I am trying to do a connection to a websocket from a html page in django. This works when i run it outside a container but it stops working inside of it .
My server inside my docker compose.
server:
stdin_open: true # docker run -i
tty: true # docker run -t
build:
dockerfile: server.Dockerfile
context: ./
volumes:
- /home/$USER/.ssh:/root/.ssh
ports:
- '8000:8000'
networks:
drone_net:
ipv4_address: 10.10.10.2
the url I use in my html page
let url = `ws://localhost:8000/ws/socket-server/`
The error i get: WebSocket connection to 'ws://localhost:8000/ws/socket-server/' failed:
This is my routing for the websocket :
websocket_urlpatterns=[
re_path(r'ws/socket-server/',consumers.ChatConsumer.as_asgi())
]
I first thought it was localhost not working but my http request works in the containe as well.
I tried to change the value of the url with different ones.
I thought it was localhost that wasnt working properly but i also use local host for http request and they were fine in the container.
I was expecting it to work.
I found the solution. Weirldy it was a problem of package channel Version. In the docker file, I took the most recent version of channels: 4.0.0. While my local computer was using channels.version 3.0.5. When I downgraded the version, it solved my problem.
Related
Both my backend (localhost:8000) and frontend (locahost:5000) containers spin up and are accessible through the browser, but I can't access the backend container from the frontend container.
From within frontend:
/usr/src/nuxt-app # curl http://localhost:8000 -v
* Trying 127.0.0.1:8000...
* TCP_NODELAY set
* connect to 127.0.0.1 port 8000 failed: Connection refused
* Trying ::1:8000...
* TCP_NODELAY set
* Immediate connect fail for ::1: Address not available
* Trying ::1:8000...
* TCP_NODELAY set
* Immediate connect fail for ::1: Address not available
* Failed to connect to localhost port 8000: Connection refused
* Closing connection 0
curl: (7) Failed to connect to localhost port 8000: Connection refused
My nuxt app (frontend) is using axios to call http://localhost:8000/preview/api/qc/. When the frontend starts up, I can see axios catching errorError: connect ECONNREFUSED 127.0.0.1:8000. In the console it says [HMR] connected though.
If I make a change to index.vue, the frontend reloads and then in the console it displays:
access to XMLHttpRequest at 'http://localhost:8000/preview/api/qc/' from origin 'http://localhost:5000' has been blocked by CORS policy: Request header field access-control-allow-origin is not allowed by Access-Control-Allow-Headers in preflight response. VM11:1 GET http://localhost:8000/preview/api/qc/ net::ERR_FAILED
I have already setup django-cors-headers (included it in INSTALLED_APPS, and set ALLOWED_HOSTS = ['*'] and CORS_ALLOW_ALL_ORIGINS = True).
In my nuxt.config.js I have set
axios: {
headers : {
"Access-Control-Allow-Origin": ["*"],
}
},
I'm stuck as to what is going wrong. I think it's likely my docker-compose or Dockerfile.
docker-compose.yml
backend:
build: ./backend
volumes:
- ./backend:/srv/app
ports:
- "8000:8000"
command: python manage.py runserver 0.0.0.0:8000
depends_on:
- db
networks:
- main
frontend:
build:
context: ./frontend
volumes:
- ./frontend:/usr/src/nuxt-app
- /usr/src/nuxt-app/node_modules
command: >
sh -c "yarn build && yarn dev"
ports:
- "5000:5000"
depends_on:
- backend
networks:
- main
networks:
main:
driver: bridge
Dockerfile
FROM node:15.14.0-alpine3.10
WORKDIR /usr/src/nuxt-app
RUN apk update && apk upgrade
RUN npm install -g npm#latest
COPY package*.json ./
RUN npm install
EXPOSE 5000
ENV NUXT_HOST=0.0.0.0
ENV NUXT_PORT=5000
What am I missing?
I think you have 2 different errors.
The first one.
My nuxt app (frontend) is using axios to call http://localhost:8000/preview/api/qc/. When the frontend starts up, I can see axios catching errorError: connect ECONNREFUSED 127.0.0.1:8000. In the console it says [HMR] connected though.
This is SSR requests from nuxt to django. Nuxt app inside the container cannot connect to localhost:8000. But you can connect to django container via http://django_container:8000/api/qc/ where django_container is name of you django container.
In nuxt config you can set up different URLs for server and client side like this. So SSR requests go to docker django container directly and client side requests go to the localhost port.
nuxt.config.js
export default {
// ...
