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From inside of a Docker container, how do I connect to the localhost of the machine?
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Can't connect to Postgres from the docker container.
I do not want user docker-compose and create a Postgres container, already got Postgres app running. I think it is a bad idea to container postgres and better use system.
OSX, Postgres10, Flask
I already made
postgresql.conf
listen_addresses = '*'
port = 5432
pg_hba.conf
host all all 0.0.0.0/0 trust
I Used trust for any result, but no effect.
Dockerfile
FROM python:3.8-alpine
RUN apk update \
&& apk add --virtual build-deps gcc musl-dev \
&& apk add python3-dev \
&& apk add postgresql-dev \
&& apk add jpeg-dev zlib-dev libjpeg \
&& pip install --upgrade pip
ENV PYTHONUNBUFFERED 1 \
&& FLASK_APP app.py
#EXPOSE 5000 5432
WORKDIR /app
ADD . /app
RUN pip install -r requirements.txt
CMD ["./bin/run.sh"]
./bin/run.sh
#!/bin/sh
#python run.py
source venv/bin/activate
set -e
flask db upgrade
exec gunicorn -b --workers 4 --access-logfile --error-logfile run:app :5000
The "docker run" command I try to use:
docker run --rm -e SQLALCHEMY_DATABASE_URI=postgresql://postgres:postgres#0.0.0.0:5432/my_db --net=host -p 5000:5000 my_container:v0.1
the command leads to error
...
psycopg2.OperationalError: could not connect to server: Connection refused
Is the server running on host "0.0.0.0" and accepting
TCP/IP connections on port 5432?
command connect me to Postgres
psql -U postgres -h 0.0.0.0
Trying to connect to host "0.0.0.0" is technically wrong. (the address 0.0.0.0 is used to other purposes no to connect to...)
Did you tried connect using the postgres container ip address instead of "0.0.0.0"?
You can get the postgres container ip address throught the following command:
docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' name_of_postgres_container
Related
I have a PostgreSQL instance running on a docker with these commands:
mkdir -p $HOME/vols/postgres
docker pull postgres:12.0
docker run --rm --name pg-docker -e POSTGRES_PASSWORD=docker \
-v $HOME/vols/postgres:/var/lib/postgresql/data \
-d -p 5432:5432 postgres
It's up and running and I can access it from DBeaver which is installed on my local-machine. Also, I've installed pgAdmin4 by these commands:
mkdir -p $HOME/vols/pgadmin4
docker pull dpage/pgadmin4
docker run --rm --name pgadmin4 -p 5050:80 \
-v $HOME/vols/pgadmin4:/var/lib/pgadmin \
-e 'PGADMIN_DEFAULT_EMAIL=amiry#manexapp.com' \
-e 'PGADMIN_DEFAULT_PASSWORD=12345678' \
-d dpage/pgadmin4
The pgAdmin is also up and running well and I can easily access it and login to it through http://localhost:5050.
But when I want to connect to my postgre-container instance via pgAdmin4-container instance, I get this error:
Unable to connect to server:
could not connect to server: Connection refused Is the server running
on host "localhost" (127.0.0.1) and accepting TCP/IP connections on
port 5432? could not connect to server: Address not available Is the
server running on host "localhost" (::1) and accepting TCP/IP
connections on port 5432?
Does anybody has an idea what's going wrong here please? Thanks in advance.
NOTE: My host machine is Fedora 31.
Inside a container, the loopback address (localhost or 127.0.0.1) refers to "this container". When you try to connect to 127.0.0.1 inside the pgAdmin4 container, it fails because your Postgres service is not running inside the pgAdmin4 container.
The easiest way to make this work is to put both of your containers on a user defined network, in which case they can simply refer to each other by name.
Start by creating a network:
docker network create dbnet
Then launch the postgres container on that network:
docker run --rm --name pg-docker -e POSTGRES_PASSWORD=docker \
--net dbnet \
-v $HOME/vols/postgres:/var/lib/postgresql/data \
-d -p 5432:5432 postgres
And finally launch the pgAdmin4 container on that network:
docker run --rm --name pgadmin4 -p 5050:80 \
--net dbnet \
-v $HOME/vols/pgadmin4:/var/lib/pgadmin \
-e 'PGADMIN_DEFAULT_EMAIL=amiry#manexapp.com' \
-e 'PGADMIN_DEFAULT_PASSWORD=12345678' \
-d dpage/pgadmin4
Now when you access your pgadmin ui, you can connect to the host pg-docker instead of localhost.
