I have a container running HAProxy version 2.0 locally on Docker port 3001.
Config file is:
global
debug
defaults
log global
mode http
timeout connect 50000
timeout client 50000
timeout server 50000
frontend main
bind *:3000
default_backend app
backend app
balance leastconn
mode http
server dummy <localhostIP>:80
Docker file is:
FROM haproxy:2.0
COPY haproxy.cfg /usr/local/etc/haproxy/haproxy.cfg
Docker Run command:
docker run -p3001 --name my-running-haproxy my-haproxy
I am issuing a postman GET to port 3000 and expecting HaProxy to redirect to my server "dummy" on local port 80. But I am not able to get any legible response back. Appreciate any inputs.
If you run the the container like you did, Docker will assign a random port on your localhost and route traffic to port 3001. You can check which port that is by running docker ps after you started the container and looking at the PORTS section:
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
6b502af649be my-haproxy "/docker-entrypoint.…" 1 minute ago Up 47 minutes 0.0.0.0:32769->3001/tcp upbeat_shtern
So on my example, you can access your application on port 32769, but this number is random.
Keep in mind, that in your example, Docker routes traffic to port 3001, whereas you configured your HAProxy to bind to port 3000. You would at least need to change the docker run command to the following:
docker run -p3000 --name my-running-haproxy my-haproxy
But usually you want to have a fixed port on localhost, e.g. port 80. Start your container like this to achieve that:
docker run -p 80:3000 --name my-running-haproxy my-haproxy
Now you can access your application at localhost:80.
Related
I have a running Docker container which shows PORTS 9191/tcp. So on my browser, I tried accessing server using localhost:9191/api/.... However, browser throws an error This site can’t be reached
Here is a log to docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c214aefed15e shah "youtube-dl-server -…" 6 seconds ago Up 5 seconds 9191/tcp boring_swirles
This is what my docker file looks like
FROM mariozig/youtube-dl_server
RUN pip install --pre youtube_dl_server
EXPOSE 9191
ENTRYPOINT ["youtube-dl-server", "--host=0.0.0.0"]
You have not mapped the docker container port to host port.
The docker container runs on a host. And The host doesn't know which requests to be directed to the docker container. For that you have to to map the host port to docker container port using -p flag in docker run command as shown below:
docker run -d -p HOST_PORT:CONTAINER_PORT IMAGE_NAME
-p in this command will specify that you are forwarding your host port to the container port. In your local host in the port HOST_PORT will call the port CONTAINER_PORT of your container.
Now when you will access the HOST_IP:HOST_PORT then the host will redirect the request to corresponding container with which this HOST_PORT has been mapped.
For example I started a tomcat docker container and mapped the tomcat container's 8080 port to host's 9092 port by using the above command. When I do docker ps I can see the mapping under PORTS as 0.0.0.0:9092->8080/tcp
My Docker container is running Rails on port 3000, and I'm publishing the port to port 8900. See:
$ docker-compose ps
Name Command State Ports
rails_poc_1 /bin/sh -c puma -C config/ ... Up 0.0.0.0:3000->8900/tcp
However, when visiting http://localhost:8900 my browser displays ERR_CONNECTION_REFUSED.
When curling port 3000 from inside the container with docker exec 8fcceed1d477 curl localhost:3000 I get a valid response which proves Rails is working properly.
Am I overlooking something?
I think you have your port mapping reversed. Your ps line should look more like:
0.0.0.0:8900->3000/tcp
If you want to access 3000 outside the container as 8900
I unable to access docker exposed port on windows machine. In details I do the following:
$ docker build -t abc01 .
$ docker run -d -p 80:4000 abc01
Then I try to reach docker container in browser:
http://192.168.99.100:4000
and get annoying result:
This site can’t be reached 192.168.99.100 refused to connect.
What is the issue?
You are exposing the right ports, however, you need to access the website at: 80 instead of 4000, given that 4000 is the port on which your application is listening.
The way exposing ports in Docker works is as follows:
docker run -p 80:4000 myImage
where
80[is the outside port]
The one is exposed on your host and you will use it in your browser
4000 [is the inside port]
The port that is used inside the container by the application
I'm unable to access a nodejs based service via http://localhost:8000 running in a docker image. I'm using Docker for Mac (https://docs.docker.com/docker-for-mac/)
I'm following the tutorial here https://nodejs.org/en/docs/guides/nodejs-docker-webapp/.
The server runs on port 8000. I start the docker image with the following:
$ docker run -p 8000:8000 -d geuis/node-server:latest
If I run docker ps I see:
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
9fa2e446918b geuis/node-server:latest "npm start" 6 seconds ago Up 5 seconds 0.0.0.0:8000->8000/tcp unruffled_lewin
If I docker exec -it 9fa2e446918b /bin/bash I can access the docker vm and I can curl http://localhost:8000 and access the server from inside the container.
However, I try the same curl http://localhost:8000 from my system terminal and its not accessible.
Not sure what I need to do next.
Try the following listen statement:
app.listen(PORT, '0.0.0.0');
From reading the tutorial you mention it looks like express is listening on localhost. This is fine if you're running locally but inside of a container, localhost is not the same localhost that's outside of the container.
0.0.0.0 is the unspecified IPv4 address and so Express will bind on any IP it can find, which will be the IP that your requests are coming in from outside the container.
I'm running gunicorn inside a docker container. I know this works because sshing into it and curling localhost:8000/things in docker container gives me the response I want, however, I am not able to reach this on my host, despite docker telling me the port has been mapped. What gives?
I ran
docker run -d -p 80:8000 myapp:version1.1 /bin/bash -c 'gunicorn things:app'
docker ps gives me
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
614df1f2708e myapp:version1.1 "/bin/bash -c 'gunico" 6 minutes ago Up 6 minutes 5000/tcp, 0.0.0.0:80->8000/tcp evil_stallman
On my host, curling locahost/things gives me
curl: (52) Empty reply from server
However, when I docker exec -t -i 614df1f2708e /bin/bash and then curl localhost:8000/things, I succesfully get my correct response.
Why isn't docker mapping my port 8000 correctly?
When you publish a port, Docker will forward requests into the container, but the container needs to be listening for them. The container has an IP address from the Docker network, and your app needs to be listening on that address.
Check your gunicorn bind setting - if it's only listening on 127.0.0.1:8000 then it's not binding to the container's IP address, and won't get requests from outside. 0.0.0.0:8000 is safe as it will bind to all addresses.