// Axios module configuration: https://go.nuxtjs.dev/config-axios
axios: {
baseURL: process.browser ? 'http://localhost:8000' : 'http://django_container:8000'
},
// ...
}
The second one.
access to XMLHttpRequest at 'http://localhost:8000/preview/api/qc/' from origin 'http://localhost:5000' has been blocked by CORS policy: Request header field access-control-allow-origin is not allowed by Access-Control-Allow-Headers in preflight response. VM11:1 GET http://localhost:8000/preview/api/qc/ net::ERR_FAILED
This is client side request from your browser to django. I think it's better to set CORS_ORIGIN_WHITELIST explicitly. Also you can allow CORS_ALLOW_CREDENTIALS. I can't guarantee it, but I hope it helps.
CORS_ALLOW_CREDENTIALS = True
CORS_ORIGIN_WHITELIST = ['http://localhost:5000', 'http://127.0.0.1:5000']
I am trying to add a tensorboard container to an existing microservice structure running behind traefik. Unfortunately, the traefik version is 1.5 so a lot of recent articles are not helpful.
Since there is a default service on www.my-server.com/, I am trying to have traefik redirect to the tensorboard service from www.my-server.com/tensorboard/. Here is my docker-compose (the part relevant for tensorboard)
tensorboard:
build: "./docker/build/images/tensorflow"
container_name: tensorboard
command: tensorboard --logdir=runs --port=8888 --host=0.0.0.0
labels:
- log.level=debug
- traefik.enable=true
- traefik.frontend.rule=Host:www.my-server.com;PathPrefix:/tensorboard/
volumes:
- ./machine_learning:/opt/src
ipc: host
When I visit www.my-server.com/tensorboard/ I get "Not Found". If I remove the host argument from the command I get "Bad Gateway". I don't understand what either of these mean but I think one of them is being able to reach the service but the service is getting the request with the prefix tensorboard and is complaining.
How do I make this work?
Turns out that the following command will solve this problem
tensorboard --logdir mylogdir --bind_all --path_prefix=/tensorboard
He everyone. I'm working with docker and trying to dockerize a simple django application that does an external http connect to a web page (real website)
so when I set in the Docker file the address of my django server that should work in the container - 127.0.0.1:8000. my app wasn't working because of the impossibility to do an external connection to the website.
but when I set the port for my server: 0.0.0.0:8000 it started to work.
So my question is: Why it behaves like that? What is the difference in this particular case? I just want to understand it.
I read some articles about 0.0.0.0 and it's like a 'generic' or 'placeholder' port that allows to use the OC default port.
127.0.0.1 is like a host that redirects the request to the current machine. I knew it.
But when I run the app at my localmachine (host: 127.0.0.0:8000) everything was working and the app could do the connection to the real website but in case of docker it stopped to work.
Thanks for any help!
Here are my sources:
Docker file
FROM python:3.6
RUN mkdir /code
WORKDIR /code
COPY requirements.txt ./
RUN pip install --no-cache-dir -r requirements.txt
COPY . ./
EXPOSE 8000
ENTRYPOINT [ "python", "manage.py" ]
CMD [ "runserver", "127.0.0.1:8000" ] # doesn't work
# CMD [ "runserver", "0.0.0.0:8000" ] - works
docker-compose.yml
version: "3"
services:
url_rest:
container_name: url_keys_rest
build:
context: .
dockerfile: Dockerfile
image: url_keys_rest_image
stdin_open: true
tty: true
volumes:
- .:/var/www/url_keys
ports:
- "8000:8000"
here is the http error that I received in case of 127.0.0.1. Maybe it will be useful.
http: error: ConnectionError: HTTPConnectionPool(host='127.0.0.1', port=8000): Max retries exceeded with url: /api/urls (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x10cd51e80>: Failed to establish a new connection: [Errno 61] Connection refused')) while doing GET request to URL: http://127.0.0.1:8000/api/urls
You must set a container’s main process to bind to the special 0.0.0.0 “all interfaces” address, or it will be unreachable from outside the container.
In Docker 127.0.0.1 almost always means “this container”, not “this machine”. If you make an outbound connection to 127.0.0.1 from a container it will return to the same container; if you bind a server to 127.0.0.1 it will not accept connections from outside.
One of the core things Docker does is to give each container its own separate network space. In particular, each container has its own lo interface and its own notion of localhost.
At a very low level, network services call the bind(2) system call to start accepting connections. That takes an address parameter. It can be one of two things: either it can be the IP address of some system interface, or it can be the special 0.0.0.0 “all interfaces” address. If you pick an interface, it will only accept connections from that interface; if you have two network cards on a physical system, for example, you can use this to only accept connections from one network but not the other.
