I have an existing node application that connects to redis at 127.0.0.1:6379. I am unable to change this.
I understand that with docker compose it connects the two services redis and node and allows them to connect using the redis hostname, however I can't change this.
How can I make it so that redis is accessible from the node application at the 127.0.0.1:6379 host and port?
Here's my docker-compose.yml file:
version: '3'
services:
redis:
image: redis
hostname: "127.0.0.1"
redis-cli:
image: redis
links:
- redis
command: redis-cli -h 127.0.0.1
Here's the output:
$ docker-compose run redis-cli
Starting install_redis_1 ... done
Could not connect to Redis at 127.0.0.1:6379: Connection refused
Could not connect to Redis at 127.0.0.1:6379: Connection refused
not connected>
You can use network_mode: host in both containers to make redis expose its 6379 on localhost, and make localhost available to redis-cli:
version: '3'
services:
redis:
image: redis
network_mode: host
redis-cli:
depends_on:
- redis
image: redis
network_mode: host
command: redis-cli -h 127.0.0.1 ping
And running it:
> docker-compose run redis-cli
Starting dockerredis_redis_1 ... done
PONG
Related
Good morning guys.
I'm having a problem connecting a nodejs application, in a container, to another container that contains a redis server. On my local machine I can connect the application to this redis container without any problem. However, when trying to upload this application in a container, a timeout error is returned.
I'm new to docker and I don't understand why I can connect to this docker container in the application running locally on my machine but that same connection doesn't work when I upload the application in a container.
I tried using docker-compose, but from what I understand it will upload in another container to the redis server, instead of using the redis container that is already in docker.
To connect to redis I'm using the following code:
createClient({
socket: {
host: process.env.REDIS_HOST,
port: Number(process.env.REDIS_PORT)
}
});
Where REDIS_HOST is the address of my container running on the server and REDIS_PORT is the port where this container is running on my server.
To run redis on docker I used the following guide: https://redis.io/docs/stack/get-started/install/docker/
I apologize if my problem was not very clear, I'm still studying docker.
You mentioned you are using Docker Compose. Here's an example showing how to start Redis in a container, and make your Node application wait for that container then use an environment variable in your Node application to specify the name of the host to connect to Redis on. In this example it connects to the container running Redis that I've called "redis":
version: "3.9"
services:
redis:
container_name: redis_kaboom
image: "redislabs/redismod"
ports:
- 6379:6379
volumes:
- ./redisdata:/data
entrypoint:
redis-server
--loadmodule /usr/lib/redis/modules/rejson.so
--appendonly yes
deploy:
replicas: 1
restart_policy:
condition: on-failure
node:
container_name: node_kaboom
build: .
volumes:
- .:/app
- /app/node_modules
command: sh -c "npm run load && npm run dev"
depends_on:
- redis
ports:
- 8080:8080
environment:
- REDIS_HOST=redis
So in your Node code you'd then use the value of process.env.REDIS_HOST to connect to the right Redis host. Here, I'm not using a password or a non-standard port, you could also supply those as environment variables that match the configuration of the Redis container in Docker Compose too if you needed to.
Disclosure: I work for Redis.
Internal connection between my Spring Boot app and postgres db works fine but when I want to connect to db through init_database.sh and pg_restore I get pg_restore: error: connection to server at "db" (192.168.224.2), port 5432 failed: Connection refused Is the server running on that host and accepting TCP/IP connections?. In this .sh script I use the same host and port as in application.properties (where connection works fine as I said before).
I simply want to do a pg_restore from init_database.sh in my Docker container.
docker-compose.yml
services:
db:
container_name: db
hostname: db
image: postgres:14-alpine
command: -c 'max_connections=250'
ports:
- "5430:5432"
environment:
POSTGRES_DB: endlessblow_db
POSTGRES_USER: kuba
POSTGRES_PASSWORD: pass
volumes:
- ./init.dump:/init.dump
- ./init_database.sh:/docker-entrypoint-initdb.d/init_database.sh
restart: always
app:
container_name: app
image: 'endlessblow-server:latest'
build: ./
ports:
- "8000:8080"
depends_on:
- db
init_database.sh
#!/bin/sh
pg_restore --no-privileges --no-owner -h db -p 5432 -U kuba -d endlessblow_db init.dump
application.properties
spring.datasource.jdbc-url=jdbc:postgresql://db:5432/endlessblow_db
spring.datasource.url=jdbc:postgresql://db:5432/endlessblow_db
spring.datasource.username=kuba
spring.datasource.password=pass
spring.datasource.driver-class-name=org.postgresql.Driver
spring.datasource.platform=postgres
spring.jpa.database-platform=org.hibernate.dialect.PostgreSQLDialect
How to solve that? Thank you!
in config of service "app", try following:
app:
...
depends_on:
- db
links:
- db
without links, docker network will isolate containers without explicitly exposing them to one another.
