I have 2 services inside my docker cluster. frontend runs on port 8090, and backend runs on port 8000. How can I make frontend call backend via local DNS like fetch('https://backend.local/')? Because if I use docker-hostname, I need to specify the port to call the back-end. Do I need to have a local DNS Server inside my docker?
You have to create a Software Defined Network (SDN) in docker and then all containers running in that network can communicate with each other using the container names or you can define alias for each and use that. A simple docker-compose file for a backend microservice and mysql database can be created using the below configs.
version: '3.2'
networks:
testNetwork:
services:
mysql-dev:
image: mysql:latest
container_name: mysql-dev
environment:
- MYSQL_ROOT_PASSWORD=root
- MYSQL_DATABASE=root
ports:
- "3306:3306"
networks:
- testNetwork
backend:
image: backend:1.0
container_name: backend
environment:
- DB_USER=root
- DB_PASS=root
- DB_NAME=root
- DB_HOST=mysql-dev
- DB_DIALECT=mysql
ports:
- "4000:4000"
working_dir: /backend
command: npm start
networks:
- testNetwork
Related
I need to resolve a container name to the IP Address from the docker host.
The reason for this is, i need a container to run on the host network, but it must be also able to resolve the container "backend" which it connects also to. (The container must be send & receive multicast packets)
docker-compose.yml
version: "3"
services:
database:
image: mongo
container_name: database
hostname: database
ports:
- "27017:27017"
backend:
image: "project/backend:latest"
container_name: backend
hostname: backend
environment:
- NODE_ENV=production
- DATABASE_HOST=database
- UUID=5025f846-7587-11ed-9ca7-8b992b5e7dd3
ports:
- "8080:8080"
depends_on:
- database
tty: true
frontend:
image: "project/frontend:latest"
container_name: frontend
hostname: frontend
ports:
- "80:80"
- "443:443"
depends_on:
- backend
environment:
- BACKEND_HOST=backend
connector:
image: "project/connector:latest"
container_name: connector
hostname: connector
ports:
- "1900:1900/udp"
#expose:
# - "1900/udp"
environment:
- NODE_ENV=production
- BACKEND_HOST=backend
- STARTUP_DELAY=1500
depends_on:
- backend
network_mode: host
tty: true
How can i resolve the hostname "backend" via docker from the docker host?
dig backend #127.0.0.11 & dig backend #172.17.0.1 did not work.
A test with a docker ubuntu image & socat proves, that i can receive ssdp multicast packets:
docker run --net host -it --rm ubuntu
socat UDP4-RECVFROM:1900,ip-add-membership=239.255.255.250:0.0.0.0,fork -
The only problem i now have is the DNS/Container name resolution from the host (network).
TL;DR
The container "connector" must be on the host network,but also be able to resolve the container name "backend" to the docker internal IP Address.
NOTE: Perhaps this is better suited on superuser or similar?
Server 1->10.0.0.47
Server 2->10.0.1.202
All ports between these two servers are open as they are in same VPN in aws
version: '3.3'
networks:
net:
external: true
services:
backend:
image: test/test-backend:prod
ports:
- "8000:8000"
depends_on:
- discovery
ERROR:Connection refused
Note When i try to change the composer like below
connection with mongo established but unable to access the service on port 8000
networks:
net:
external: true
services:
backend:
image: test/test-backend:prod
expose:
- "27017:27017"
ports:
- "8000:8000"
depends_on:
- discovery
The Expose instruction does not change anything, it's for documentation only. You can read more about it in the Dockerfile reference.
If the 2 Server are in the same Docker network, you could change the mongoDB port to 8000 in its installation configuration. Then, you don't need to specify a port etc. in the docker-compose configuration.
If you want to access the mongoDB service from outside, you have to change the docker-compose configuration to:
ports:
- "8000:27017"
So I have this docker compose file
version: "2.1"
services:
nginx:
image: pottava/proxy
ports:
- 8080:80
environment:
- PROXY_URL=http://transmission-container:5080/
- BASIC_AUTH_USER=admin
- BASIC_AUTH_PASS=admin
- ACCESS_LOG=true
transmission:
image: linuxserver/transmission
container_name: transmission-container
ports:
- 5080:9091
restart: unless-stopped
I'm new to docker compose and trying it out for the first time. I need to be able to access the transmission service via http://localhost:8080 but nginx is returning a 502.