So, if you set a service to bind to 127.0.0.1, that’s the address of the lo interface, and the service will only accept connections from that interface. But each container has its own lo interface and its own localhost, so this setting causes the service to refuse connections unless they’re initiated from within the container itself. It you set it to bind to 0.0.0.0, it will also accept connections from the per-container eth0 interface, where all connections from outside the container arrive.
My understanding is that docker is randomly assigning IP address to each container instead of localhost(127.*.*.*). So using 0.0.0.0 to listen inside the docker application will work. I tried to connect local database inside a docker file before with localhost. It doesn't work as well. I guess it is due to this reason. Correct me if I am wrong plz!
Update: I attach an intuitive image to show how docker interact with those ip addresses. Hope this will help to understand.
I keep on getting the error message: redis.exceptions.ResponseError: NOAUTH Authentication required.. (I'm using celery to perform background tasks).
My settings.py looks like this:
CELERY_BROKER_URL = 'redis://user:my_strong_password#'+REDIS_IP+':6379/0'
the docker-compose I have:
services:
redis:
image: redis:latest
container_name: jh_redis
ports:
- '6379:6379'
command: redis-server --appendonly yes --requirepass my_strong_password
you can see that my attempt to provide the password (--requirepass) is exactly as it shown in the settings.py however, while the docker is up and running I still get the subject error message.
I have tried different combination such as:
--requirepass user:my_strong_password
but still didn't work.
Note: when I take off the entire command line - it works (but 32 hours after - I get the error message and it stop working).
What should be the appropriate settings in docker-compose to have it work smoothly?
According to the celery docs, your broker url should be in this format:
redis://:password#hostname:port/db_number
i.e., you should remove user from the broker_url.
I have Docker configured to run Postgres and Django using docker-compose.yml and it is working fine.
The trouble I am having is with Selenium not being able to connect to the Django liveserver.
Now it makes sense (to me at least) that django has to access selenium to control the browser and selenium has to access django to access the server.
I have tried using the docker 'ambassador' pattern using the following configuration for docker-compose.yml from here: https://github.com/docker/compose/issues/666
postgis:
dockerfile: ./docker/postgis/Dockerfile
build: .
container_name: postgis
django-ambassador:
container_name: django-ambassador
image: cpuguy83/docker-grand-ambassador
volumes:
- "/var/run/docker.sock:/var/run/docker.sock"
command: "-name django -name selenium"
django:
dockerfile: ./docker/Dockerfile-dev
build: .
command: python /app/project/manage.py test my-app
container_name: django
volumes:
- .:/app
ports:
- "8000:8000"
- "8081:8081"
links:
- postgis
- "django-ambassador:selenium"
environment:
- SELENIUM_HOST=http://selenium:4444/wd/hub
selenium:
container_name: selenium
image: selenium/standalone-firefox-debug
ports:
- "4444:4444"
- "5900:5900"
links:
- "django-ambassador:django"
When I check http://DOCKER-MACHINE-IP:4444/wd/hub/static/resource/hub.html
I can see that firefox starts, but all the tests fail as firefox is unable to connect to django
'Firefox can't establish a connection to the server at localhost:8081'
I also tried this solution here https://github.com/docker/compose/issues/1991
however this is not working cause I can't get django to connect to postgis and selenium at the same time
'django.db.utils.OperationalError: could not translate host name "postgis" to address: Name or service not known'
I tried using the networking feature as listed below
postgis:
dockerfile: ./docker/postgis/Dockerfile
build: .
container_name: postgis
net: appnet
django:
dockerfile: ./docker/Dockerfile-dev
build: .
command: python /app/project/manage.py test foo
container_name: django
volumes:
- .:/app
ports:
- "8000:8000"
- "8081:8081"
net: appnet
environment:
- SELENIUM_HOST=http://selenium:4444/wd/hub
selenium:
container_name: selenium
image: selenium/standalone-firefox-debug
ports:
- "4444:4444"
- "5900:5900"
net: appnet
but the result is the same
'Firefox can't establish a connection to the server at localhost:8081'
So how can I get selenium to connect to django?
I have been playing around with this for days - would really appreciate any help.
More Info
Another weird thing is that when the testserver is running not using docker (using my old config of virtualenv etc.) if I run ./manage.py test foo I can access the server through any browser at http://localhost:8081 and get served up webpages, but I can't access the test server when I run the equivalent command if I run it under docker. This is weird cause I am mapping port 8081:8081 - is this related?
