How to correctly block access to a port forwarded docker container?

Ryan

2/9/23, 4:47 PM

I have a VPS running docker. I have an Apache container running that port forwards some random port to port 80 in the container.

I can hit my VPS IP on the random port and it loads the site as expected.

In addition, I've setup SSL on my Nginx reverse proxy and am wanting SSL termination via Nginx which forwards the request in cleartext to the container. This is also working, but the container port is still exposed to the outside world.

What is the recommended approach to only allow what is defined in my nginx conf to be what is exposed? In other words, how can I secure the container to be only accessible to nginx?

154

0 + 0

nginx

docker

Score:1

Server

Gerald Schneider

2/9/23, 4:50 PM

By default docker binds mapped ports to 0.0.0.0, which exposes it to all interfaces. If you don't want that, you can bind it to the local interface only.

docker run -p 127.0.0.1:8080:80 httpd

0 + 0

Ryan

2/9/23, 4:51 PM

Thanks, that was easy. For some reason I was thinking 0.0.0.0 was already binding to localhost and forgot it was exposing to all and not just local. Thanks for the quick response and explanation.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: How to correctly block access to a port forwarded docker container?

TH: จะบล็อกการเข้าถึงคอนเทนเนอร์นักเทียบท่าที่ส่งต่อพอร์ตได้อย่างไร

RO: Cum să blochezi corect accesul la un container docker redirecționat prin port?

RU: Как правильно заблокировать доступ к док-контейнеру с перенаправлением портов?

VI: Làm cách nào để chặn chính xác quyền truy cập vào bộ chứa docker chuyển tiếp cổng?

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.