Running multiple docker containers in the same environment - docker

Can't seem to connect API running on my localhost with webapp that's running as well on another local host. Note they are containerized on 2 different containers. API calls don't seem to get endpoints on my application.
What's the way to run them both in the same environment?
I've used maven to create a .jar of my app and did docker build and docker run on specified port on localhost. Currently searching how to run docker-compose of these two so that endpoints can be reached. (note API is on port:1026 and app on port:1028)
Any ideas?

Related

Remote HTTP Endpoint to Docker Application

I have a demo application running perfectly on my local environment. However, I would like to run the same application remotely by giving it a HTTP endpoint. My goal is to test the performance of the application.
How to give a HTTP endpoint to any multi container docker application?
The following is the Github repository link for the demo application
https://github.com/LonareAman/BankCQRS.git
Use docker-compose and handle containers based on what you need
One of your containers should be web server like nginx. And then bind your machine port to your nginx like 80:80
Then handle your containers in nginx and make a proxy to them
You can find some samples in https://testdriven.io/blog/dockerizing-django-with-postgres-gunicorn-and-nginx/

Cannot connect to RabbitMQ Server from another containerised .Net core RabbitMQ client

I have been able to set up containerised RabbitMQ server, and reach into it with basic .NET Core clients and check message send and receive working using management portal on http://localhost:15672/.
But I am having real frustrations when I also Containerise my Sender/Receiver .NET Core clients, on being able to establish a connection. I have set up an explicit "shipnetwork", so all containers in the following docker-compose deployment should see each other.
This is the Error I get in the sender attempting the connection:
My SendRabbit .NET core App is as follows. This code was working on my local Windows 10 development machine, with a host of 'localhost' against the RabbitMQ server running as a container. But when I change this to a [linux] docker project, and set the host to "rabbitmq", to correspond to the service name in the docker compose. Now I just get Endpoint Connection errors exceptions within my Sender container.
I have also attempted the same RabbitMQ server and Sender Image with the same docker-compose on a Google Cloud Linux Virtual Machine, and get the same errors. So I do not think it is the Windows 10 docker hosting VM environment hassles.
I thought docker was going to make development and deployment of microservices, but setting up a basic RabbitMQ connections is proving to be a real pain.
I have thought that maybe the rabbitmq server is not up and running, so perhaps ambitious to put in the same docker-compose. But I have checked running my SendRabbit container
$docker run --network shipnetwork sendrabbit
some minutes later. But I still get the same connection error
docker networks **** networks !
When I checked the actual docker networks, I had:
bridge
host
shipnetwork
rabbitship_shipnetwork
The docker compose was actually creating the 'new' network: rabbitship_shipnetwork every time it was spun up, and placing the rabbimq server on that network. The netwrok is named from appending the directory name, with the name in the compsos yaml. So I was using the wrong network in my senders. So I should have been using
$docker run --network rabbitship_shipnetwork sendrabbit
This works fine, and creates messages into the rabbitmq server
So I don't feel that docker-compose is actually very helpful in creating networks, since it is sensitive to the directory name it is run in ! Its unlikely that I can build an app .docker files, and deploy all Apps from a single directory, especially when rabbitmq has to be started separately, before senders and receivers can use it.
docker-compose 0