UPDATE: OK. larsks added a full detailed answer with creating a custom network approach, which makes more sense. I'll try it and let you know.
OK. I recognized there is a network problem and pgAdmin4-docker cannot see pg12-docker. So, I did these steps to solve the problem:
A. Stop pgadmin4 container by:
docker stop pgadmin4
This will also delete the container, because I have ran it by --rm flag.
B. Find the network-name and IP associated to pg12-docker by running:
docker inspect pg12-docker
This will echo a large JSON-file. Find the Networks node:
"Networks": {
"bridge": {
"Gateway": "172.17.0.1",
"IPAddress": "172.17.0.2",
// other lines omitted
}
}
You will see the network-name as the first child of JSON (bridge in this example) and also the IPAddress. Note theme somewhere.
C. Re-run the pgAdmin4-docker again with --network [NetworkName] parameter; replace [NetworkName] with the name you got in previous step (bridge in this example).
docker run --rm --name pgadmin4 -p 5050:80 --network bridge \
-v $HOME/vols/pgadmin4:/var/lib/pgadmin \
-e 'PGADMIN_DEFAULT_EMAIL=amiry#manexapp.com' \
-e 'PGADMIN_DEFAULT_PASSWORD=12345678' \
-d dpage/pgadmin4
D. Access (or refresh) http://localhost:5050 and login to it. In Add server section, use the IPAddress you got in step B. and you are good to go.
Using
host.docker.internal
instead of localhost
I have my flask app app.py:
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
APP = Flask(__name__)
DB = SQLAlchemy()
if __name__ == '__main__':
APP.config.from_mapping(
SQLALCHEMY_DATABASE_URI='postgres://postgres:password#0.0.0.0:5432',
SQLALCHEMY_TRACK_MODIFICATIONS=False
)
DB.init_app(APP)
DB.create_all(app=APP)
APP.run(use_reloader=False, host='0.0.0.0', port='5000')
and I have a Dockerfile for it:
FROM python:3.6-alpine
RUN apk update && apk add postgresql-dev gcc python3-dev musl-dev
WORKDIR /root
COPY app.py .
RUN pip3 install Flask==1.0.2
RUN pip3 install psycopg2-binary==2.7.6.1
RUN pip3 install Flask-SQLAlchemy==2.3.2
CMD ["python3", "app.py"]
I run:
docker build . --tag flaskapp:1
docker run -d -p 5432:5432 -e POSTGRES_PASSWORD=password --name database postgres
docker run --rm -p 5000:5000 flaskapp:1
I then get an exception which points out:
sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) could not connect to server: Connection refused
Is the server running on host "0.0.0.0" and accepting
TCP/IP connections on port 5432?
How do I fix this?
You have specified 0.0.0.0 as the IP address to connect to, which doesn't make sense. 0.0.0.0 is the "Any Address". You probably saw a message that postgres was listening on 0.0.0.0, which is where you got it from. In the context of a server listening on 0.0.0.0, it means that it is listening on all ipv4 interfaces. See https://en.wikipedia.org/wiki/0.0.0.0 for more information about the special 0.0.0.0 address and what it means.
If you want to connect to the postgres service, then you would need to use a valid ip address or dns name of where it is running.
In Docker, if you have multiple named containers connected to the same user-defined network, you can make use of the built-in service discovery mechanism that Docker ships with.
Here's a modified set of commands to run to take advantage of this:
docker network create mynet
docker run -d -p 5432:5432 -e POSTGRES_PASSWORD=password --net mynet --name database postgres
docker run --rm -p 5000:5000 --net mynet flaskapp:1
Be sure to change your code to connect to postgres://postgres:password#database:5432 instead of postgres://postgres:password#0.0.0.0:5432
I'm working out how to run openproject with docker. I'm working through openproject/docker.
I've got the docker image running with an external postgres directory.
I'm now working out how to connect to an existing running instance of postgresql.
The command line I'm using looks ok according to the official documentation.
