Prevent publishing ports defined in compose file - docker

I have a docker compose file that defines a service that will run my application and a service that that application is dependent on to run:
services:
frontend:
build:
context: .
volumes:
- "../.:/opt/app"
ports:
- "8080:8080"
links:
- redis
image: node
command: ['yarn', 'start']
redis:
image: redis
expose:
- "6379"
For development this compose file exposes 8080 so that I can access the running code from a browser.
In jenkins however I can't expose that port as then two jobs running simultaneously would conflict trying to bind to the same port on jenkins.
Is there a way to prevent docker-compose from binding service ports? Like an inverse of the --service-ports flag?
For context:
In jenkins I run tests using docker-compose run frontend yarn test which won't map ports and so isn't a problem.
The issue presents when I try to run end to end browser tests against the application. I use a container to run CodeceptJS tests against a running instance of the app. In that case I need the frontend to start before I run the tests, as they will fail if the app is not up.

Q. Is there a way to prevent docker-compose from binding service ports?
It has no sense to prevent something that you are asking to do. docker-compose will start stuff as the docker-compose.yml file indicates.
I propose duplicate the frontend service using extends::
version: "2"
services:
frontend-base:
build:
context: .
volumes:
- "../.:/opt/app"
image: node
command: ['yarn', 'start']
frontend:
extends: frontend-base
links:
- redis
ports:
- "8080:8080"
frontend-test:
extends: frontend-base
links:
- redis
command: ['yarn', 'test']
redis:
image: redis
expose:
- "6379"
So use it as this:
docker-compose run frontend # in dev environment
docker-compose run frontend-test # in jenkins
Note that extends: is not available in version: "3", but they will bring it back again in the future.

For preventing to publish ports outside the docker network you just
need to write on a single port in the ports segment.
Instead of using this:
ports:
- 8080:8080
Just use this one(at below):
ports:
- 8080

Related

Docker container can't talk to another container

I have a docker compose file set up with 3 separate containers (Flask, Nginx and Solr)
After starting up all 3 run successfully but my Flask application can't connect to my Solr instance and when I run:
wget -S http://localhost:8983/solr/CORE_NAME/select
I get the error "Connecting to localhost (localhost)|127.0.0.1|:8983... failed: Connection refused."
I am fairly new to docker and been around a few different forums looking at this issue but nothing has worked so far. I have tried creating a network also but running into the same issue.
Here is my docker-compose.yml.
version: "2.7"
services:
nginx:
build:
context: .
dockerfile: Dockerfile-nginx
container_name: nginx
ports:
- "80:80"
- "8181:8181"
volumes:
- ./:/opt/ee1
- ee1-logs-volume:/var/log/ee1
- ./:/usr/local/websites/ee1
- sockets-volume:/tmp
depends_on:
- flask
flask:
build:
context: .
dockerfile: Dockerfile-flask
entrypoint: ["/bin/bash", "./system/start-uwsgi-docker.bash"]
container_name: flask
user: root
restart: always
volumes:
- ./:/opt/ee1
- ./ee1config.ini:/opt/ee1config.ini
- ee1jobs-logs-volume:/var/log/ee1
- ./:/usr/local/websites/ee1
- sockets-volume:/tmp
links:
- solr
solr:
build:
context: .
dockerfile: Dockerfile-solr
container_name: solr
volumes:
- data:/var/solr
entrypoint:
- bash
- "-c"
- "precreate-core ee1_1; precreate-core ee1_2; exec solr -f"
ports:
- "8983:8983"
volumes:
sockets-volume: {}
ee1-logs-volume: {}
data:
Every docker container is - network wise - a separate host with it's own IP.
Traffic to localhost or 127.0.0.1 will definitely never leave that container.
So what you need to find out is the IP of the server container (solr) you actually want to talk to, then configure the client container (flask) accordingly. This can be done by e.g. docker inspect. Be aware that upon container restart the IPs can change. You will want to use something like DNS rather than raw IPs.
Since you use docker compose, each container for a service joins the same network and is both reachable by other containers on that network, and discoverable by them at a hostname identical to the container name.
For more details check out
https://docs.docker.com/compose/networking/
https://docs.docker.com/network/

setup networking of multiple docker containers in different projects using docker-compose

