Add SkaffoldYamlGenerator (#16)

Author: TadCordle

skaffold-plugins-core/src/main/java/com/google/cloud/tools/skaffold/yaml/SkaffoldYamlGenerator.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2018 Google LLC. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.google.cloud.tools.skaffold.yaml;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableList;
+
+/**
+ * Automatically generates contents of a skaffold.yaml from a provided set of Kubernetes manifests.
+ */
+public class SkaffoldYamlGenerator {
+
+  private final ImmutableList<String> manifestPaths;
+
+  /**
+   * Creates a new {@link SkaffoldYamlGenerator}.
+   *
+   * @param manifestPaths a non-empty list of paths to Kubernetes yamls (may include glob patterns)
+   */
+  public SkaffoldYamlGenerator(ImmutableList<String> manifestPaths) {
+    Preconditions.checkArgument(manifestPaths.size() > 0);
+    this.manifestPaths = manifestPaths;
+  }
+
+  /**
+   * Generates the skaffold.yaml contents.
+   *
+   * @return the skaffold.yaml contents as a string
+   */
+  public String generate() {
+    StringBuilder output = new StringBuilder();
+    output.append("apiVersion: skaffold/v1alpha2\n");
+    output.append("kind: Config\n");
+    output.append("deploy:\n");
+    output.append("  kubectl:\n");
+
+    // Add manifests
+    output.append("    manifests:\n");
+    for (String manifestPath : manifestPaths) {
+      output.append("    - ");
+      output.append(manifestPath);
+      output.append("\n");
+    }
+
+    return output.toString();
+  }
+}

skaffold-plugins-core/src/test/java/com/google/cloud/tools/skaffold/yaml/SkaffoldYamlGeneratorTest.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2018 Google LLC. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.google.cloud.tools.skaffold.yaml;
+
+import com.google.common.base.Joiner;
+import com.google.common.collect.ImmutableList;
+import com.google.common.io.Resources;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.List;
+import org.junit.Assert;
+import org.junit.Test;
+
+/** Tests for {@link SkaffoldYamlGenerator}. */
+public class SkaffoldYamlGeneratorTest {
+
+  @Test
+  public void testGenerate() throws URISyntaxException, IOException {
+    // Read all lines and join with \n to avoid Windows test failing
+    List<String> lines =
+        Files.readAllLines(
+            Paths.get(Resources.getResource("SkaffoldYamlGeneratorTest/generated.yaml").toURI()),
+            StandardCharsets.UTF_8);
+    String expected = Joiner.on('\n').join(lines) + "\n";
+
+    ImmutableList<String> paths = ImmutableList.of("MANIFEST_PATH_1", "MANIFEST_PATH_2");
+    SkaffoldYamlGenerator generator = new SkaffoldYamlGenerator(paths);
+
+    Assert.assertEquals(expected, generator.generate());
+  }
+}

skaffold-plugins-core/src/test/resources/SkaffoldYamlGeneratorTest/generated.yaml

@@ -0,0 +1,7 @@
+apiVersion: skaffold/v1alpha2
+kind: Config
+deploy:
+  kubectl:
+    manifests:
+    - MANIFEST_PATH_1
+    - MANIFEST_PATH_2