Docker tutorial, localhost:4000 is inaccessible - docker

Following the tutorial on https://docs.docker.com/get-started/part2/.
I start my docker container with docker run -p 4000:80 friendlyhello
and see
* Serving Flask app "app" (lazy loading)
* Environment: production
WARNING: This is a development server. Do not use it in a production deployment.
Use a production WSGI server instead.
* Debug mode: off
* Running on http://0.0.0.0:8088/ (Press CTRL+C to quit)
But it's inaccessible from the expected path of localhost:4000.
$ curl http://localhost:4000/
curl: (7) Failed to connect to localhost port 4000: Connection refused
$ curl http://127.0.0.1:4000/
curl: (7) Failed to connect to 127.0.0.1 port 4000: Connection refused
Okay, so maybe it's not on my local host. Getting the container ID I retrieve the IP with
docker inspect --format '{{ .NetworkSettings.IPAddress }}' 7e5bace5f69c
and it returns 172.17.0.2 but no luck! curl continues to give the same responses. I can confirm something is running on 4000....
lsof -i :4000
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
com.docke 94812 travis 18u IPv6 0x7516cbae76f408b5 0t0 TCP *:terabase (LISTEN)
I'm pulling my hair out on this. I've read through the troubleshooting guide and can confirm
* not on a proxy
* don't use a custom dns
* I'm having issues connecting to docker, not docker connecting to my pip server.
Running the app.py with python app.py the server starts and I'm able to hit it. What am I missing?

Did you accidentally put port=8088 at the bottom of your app.py file? When you are running this the last line of your output is saying that your python app is exposed on port 8088 not 80.
To confirm you can run either modify the app.py file and rebuild the image, or alternatively you could run: docker run -p 4000:8088 friendlyhello which would map your local port 4000 to 8088 in the container.

Try to run it using:
docker run -p 4000:8088 friendlyhello
As you can see from the logs, your app starts on port 8088, but you connect 4000 to 80 where on 80, nothing is actually listening.

Related

Docker: ssh -L to docker container - connection refused

I'm having problems to get my ssh tunnel working for my container in a docker swarm cluster.
ssh connection on my local machine:
ssh -L 7180:test.XXX:7180 user#XXX
In my Dockerfile on the remote machine:
EXPOSE 7180
Container start:
docker -H test:2379 --tlsverify run -d -p 7180:7180 --net=my-net
I tried to connect in Firefox via:
localhost:7180
Unfortunately the connection gets refused on the remote machine:
channel 3: open failed: connect failed: Connection refused
"docker container ls" prints following for the ports:
xxx:7180->7180/tcp
Inside my container "netstat -ntlp | grep LISTEN" prints:
tcp 0 0 0.0.0.0:7180 0.0.0.0:* LISTEN -
I'm new to this but after all what I've read so far this should actually work. I'm using "--net=my-net" because I want to setup my own network later. I had the same issue with "--net=host". What am I doing wrong?
The ssh command should be:
ssh -L 7180:127.0.0.1:7180 user#XXX
And then from your browser, you would go to:
http://127.0.0.1:7180
I've avoided using "localhost" because some machines map this to IPv6 even if you don't have IPv6 configured.
When testing this tunnel, make sure your application is listening on the remote server by doing an ssh to that server and run a curl command directly on the server to 127.0.0.1:7180. If it doesn't work there, you would repeat your debugging with netstat inside the container and verifying the port is published in thedocker ps` output.
I got it working with
ssh -D localhost:7180 -f -C -q -N user#XXX
and using
xxx:7180
in my browser (instead of localhost).
localhost and --net=host did not work for me with ssh -L.

curl (56) Recv failure: Connection reset by peer - when hitting docker container

getting this error while curl the application ip
curl (56) Recv failure: Connection reset by peer - when hitting docker container
Do a small check by running:
docker run --network host -d <image>
if curl works well with this setting, please make sure that:
You're mapping the host port to the container's port correctly:
docker run -p host_port:container_port <image>
Your service application (running in the container) is running on localhost or 0.0.0.0 and not something like 127.0.0.1
I GOT the same error
umesh#ubuntu:~/projects1$ curl -i localhost:49161
curl: (56) Recv failure: Connection reset by peer
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
in my case it was due wrong port no
|---MY Projects--my working folder
--------|Dockerfile ---port defined 8080
--------|index.js-----port defined 3000
--------|package.json
then i was running ::::
docker run -p 49160:8080 -d umesh1/node-web-app1
so as the application was running in port 3000 in index.js it was not able to connect to the application got the error as u were getting
So TO SOLVE THE PROBLEM
deleted the last container/image that was created my worong port
just change the port no of INDEX.JS
|---MY Projects--my working folder
--------|Dockerfile ---port defined 8080
--------|index.js-----port defined 8080
--------|package.json
then build the new image
docker build -t umesh1/node-web-app1 .
running the image in daemon mode with exposed port
docker run -p 49160:8080 -d umesh1/node-web-app1
THUS MY APPLICATION WAS RUNNING without any error listing on port 49161
I have same when bind to port that is not lissened by any service inside container.
So check -p option
-p 9200:9265
-p <port in container>:<port in host os to be binded to>