Hello I have multiple projects that have there own dockerfiles and docker-compose.yml files. I am not too familiar on how I would setup the networking between these projects. So they could share the same databases and the project would be able to talk to on another. Does anyone have suggests?
Right now, In one of the projects I am just pulling in all the dockerfile into a docker-compose.yml and setting-up all the services I need from all the other projects in this yml file. I do not think this is ideal and there is a high level a coupling between the services.
version: "3"
services:
db:
image: mysql/mysql-server
ports:
- 3306:3306
mongo:
image: mongo
restart: always
rails_app:
build:
context: ${RAILS_APP_PATH}
dockerfile: Dockerfile
volumes:
- ${RAILS_APP_PATH}:/application
ports:
- 4000:4000
depends_on:
- db
- mongo
links:
- db
- mongo
frontend:
build:
context: ${FRONTEND_PATH}
ports:
- ${EXPOSED_PORT}:${EXPOSED_PORT}
depends_on:
- go_services
links:
- go_services
go_services:
build:
context: .
dockerfile: Dockerfile
ports:
- "8080:8080"
depends_on:
- db
- mongo
- rails_app
links:
- db
- mongo
- rails_app
The trick is to use an External Docker Network.
Set up the network and the Containers can talk to each other by their Service Names.
Setup the the network on the Host
docker network create my-net
First compose file
version: '3.9'
services:
mymongo:
image: mongo:latest
restart: unless-stopped
container_name: mongo
environment:
MONGO_INITDB_DATABASE: mymongo
MONGO_INITDB_ROOT_USERNAME: root
MONGO_INITDB_ROOT_PASSWORD: password
volumes:
- ./database:/data/db
ports:
- "27017:27017"
networks:
default:
external: true
name: my-net
Second compose file
version: '3.9'
services:
ui:
build:
context: ./build
dockerfile: Dockerfile_ui
image: ui
restart: "no"
container_name: ui
ports:
- "8005:3000"
command: ["npm", "start"]
networks:
default:
external: true
name: my-net
You can do this without any special Compose setup, if:
each project is self-contained (they do not share databases)
the service locations are configurable via environment variables
you don't mind communicating via the host
If you're thinking about scaling up this project at all, this approach can look attractive. It will work even if you're running each Compose file on a different host, and it translates well into clustered environments like Kubernetes.
Go ahead and break up your Compose file into several independent ones:
# rails/docker-compose.yml
version: '3.8'
services:
db:
image: mysql/mysql-server
app:
build: .
ports: ['4000:4000']
depends_on: [db]
# go/docker-compose.yml
services:
mongo:
image: mongo
service:
build: .
ports: ['8080:8080']
depends_on: [mongo]
environment:
- RAILS_APP_URL
The very last line here passes the RAILS_APP_URL environment variable from the host environment into the container.
You can start the Rails application independently:
docker-compose -f ./rails/docker-compose.yml up -d
You need to find some hostname where the container can call back to the host. On MacOS and Windows hosts, Docker provides a special hostname host.docker.internal for this. You can then connect the client container to the published port of its server:
export RAILS_APP_URL=http://host.docker.internal:4000
docker-compose -f ./go/docker-compose.yml up
If you're doing development, you can run the service you're working on locally, and its dependencies in containers, and point the environment variable at the container
go build -o ./server ./cmd/server
export RAILS_APP_URL=http://localhost:4000
./server
If you want to run this setup on multiple hosts but without using a dedicated cluster manager like Docker Swarm or Kubernetes, set the environment variable to point at the DNS name of the host running the service. If you did want to translate this to Kubernetes, a Helm "chart" would be analogous, containing the Deployment, Service, etc. and dependencies for a single component, and you could configure the other service's URL through Helm values.

How to network between multiple containers of the same image in docker-compose?

I am using docker-compose and my configuration file is simply:
version: '3.7'
volumes:
mongodb_data: {}
services:
mongodb:
image: mongo:4.4.3
restart: always
ports:
- "27017:27017"
volumes:
- mongodb_data:/data/db
environment:
- MONGO_INITDB_ROOT_USERNAME=root
- MONGO_INITDB_ROOT_PASSWORD=super-secure-password
rocket:
build:
context: .
depends_on:
- mongodb
image: rocket:dev
dns:
- 1.1.1.1
- 8.8.8.8
volumes:
- .:/var/rocket
ports:
- "30301-30309:30300"
I start MongoDB with docker-compose up, and then in new terminal windows run two Node.js application each with all the source code in /var/rocket with:
# 1st Node.js application
docker-compose run --service-ports rocket
# 2nd Node.js application
docker-compose run --service-ports rocket
The problem is that the 2nd Node.js application service needs to communicate with the 1st Node.js application service on port 30300. I was able to get this working by referencing the 1st Node.js application by the id of the Docker container:
Connect to 1st Node.js application service on: tcp://myapp_myapp_run_837785c85abb:30300 from the 2nd Node.js application service.
Obviously this does not work long term as the container id changes every time I docker-compose up and down. Is there a standard way to do networking when you start multiple of the same container from docker-compose?
You can run the same image multiple times in the same docker-compose.yml file:
version: '3.7'
services:
mongodb: { ... }
rocket1:
build: .
depends_on:
- mongodb
ports:
- "30301:30300"
rocket2:
build: .
depends_on:
- mongodb
ports:
- "30302:30300"
As described in Networking in Compose, the containers can communicate using their respective service names and their "normal" port numbers, like rocket1:30300; any ports: are ignored for this. You shouldn't need to manually docker-compose run anything.
Well you could always give specific names to your two Node containers:
$ docker-compose run --name rocket1 --service-ports rocket
$ docker-compose run --name rocket2 --service-ports rocket
And then use:
tcp://rocket1:30300

