updated docs and added a missing test

Author: ram-pivot

TILE_AUTHOR_GUIDE.md

@@ -129,6 +129,43 @@ The property definition in [releen/hello-tile/properties/hello.yml](https://gith
 in referenced in `base.yml` using `$( property "port" )`.
 Most other product template part functions behave similarly.
 
+### Carvel / Kubernetes Tile Metadata (`base.yml`)
+
+When building Carvel/Kubernetes tiles using `kiln carvel bake`, the `base.yml` metadata file supports the following additional top-level fields:
+
+- `supports_parallel_deploys` (boolean): Indicates whether the tile supports parallel deployments in Ops Manager.
+- `requires_product_versions` (list): Specifies product version dependencies required by the tile.
+  - `name`: Product name.
+  - `version`: Version requirement constraint (e.g. `>=1.0.0`).
+  - `optional` (boolean): Whether the dependency is optional.
+- `compatible_kubernetes_distributions` (list): Supported Kubernetes distribution criteria.
+  - `name`: Distribution name (e.g. `k0s`).
+  - `version`: Version requirement constraint (e.g. `>0.0.0`).
+- `package_installs` (list): References to Carvel package install templates.
+
+Example Carvel tile `base.yml`:
+
+```yaml
+name: k8s-tile-name
+label: "My K8s Tile"
+icon_image: $( icon )
+metadata_version: "3.2.0"
+minimum_version_for_upgrade: 0.0.0
+product_version: $( version )
+rank: 1
+serial: false
+supports_parallel_deploys: true
+requires_product_versions:
+  - name: some-other-product
+    version: ">=1.0.0"
+    optional: true
+compatible_kubernetes_distributions:
+  - name: k0s
+    version: ">0.0.0"
+package_installs:
+  - $( package "my-package" )
+```
+
 ## <a id="bosh-release-tarballs"></a> Managing BOSH Release Tarballs
 
 `kiln fetch` downloads BOSH Release Tarballs from any of the following "sources"

internal/acceptance/carvel/fixtures/sample-tile/base.yml

@@ -17,3 +17,8 @@ package_installs:
 compatible_kubernetes_distributions:
 - name: k0s
   version: '>0.0.0'
+supports_parallel_deploys: true
+requires_product_versions:
+- name: some-other-product
+  version: '>=1.0.0'
+  optional: true

internal/carvel/baker_test.go

@@ -558,6 +558,48 @@ consumes:
 					Expect(err.Error()).To(ContainSubstring("tile metadata_version too old"))
 				})
 			})
+
+			When("the tile does not set parallel deploys or product version requirements", func() {
+				BeforeEach(func() {
+					m := models.Metadata{
+						Name:                     "k8s-tile-test",
+						Label:                    "test tile",
+						IconImage:                "$( icon )",
+						MetadataVersion:          "3.2.0",
+						MinimumVersionForUpgrade: "0.0.0",
+						ProductVersion:           "$( version )",
+						Rank:                     1,
+						Serial:                   false,
+						PropertyBlueprints: []string{
+							`$( property "database_name" )`,
+							`$( property "admin_password" )`,
+						},
+						FormTypes:       []string{`$( form "db_props" )`},
+						Variables:       []proofing.Variable{},
+						PackageInstalls: []string{`$( package "test-install" )`},
+					}
+					yamlData, err := yaml.Marshal(&m)
+					Expect(err).NotTo(HaveOccurred())
+					err = os.WriteFile(path.Join(inputPath, "base.yml"), yamlData, 0644) // 0644 sets file permissions
+					Expect(err).NotTo(HaveOccurred())
+				})
+
+				It("omits both fields from the generated base.yml", func() {
+					Expect(err).NotTo(HaveOccurred())
+
+					yamlPath := path.Join(outputPath, "base.yml")
+					rawYaml, err := os.ReadFile(yamlPath)
+					Expect(err).NotTo(HaveOccurred())
+					Expect(string(rawYaml)).NotTo(ContainSubstring("supports_parallel_deploys"))
+					Expect(string(rawYaml)).NotTo(ContainSubstring("requires_product_versions"))
+
+					outMeta := models.MetadataOut{}
+					err = yaml.Unmarshal(rawYaml, &outMeta)
+					Expect(err).NotTo(HaveOccurred())
+					Expect(outMeta.SupportsParallelDeploys).To(BeFalse())
+					Expect(outMeta.RequiresProductVersions).To(BeEmpty())
+				})
+			})
 		})
 	})