nixos/modules/jenkins: Add option to add CLI

Signed-off-by: Pamplemousse <xav.maso@gmail.com>
(cherry picked from commit 4265efef54bd5e2fe6d7dff3241d69ef3e86b161)

nixos/modules/services/continuous-integration/jenkins/default.nix

@@ -2,6 +2,7 @@
 with lib;
 let
   cfg = config.services.jenkins;
+  jenkinsUrl = "http://${cfg.listenAddress}:${toString cfg.port}${cfg.prefix}";
 in {
   options = {
     services.jenkins = {
@@ -141,14 +142,34 @@ in {
           Additional command line arguments to pass to the Java run time (as opposed to Jenkins).
         '';
       };
+
+      withCLI = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Whether to make the CLI available.
+
+          More info about the CLI available at
+          <link xlink:href="https://www.jenkins.io/doc/book/managing/cli">
+          https://www.jenkins.io/doc/book/managing/cli</link> .
+        '';
+      };
     };
   };
 
   config = mkIf cfg.enable {
-    # server references the dejavu fonts
+    environment = {
-    environment.systemPackages = [
+      # server references the dejavu fonts
-      pkgs.dejavu_fonts
+      systemPackages = [
-    ];
+        pkgs.dejavu_fonts
+      ] ++ optional cfg.withCLI cfg.package;
+
+      variables = {}
+        // optionalAttrs cfg.withCLI {
+          # Make it more convenient to use the `jenkins-cli`.
+          JENKINS_URL = jenkinsUrl;
+        };
+    };
 
     users.groups = optionalAttrs (cfg.group == "jenkins") {
       jenkins.gid = config.ids.gids.jenkins;
@@ -215,7 +236,7 @@ in {
       '';
 
       postStart = ''
-        until [[ $(${pkgs.curl.bin}/bin/curl -L -s --head -w '\n%{http_code}' http://${cfg.listenAddress}:${toString cfg.port}${cfg.prefix} | tail -n1) =~ ^(200|403)$ ]]; do
+        until [[ $(${pkgs.curl.bin}/bin/curl -L -s --head -w '\n%{http_code}' ${jenkinsUrl} | tail -n1) =~ ^(200|403)$ ]]; do
           sleep 1
         done
       '';