How should I change my compose file so that http://localhost:8080 will connect to the transmission service?
How can I make the transmission service not accessible via http://localhost:5080 and only accessible via http://localhost:8080 using docker compose?
I have tested the code below, it is working
version: "2.1"
services:
nginx:
image: pottava/proxy
ports:
- 8080:80
environment:
- PROXY_URL=http://transmission-container:9091/
- BASIC_AUTH_USER=admin
- BASIC_AUTH_PASS=admin
- ACCESS_LOG=true
transmission:
image: linuxserver/transmission
container_name: transmission-container
expose:
- "9091"
restart: unless-stopped
You no need to expose port 5080 to the host, the Nginx container can access directly the container port. The proxy URL needs to point to port 9091. Now you can't directly access the transmission service but need to go though the proxy server.
You should be able to access the other container using the service name and container port:
- PROXY_URL=http://transmission:9091/
If you do not want to access the transmission service from locahost, do not declare the host port:
ports:
- 9091
I have a setup where I build 2 dockers with docker-compose.
1 container is a web application. I can access it with port 8080. Another container is ElasticSearch; it's accessible with port 9200.
This is the content of my docker-compose.yml file:
version: '3'
services:
serverapplication:
build: "serverapplication"
entrypoint:
- bash
- -x
- init.sh
command: ["jdbcUrl=${jdbcUrl} dbUser=${dbUser} dbUserPassword=${dbUserPassword}"]
ports:
- "8080:8080"
- "8443:8443"
- "8787:8787"
elasticsearch:
build: "elasticsearch"
environment:
- discovery.type=single-node
ports:
- "9200:9200"
- "9300:9300"
When I browse to http://localhost:8080/serverapplication I can see my server application.
When I browse to http://localhost:9200/ I can see the default page of ElasticSearch.
But when I try to access ElasticSearch from inside the serverapplication, I get a "connection refused". It seems that the 9200 port is unreachable at localhost for the server application.
How can I fix this?
It's never safe to use localhost, since localhost means something else for your host system, for elasticsearch and for your server application. You're only able to access the containers from your host's localhost because you're mapping container ports onto your host's ports.
put them in the same network
give the containers a name
access elasticsearch through its containername, which Docker automatically resolves to the current IP of your elasticsearch container.
Code:
version: '3'
services:
serverapplication:
container_name: serverapplication
build: "serverapplication"
entrypoint:
- bash
- -x
- init.sh
command: ["jdbcUrl=${jdbcUrl} dbUser=${dbUser} dbUserPassword=${dbUserPassword}"]
ports:
- "8080:8080"
- "8443:8443"
- "8787:8787"
networks:
- my-network
elasticsearch:
container_name: elasticsearch
build: "elasticsearch"
environment:
- discovery.type=single-node
ports:
- "9200:9200"
- "9300:9300"
networks:
- my-network
networks:
my-network:
driver: bridge
Your server application must use the host name elasticsearch to access elasticsearch service i.e., http://elasticsearch:9200
Your serverapplication and elasticsearch are running in different containers. The localhost of serverapplication is different from localhost of elasticsearch.
docker-compose sets up a network between the containers such that they can be accessed with their service names. So from your serverapplication, you must use the name 'elasticsearch' to connect to it.
I am trying to set up a 2 node private IPFS cluster using docker. For that purpose I am using ipfs/ipfs-cluster:latest image.
My docker-compose file looks like :
version: '3'
services:
peer-1:
image: ipfs/ipfs-cluster:latest
ports:
- 8080:8080
- 4001:4001
- 5001:5001
volumes:
- ./cluster/peer1/config:/data/ipfs-cluster
peer-2:
image: ipfs/ipfs-cluster:latest
ports:
- 8081:8080
- 4002:4001
- 5002:5001
volumes:
- ./cluster/peer2/config:/data/ipfs-cluster
While starting the containers getting following error
ERROR ipfshttp: error posting to IPFS: Post http://127.0.0.1:5001/api/v0/repo/stat?size-only=true: dial tcp 127.0.0.1:5001: connect: connection refused ipfshttp.go:745
Please help with the problem.