No matter what I try I can't seem to get my node app to connect to redis between containers within the same docker-compose yml config. I've seen a lot of similar questions but none of the answers seem to work.
I'm using official images in both cases, not building my own
I am putting "redis" as my host and setting it as hostname in my docker compose YML config
const client = redis.createClient({ host: "redis" });
in my redis.conf I am using bind 0.0.0.0
This what the console is printing out:
Redis connection to redis:6379 failed - getaddrinfo ENOTFOUND redis redis:6379
Error: connect ECONNREFUSED 127.0.0.1:6379
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1107:14)
errno: 'ECONNREFUSED',
code: 'ECONNREFUSED',
syscall: 'connect',
address: '127.0.0.1',
port: 6379
}
This is my docker-compose.yml
version: '3'
services:
server:
image: "node:10-alpine"
working_dir: /usr/src/app
user: "node"
command: "npm start"
volumes:
- .:/usr/src/app
ports:
- '3000:3000'
- '3001:3001'
- '9229:9229' # Node debugging port
environment:
- IS_DOCKER=1
- NODE_ENV=DEVELOPMENT
depends_on:
- db
db:
image: "redis:5.0-alpine"
expose:
- '6379'
volumes:
- ./redis.conf:/usr/local/etc/redis/redis.conf
- redis-data:/data
command:
- redis-server
- /usr/local/etc/redis/redis.conf
hostname: redis
volumes:
redis-data:
UPDATE
Here's my redis.conf, it's not much.
bind 0.0.0.0
appendonly yes
appendfilename "my_app.aof"
appendfsync always
UPDATE 2
Things I've noticed and tried
in my original setup, when I run docker inspect I can see they are both joined to the same network. when I exec.../bin/bash into the redis container I can successfully ping the server container but when I'm in the server container it can not ping the redis one.
network_mode: bridge -adding that to both containers does not work
I did get one baby step closer by trying out this:
server:
network_mode: host
redis:
network_mode: service:host
I'm on a Mac and in order to get host mode to work you need to do that. It does work in the sense that my server successfully connects to the redis container. However, hitting localhost:3000 does not work even though I'm forwarding the ports
version: '3'
services:
server:
image: "node:10-alpine"
#network_mode: bridge
#links is necessary if you use network_mode: bridge
#links: [redis]
networks:
- default
working_dir: /usr/src/app
user: "node"
command: "npm start"
volumes:
- .:/usr/src/app
ports:
- '3000:3000'
- '3001:3001'
- '9229:9229' # Node debugging port
environment:
- IS_DOCKER=1
- NODE_ENV=DEVELOPMENT
depends_on:
- redis
redis:
image: "redis:5.0-alpine"
#container_name: redis
#network_mode: bridge
networks:
- default
expose:
- '6379'
volumes:
- ./redis.conf:/usr/local/etc/redis/redis.conf
- redis-data:/data
command:
- redis-server
- /usr/local/etc/redis/redis.conf
volumes:
redis-data:
networks:
default:
Rename the container to the hostname you want to use: redis in your case instead of db. To make it accessible over the docker network you will have to put them on the same network like above or use network_mode: bridge and links: [redis] instead.
Try this to test your network:
docker ps to get the current container id or running name from the server container
docker exec -it id/name /bin/sh
Now you have a shell inside server and should be able to resolve redis via:
ping redis or nc -zv redis 6379
For those who still getting this error
i found that in new versions of redis - 4 and up
you need to configure the client like this:
const client = createClient({
socket: {
host: host,
port: process.env.REDIS_PORT,
},
});
it solved my problem
then in docker compose file you don't need to specify ports
version: "3.4"
services:
redis-server:
image: "redis:latest"
restart: always
api:
depends_on:
- redis-server
restart: always
build: .
ports:
- "5000:5000"
I can't figure out how to connect to my redis service from my app service. Using DDocker version 18.03.1-ce, build 9ee9f40ocker for Mac.
