Use ETag header received from backend

app/assets/javascripts/pipelines/components/graph/graph_component_wrapper.vue

@@ -23,6 +23,9 @@ export default {
     pipelineProjectPath: {
       default: '',
     },
+    graphqlResourceEtag: {
+      default: '',
+    },
   },
   data() {
     return {
@@ -45,7 +48,7 @@ export default {
           },
           headers: {
             'X-GITLAB-GRAPHQL-FEATURE-CORRELATION': 'verify/ci/pipeline-graph',
-            'X-GITLAB-GRAPHQL-RESOURCE-ETAG': `pipelines/id/${this.pipelineIid}`,
+            'X-GITLAB-GRAPHQL-RESOURCE-ETAG': this.graphqlResourceEtag,
             'X-REQUESTED_WITH': 'XMLHttpRequest',
           },
         };

app/assets/javascripts/pipelines/components/graph/linked_pipelines_column.vue

@@ -72,14 +72,17 @@ export default {
       this.$apollo.addSmartQuery('currentPipeline', {
         query: getPipelineDetails,
         pollInterval: 10000,
-        context: {
-          fetchOptions: {
-            method: 'GET',
-          },
-          headers: {
-            'X-GITLAB-GRAPHQL-FEATURE-CORRELATION': 'verify/ci/pipeline-graph',
-            'X-GITLAB-GRAPHQL-RESOURCE-ETAG': 'pipelines/id/123',
-          },
+        context() {
+          return {
+            fetchOptions: {
+              method: 'GET',
+            },
+            headers: {
+              'X-GITLAB-GRAPHQL-FEATURE-CORRELATION': 'verify/ci/pipeline-graph',
+              'X-GITLAB-GRAPHQL-RESOURCE-ETAG': this.graphqlResourceEtag,
+              'X-REQUESTED_WITH': 'XMLHttpRequest',
+            },
+          }
         },
         variables() {
           return {

app/assets/javascripts/pipelines/pipeline_details_bundle.js

@@ -99,6 +99,7 @@ export default async function initPipelineDetailsBundle() {
         pipelineProjectPath,
         pipelineIid,
         metricsPath,
+        graphqlResourceEtag,
       );
     } catch {
       Flash(__('An error occurred while loading the pipeline.'));

app/assets/javascripts/pipelines/pipeline_details_graph.js

@@ -16,7 +16,7 @@ const apolloProvider = new VueApollo({
   ),
 });
 
-const createPipelinesDetailApp = (selector, pipelineProjectPath, pipelineIid, metricsPath) => {
+const createPipelinesDetailApp = (selector, pipelineProjectPath, pipelineIid, metricsPath, graphqlResourceEtag) => {
   // eslint-disable-next-line no-new
   new Vue({
     el: selector,
@@ -28,6 +28,7 @@ const createPipelinesDetailApp = (selector, pipelineProjectPath, pipelineIid, me
       metricsPath,
       pipelineProjectPath,
       pipelineIid,
+      graphqlResourceEtag,
       dataMethod: GRAPHQL,
     },
     errorCaptured(err, _vm, info) {