[7.x] Optimistic concurrency control for updating ingest pipelines

modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/290_versioned_update.yml

@@ -0,0 +1,177 @@
+---
+"Test pipeline versioned updates":
+  - skip:
+      version: " - 7.15.99"
+      reason: "added versioned updates in 7.16.0"
+
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "set" : {
+                  "field" : "field2",
+                  "value": "_value"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  # conditional update fails because of missing version
+  - do:
+      catch: bad_request
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        if_version: 1
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "set" : {
+                  "field" : "field2",
+                  "value": "_value"
+                }
+              }
+            ]
+          }
+
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        body:  >
+          {
+            "description": "_description",
+            "version": 1,
+            "processors": [
+              {
+                "set" : {
+                  "field" : "field2",
+                  "value": "_value"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      ingest.get_pipeline:
+        id: "my_pipeline"
+  - match: { my_pipeline.version: 1 }
+
+  # required version does not match specified version
+  - do:
+      catch: bad_request
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        if_version: 99
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "set" : {
+                  "field" : "field2",
+                  "value": "_value"
+                }
+              }
+            ]
+          }
+
+  # may not update to same version
+  - do:
+      catch: bad_request
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        if_version: 1
+        body:  >
+          {
+            "version": 1,
+            "description": "_description",
+            "processors": [
+              {
+                "set" : {
+                  "field" : "field2",
+                  "value": "_value"
+                }
+              }
+            ]
+          }
+
+  # cannot conditionally update non-existent pipeline
+  - do:
+      catch: bad_request
+      ingest.put_pipeline:
+        id: "my_pipeline2"
+        if_version: 1
+        body:  >
+          {
+            "version": 1,
+            "description": "_description",
+            "processors": [
+              {
+                "set" : {
+                  "field" : "field2",
+                  "value": "_value"
+                }
+              }
+            ]
+          }
+
+  # conditionally update to specified version
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        if_version: 1
+        body:  >
+          {
+            "version": 99,
+            "description": "_description",
+            "processors": [
+              {
+                "set" : {
+                  "field" : "field2",
+                  "value": "_value"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      ingest.get_pipeline:
+        id: "my_pipeline"
+  - match: { my_pipeline.version: 99 }
+
+  # conditionally update without specified version
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        if_version: 99
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "set" : {
+                  "field" : "field2",
+                  "value": "_value"
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      ingest.get_pipeline:
+        id: "my_pipeline"
+  - match: { my_pipeline.version: 100 }
+
+  - do:
+      ingest.delete_pipeline:
+        id: "my_pipeline"
+  - match: { acknowledged: true }

rest-api-spec/src/main/resources/rest-api-spec/api/ingest.put_pipeline.json

@@ -27,6 +27,10 @@
       ]
     },
     "params":{
+      "if_version":{
+        "type":"int",
+        "description":"Required version for optimistic concurrency control for pipeline updates"
+      },
       "master_timeout":{
         "type":"time",
         "description":"Explicit operation timeout for connection to master node"

server/src/main/java/org/elasticsearch/action/ingest/PutPipelineRequest.java

@@ -8,6 +8,7 @@
 
 package org.elasticsearch.action.ingest;
 
+import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionRequestValidationException;
 import org.elasticsearch.action.support.master.AcknowledgedRequest;
 import org.elasticsearch.common.bytes.BytesReference;
@@ -22,27 +23,39 @@
 
 public class PutPipelineRequest extends AcknowledgedRequest<PutPipelineRequest> implements ToXContentObject {
 
-    private String id;
-    private BytesReference source;
-    private XContentType xContentType;
+    private final String id;
+    private final BytesReference source;
+    private final XContentType xContentType;
+    private final Integer version;
 
     /**
      * Create a new pipeline request with the id and source along with the content type of the source
      */
-    public PutPipelineRequest(String id, BytesReference source, XContentType xContentType) {
+    public PutPipelineRequest(String id, BytesReference source, XContentType xContentType, Integer version) {
         this.id = Objects.requireNonNull(id);
         this.source = Objects.requireNonNull(source);
         this.xContentType = Objects.requireNonNull(xContentType);
+        this.version = version;
+    }
+
+    public PutPipelineRequest(String id, BytesReference source, XContentType xContentType) {
+        this(id, source, xContentType, null);
     }
 
     public PutPipelineRequest(StreamInput in) throws IOException {
         super(in);
         id = in.readString();
         source = in.readBytesReference();
         xContentType = in.readEnum(XContentType.class);
+        if (in.getVersion().onOrAfter(Version.V_7_16_0)) {
+            version = in.readOptionalInt();
+        } else {
+            version = null;
+        }
     }
 
     PutPipelineRequest() {
+        this(null, null, null, null);
     }
 
     @Override
@@ -62,12 +75,19 @@ public XContentType getXContentType() {
         return xContentType;
     }
 
+    public Integer getVersion() {
+        return version;
+    }
+
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
         out.writeString(id);
         out.writeBytesReference(source);
         out.writeEnum(xContentType);
+        if (out.getVersion().onOrAfter(Version.V_7_16_0)) {
+            out.writeOptionalInt(version);
+        }
     }
 
