graph: Add a boolean gauge to track failure status of deployments

Author: lutter

core/src/subgraph/instance_manager.rs

@@ -555,6 +555,7 @@ where
             }
 
             let start = Instant::now();
+            let deployment_failed = ctx.block_stream_metrics.deployment_failed.clone();
 
             let res = process_block(
                 &logger,
@@ -579,6 +580,7 @@ where
 
                         ctx.inputs.store.unfail()?;
                     }
+                    deployment_failed.set(0.0);
 
                     if needs_restart {
                         // Cancel the stream for real
@@ -613,6 +615,7 @@ where
                         handler: None,
                         deterministic: e.is_deterministic(),
                     };
+                    deployment_failed.set(1.0);
 
                     store_for_err
                         .fail_subgraph(error)

graph/src/blockchain/block_stream.rs

@@ -84,6 +84,7 @@ pub enum BlockStreamEvent<C: Blockchain> {
 #[derive(Clone)]
 pub struct BlockStreamMetrics {
     pub deployment_head: Box<Gauge>,
+    pub deployment_failed: Box<Gauge>,
     pub reverted_blocks: Box<Gauge>,
     pub stopwatch: StopwatchMetrics,
 }
@@ -107,11 +108,19 @@ impl BlockStreamMetrics {
             .new_gauge(
                 "deployment_head",
                 "Track the head block number for a deployment",
-                labels,
+                labels.clone(),
             )
             .expect("failed to create `deployment_head` gauge");
+        let deployment_failed = registry
+            .new_gauge(
+                "deployment_failed",
+                "Boolean gauge to indicate whether the deployment has failed (1 == failed)",
+                labels,
+            )
+            .expect("failed to create `deployment_failed` gauge");
         Self {
             deployment_head,
+            deployment_failed,
             reverted_blocks,
             stopwatch,
         }