Docker Pgadmin 4

EDIT
Turned out to a problem with the image, I tried another one and it works fine
I'm trying to run Pgadmin 4 as server mode using Docker on Debian 9. I have followed the instructions on https://hub.docker.com/r/dpage/pgadmin4/ I start it by the following command
docker run -p 5050:5050 -e "PGADMIN_DEFAULT_EMAIL=myemail#gmail.com" -e "PGADMIN_DEFAULT_PASSWORD=a12345678" -d dpage/pgadmin4
I don't get any errors, and docker ps shows the status as below
root#poweredge:~# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c4b11e4bceb7 dpage/pgadmin4 "/bin/bash /entry.sh" 12 seconds ago Up 10 seconds 80/tcp, 443/tcp, 0.0.0.0:5050->5050/tcp upbeat_jackson
But when I go to serverip:5050 nothing loads. Any idea what the problem may be here?
On the local machine when I execute curl http://localhost:5050 I get Connection reset by peer if the docker instance is running
root#poweredge:~# curl http://localhost:5050
curl: (56) Recv failure: Connection reset by peer
if I stop the Docker instance, I get
root#poweredge:~# curl http://localhost:5050
curl: (7) Failed to connect to localhost port 5050: Connection refused
PgAdmin 4 docker container has exposed port 80 and 443 by default. You can checck the Dockerfile here https://github.com/postgres/pgadmin4/blob/master/pkg/docker/Dockerfile
So the port mapping parameter in the command has to be updated (-p host_port: container_port)
Below is the updated command to access pgadmin4 via http (port 80)
docker run -p 5050:80 -e "PGADMIN_DEFAULT_EMAIL=myemail#gmail.com" -e "PGADMIN_DEFAULT_PASSWORD=a12345678" -d dpage/pgadmin4
After starting the container you should be able to access it via http://localhost:5050
Are you trying to access it out side your virtual box? If yes, check if you have port forwarding rules of your Virtual machine set correctly:

How to get my docker centos sshd passwordless server running?