Running shell script against Localstack in docker container

I've been using localstack to develop a service against locally. I've just been running their docker image via docker run --rm -p 4567-4583:4567-4583 -p 8080:8080 localstack/localstack
And then I manually run a small script to set up my S3 buckets, SQS queues, etc.
Now, I'd like to make this easier for others so I thought I'd just add a Dockerfile and docker-compose.yml file. Unfortunately, when I try to get this up and running, using docker-compose up I get an error that the command from my setup script can't connect to the localstack services.
make_bucket failed: s3://localbucket Could not connect to the endpoint URL: "http://localhost:4572/localbucket"
Dockerfile:
FROM localstack/localstack
#since this is just local dev set up, localstack doesn't require
anything specific here.
ENV AWS_DEFAULT_REGION='[useast1]'
ENV AWS_ACCESS_KEY_ID='[lloyd]'
ENV AWS_SECRET_ACCESS_KEY='[christmas]'
COPY bin/localSetup.sh /localSetup.sh
COPY fixtures/notifications.json /notifications.json
RUN ["chmod", "+x", "/localSetup.sh"]
RUN pip install awscli
# expose service & web dashboard ports
EXPOSE 4567-4582 8080
ENTRYPOINT ["/localSetup.sh"]
docker-compose.yml
version: '3'
services:
localstack:
build: .
ports:
- "8080:8080"
- "4567-4582:4567-4582"
localSetup.sh
#!/bin/bash
aws --endpoint-url=http://localhost:4572 s3 mb s3://localbucket
#additional similar calls but left off for brevity
I've tried switching localhost to 127.0.0.1 in my script commands, but I wind up with the same error. I'm probably missing something silly here.
There is another way to create your custom AWS resources when localstack freshly starts up. Since you already have a bash script for your resources, you can simply volume mount your script to /docker-entrypoint-initaws.d/.
So my docker-compose file would be:
localstack:
image: localstack/localstack:latest
container_name: localstack_aws
ports:
- '4566:4566'
volumes:
- './localSetup.sh:/etc/localstack/init/ready.d/init-aws.sh'
Also, I would prefer awslocal over aws --endpoint in the bash script, as it leverages the credentials work and endpoint for you.
try adding hostname to the docker-compose file and editing your entrypoint file to reflect that hostname.
docker-compose.yml
version: '3'
services:
localstack:
build: .
hostname: localstack
ports:
- "8080:8080"
- "4567-4582:4567-4582"
localSetup.sh
#!/bin/bash
aws --endpoint-url=http://localstack:4572 s3 mb s3://localbucket
This was my docker-compose-dev.yaml I used for testing out an app that was using localstack. I used the command docker-compose -f docker-compose-dev.yaml up, I also used the same localSetup.sh you used.
version: '3'
services:
localstack:
image: localstack/localstack
hostname: localstack
ports:
- "4567-4584:4567-4584"
- "${PORT_WEB_UI-8082}:${PORT_WEB_UI-8082}"
environment:
- SERVICES=s3
- DEBUG=1
- DATA_DIR=${DATA_DIR- }
- PORT_WEB_UI=${PORT_WEB_UI- }
- DOCKER_HOST=unix:///var/run/docker.sock
volumes:
- "${TMPDIR:-/tmp/localstack}:/tmp/localstack"
- "/var/run/docker.sock:/var/run/docker.sock"
networks:
- backend
sample-app:
image: "sample-app/sample-app:latest"
networks:
- backend
links:
- localstack
depends_on:
- "localstack"
networks:
backend:
driver: 'bridge'