     @Override

server/src/main/java/org/elasticsearch/ingest/IngestService.java

@@ -39,6 +39,7 @@
 import org.elasticsearch.cluster.metadata.MetadataIndexTemplateService;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.service.ClusterService;
+import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.regex.Regex;
 import org.elasticsearch.common.settings.Settings;
@@ -55,7 +56,9 @@
 import org.elasticsearch.plugins.IngestPlugin;
 import org.elasticsearch.script.ScriptService;
 import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.xcontent.XContentBuilder;
 
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -394,7 +397,9 @@ public void putPipeline(
 
         Map<String, Object> pipelineConfig = null;
         IngestMetadata currentIngestMetadata = state.metadata().custom(IngestMetadata.TYPE);
-        if (currentIngestMetadata != null && currentIngestMetadata.getPipelines().containsKey(request.getId())) {
+        if (request.getVersion() == null &&
+            currentIngestMetadata != null &&
+            currentIngestMetadata.getPipelines().containsKey(request.getId())) {
             pipelineConfig = XContentHelper.convertToMap(request.getSource(), false, request.getXContentType()).v2();
             PipelineConfiguration currentPipeline = currentIngestMetadata.getPipelines().get(request.getId());
             if (currentPipeline.getConfigAsMap().equals(pipelineConfig)) {
@@ -494,16 +499,66 @@ private static List<Tuple<Processor, IngestMetric>> getProcessorMetrics(Compound
         return processorMetrics;
     }
 
+    // visible for testing
     public static ClusterState innerPut(PutPipelineRequest request, ClusterState currentState) {
         IngestMetadata currentIngestMetadata = currentState.metadata().custom(IngestMetadata.TYPE);
+
+        BytesReference pipelineSource = request.getSource();
+        if (request.getVersion() != null) {
+            PipelineConfiguration currentPipeline = currentIngestMetadata != null
+                ? currentIngestMetadata.getPipelines().get(request.getId())
+                : null;
+            if (currentPipeline == null) {
+                throw new IllegalArgumentException(String.format(
+                    Locale.ROOT,
+                    "version conflict, required version [%s] for pipeline [%s] but no pipeline was found",
+                    request.getVersion(),
+                    request.getId()
+                ));
+            }
+
+            final Integer currentVersion = currentPipeline.getVersion();
+            if (Objects.equals(request.getVersion(), currentVersion) == false) {
+                throw new IllegalArgumentException(String.format(
+                    Locale.ROOT,
+                    "version conflict, required version [%s] for pipeline [%s] but current version is [%s]",
+                    request.getVersion(),
+                    request.getId(),
+                    currentVersion
+                ));
+            }
+
+            Map<String, Object> pipelineConfig = XContentHelper.convertToMap(request.getSource(), false, request.getXContentType()).v2();
+            final Integer specifiedVersion = (Integer) pipelineConfig.get("version");
+            if (pipelineConfig.containsKey("version") && Objects.equals(specifiedVersion, currentVersion)) {
+                throw new IllegalArgumentException(String.format(
+                    Locale.ROOT,
+                    "cannot update pipeline [%s] with the same version [%s]",
+                    request.getId(),
+                    request.getVersion()
+                ));
+            }
+
+            // if no version specified in the pipeline definition, inject a version of [request.getVersion() + 1]
+            if (specifiedVersion == null) {
+                pipelineConfig.put("version", request.getVersion() == null ? 1 : request.getVersion() + 1);
+                try {
+                    XContentBuilder builder = XContentBuilder.builder(request.getXContentType().xContent()).map(pipelineConfig);
+                    pipelineSource = BytesReference.bytes(builder);
+                } catch (IOException e) {
+                    throw new IllegalStateException(e);
+                }
+            }
+        }
+
         Map<String, PipelineConfiguration> pipelines;
         if (currentIngestMetadata != null) {
             pipelines = new HashMap<>(currentIngestMetadata.getPipelines());
         } else {
             pipelines = new HashMap<>();
         }
 
-        pipelines.put(request.getId(), new PipelineConfiguration(request.getId(), request.getSource(), request.getXContentType()));
+        pipelines.put(request.getId(), new PipelineConfiguration(request.getId(), pipelineSource, request.getXContentType()));
         ClusterState.Builder newState = ClusterState.builder(currentState);
         newState.metadata(Metadata.builder(currentState.getMetadata())
             .putCustom(IngestMetadata.TYPE, new IngestMetadata(pipelines))

server/src/main/java/org/elasticsearch/ingest/PipelineConfiguration.java

@@ -96,6 +96,22 @@ BytesReference getConfig() {
         return config;
     }
 
+    public Integer getVersion() {
+        Map<String, Object> configMap = getConfigAsMap();
+        if (configMap.containsKey("version")) {
+            Object o = configMap.get("version");
+            if (o == null) {
+                return null;
+            } else if (o instanceof Number) {
+                return ((Number) o).intValue();
+            } else {
+                throw new IllegalStateException("unexpected version type [" + o.getClass().getName() + "]");
+            }
+        } else {
+            return null;
+        }
+    }
+
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject();