Docker Network Understanding - docker

I'm trying to set up a 3 containers architecture for a web app (front-end, back-end, database). I created two networks one for the back (database + back-end), the other for the front (front + back). I am using compose to start the services.
I can't access my front container from my host even though I published a port.
Am I missing something to make it work ?
Here is my docker-compose.yml file.
services:
api:
image: ruby:3.1.2
command: sh -c "rm -f /app/tmp/pids/server.pid && bundle install && rails s"
working_dir: /app
depends_on:
- database
networks:
- back
- front
ports:
- "3000:3000"
volumes:
- type: bind
source: ../api
target: /app
web:
image: node
working_dir: /app
command: sh -c "yarn install && yarn build && yarn dev"
depends_on:
- api
networks:
- front
- host
volumes:
- type: bind
source: ../frontend
target: /app
ports:
- "8000:5173"
database:
image: keinos/sqlite3
networks:
- back
expose:
- "3306"
volumes:
- citrine-db:/db
networks:
back:
driver: bridge
front:
driver: bridge
host:
volumes:
citrine-db:

Based on this:
I get a connection refused when I try accesing ip_address:5173
It sounds like your application is only listening on the localhost address (127.0.0.1). You need it to listen on "all addresses" (0.0.0.0). This is why you're able to connect to localhost:5173 from inside the container, but connections from outside the container are failing.

Related

Docker communication from one container to another

I have two docker containers. I'm trying to curl between one and the other container.
I've set up a common network.
Here is my docker-compose:
version: '3.8'
services:
web:
build: ./webapp/.
container_name: storyweb
command: python3 /app/manage.py runserver 0.0.0.0:8000
volumes:
- ./webapp/:/app/
ports:
- 8007:8000
networks:
- backend
env_file:
- ./.env.dev
novnc:
container_name: dramatica
build: ./dramatica/.
environment:
# Adjust to your screen size
- DISPLAY_WIDTH=1200
- DISPLAY_HEIGHT=800
- PUID=1000
- PGID=1000
ports:
- "8008:8080"
volumes:
- ./dramatica:/app
networks:
- backend
restart: unless-stopped
depends_on:
- web
entrypoint: /app/entrypoint.sh
networks:
backend:
driver: bridge
I'm tryin gto curl from inside vovnc container:
curl -i web:8007
I've also tried storyweb.
Any idea why this is not working?
When your server container runs a server process
python3 /app/manage.py runserver 0.0.0.0:8000
connections between containers need to go to that port 8000. ports: aren't used or required here, and can be removed if you don't require the service to be directly accessible from outside containers on the same Docker network.
If you are trying the command curl -i web:8007 from your host machine. It will not work. You try this command from inside a container. You can try the following method
curl -i localhost:8007
docker-compose novnc curl -i web:8007

Rails Unable to make API request inside docker SocketError (Failed to open TCP connection to xxx:443 (getaddrinfo: Name does not resolve))

I'm really confused why I'm unable to make API requests to any site. for example, I want to run :
HTTParty.get("https://fakerapi.it/api/v1/persons")
It runs well on my machine. (without docker).
But if I run it inside docker, I got :
SocketError (Failed to open TCP connection to fakerapi.it:443 (getaddrinfo: Name does not resolve))
It happens not only for this site. But for all sites.
So I guess there's something wrong with my docker settings. But I'm not sure where to start.
I'm new to docker. So any advice means a lot to me.
Below is my docker-compose.yaml
version: '3.4'
services:
db:
image: mysql:8.0.17 #using official mysql image from docker hub
restart: always
environment:
MYSQL_ROOT_PASSWORD: root
volumes:
- db_data:/var/lib/mysql
ports:
- "3307:3306"
backend:
build:
context: .
dockerfile: backend-dev.Dockerfile
ports:
- "3001:3001"
volumes:
#the host repos are mapped to the container's repos
- ./backend:/my-project
#volume to cache gems
- bundle:/bundle
depends_on:
- db
stdin_open: true
tty: true
env_file: .env
command: /bin/sh -c "rm -f tmp/pids/server.pid && rm -f tmp/pids/delayed_job.pid && bundle exec bin/delayed_job start && bundle exec rails s -p 3001 -b '0.0.0.0'"
frontend:
build:
context: .
dockerfile: frontend-dev.Dockerfile
ports:
- "3000:3000"
links:
- "backend:bb"
depends_on:
- backend
volumes:
#the host repos are mapped to the container's repos
- ./frontend/:/my-project
# env_file: .env
environment:
- NODE_ENV=development
command: /bin/sh -c "yarn dev --port 3000"
volumes:
db_data:
driver: local
bundle:
driver: local
How I try to run:
docker-compose run backend /bin/sh
rails c
HTTParty.get("https://fakerapi.it/api/v1/persons")
Any idea how can I fix this?

Nuxt.js 500 NuxtServerError under docker-compose

my system contains 3 dockers:
mongodb
api backend, built with Nestjs
web application, build with Nuxt.js
the mongo and the backend seems to be working, because i can access the swagger at localhost:3000/api/.
the Nuxtjs web app is failing, and i'm getting 500 Nuxtserver error.
Dockerfile (for the web app):
FROM node:12.13-alpine
ENV APP_ROOT /src
RUN mkdir ${APP_ROOT}
WORKDIR ${APP_ROOT}
ADD . ${APP_ROOT}
RUN npm install
RUN npm run build
ENV HOST 0.0.0.0
EXPOSE 4000
docker-compose.yml:
version: "3"
services:
# backend nestjs app
api:
image: nestjs-api-server
container_name: my-api
depends_on:
- db
restart: unless-stopped
environment:
- NODE_ENV=production
ports:
- 3000:3001
networks:
- mynet
links:
- db
# mongodb
db:
image: mongo
container_name: db_mongo
restart: unless-stopped
volumes:
- ~/data/:/data/db
ports:
- 27017:27017
networks:
- mynet
# front web app, nuxt.js
web:
image: nuxtjs-web-app
container_name: my-web
depends_on:
- api
restart: always
ports:
- 4000:4000
environment:
- BASE_URL=http://localhost:3000/api
command:
"npm run start"
networks:
- mynet
networks:
mynet:
driver: bridge
Looks like the nuxtjs app cannot connect to the api. in the log i see:
ERROR connect ECONNREFUSED 127.0.0.1:3000
But why? the swagger (coming from the same api) works fine on http://localhost:3000/api/#/.
Any idea?
environment:
- BASE_URL=http://localhost:3000/api
localhost in a container means inside that particular container. i.e., it will try to resolve port 3000 in my-web container itself.
Basically from front-end you cannot do container communication. May be you can communicate via public hostname or ip or you can make use of extra_hosts concept in docker-compose to resolve localhost.
Got it. The problem was in nuxtServerInit. This is a very special method on vuex, and it is running in the server. i called $axios from it, and i guess you can't do that.
once i commented that method, it's working fine.

Docker Compose cannot connect to database

I'm using nestjs for my backend and using typeorm as ORM.
I tried to define my database and my application in an docker-compose file.
If I'm running my database as a container and my application from my local machine it works well. My program connects and creates the tables etc.
But if I try to connect the database from within my container or to start the container with docker-compose up it fails.
Always get an ECONNREFUSED Error.
Where is my mistake ?
docker-compose.yml
version: '3.1'
volumes:
dbdata:
services:
db:
image: postgres:10
volumes:
- ./dbData/:/var/lib/postgresql/data
restart: always
environment:
- POSTGRES_PASSWORD=${TYPEORM_PASSWORD}
- POSTGRES_USER=${TYPEORM_USERNAME}
- POSTGRES_DB=${TYPEORM_DATABASE}
ports:
- ${TYPEORM_PORT}:5432
backend:
build: .
ports:
- "3001:3000"
command: npm run start
volumes:
- .:/src
Dockerfile
FROM node:10.5
WORKDIR /home
# Bundle app source
COPY . /home
# Install app dependencies
#RUN npm install -g nodemon
# If you are building your code for production
# RUN npm install --only=production
RUN npm i -g #nestjs/cli
RUN npm install
EXPOSE 3000
.env
# .env
HOST=localhost
PORT=3000
NODE_ENV=development
LOG_LEVEL=debug
TYPEORM_CONNECTION=postgres
TYPEORM_HOST=localhost
TYPEORM_USERNAME=postgres
TYPEORM_PASSWORD=postgres
TYPEORM_DATABASE=mariokart
TYPEORM_PORT=5432
TYPEORM_SYNCHRONIZE=true
TYPEORM_DROP_SCHEMA=true
TYPEORM_LOGGING=all
TYPEORM_ENTITIES=src/database/entity/*.ts
TYPEORM_MIGRATIONS=src/database/migrations/**/*.ts
TYPEORM_SUBSCRIBERS=src/database/subscribers/**/*.ts
I tried to use links but it don't work in the container.
Take a look at your /etc/hosts inside the backend container. You will see
192.0.18.1 dir_db_1
or something like that. The IP will be different and dir will represent the dir you're in. Therefore, you must change TYPEORM_HOST=localhost to TYPEORM_HOST=dir_db_1.
Although, I suggest you set static names to your containers.
services:
db:
container_name: project_db
...
backend:
container_name: project_backend
In this case you can always be sure, that your container will have a static name and you can set TYPEORM_HOST=project_db and never worry about the name ever again.
You can create a network and share among two services.
Create network for db and backend services:
networks:
common-net: {}
and add the network to these two services. So your .yml file would like below after edit:
version: '3.1'
volumes:
dbdata:
services:
db:
image: postgres:10
volumes:
- ./dbData/:/var/lib/postgresql/data
restart: always
environment:
- POSTGRES_PASSWORD=${TYPEORM_PASSWORD}
- POSTGRES_USER=${TYPEORM_USERNAME}
- POSTGRES_DB=${TYPEORM_DATABASE}
ports:
- ${TYPEORM_PORT}:5432
networks:
- common-net
backend:
build: .
ports:
- "3001:3000"
command: npm run start
volumes:
- .:/src
networks:
- common-net
networks:
common-net: {}
Note1: After this change, there is no need to expose the Postgres port externally unless you have a reason for it. You can remove that section.
Note2: TYPEORM_HOST should be renamed to db. Docker would resolve the IP address of db service by itself.