Access Docker daemon on Host without knowing Host OS

I use docker-compose to spin up a few containers as part of an application I'm developing. One of the containers needs to start a docker swarm service on the host machine. On Docker for Windows and Docker for Mac, I can connect to the host docker daemon using the REST Api by using the "host.docker.internal" DNS name and this works great. However, if I run the same compose file on linux, "host.docker.internal" does not work (yet, seems it may be coming in the next version of docker). To make matters worse, on Linux I can use network mode of "host" to work around the issue but that isn't supported on Windows or Mac.
How can I either:
Create a docker-compose file or structure a containerized application to be slightly different based on the host platform (windows|mac|linux) without having to create multiple docker-compose.yml files or different application code?
Access the host docker daemon in a consistent way regardless of the host OS?
If it matters, the container that is accessing the docker daemon of the host is using the docker python sdk and making api calls to docker over tcp without TLS (this is used for development only).
Update w/ Solution Detail
For a little more background, there's a web application (aspnet core/C#) that allows users to upload a zip file. The zip file contains, among other things, an exported docker image file. There's also an nginx container in front of all of this to allow for ssl termination and load balancing. The web application pulls out the docker image, then using the docker daemon's http api, loads the image, re-tags the image, then pushes it to a private docker repository (which is running somewhere on the developer's network, external to docker). After that, it posts a message to a message queue where a separate python application uses the python docker library to deploy the docker image to a docker swarm.
For development purposes, the applications all run as containers and thus need to interact with docker running on the host machine as a stand alone swarm node. SoftwareEngineer's answer lead me down the right path. I mapped the docker socket from the host into the web application container at first but ran into a limitation of .net core that won't be resolved until .net 5 which is that there's no clean way of doing http over a unix socket.
I worked around that issue by eventually realizing that nginx can reverse proxy http traffic to a unix socket. I setup all containers (including the dynamically loaded swarm service from the zips) to be part of an overlay network to give them all access to each other and allowing me to hit an http endpoint to control the host machine's docker/swarm daemon over http.
The last hurdle I ran into was that nginx couldn't write to the mapped in /var/run/docker.sock file so I modified nginx.conf to allow it to run as root within the container.
As far as I can tell, the docker socket is available at the path /var/run/docker.sock on all systems. I have personally verified this with a recent Linux distro (Ubuntu), Windows 10 Pro running Docker for Windows (2.2.0) with both WSL2 (Ubuntu and Alpine) and the windows cmd (cli) and powershell. From memory, it works with OSX too, and I used to do the same thing in WSL1.
Mapping this into a container is achieved on any terminal with the -v, --volume, or --mount flags. So,
docker container run -v /var/run/docker.sock:/var/run/docker.sock
Mounts the socket into an identical path within the container. This means that you can access the socket using the standard docker client (docker) from within the container with no extra configuration. Using this path inside a Linux container is recommended because the standard location and is likely to be less confusing to anyone maintaining your code in the future (including yourself).

Can't access certain services running on host machine from inside docker container

We're trying to setup a GitLab Runner, which is resposible for building and testing our web application. For running the jobs we use the Docker executor with DinD.
Our problem is now: When trying to access certain services from inside the Runner Container (docker image) we get a timeout and no response back. It includes:
logging in to our own docker registry which is hosted on the same
system
wget on our domain (which is hosted on the same system)
What we can do:
ping our domain as well as the registry
ping other domains
wget other domains
Logging into the registry and wget our domain is successful when trying it native on the server and not in a docker container.
So it maybe looks like a docker problem.
Hope someone can help us.

Nodejs Docker Development microservices

I'm building a application with microservices architecture.
So basically, my app look like this
API GATEWAY(port 3000) => USERS-SERVICE(port 9090), AUTH-SERVICE(port 8080), SEND-SMS-SERVICE(port 7070).
all work fine until now.
now I try to implement docker in my project. I build an image for each service
and run container instance for each on my local machine.
now I want to develop new service Customer-Service. and this service run on
http://localhost:3030
.
question:
1) How i can request http://localhost:3030 from api gateway, if in development I run api-gateway from container.
You must understand the network concept, when you start independent docker instance and you don't define the network they will be unreachable between them.
There is other things, you CAN'T access to one micro service hosted in a Docker to other Micro services hosted in other docker image using localhost, localhost is a 127.0.0.1. This is a call for the local machine. Then the concept of docker is like "diferent machines running on a same machine" is like a virtual machine but docker shares the host machine kernel.
You can access to another docker image in 2 ways.
Configure in a host network, which i do not recommend
Create a network, add every docker image instance to this network and call other micro services using the container name. IE you can use http://my-service-1:3400/api/v1/post
I recommend you to use docker-compose.
This is one of my repositories, I created with the propuse of share an Node App using JWT, but this project use Docker and docker-compose
https://github.com/camiloperezv/jwt-template
how you can see, i define an Network attribute in the docker-compose.ymland use this network in all of my services.
In the service section you will put all your micro-services, and in the code you will make the http request using the container name instead of using localhost or an IP address.
In my services y use the build: . this is for development propuse, in production you should use the pre build docker image instead of building it on the production server.
Feel free to use my github code.
Regards
As far as I understand from the question, a new service Costumer-Service runs on http://localhost:3030 on the host machine.
If yes, api-gateway docker container should be started in the host network:
docker run --network host -d <api-gateway_image_name>
After this Costumer-Service will be reachable on localhost:3030 from the api-gateway container.

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