EDIT. Added in the missing -p.
docker run -p 8082:80 -p 5432:5432 --name openproject_dev -e SECRET_KEY_BASE=secret -e DATABASE_URL=postgresql://openproject:openproject-dev-
password#localhost:5432/openproject_dev \
-v /Users/admin/var/lib/openproject/logs:/var/log/supervisor \
-v /Users/admin/var/lib/openproject/static:/var/db/openproject openproject/community:5.0
I've ommitted the -d [deamon] flag so I can see any errors.
When the docker container is being created I get
-----> You're using an external database. Not initializing a local database cluster.
/usr/src/app /usr/src/app
Starting memcached: memcached.
Which I expect.
Then I get an error about connecting to the postgresql server which I don't expect.
...
PG::ConnectionBad: could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5432?
could not connect to server: Cannot assign requested address
Is the server running on host "localhost" (::1) and accepting
TCP/IP connections on port 5432?
/usr/local/bundle/gems/activerecord-
4.2.7.1/lib/active_record/connection_adapters/postgresql_adapter.rb:651:in `initialize'
I'm guessing the script initialising the container is expecting postgres to be running and it's not. How would you make the docker container port forward requests to 5432 to the host machine on the command line? ... the opposite of docker run -p 5432:5432 ... which exposes 5432 from the docker container to the host.
-e DATABASE_URL=postgresql://openproject:openproject-dev-
password#localhost:5432/openproject_dev
When you add this url, the container expects postgres to be running on localhost, i.e. in itself.
If you are running postgres on your host machine, you can let the container share the network stack with the host by passing --network host in the run command. In that case, localhost will refer to the host machine where postgres is running.
Your approach is wrong currently
docker run -p 8082:80 -p 5432:5432 --name openproject_dev -e SECRET_KEY_BASE=secret -e DATABASE_URL=postgresql://openproject:openproject-dev-password#localhost:5432/openproject_dev \
-v /Users/admin/var/lib/openproject/logs:/var/log/supervisor \
-v /Users/admin/var/lib/openproject/static:/var/db/openproject openproject/community:5.0
when you used -p 5432:5432 it means that you expect something to run inside docker on that port and you want your host machine 5432 port to map to 5432 inside docker.
Next if you were able to run that command, even though nothing is listening inside container, then that would imply that the port on your host is available. This means postgress is not listening on 5432 on host also. It may be listening on a socket. You should try to execute below command on host
psql -h 127.0.0.1
If you are not able to connect on host using this that means the postgres db is bind to a socket file and not to a IP. Now you have few options that you can exercise
Mount the socket
docker run -p 8082:80 -p 5432:5432 --name openproject_dev -e SECRET_KEY_BASE=secret -e DATABASE_URL=postgresql://openproject:openproject-dev-password#localhost:5432/openproject_dev \
-v /Users/admin/var/lib/openproject/logs:/var/log/supervisor \
-v : \
-v /Users/admin/var/lib/openproject/static:/var/db/openproject openproject/community:5.0
Bind on 0.0.0.0 on host
If you don't want to mount volume then you should change the bind address of psql to 0.0.0.0 and then change your database url to -e DATABASE_URL=postgresql://openproject:openproject-dev-password#<YOURMACHINEIP>:5432/openproject_dev
Run on host network
docker run --net host --name openproject_dev -e SECRET_KEY_BASE=secret -e DATABASE_URL=postgresql://openproject:openproject-dev-password#localhost:5432/openproject_dev \
-v /Users/admin/var/lib/openproject/logs:/var/log/supervisor \
-v : \
-v /Users/admin/var/lib/openproject/static:/var/db/openproject openproject/community:5.0
I'm trying to use a Docker container to run a PostgreSQL server, and connect with it from my host machine.
My configuration is:
Host machine: Mac OS X 10.10.5
Docker 1.10.1
I've done this:
Step 1: create a volume for permanent postgres data
docker volume create --name postgres_data
Step 2: Start the postgres instance
UPDATE: As suggested in comments, I specified port mapping when running the container
docker run --name my_postgres_container -e POSTGRES_PASSWORD=my_password -v postgres_data:/var/lib/postgresql/data -p 5432:5432 -d postgres:9.1
Step 3: connect to Docker instance by doing this:
docker run -it --link my_postgres_container:postgres --rm postgres:9.1 sh -c 'exec psql -h "$POSTGRES_PORT_5432_TCP_ADDR" -p "$POSTGRES_PORT_5432_TCP_PORT" -U postgres'
But I want to connect to that instance just by:
psql -h localhost -p 5432 -U postgres
Like if I had installed Postgres locally in my host machine.
