
-
 global:
   cloudProvider: google

deploy/services/helm-charts/dss/values.schema.json

@@ -133,7 +133,8 @@
       "type": "object",
       "properties": {
         "image": {
-          "type": "string"
+          "type": "string",
+          "description": "Image of the DSS. Please note that the usage of the `latest` tag is discouraged to prevent accidental upgrades in case of restart. Example: `docker.io/interuss/dss:v0.15.0`. Official image releases: https://hub.docker.com/r/interuss/dss/tags"
         },
         "conf": {
           "type": "object",

deploy/services/helm-charts/dss/values.yaml

@@ -13,6 +13,3 @@ cockroachdb:
         enabled: false
   ingress:
     enabled: false
-
-dss:
-  image: docker.io/interuss/dss:v0.7.0