gocd-agent: 16.7.0 startup fixes + test improvements

- Agent now takes a full URL to the Go.CD server
- Instruct the agent to attempt restart every 30s upon failure
- Test's Accept header did not match the server's expectation
- Replace the tests' complex Awk matches with calls to `jq`

nixos/modules/services/continuous-integration/gocd-agent/default.nix

···
       };
 
       goServer = mkOption {
-        default = "127.0.0.1";
+        default = "https://127.0.0.1:8154/go";
         type = types.str;
         description = ''
-          Address of GoCD Server to attach the Go.CD Agent to.
-        '';
-      };
-
-      goServerPort = mkOption {
-        default = 8153;
-        type = types.int;
-        description = ''
-          Port that Go.CD Server is Listening on.
+          URL of the GoCD Server to attach the Go.CD Agent to.
         '';
       };
 
···
 
       extraOptions = mkOption {
         default = [ ];
-        example = [ 
-          "-X debug" 
+        example = [
+          "-X debug"
           "-Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5006"
           "-verbose:gc"
           "-Xloggc:go-agent-gc.log"
···
               config.environment.sessionVariables;
         in
           selectedSessionVars //
-            { 
+            {
               NIX_REMOTE = "daemon";
               AGENT_WORK_DIR = cfg.workDir;
               AGENT_STARTUP_ARGS = ''${concatStringsSep " "  cfg.startupOptions}'';
···
         ${pkgs.jre}/bin/java ${concatStringsSep " " cfg.startupOptions} \
                         ${concatStringsSep " " cfg.extraOptions} \
                               -jar ${pkgs.gocd-agent}/go-agent/agent-bootstrapper.jar \
-                              ${cfg.goServer} \
-                              ${toString cfg.goServerPort}
+                              -serverUrl ${cfg.goServer}
       '';
 
       serviceConfig = {
         User = cfg.user;
         WorkingDirectory = cfg.workDir;
+        RestartSec = 30;
+        Restart = "on-failure";
       };
     };
   };

nixos/tests/gocd-agent.nix

···
 
 let
   serverUrl = "localhost:8153/go/api/agents";
-  header = "Accept: application/vnd./go.cd/v2+json";
+  header = "Accept: application/vnd.go.cd.v2+json";
 in
 
 import ./make-test.nix ({ pkgs, ...} : {
···
     maintainers = [ grahamc swarren83 ];
   };
 
-nodes = {
-  gocd_agent =
-    { config, pkgs, ... }:
-    { 
-      virtualisation.memorySize = 2048;
-      services.gocd-agent = {
-        enable = true;
-      };
-      services.gocd-server = {
-        enable = true;
+  nodes = {
+    gocd_agent =
+      { config, pkgs, ... }:
+      {
+        virtualisation.memorySize = 2048;
+        services.gocd-agent = {
+          enable = true;
+        };
+        services.gocd-server = {
+          enable = true;
+        };
       };
-    };
-};
+  };
 
   testScript = ''
     startAll;
     $gocd_agent->waitForUnit("gocd-server");
     $gocd_agent->waitForOpenPort("8153");
     $gocd_agent->waitForUnit("gocd-agent");
-    $gocd_agent->waitUntilSucceeds("curl -s -f ${serverUrl} -H '${header}' | awk -F \" '/\"uuid\":\s\"[a-zA-Z0-9]{8}-[a-zA-Z0-9]{4}-[a-zA-Z0-9]{4}-[a-zA-Z0-9]{4}-[a-zA-Z0-9]{12}/ {print $4}'");
-    $gocd_agent->waitUntilSucceeds("curl -s -f ${serverUrl} -H '${header}' | awk -F \" '/\"agent_state\":\s\"Idle\"/'");
+    $gocd_agent->waitUntilSucceeds("curl ${serverUrl} -H '${header}' | ${pkgs.jq}/bin/jq -e ._embedded.agents[0].uuid");
+    $gocd_agent->succeed("curl ${serverUrl} -H '${header}' | ${pkgs.jq}/bin/jq -e ._embedded.agents[0].agent_state | grep -q Idle");
   '';
 })