nixos/phoebus-save-and-restore: don't automatically enable elasticsearch

see epics-extensions#75, epics-extensions#54, follow-up of epics-extensions#60

Specify in documentation that enabling ElasticSearch needs to be done
only once.

docs/nixos-services/user-guides/phoebus-alarm.rst

@@ -52,7 +52,9 @@ and Kafka’s ``clusterId``:
 
      services.phoebus-alarm-logger.settings."bootstrap.servers" = kafkaListenSockAddr;
 
-     # Single-server Kafka setup
+     # Phoebus alarm needs Kafka.
+     # If not already enabled elsewhere in your configuration,
+     # the code below shows a single-server Kafka setup:
      services.apache-kafka = {
        enable = true;
        # Replace with a randomly generated uuid. You can get one by running:
@@ -89,6 +91,9 @@ and Kafka’s ``clusterId``:
      # Open kafka to the outside world
      networking.firewall.allowedTCPPorts = [9092];
 
+     # Phoebus save-and-restore needs ElasticSearch.
+     # If not already enabled elsewhere in your configuration,
+     # Enable it with the code below:
      services.elasticsearch = {
        enable = true;
        package = pkgs.elasticsearch7;

docs/nixos-services/user-guides/phoebus-save-and-restore.rst

@@ -29,6 +29,14 @@ add this to your configuration:
        openFirewall = true;
      };
 
+     # Phoebus save-and-restore needs ElasticSearch.
+     # If not already enabled elsewhere in your configuration,
+     # Enable it with the code below:
+     services.elasticsearch = {
+       enable = true;
+       package = pkgs.elasticsearch7;
+     };
+
      # Elasticsearch, needed by Phoebus Save-and-restore, is not free software (SSPL | Elastic License).
      # To accept the license, add the code below:
      nixpkgs.config.allowUnfreePredicate = pkg:

nixos/modules/phoebus/save-and-restore.nix

@@ -8,8 +8,6 @@
   cfg = config.services.phoebus-save-and-restore;
   settingsFormat = pkgs.formats.javaProperties {};
   configFile = settingsFormat.generate "phoebus-save-and-restore.properties" cfg.settings;
-
-  localElasticsearch = cfg.settings."elasticsearch.network.host" == "localhost";
 in {
   options.services.phoebus-save-and-restore = {
     enable = lib.mkEnableOption ''
@@ -81,7 +79,7 @@ in {
       description = "Phoebus Save-and-restore";
 
       wantedBy = ["multi-user.target"];
-      after = lib.mkIf localElasticsearch ["elasticsearch.service"];
+      after = ["elasticsearch.service"];
 
       serviceConfig = {
         ExecStart = "${lib.getExe pkgs.epnix.phoebus-save-and-restore} --spring.config.location=file://${configFile}";
@@ -140,12 +138,6 @@ in {
       };
     };
 
-    services.elasticsearch = lib.mkIf localElasticsearch {
-      enable = true;
-      # Should be kept in sync with the phoebus-alarm-logger and phoebus-olog services
-      package = pkgs.elasticsearch7;
-    };
-
     networking.firewall.allowedTCPPorts = lib.mkIf cfg.openFirewall [
       (lib.toInt cfg.settings."server.port")
     ];

nixos/tests/phoebus/save-and-restore.nix

@@ -7,12 +7,18 @@
   meta.maintainers = with epnixLib.maintainers; [minijackson];
 
   nodes = {
-    server = {
+    server = {pkgs, ...}: {
       services.phoebus-save-and-restore = {
         enable = true;
         openFirewall = true;
       };
 
+      services.elasticsearch = {
+        enable = true;
+        # Should be kept in sync with the phoebus-alarm-logger and phoebus-olog services
+        package = pkgs.elasticsearch7;
+      };
+
       nixpkgs.config.allowUnfreePredicate = pkg:
         builtins.elem (lib.getName pkg) [
           # Elasticsearch can be used as an SSPL-licensed software, which is