Note: I am using OSX and Docker v1.9.1
I ended up coming up with a better solution that didn't require me to hardcode the IP Address. Below is the configuration I used to run tests in django with docker.
Docker-compose file
# docker-compose base file for everything
version: '2'
services:
postgis:
build:
context: .
dockerfile: ./docker/postgis/Dockerfile
container_name: postgis
volumes:
# If you are using boot2docker, postgres data has to live in the VM for now until #581 fixed
# for more info see here: https://github.com/boot2docker/boot2docker/issues/581
- /data/dev/docker_cookiecutter/postgres:/var/lib/postgresql/data
django:
build:
context: .
dockerfile: ./docker/django/Dockerfile
container_name: django
volumes:
- .:/app
depends_on:
- selenium
- postgis
environment:
- SITE_DOMAIN=django
- DJANGO_SETTINGS_MODULE=settings.my_dev_settings
links:
- postgis
- mailcatcher
selenium:
container_name: selenium
image: selenium/standalone-firefox-debug:2.52.0
ports:
- "4444:4444"
- "5900:5900"
Dockerfile (for Django)
ENTRYPOINT ["/docker/django/entrypoint.sh"]
In Entrypoint file
#!/bin/bash
set -e
# Now we need to get the ip address of this container so we can supply it as an environmental
# variable for django so that selenium knows what url the test server is on
# Use below or alternatively you could have used
# something like "$# --liveserver=$THIS_DOCKER_CONTAINER_TEST_SERVER"
if [[ "'$*'" == *"manage.py test"* ]] # only add if 'manage.py test' in the args
then
# get the container id
THIS_CONTAINER_ID_LONG=`cat /proc/self/cgroup | grep 'docker' | sed 's/^.*\///' | tail -n1`
# take the first 12 characters - that is the format used in /etc/hosts
THIS_CONTAINER_ID_SHORT=${THIS_CONTAINER_ID_LONG:0:12}
# search /etc/hosts for the line with the ip address which will look like this:
# 172.18.0.4 8886629d38e6
THIS_DOCKER_CONTAINER_IP_LINE=`cat /etc/hosts | grep $THIS_CONTAINER_ID_SHORT`
# take the ip address from this
THIS_DOCKER_CONTAINER_IP=`(echo $THIS_DOCKER_CONTAINER_IP_LINE | grep -o '[0-9]\+[.][0-9]\+[.][0-9]\+[.][0-9]\+')`
# add the port you want on the end
# Issues here include: django changing port if in use (I think)
# and parallel tests needing multiple ports etc.
THIS_DOCKER_CONTAINER_TEST_SERVER="$THIS_DOCKER_CONTAINER_IP:8081"
echo "this docker container test server = $THIS_DOCKER_CONTAINER_TEST_SERVER"
export DJANGO_LIVE_TEST_SERVER_ADDRESS=$THIS_DOCKER_CONTAINER_TEST_SERVER
fi
eval "$#"
In your django settings file
SITE_DOMAIN = 'django'
Then to run your tests
docker-compose run django ./manage.py test
Whenever you see localhost, try first to port-forward that port (at the VM level)
See "Connect to a Service running inside a docker container from outside"
VBoxManage controlvm "default" natpf1 "tcp-port8081,tcp,,8081,,8081"
VBoxManage controlvm "default" natpf1 "udp-port8081,udp,,8081,,8081"
(Replace default with the name of your docker-machine: see docker-machine ls)
This differs for port mapping at the docker host level (which is your boot2docker-based Linux host)
The OP luke-aus confirms in the comments:
entering the IP address for the network solved the problem!
I've been struggling with this as well, and I finally found a solution that worked for me. You can try something like this:
postgis:
dockerfile: ./docker/postgis/Dockerfile
build: .
django:
dockerfile: ./docker/Dockerfile-dev
build: .
command: python /app/project/manage.py test my-app
volumes:
- .:/app
ports:
- "8000:8000"
links:
- postgis
- selenium # django can access selenium:4444, selenium can access django:8081-8100
environment:
- SELENIUM_HOST=http://selenium:4444/wd/hub
- DJANGO_LIVE_TEST_SERVER_ADDRESS=django:8081-8100 # this gives selenium the correct address
selenium:
image: selenium/standalone-firefox-debug
ports:
- "5900:5900"
I don't think you need to include port 4444 in the selenium config. That port is exposed by default, and there's no need to map it to the host machine, since the django container can access it directly via its link to the selenium container.
[Edit] I've found you don't need to explicitly expose the 8081 port of the django container either. Also, I used a range of ports for the test server, because if tests are run in parallel, you can get an "Address already in use" error, as discussed here.