From 8346b68a288ed20eab50a8dbeb959ac6e2ef5f15 Mon Sep 17 00:00:00 2001
From: Richard Hansen <rhansen@rhansen.org>
Date: Sat, 21 Jan 2023 19:11:28 -0500
Subject: [PATCH] fix: Ignore `VIRTUAL_HOST` set to the empty string

Fixes #2144
---
 nginx.tmpl                       |  4 ++++
 test/test_vhost-empty-string.py  | 10 +++++++++
 test/test_vhost-empty-string.yml | 37 ++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+)
 create mode 100644 test/test_vhost-empty-string.py
 create mode 100644 test/test_vhost-empty-string.yml

diff --git a/nginx.tmpl b/nginx.tmpl
index 18a2d23..f2e2bcf 100644
--- a/nginx.tmpl
+++ b/nginx.tmpl
@@ -271,6 +271,10 @@ server {
 {{- range $host, $containers := groupByMulti $globals.containers "Env.VIRTUAL_HOST" "," }}
 
     {{- $host := trim $host }}
+    {{- if not $host }}
+        {{- /* Ignore containers with VIRTUAL_HOST set to the empty string. */}}
+        {{- continue }}
+    {{- end }}
     {{- $is_regexp := hasPrefix "~" $host }}
     {{- $upstream_name := when (or $is_regexp $globals.sha1_upstream_name) (sha1 $host) $host }}
 
diff --git a/test/test_vhost-empty-string.py b/test/test_vhost-empty-string.py
new file mode 100644
index 0000000..707becb
--- /dev/null
+++ b/test/test_vhost-empty-string.py
@@ -0,0 +1,10 @@
+import re
+
+
+def test_vhost_empty_string(docker_compose, nginxproxy):
+    conf = nginxproxy.get_conf().decode()
+    assert re.search(r"(?m)^\s*server_name\s+web2\.nginx-proxy\.test\s*;", conf)
+    assert re.search(r"(?m)^\s*server_name\s+web3\.nginx-proxy\.test\s*;", conf)
+    assert re.search(r"(?m)^\s*server_name\s+web4a\.nginx-proxy\.test\s*;", conf)
+    assert re.search(r"(?m)^\s*server_name\s+web4b\.nginx-proxy\.test\s*;", conf)
+    assert not re.search(r"(?m)^\s*server_name\s*;", conf)
diff --git a/test/test_vhost-empty-string.yml b/test/test_vhost-empty-string.yml
new file mode 100644
index 0000000..83dd554
--- /dev/null
+++ b/test/test_vhost-empty-string.yml
@@ -0,0 +1,37 @@
+services:
+  sut:
+    image: nginxproxy/nginx-proxy:test
+    volumes:
+      - /var/run/docker.sock:/tmp/docker.sock:ro
+  web1:
+    image: web
+    expose:
+      - "81"
+    environment:
+      WEB_PORTS: "81"
+      # The space is intentional (should be trimmed).
+      VIRTUAL_HOST: " "
+  web2:
+    image: web
+    expose:
+      - "82"
+    environment:
+      WEB_PORTS: "82"
+      # The space is intentional (should be trimmed).
+      VIRTUAL_HOST: "web2.nginx-proxy.test ,"
+  web3:
+    image: web
+    expose:
+      - "83"
+    environment:
+      WEB_PORTS: "83"
+      # The space is intentional (should be trimmed).
+      VIRTUAL_HOST: " ,web3.nginx-proxy.test"
+  web4:
+    image: web
+    expose:
+      - "84"
+    environment:
+      WEB_PORTS: "84"
+      # The spaces are intentional (should be trimmed).
+      VIRTUAL_HOST: "web4a.nginx-proxy.test, , web4b.nginx-proxy.test"