Nifi install using Docker - Can´t access the webserver - docker

I'm new to both docker and Nifi, I found this command that installs via docker and used it on a virtual machine that I have in GCP but I would like to access this container via webserver. In docker ps this appears to me:
What command do I need to execute to gain access to the tool via port 8080?

The container has already exposed port 8080 on the host, as evidence by the output 0.0.0.0:8080->8080/tcp. You read that as {HOST_INTERFACE}:{HOST_PORT}->{CONTAINER_PORT}/{PROTOCOL}.
Navigate to http://SERVER_ADDRESS:8080/ (or maybe http://SERVER_ADDRESS:8080/nifi) using your web browser. You may need to modify the firewall rules applied to your VM to ensure that you can access that port from your local machine.

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Docker cannot access exposed port inside container

I have a container for which I expose my port to access a service running within the container. I am not exposing my ports outside the container i.e. to the host (using host network on mac). On getting inside the container using exec -t and running a curl for a post request, I get the error:
curl command: curl http://localhost:19999
Failed connect to localhost:19999; Connection refused.
I have the expose command in my dockerfile and do not want to expose ports to my host. My service is also up and running inside the container. I also have the property within config set as
"ExposedPorts": {"19999/tcp": {}}
(obtained through `docker inspect <container id/name>\ Any idea on why this is not working? Using docker for Mac
I'd post my docker-compose file too but this is being built through maven. I can ensure that I am exposing my port using 19999:19999. Another weird issue is that on disabling my proxies it would run a very light weight command for my custom service and wouldn't run it again returning the same error as above. The issue only occurs on my machine and not others
Hints:
The app must be listening on port 19999 which is probably not.
The EXPOSE that you're using inside the Dockerfile does nothing.
Usually there is no need to change the default port on which an application is listening, hence each container has its own IP and you shouldn't run in a port conflict.
Answer:
Instead of curling 19999 try to use the default port on which your app would normally be listening to(it's hard to guess what you are trying to run).
If you don't publish a port (with the docker run -p option or the Docker Compose ports: option), you cannot directly reach the container on Docker for Mac. See the Known limitations, use cases, and workarounds in the Docker Desktop for Mac documentation: the "per-container IP addressing is not possible" item ism what you're trying to attempt.
The docker inspect IP address is basically useless, except in one very specific Docker configuration (on a native-Linux host, calling from outside of Docker, on the same host); I wouldn't bother looking it up.
The Dockerfile EXPOSE directive and similar runtime options do very little and mostly serve as documentation. Even if you have that configured you still need to separately publish the port when you start the container to reach it from outside of Docker space.

Resource cannot be found error when accessing a page in Docker Container

I created a asp.net webform project in Visual Studio with Docker support (Windows). When I run the project using Visual Studio page comes up as below
Visual Studio creates a docker image which I saw using command
docker images
See image below (webapplication3)
Now I run another instance of Image (webapplication3) by command
Docker run webapplication3:dev
I can see container running
Docker ps
see image below
But now when I access this new running container using ip http://172.17.183.118/PageA.aspx
it's not coming up, see image below (I have taken IP 172.17.183.118 from docker inspect command, so it is correct.
Can someone tell me why am I not able to view the page? Why is it saying "Resource cannot be found" error?
When you run a Docker container default, the container will run with an internal IP address and an expose port map the local machine port, and the IP address will go out to the internet through the docker bridge which associated with the local machine network interface.
When you access the container inside the local machine, you just need to access the localhost with the port shows you. In your issue, you need to access the address http://localhost:62774/PageA.aspx. If you want to access the container from the Internet, you should access the IP address of your local machine with the port. For you, it means the address http://your-local-machine-public-ip:62774/PageA.aspx.
You can get more details from Docker Network. Also, I suggest you'd better run the container with the special port you plan just like docker run -d -p nodePort:containerPort --name containerName yourImage.

