feat: add support for nix store paths in variables

by exporting them at runtime and removing them from the pipeline
definition itself
closes #3

flake.nix

@@ -42,9 +42,14 @@
               when = "delayed";
               start_in = "1 hour";
               deps = [pkgs.hello pkgs.curl];
+              variables = {
+                TEST = "test";
+                TEST_WITH_DERIVATION = "${pkgs.hello}/test";
+              };
               script = [
                 "hello"
                 "curl google.de"
+                "echo $TEST $TEST_WITH_DERIVATION"
               ];
             };
             "test-non-nix" = {

lib/flakeModule.nix

@@ -138,10 +138,25 @@
         # before, we just allowed pkgs inside the script string directly, but now with the ability to source this file
         # we can support different architectures between runners (eg. the arch of the initial runner does not matter)
         jobsMappedForDeps =
-          mapAttrs (key: job: {
+          mapAttrs (key: job: let
+            variablesWithStorePaths =
+              lib.concatMapAttrs (
+                name: value:
+                  if lib.hasInfix "/nix/store/" value
+                  then {
+                    ${name} = value;
+                  }
+                  else {}
+              )
+              (job.variables or {});
+            variableExports = lib.concatMapStrings (x: "${x}\n") (
+              lib.mapAttrsToList (name: value: "export ${name}=\"${value}\"") variablesWithStorePaths
+            );
+          in {
             name = "gitlab-ci-job-deps:${key}";
             value = pkgs.writeShellScript "gitlab-ci-job-deps:${key}" ''
               export PATH="${lib.makeBinPath job.deps}:$PATH";
+              ${variableExports}
             '';
           })
           jobs;
@@ -166,6 +181,13 @@
                   job))
               // lib.optionalAttrs job.nix {
                 image = job.image;
+                variables = lib.concatMapAttrs (name: value:
+                  if lib.hasInfix "/nix/store/" value
+                  then {}
+                  else {
+                    ${name} = value;
+                  })
+                (job.variables or {});
               }
             ) ["nix" "deps"];
           })