From 6b4a8c8dbd4b2a7d48e1699e3e13204f372b1392 Mon Sep 17 00:00:00 2001
From: Johnny Graettinger <johnny@estuary.dev>
Date: Tue, 15 Oct 2024 18:16:51 -0500
Subject: [PATCH] go/network: remove creation publication ID from SNI cache

This prevents a deletion and re-creation of a task with the same name
from then failing to resolve, because both the old and new task will
share a common shardIDPrefix.
---
 go/network/sni.go      | 10 +++++++++-
 go/network/sni_test.go | 31 +++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 go/network/sni_test.go

diff --git a/go/network/sni.go b/go/network/sni.go
index e174d8608c..8be19822c7 100644
--- a/go/network/sni.go
+++ b/go/network/sni.go
@@ -64,8 +64,16 @@ func parseSNI(target string) (parsedSNI, error) {
 
 func newResolvedSNI(parsed parsedSNI, shard *pc.ShardSpec) resolvedSNI {
 	var shardIDPrefix = shard.Id.String()
+
+	// Strip final Shard ID suffix, like `00000000-00000000`.
+	if ind := strings.LastIndexByte(shardIDPrefix, '/'); ind != -1 {
+		shardIDPrefix = shardIDPrefix[:ind]
+	}
+	// Strip embedded creation publication ID, like `0123457890abcdef`.
+	// If we didn't do this, a deletion and creation of a task with the
+	// same name would break our resolution index cache.
 	if ind := strings.LastIndexByte(shardIDPrefix, '/'); ind != -1 {
-		shardIDPrefix = shardIDPrefix[:ind+1] // Including trailing '/'.
+		shardIDPrefix = shardIDPrefix[:ind+1] // Retain trailing '/'.
 	}
 
 	var portProtocol = shard.LabelSet.ValueOf(labels.PortProtoPrefix + parsed.port)
diff --git a/go/network/sni_test.go b/go/network/sni_test.go
new file mode 100644
index 0000000000..6f7913a7f7
--- /dev/null
+++ b/go/network/sni_test.go
@@ -0,0 +1,31 @@
+package network
+
+import (
+	"testing"
+
+	"github.com/estuary/flow/go/labels"
+	"github.com/stretchr/testify/require"
+	pb "go.gazette.dev/core/broker/protocol"
+	pc "go.gazette.dev/core/consumer/protocol"
+)
+
+func TestResolveSNIMapping(t *testing.T) {
+	var (
+		parsed = parsedSNI{
+			hostname: "abcdefg",
+			port:     "8080",
+		}
+		shard = &pc.ShardSpec{
+			Id: "capture/AcmeCo/My/Capture/source-http-ingest/0f05593ad1800023/00000000-00000000",
+			LabelSet: pb.MustLabelSet(
+				labels.PortProtoPrefix+"8080", "leet",
+				labels.PortPublicPrefix+"8080", "true",
+			),
+		}
+	)
+	require.Equal(t, resolvedSNI{
+		shardIDPrefix: "capture/AcmeCo/My/Capture/source-http-ingest/",
+		portProtocol:  "leet",
+		portIsPublic:  true,
+	}, newResolvedSNI(parsed, shard))
+}