The problem is port 5432 is not exposed. So, I can't connect with it:
sudo lsof -i -P | grep -i "listen" --> no port 5432 open
UPDATE 2: Even stranger. I've also done this:
Stop Docker. Then, run a normal PostgreSQL 9.4.4 instance in my host machine (no docker involved here, just postgres running in my Mac OS X host, listening on port 5432). Everything is normal:
sudo lsof -i -P | grep -i "postgres"
postgres 14100 jorge 6u IPv4 0x780274158cebef01 0t0 TCP localhost:5432 (LISTEN)
I can connect with my local postgres instance without any problem (look the output of the command: is the postgres compiled for Mac OS X, my host):
psql -h localhost -U postgres -c "select version()"
version
---------------------------------------------------------------------------------------------------------------------------------------
PostgreSQL 9.4.4 on x86_64-apple-darwin14.3.0, compiled by Apple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn), 64-bit
(1 row)
Now the fun part. I start my Docker instance again, while the host PostgreSQL instance is running.
It starts! (and it shouldn't). I can even connect using docker run...
docker run -it --link my_postgres_instance:postgres --rm postgres:9.1 sh -c 'exec psql -h "$POSTGRES_PORT_5432_TCP_ADDR" -p "$POSTGRES_PORT_5432_TCP_PORT" -U postgres'
If I run select version() now, it shows postgres running inside my docker instance at the same time postgres is running in my host, out of docker, using the same 5432 port. (Look at the ouput, is postgres compiled for Debian, the OS inside the postgres:9.1 container)
postgres=# select version();
version
------------------------------------------------------------------------------------------------
PostgreSQL 9.1.20 on x86_64-unknown-linux-gnu, compiled by gcc (Debian 4.9.2-10) 4.9.2, 64-bit
(1 row)
Why?
Does it make sense? My final goal is to run a Django app in another Docker container and connect with my Postgres instance. How could I do that?
It's 2018 and I just had a similar problem. The solution for me seemed to be with the order of props to docker. e.g. this resulted in no port being exposed;
docker run -d --name posttest postgres:alpine -e POSTGRES_PASSWORD=fred -p 5432:5432
while this worked fine (image exposed port 5432 as expected);
docker run --name posttest -d -p 5432:5432 -e POSTGRES_PASSWORD=fred postgres:alpine
Run the postgre image with the correct Port Mapping using -p <host_port>:<container_port>:
docker run --same-options-as-step-one -d -p 5432:5432 postgres:9.1
Your docker host is a virtual machine, which has it's own IP adddres.
You can detect this IP address by entering the following command:
docker-machine ip
The answer will be something like 192.168.99.100
When you have mapped the ports using the -p 5432:5432 switch, you will be able to connect to postgres with any tool from your dev machine using the IP address mentioned.
I was able to connect using container IP or host IP, except localhost (127.0.0.1).
To get container id run
docker ps
Find required container id and run
docker inspect --format='{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' <container_id>
Port must be exposed.
Here is an example of docker-compose.yml which starts two containers postgres and adminer, which is database management tool you can use to connect to postgres:
version: '3'
services:
adminer:
image: adminer
restart: always
ports:
- 8080:8080
postgres:
image: postgres:11.4-alpine
restart: always
ports:
- "5432:5432"
environment:
POSTGRES_USER: postgres
POSTGRES_PASSWORD: postgres
I had a similar issue. My problem was simply 0.0.0.0 not mapping to localhost so I just had to add to psql
psql --host=0.0.0.0
This is presuming
docker port <container name>
outputs
5432/tcp -> 0.0.0.0:5432
Other answers work, but don't explain why they work.
Given the command:
psql -h localhost -p 5432:5432 -U postgres
localhost is actually a special value that tells psql to look for a unix socket connection, instead of going over TCP. We can't use unix sockets to connect to docker services.
Changing the command like so fixes it, by forcing TCP:
psql -h 127.0.0.1 -p 5432:5432 -U postgres
That will work as long as you docker run ... -p 5432:5432 .... Specifying the IP returned by docker-machine ip also forces TCP, so that also works.
I had a similar problem working in a VMWare virtual machine with Lubuntu. The VM had been paused and then was restarted. The PostgreSQL Docker container was correctly mapped and listening on localhost:5432, but I always got:
psql: server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
Restarting the VM solved the problem in my case.
