Support LOG_FORMAT env variable.

nginx.tmpl

@@ -210,10 +210,7 @@ map $proxy_x_forwarded_proto $proxy_x_forwarded_ssl {
 
 gzip_types text/plain text/css application/javascript application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;
 
-log_format vhost '$host $remote_addr - $remote_user [$time_local] '
-                 '"$request" $status $body_bytes_sent '
-                 '"$http_referer" "$http_user_agent" '
-                 '"$upstream_addr"';
+log_format vhost '{{ or $globals.Env.LOG_FORMAT "$host $remote_addr - $remote_user [$time_local] \"$request\" $status $body_bytes_sent \"$http_referer\" \"$http_user_agent\" \"$upstream_addr\"" }}';
 
 access_log off;
 

test/test_log_format.py

@@ -0,0 +1,11 @@
+import pytest
+
+def test_log_format(docker_compose, nginxproxy):
+    r = nginxproxy.get("http://nginx-proxy.test/port")
+    assert r.status_code == 200
+    assert r.text == "answer from port 81\n"
+    sut_container = docker_compose.containers.get("sut")
+    docker_logs = sut_container.logs(stdout=True, stderr=True, stream=False, follow=False)
+    docker_logs = docker_logs.decode("utf-8").splitlines()
+    docker_logs = [line for line in docker_logs if "GET /port" in line]
+    assert "request_time=" in docker_logs[0]

test/test_log_format.yml

@@ -0,0 +1,17 @@
+# GIVEN a webserver with VIRTUAL_HOST set to web1.tld
+web1:
+  image: web
+  expose:
+    - "81"
+  environment:
+    WEB_PORTS: 81
+    VIRTUAL_HOST: nginx-proxy.test
+
+# WHEN nginx-proxy runs with DEFAULT_HOST set to web1.tld
+sut:
+  container_name: sut
+  image: nginxproxy/nginx-proxy:test
+  volumes:
+    - /var/run/docker.sock:/tmp/docker.sock:ro
+  environment:
+    LOG_FORMAT: "$$remote_addr - $$remote_user [$$time_local] \"$$request\" $$status $$body_bytes_sent \"$$http_referer\" \"$$http_user_agent\" request_time=$$request_time $$upstream_response_time"