Why Dockerfile doesn't run multiple commands

I want use Docker run my project(react+nodejs+mongodb),
Dockerfile:
FROM node:8.9-alpine
ENV NODE_ENV production
WORKDIR /usr/src/app
COPY ["package.json", "package-lock.json*", "npm-shrinkwrap.json*", "./"]
RUN npm install --production --silent && mv node_modules ../
COPY . .
CMD nohup sh -c 'npm start && node ./server/server.js'
docker-compose.yml:
version: '2.1'
services:
chat:
image: chat
container_name: chat
build: .
environment:
NODE_ENV: production
ports:
- "3000:3000"
- "8080:8080"
volumes:
- ./:/usr/src/app
links:
- mongo
mongo:
container_name: mongo
image: mongo
ports:
- "27017:27017"
run docker-compose up --build, the 3000 port is worked, but the 8080 port dies
localhost:3000
localhost:8080
I would suggest create a container for the server and have it seperate from the "chat" container. Its best to have each container do one thing and one thing only (almost like the philosophy behind unix commands)
In any case here is some modifications that I would make to the compose file.
version: '2.1'
services:
chat:
image: chat
container_name: chat
build: .
environment:
NODE_ENV: production
ports:
- "3000:3000"
- "8080:8080"
volumes:
- ./:/usr/src/app
links:
- mongo
mongo:
container_name: mongo
image: mongo
# You don't need to expose this port to the outside world. Because you linked the two containers the chat app
# will be able to connect to mongodb using hostname mongodb inside the container network.
# ports:
# - "27017:27017"
Btw what happens if you run:
$ docker-compose down
and then
$ docker-compose up
$ docker ps
can you see the ports exposed in docker ps output?
your chat service depends on mongo so you also need to have this in your chat
depends_on:
- mongo
This docker-compose file works for me. Note that i am saving the data from the database to a local directory. You should add this directory to gitignore.
version: "3.2"
services:
mongo:
container_name: mongo
image: mongo:latest
environment:
- MONGO_INITDB_ROOT_USERNAME=root
- MONGO_INITDB_ROOT_PASSWORD=password
- NODE_ENV=production
ports:
- "28017:27017"
expose:
- 28017 # you can connect to this mongodb with studio3t
volumes:
- ./mongodb-data:/data/db
restart: always
networks:
- docker-network
express:
container_name: express
environment:
- NODE_ENV=development
restart: always
build:
context: .
args:
buildno: 1
expose:
- 3000
ports:
- "3000:3000"
links:
- mongo # link this service to the database service
depends_on:
- mongo
command: "npm start" # override the default command to use nodemon in dev
networks:
- docker-network
networks:
docker-network:
driver: bridge
You may also find that using node you have to wait for the mongodb container to be ready before you can connect to the database.

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