Try this to install postgresql
docker run --name postgres -d -p 5432:5432 -e POSTGRES_PASSWORD=fred postgres:alpine
Or Change port host machine Heree (mac)
docker run --name postgres -d -p 5436:5432 -e POSTGRES_PASSWORD=fred postgres:alpine
Tip:
Install pgadmin4
docker run -p 5050:80 -e "PGADMIN_DEFAULT_EMAIL=name#example.com" -e "PGADMIN_DEFAULT_PASSWORD=admin" -d dpage/pgadmin4
I started a postgresql server in docker and exposed the 5432 port by sudo docker run -it -p 5432:5432 9c421f1a239c bash and start the postgres server manually inside the docker container, but cannot connect to it with command: psql -h 172.17.0.63 -U venti. 172.17.0.63 is a right IP, and venti is my pg username. But get error:
psql: could not connect to server: Connection refused
Is the server running on host "172.17.0.63" and accepting
TCP/IP connections on port 5432?
My pg_hba.conf looks like this:
local all postgres peer
host all all 0.0.0.0/0 trust
local all all trust
Connecting to pg server inside container works successfully.
Dockerfile:
FROM ubuntu:12.04
RUN apt-get update
RUN apt-get install -y gcc libc-dev-bin libc6 libc6-dev libssl-dev libkrb5-dev comerr-dev
RUN apt-get install -y postgresql-common libpq-dev postgresql-9.1-postgis --fix-missing
RUN apt-get install -y postgresql postgresql-client
USER postgres
ENV PGDATA /etc/postgresql/9.1/main
ENV LOGDIR /etc/postgresql/9.1/main/postgresql.log
WORKDIR /usr/lib/postgresql/9.1/bin
USER root
RUN apt-get install -y vim
USER postgres
RUN sed -e '90d' -i /etc/postgresql/9.1/main/pg_hba.conf
RUN sed -e '91d' -i /etc/postgresql/9.1/main/pg_hba.conf
RUN echo "host all all 0.0.0.0/0 trust" >> '/etc/postgresql/9.1/main/pg_hba.conf'
RUN echo "local all all trust" >> '/etc/postgresql/9.1/main/pg_hba.conf'
RUN ./pg_ctl start && sleep 8 && ./createdb pg && ./createdb bloodstone \
&& createuser -Upostgres -s venti \
&& createdb -Uventi -Oventi venti
# ENTRYPOINT ./pg_ctl start && bash -c "while true; do echo "" > /dev/null; sleep 1; done"
VOLUME $PGDATA
EXPOSE 5432
It's merely a misconfiguration. I should have set pg to listen on public addresses or make a port mapping. I fixed this by editing pg config file with sed:
RUN sed -e "s/[#]\?listen_addresses = .*/listen_addresses = '*'/g" -i '/etc/postgresql/9.1/main/postgresql.conf'
Add this to a proper place in your Dockerfile, and you should be OK.
To troubleshoot postgres auth problems in general, look at the postgres log/stderr to see verbose reasons why it failed. (I see your problem is solved but if anyone runs into similar problems)
To find the postgres log location: "show log_destination;" if you have a working psql (eg locally on the postgres server box)
I see yours is set to "/etc/postgresql/9.1/main/postgresql.log". You can connect to the container to see the log with "docker exec -it container_name bash".
Alternately, if a container runs postgres directly, "docker attach db_container_name" views postgres stderr messages.
Note that by default user postgres does not have a password and uses only ident auth.
I also faced similar issue. Try running docker-compose up twice.
The reason is, that in my docker-compose.yml file the DB service was below the Web service in which it was trying to connect to DB which does not exists yet.
**
version: '2'
services:
nginx:
image: nginx:latest
container_name: ng01
ports:
- "8000:8000"
volumes:
- ./src:/src
- ./config/nginx:/etc/nginx/conf.d
- /static:/static <--- HERE
depends_on:
- web
web:
build: .
container_name: dg01
command: bash -c "python /src/IMS/manage.py makemigrations && python /src/IMS/manage.py migrate && gunicorn IMS.wsgi -b
0.0.0.0:8000"
depends_on:
- db
volumes:
- ./src:/src
- /static:/static
expose:
- "8000"
db:
image: postgres:latest
container_name: ps01**