docker - multiple databases on local

I have 2 applications that are separate codebases, and they each have their own database on the same db server instance.
I am trying to replicate this in docker, locally on my laptop. I want to be able to have both apps use the same database instance.
I would like
both apps to start in docker at the same time
both apps to be able to access the database on localhost
the database data is persisted
be able to view the data in the database using an IDE on localhost
So each of my apps has its own dockerfile and docker-compose file.
On app1, I start the docker instance of the app which is tied to the database. It all starts fine.
When I try to start app2, I get the following error:
ERROR: for app2_mssql_1 Cannot start service mssql: driver failed programming external connectivity on endpoint app2_mssql_1 (12d550c8f032ccdbe67e02445a0b87bff2b2306d03da1d14ad5369472a200620): Bind for 0.0.0.0:1433 failed: port is already allocated
How can i have them both running at the same time? BOTH apps need to be able to access each others database tables!
Here is the docker-compose.yml files
app1:
version: "3"
services:
web:
build:
context: .
args:
volumes:
- .:/app
ports:
- "3000:3000"
depends_on:
- mssql
mssql:
image: 'microsoft/mssql-server-linux'
ports:
- '1433:1433'
environment:
- ACCEPT_EULA=Y
- SA_PASSWORD=P455w0rd!
volumes:
- app1_db:/var/lib/mssql/data
volumes:
app1_db:
and here is app2:
version: "3"
services:
web:
build:
context: .
args:
volumes:
- .:/app
ports:
- "3000:3000"
depends_on:
- mssql
mssql:
image: 'microsoft/mssql-server-linux'
ports:
- '1433:1433'
environment:
- ACCEPT_EULA=Y
- SA_PASSWORD=P455w0rd!
volumes:
- app2_db:/var/lib/mssql/data
volumes:
app2_db:
Should I be using the same volume in each docker-compose file?
I guess the problem is in each app i am spinning up 2 different db instances, when in reality I guess i just want one, and it be used by all my apps?
The ports part in docker-compose file will bound the container port to host's port which causes port conflict in your case.
You need to remove the ports part from at least one of the compose file. This way, docker-compose can be up for both. And you can have access to both app at same time. But remember both apps will be placed in separate network bridges.
How docker-compose up works:
Suppose your app is in a directory called myapp, and your docker-compose.yml
When you run docker-compose up, the following happens:
A network called myapp_default is created.
A container is created using web’s configuration. It joins the network myapp_default under the name web.
A container is created using db’s configuration. It joins the network myapp_default under the name db.
If you run the second docker-compose.yml in different folder myapp2, then the nework will be myapp2_default.
Current configuration creates two volumes, two datebase containers and two apps. If you can make them run in the same network and run database as the single container it will work.
I don't think you are expecting two database container two two volumes.
Approach 1:
docker-compose.yml as a single compose.
version: "3"
services:
app1:
build:
context: .
args:
volumes:
- .:/app # give the path depending up on the docker file of app1.
ports:
- "3030:3000"
depends_on:
- mssql
app2:
build:
context: .
args:
volumes:
- .:/app # give the path depending up on the docker file of app2.
ports:
- "3032:3000"
depends_on:
- mssql
mssql:
image: 'microsoft/mssql-server-linux'
ports:
- '1433:1433'
environment:
- ACCEPT_EULA=Y
- SA_PASSWORD=SqlServer1234!
volumes:
- app_docker_db:/var/lib/mssql/data
volumes:
app_docker_db:
Approach 2:
To Isolate it further, still want to run them as the sepeare composefiles, create three compose file with network.
docker-compose.yml for database with network
version: "3"
services:
mssql:
image: 'microsoft/mssql-server-linux'
ports:
- '1433:1433'
environment:
- ACCEPT_EULA=Y
- SA_PASSWORD=SqlServer1234!
volumes:
- app_docker_db:/var/lib/mssql/data
networks:
- test_network
volumes:
app_docker_db
networks:
test_network:
docker-ompose.yml for app1
remove the database container and add below lines to your compose file
version: "3"
services:
app1:
build:
context: .
args:
volumes:
- .:/app # give the path depending up on the docker file of app1.
ports:
- "3030:3000"
networks:
default:
external:
name: my-pre-existing-network
Do the same for another docker-compose by replacing the docker-compose file.
There are many other option to create docker-compose files. Configure the default network and Use a pre-existing network
You're exposing the same port (1433) two times to the host machine. (This is what "ports:..." does). This is not possible as it would block the same port on your host (That's what the message says).
I think the most common way in these cases is that you link your db's to your apps. (See https://docs.docker.com/compose/compose-file/#links). By doing this your applications can still access the databases on their common ports (1433), but the databases are not accessible from the host anymore (only from the container that is linked to it).
Another error I see in your docker compose file is that both applications are exposed by the same ports. This is also not possible for the same reason. I would suggest that you change one of them to "3000:3001", so you can access this application on port 3001.

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