Can't connect to ASP.Net site in Docker for Windows

I am having difficulty connecting from the host to an ASP.Net website running in a Windows container on Docker. I can connect to a website running in a Linux container without any problem.
I have tried connecting to both localhost and to the IP port assigned to the container but in both cases I just get a timeout error.
I have tried several ASP.Net examples which are already pre-built along with trying to build my own custom image. In every case I get the same timeout error. I have also tried uninstalling and re-installing docker but that didn't change anything.
I am running Windows 10 Pro and Docker Community Edition Version 17.03.1-ce-win12 (12058)
Ultimately I was able to completely reset my container network using a customized older version of the Microsoft Vitualization cleanup scripts. https://github.com/Microsoft/Virtualization-Documentation/tree/live/windows-server-container-tools/CleanupContainerHostNetworking This reset my container network and everything is now working as expected.
SUMMARY:
When the published port/s for a container are defined using the EXPOSE directive in the container's Dockerfile, the -P argument must be used with the docker run command in order to "activate" those exposed port/s.
It is not possible for a Windows container host to access containers that it is running using localhost, 127.0.0.1 or its external host IP address. Access containers running on a given host, A, by using the IP address of A from a second host, B. Alternatively, you can use the IP address of a container directly.
FULL EXPLANATION:
So there are a few nuances with ensuring that the proper firewall rules are created, and your containers are actually accessible on their published port/s.
For instance, I'll assume that your ASP.Net containerized application is defined by a container image, which was defined by a Dockerfile. If so, you probably defined the published port for the image/app using the Dockerfile EXPOSE directive. In this case, when you actually run the container you need to "activate" that published port using the "-P" argument to the docker run command.
For example, if your container image is web_app, and the Dockerfile for that image included the line, EXPOSE 80, then when you go ahead and run that image you need to do something like:
C:\> docker run -P web_app
Once the container is running, it should be available on container port 80. You can then go ahead and view the app via browser. To do that you have two options:
You can access the app from your container host, using the container IP and port
Find the container IP using docker network inspect nat, then looking for the endpoint/IP address that corresponds with your container.
You can also fund the container IP by running docker exec <CONTAINER ID> ipconfig, where <CONTAINER ID> is the ID of your container.
You can get the ID of your container and the exposed port for your container by running docker ps on the container host.
You can access the app from another host machine, using the container host IP and host port
You can find the IP address of your host using ipconfig.
You can identify the host port upon which your app is exposed, by running docker ps from the host. Then, under PORTS you'll see a mapping of the form 0.0.0.0:<HOST PORT>-><CONTAINER PORT>/TCP. In this mapping <HOST PORT>, is the port upon which your app is available on the host.
Once you have the IP address of your container host, and the port upon which your app is available on the host, you can use that information to access your app from a browser on a separate host.
NOTE: Today you cannot access a container in this way from its own host--currently a Windows container host cannot access the containers it is running, despite whether localhost, 127.0.0.1 or the host IP address is used.

Access docker remote API from container

I'm trying to access Docker remote API from within a container because I need to start other containers.
The host address is 172.19.0.1, so I'm using http://172.19.0.1:2375/images/json to get the list of images (from host, http://localhost:2375/images/json works as expected.
The connection is refused, I guess because Docker (for Windows) listens on 127.0.0.1 and not on 0.0.0.0.
I've tried to change configuration (both from UI and daemon.json) adding the entry:
"hosts": ["tcp://0.0.0.0:2375"]
but the daemon fails to start. How can I access the api?
You can set DOCKER_OPTS in windows as below and try. In Windows, Docker runs inside a VM. So, you have to ssh into the VM and make the changes.
DOCKER_OPTS='-H tcp://0.0.0.0:4243 -H unix:///var/run/docker.sock'
Check if it works for you.
Update :- To ssh into the VM (assuming default is the VM name you have created using Docker toolbox), enter the following command in the Docker Quickstart Terminal,
docker-machine ssh default
You can find more details here.
You could link the host's /var/run/docker.sock within the container where you need it. This way, you don't expose the Docker Remote API via an open port.
Be aware that it does provide root-like access to docker.
-v /var/run/docker.sock:/var/run/docker.sock
You should use "tcp://host.docker.internal:2375" to connect to host machine from container. Please make sure that you can ping the "host.docker.internal" address
https://github.com/docker/for-win/issues/1976

Access docker-machine VM ports without port forwarding

I'm trying to learn Docker and so far I have run into a lot of "work arounds" that are needed in docker-machine but not in boot2docker.
My current issue is accessing my docker containers from my host.
I have my Windows host, running a VM created with docker-machine, and inside that docker VM I'm running a simple nginx server container.
The nginx container is ran to expose it's 80 port to the docker-machine's 8000.
docker run -d -p 8000:80 nginx
And what I'm trying to achieve is being able to open this server from my Windows using a browser.
If I in Windows use curl (Git bash, not ssh-ed into the docker-machine VM) using the IP that docker-machine ip gives me, then it works. But using my browser doesn't (I'm using Microsoft Edge currently), I can get the browser to work if I set up a NAT port forwarding.
curl $(docker-machine ip dev):8000
As I've read it should be possible to access the VM ports without specifying port forwarding rules for every port, that VirtualBox should expose and forward those automatically.
What am I doing wrong or do I have to specify port forwarding rules for every port between my VM and host OS that I want to use?
After another day of digging I had the wild and crazy idea to try another browser and it works fine.
So for anyone running into this issue and you're using Microsoft Edge (to try it out like me), switch browser. Chrome and even old IE works fine.
In Bash, $(docker-machine ip dev) means "run the command docker-machine ip dev, take the output of that command and insert it into the command-line here".
If you run
docker-machine ip dev
in your shell, it will print an IP address which you can use in your web browser.
If you put this address in /etc/hosts (or your platform's analog) you can use a friendly alias for the IP address.
In my case, it was because my browser was configured with a proxy pac (Proxy_auto-config file) which did not include 192.169.x.y internal boot2docker machines ips.
That means:
the browser tries to contact the enterprise proxy (and that fails),
while a regular CMD shell session, with a NO_PROXY environment variable set to 192.168.x.y, would allow a curl http://192.168.x.y/... to work without a glitch.

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