Is there any proper documentation about how to setup a IPFS cluster on docker. This document misses on lot of details.
Thank you.
I figured out how to run a multi-node IPFS cluster on docker environment.
The current ipfs/ipfs-cluster which is version 0.4.17 doesn't run ipfs peer i.e. ipfs/go-ipfs in it. We need to run it separately.
So now in order to run a multi-node (2 node in this case) IPSF cluster in docker environment we need to run 2 IPFS peer container and 2 IPFS cluster container 1 corresponding to each peer.
So your docker-compose file will look as follows :
version: '3'
networks:
vpcbr:
driver: bridge
ipam:
config:
- subnet: 10.5.0.0/16
services:
ipfs0:
container_name: ipfs0
image: ipfs/go-ipfs
ports:
- "4001:4001"
- "5001:5001"
- "8081:8080"
volumes:
- ./var/ipfs0-docker-data:/data/ipfs/
- ./var/ipfs0-docker-staging:/export
networks:
vpcbr:
ipv4_address: 10.5.0.5
ipfs1:
container_name: ipfs1
image: ipfs/go-ipfs
ports:
- "4101:4001"
- "5101:5001"
- "8181:8080"
volumes:
- ./var/ipfs1-docker-data:/data/ipfs/
- ./var/ipfs1-docker-staging:/export
networks:
vpcbr:
ipv4_address: 10.5.0.7
ipfs-cluster0:
container_name: ipfs-cluster0
image: ipfs/ipfs-cluster
depends_on:
- ipfs0
environment:
CLUSTER_SECRET: 1aebe6d1ff52d96241e00d1abbd1be0743e3ccd0e3f8a05e3c8dd2bbbddb7b93
IPFS_API: /ip4/10.5.0.5/tcp/5001
ports:
- "9094:9094"
- "9095:9095"
- "9096:9096"
volumes:
- ./var/ipfs-cluster0:/data/ipfs-cluster/
networks:
vpcbr:
ipv4_address: 10.5.0.6
ipfs-cluster1:
container_name: ipfs-cluster1
image: ipfs/ipfs-cluster
depends_on:
- ipfs1
- ipfs-cluster0
environment:
CLUSTER_SECRET: 1aebe6d1ff52d96241e00d1abbd1be0743e3ccd0e3f8a05e3c8dd2bbbddb7b93
IPFS_API: /ip4/10.5.0.7/tcp/5001
ports:
- "9194:9094"
- "9195:9095"
- "9196:9096"
volumes:
- ./var/ipfs-cluster1:/data/ipfs-cluster/
networks:
vpcbr:
ipv4_address: 10.5.0.8
This will spin 2 peer IPFS cluster and we can store and retrieve file using any of the peer.
The catch here is we need to provide the IPFS_API to ipfs-cluster as environment variable so that the ipfs-cluster knows its corresponding peer. And for both the ipfs-cluster we need to have the same CLUSTER_SECRET.
According to the article you posted:
The container does not run go-ipfs. You should run the IPFS daemon
separetly, for example, using the ipfs/go-ipfs Docker container. We
recommend mounting the /data/ipfs-cluster folder to provide a custom,
working configuration, as well as persistency for the cluster data.
This is usually achieved by passing -v
:/data/ipfs-cluster to docker run).
If in fact you need to connect to another service within the docker-compose, you can simply refer to it by the service name, since hostname entries are created in all the containers in the docker-compose so services can talk to each other by name instead of ip
Additionally:
Unless you run docker with --net=host, you will need to set $IPFS_API
or make sure the configuration has the correct node_multiaddress.
The equivalent of --net=host in docker-compose is network_mode: "host" (incompatible with port-mapping) https://docs.docker.com/compose/compose-file/#network_mode