I'm running my docker container with:
docker run -d sequenceiq/hadoop-docker:2.6.0
The Dockerfile is here.
After it is started on my mac - I'm running docker ps and getting:
6bfa4f2fd3b5 sequenceiq/hadoop-docker:2.6.0 "/etc/bootstrap.sh -d" 4 minutes ago Up 4 minutes 22/tcp, 8030-8033/tcp, 8040/tcp, 8042/tcp, 8088/tcp, 49707/tcp, 50010/tcp, 50020/tcp, 50070/tcp, 50075/tcp, 50090/tcp kind_hawking
Then I'm running
ssh -v localhost -p 22
and I'm getting
OpenSSH_7.4p1, LibreSSL 2.5.0
debug1: Reading configuration data /Users/User/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Connecting to localhost [::1] port 22.
debug1: connect to address ::1 port 22: Connection refused
debug1: Connecting to localhost [127.0.0.1] port 22.
debug1: connect to address 127.0.0.1 port 22: Connection refused
ssh: connect to host localhost port 22: Connection refused
Assumptions: I think this is not a duplicate of the other centos sshd questions as this is a different centos version. (For those that are similar - it is doing what the potentially similar question is asking and it is not working).
My question is: How to get my docker centos sshd passwordless server running?
Edit:
#Andrew has been super-helpful in helping me refine my question - so here goes.
Here is my updated Dockerfile
FROM sequenceiq/hadoop-docker:2.6.0
CMD ["/etc/bootstrap.sh", "-d"]
# Hdfs ports
EXPOSE 50010 50020 50070 50075 50090 8020 9000
# Mapred ports
EXPOSE 10020 19888
#Yarn ports
EXPOSE 8030 8031 8032 8033 8040 8042 8088
#Other ports
EXPOSE 49707 2122
EXPOSE 9000
EXPOSE 2022
Now I'm building this with:
sudo docker build -t my-hdfs .
Then I'm running this with:
sudo docker run -d -p my-hdfs
Then I'm checking the processes with:
sudo docker ps
with a result like:
d9c9855cfaf0 my-hdfs "/etc/bootstrap.sh -d" 2 minutes ago
Up 2 minutes 0.0.0.0:32801->22/tcp, 0.0.0.0:32800->2022/tcp,
0.0.0.0:32799->2122/tcp, 0.0.0.0:32798->8020/tcp, 0.0.0.0:32797->8030/tcp,
0.0.0.0:32796->8031/tcp, 0.0.0.0:32795->8032/tcp, 0.0.0.0:32794->8033/tcp,
0.0.0.0:32793->8040/tcp, 0.0.0.0:32792->8042/tcp, 0.0.0.0:32791->8088/tcp,
0.0.0.0:32790->9000/tcp, 0.0.0.0:32789->10020/tcp, 0.0.0.0:32788->19888/tcp,
0.0.0.0:32787->49707/tcp, 0.0.0.0:32786->50010/tcp, 0.0.0.0:32785->50020/tcp,
0.0.0.0:32784->50070/tcp, 0.0.0.0:32783->50075/tcp, 0.0.0.0:32782->50090/tcp
agitated_curran
Then to get the IP address I'm running:
docker inspect --format '{{ .NetworkSettings.IPAddress }}' d9c9855cfaf0
with a result like
172.17.0.3
Then I'm testing it with:
ssh -v 172.17.0.3 -p 32800
This gives a result:
OpenSSH_7.4p1, LibreSSL 2.5.0
debug1: Reading configuration data /Users/User/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Connecting to 172.17.0.3 [172.17.0.3] port 32800.
debug1: connect to address 172.17.0.3 port 32800: Operation timed out
ssh: connect to host 172.17.0.3 port 32800: Operation timed out
My question is: How to get my docker centos sshd passwordless server running?
You are trying to connect to you local ssh server instead of container. To connect to any port inside container, you need to expose and publish it and possibly map it to another one, especially in case when you want to run multiple similar containers on different ports on the same host. See Expose.
So in your case your command should be
docker run -p 2222:22 -d sequenceiq/hadoop-docker:2.6.0
And ssh command
ssh -v localhost -p 2222
Exposing docker port (as seen in your linked docker file) makes it accessible
to other docker containers, but not to your host machine. To understand difference between exposed and published ports see this question
However, when i tried to connect to port 2222 it haven't worked. Looking at Dockerfile of 2.6.0 version, i've found that it has a bug, where sshd configured to listen on port 2122, but exposed port is 22, as can be seen here. Also, when i'm tried to build a lastest Dockerfile you provided, it failed at step 31, so you might want to inverstigate further.
Edit after question update:
Look at docker ps output you provided, and on Dockerfile. sshd configured to listen on port 2122 (if you haven’t changed that though since we don't have a complete dockerfile of yours), and in output we see
0.0.0.0:32799->2122/tcp
0.0.0.0:32800->2022/tcp
You should connect as ssh -v localhost -p 32799 instead of 32800 since nothing is listening on port 2022 inside container

failed: port is already allocated

I use Docker for running Oracle 11g Express on macOS Sierra 10.12.2
https://github.com/wnameless/docker-oracle-xe-11g
This is my error:
Last login: Sat Jan 7 22:42:11 on ttys000
➜ ~ docker run -d -p 49160:22 -p 49161:1521 wnameless/oracle-xe-11g
docker: Cannot connect to the Docker daemon. Is the docker daemon running on this host?.
See 'docker run --help'.
➜ ~ docker run -d -p 49160:22 -p 49161:1521 wnameless/oracle-xe-11g
043d8caecbb45d6e2e5999b69a2f760c20d53ff3aa2fad78cb1eb70acb058a1f
docker: Error response from daemon: driver failed programming external connectivity on endpoint serene_lalande (08bb0bd9684c0f92db7b736986bf894d3a57a714324405823496d13e175e7491): Error starting userland proxy: Bind for 0.0.0.0:49161 failed: port is already allocated.
➜ ~
I diagnostic:
➜ ~ netstat -anp tcp | grep 49161
tcp4 0 0 192.168.1.2.49161 17.188.166.13.5223 ESTABLISHED
➜ ~
➜ ~ docker --version
Docker version 1.12.5, build 7392c3b
My Dianostic ID: 20EB9506-CC72-4093-8A15-60E05A841ED1
I don't know why. Before that few weeks, it run success. Nearly, I change, release new DHCP IP. How to run Docker instance has Oracle 11g express success?
you can't launch twice
docker run -d -p 49160:22
as this means you want to allocate the port 49160 on the host twice, of course, the second time, you get you error message, try for the second run
docker run -d -p 49161:22
You will need to use a different port instead of 49161. Try a port less than 49152.
You have a pre-existing connection between the the port 49161 on your computer and port 5223 on a remote Apple server. That port, therefore, cannot be used for anything else until that connection ceases to exist. Port 5223 is used for Apple's push notifications. As best as I can tell, your computer so happened to use the random port 49161 to connect to Apple's server this time. Previously when that Docker container worked, I would bet port 49161 on your computer was not then used.
Whenever you connect to a remote server, your own computer allocates a random port number for that connection. This time around, your computer allocated 49161 when it connected to Apple's push notifications service. Next time, it could be a completely different number. See https://en.wikipedia.org/wiki/Ephemeral_port

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