I've tried connecting the various ways I've found on similar questions:
const client = redis.createClient({ host: 'localhost', port: 6379});
const client = redis.createClient({ host: 'redis', port: 6379});
const client = redis.createClient('redis://redis:6379');
const client = redis.createClient('redis', 6379); // and reversed args
I always get some form of:
Error: Redis connection to localhost:6379 failed - connect ECONNREFUSED 127.0.0.1:6379
Error: Redis connection to redis:6379 failed - connect ECONNREFUSED 172.20.0.2:6379
Docker containers
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0fd798d58561 app_app "pm2-runtime start e…" 2 seconds ago Up 7 seconds app
65d148e498f7 app_redis "docker-entrypoint.s…" About a minute ago Up 8 seconds 0.0.0.0:6379->6379/tcp redis
Redis works:
$ docker exec -it redis /bin/bash
root#65d148e498f7:/data# redis-cli ping
PONG
Redis Dockerfile (pretty simple)
FROM redis:4.0.9
COPY redis.conf /usr/local/etc/redis/redis.conf
CMD ["redis-server", "/usr/local/etc/redis/redis.conf"]
app Dockerfile
FROM node:10.3.0-slim
RUN mkdir -p /app
COPY src/* /app/
CMD ["pm2-runtime", "start", "/app/ecosystem.config.js"]
docker-compose.yml
version: "3"
services:
redis:
build: ./redis/
container_name: redis
restart: unless-stopped
ports:
- "6379:6379"
expose:
- "6379"
volumes:
- /var/run/docker.sock:/var/run/docker.sock
environment:
- 'API_PORT=6379'
- 'NODE_ENV=production'
app:
depends_on:
- redis
build: ./app/
container_name: app
restart: unless-stopped
volumes:
- /var/run/docker.sock:/var/run/docker.sock
- /app/node_modules
environment:
- 'NODE_ENV=production'
It looks like your redis image is configured to listen on 127.0.0.1 rather than all interfaces. This is not an issue with the default redis images, so either use the official image from docker hub, or correct your configuration to listen on 0.0.0.0.
You'll be able to verify this with netshoot:
docker run --rm --net container:app_redis nicolaka/netshoot netstat -ltn
In the redis conf, listening on all interface is done by commenting out the "bind" line in redis.conf.
Let me explain it in simple language. When you run docker-compose up it runs redis and app in separate containers. Now your app needs to connect/access the redis container (remember redis is not at your machines localhost, its inside a container and runs inside it at default port 6379). By default Docker will keep app container and redis container in same network and you can access a container by its service name (which in your case is redis and app) so in order to access redis from app container all you need is to use the default port 6379 and host will be the service name (in your case "redis").
For a node application running in a container get access to Redis (which was also running in a container) by
const redis = require("redis");
const client = redis.createClient(6379, "service-name-for-redis-container");
I solve this problem changing the redis host from 'localhost' to 'redis', exemple:
REDIS_HOST=redis
REDIS_PORT=6379
After the change my docker service started to comunicate with redis.
Original forum answer: https://forums.docker.com/t/connecting-redis-from-my-network-in-docker-net-core-application/92405
In my case the problem was that I was binding a different port on redis:
redis:
image: redis
ports:
- 49155:6379
And I was trying to connect to port 49155 but I needed to connect through port 6379 since the connection is from another service.
localhost from the app container's perspective won't be able to leave the app container. So the best bet is to use redis or the host's ip address.
If you want to reach redis from the app container, you'll need to link them or put them into the same network. Please add a network property to both services, using the same network name. Docker will then provide you with with valid dns lookups for the service names.
See the official docs at https://docs.docker.com/compose/compose-file/#networks (for the service: property) and https://docs.docker.com/compose/compose-file/#network-configuration-reference (for the top-level networks property).
I have been trying for a while to get information from a postgres container to a node container with docker. I used a docker-compose file provided below:
version: "3"
services:
postgres:
image: postgres:latest
volumes:
- ./pgdata:/var/lib/postgresql/data
ports:
- "5432:5432"
networks:
- webnet
environment:
POSTGRES_USER: 'postgres'
POSTGRES_PASSWORD: 'root'
POSTGRES_DB: 'tweets1'
PGDATA: '/tmp'
web:
image: node-app
ports:
- "4556:3000"
depends_on:
- "postgres"
links:
- postgres
networks:
- webnet
command: ["./wait-for-it.sh","postgres:5432","--","node","dashboard.js"]
networks:
webnet:
After I run docker-compose up, everything in the log looks fine. Postgres starts first and I actually can access the database using
psql -h localhost -p 3030 -U postgres tweets1
When I load the node-web app in my browser everything loads perfectly except from the information that should be retrieved from the database. I get the following error in the log of my container:
{Error: connect ECONNREFUSED 127.0.0.1:5432 at
TCPConnectWrap.afterConnect [as oncomplete] (net.js:1158:14)
code: 'ECONNREFUSED',
syscall: 'connect',
address: '127.0.0.1',
port: 5432 }
I have been trying to use the host.docker.internal in my PG config variable but its not working either. When I check my containers through docker container ps. Both are up and running.
Thank you very much in advance!
Your first command:
psql -h localhost -p 3030 -U postgres tweets1
works on your host because you added a port binding when you declared the postgres container. The port binding does not apply to other containers though.
Container -> Container connections require a regular network connection.
You will find that usually the linked containers are declared in the containers' /etc/hosts by docker, using the names you assigned to the containers.
So, while in the web container try:
psql -h postgres -p 3030 -U postgres tweets1
Finally:
In your code, you should connect to the postgres host not localhost.