feat(migrations): Add spelLoadBalancersMigration (#1025)

Remove spelLoadBalancers and spelTargetGroups from all deploy stages' clusters objects.

Companion PR to spinnaker/deck#8957

Co-authored-by: Chris Thielen <github@sandgnat.com>

front50-migrations/src/main/java/com/netflix/spinnaker/front50/migrations/SpelLoadBalancersMigration.java

@@ -0,0 +1,86 @@
+package com.netflix.spinnaker.front50.migrations;
+
+import com.netflix.spinnaker.front50.model.pipeline.Pipeline;
+import com.netflix.spinnaker.front50.model.pipeline.PipelineDAO;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Component;
+
+@Component
+@Slf4j
+public class SpelLoadBalancersMigration implements Migration {
+  private final PipelineDAO pipelineDAO;
+
+  public SpelLoadBalancersMigration(PipelineDAO pipelineDAO) {
+    this.pipelineDAO = pipelineDAO;
+  }
+
+  public boolean isValid() {
+    return true;
+  }
+
+  public void run() {
+    log.info("Starting spelLoadBalancers migration");
+    Collection<Pipeline> pipelines = pipelineDAO.all();
+    int migratedCount = 0;
+    int failureCount = 0;
+    for (Pipeline pipeline : pipelines) {
+      try {
+        if (migrate(pipeline)) {
+          migratedCount++;
+        }
+      } catch (Exception e) {
+        log.error(
+            "Failed to migrate pipeline {} ({}) for {} spelLoadBalancersMigration",
+            pipeline.getName(),
+            pipeline.getId(),
+            pipeline.getApplication(),
+            e);
+        failureCount++;
+      }
+    }
+    log.info(
+        "Done with spelLoadBalancers migration (migrated {} pipelines; {} failed to migrate)",
+        migratedCount,
+        failureCount);
+  }
+
+  /** Removes spelLoadBalancers and spelTargetGroups from all deploy stage[].clusters[] */
+  private boolean migrate(Pipeline pipeline) {
+    List<Map<String, Object>> clusters =
+        ((List<Map<String, Object>>) pipeline.getOrDefault("stages", Collections.emptyList()))
+            .stream()
+                .filter(stage -> "deploy".equals(stage.get("type")))
+                .flatMap(
+                    stage ->
+                        ((List<Map<String, Object>>)
+                                stage.getOrDefault("clusters", Collections.emptyList()))
+                            .stream())
+                .filter(
+                    cluster ->
+                        cluster.get("spelLoadBalancers") != null
+                            || cluster.get("spelTargetGroups") != null)
+                .collect(Collectors.toList());
+
+    if (clusters.isEmpty()) {
+      return false;
+    }
+
+    for (Map<String, Object> cluster : clusters) {
+      cluster.remove("spelLoadBalancers");
+      cluster.remove("spelTargetGroups");
+    }
+    pipelineDAO.update(pipeline.getId(), pipeline);
+    log.info(
+        "Migrated pipeline {} ({}) for {} spelLoadBalancersMigration",
+        pipeline.getName(),
+        pipeline.getId(),
+        pipeline.getApplication());
+
+    return true;
+  }
+}