Cannot access tomcat8 server running in docker container from host machine - docker

I am trying to connect to a web app running on tomcat8 in a docker container.
I am able to access it from within the container doing lynx http://localhost:8080/myapp, but when I try to access it from the host I only get HTTP request sent; waiting for response.
I am exposing port 8080 in the Dockerfile, I am using sudo docker inspect mycontainer | grep IPAddress to get the ip address of the container.
The command I am using to run the docker container is this:
sudo docker run -ti --name myapp --link mysql1:mysql1 --link rabbitmq1:rabbitmq1 -e "MYSQL_HOST=mysql1" -e "MYSQL_USER=myuser" -e "MYSQL_PASSWORD=mysqlpassword" -e "MYSQL_USERNAME=mysqlusername" -e "MYSQL_ROOT_PASSWORD=rootpassword" -e "RABBITMQ_SERVER_ADDRESS=rabbitmq1" -e "MY_WEB_ENVIRONMENT_ID=qa" -e "MY_WEB_TENANT_ID=tenant1" -p "8080:8080" -d localhost:5000/myapp:latest
My Dockerfile:
FROM localhost:5000/web_base:latest
MAINTAINER "Me" <me#my_company.com>
#Install mysql client
RUN yum -y install mysql
#Add Run shell script
ADD run.sh /home/ec2-user/run.sh
RUN chmod +x /home/ec2-user/run.sh
EXPOSE 8080
ENTRYPOINT ["/bin/bash"]
CMD ["/home/ec2-user/run.sh"]
My run.sh:
sudo tomcat8 start && sudo tail -f /var/log/tomcat8/catalina.out
Any ideas why I can access it from within the container but not from the host?
Thanks

What does your docker run command look like? You still need to do -p 8080:8080. Expose in the dockerfile only exposes it for linked containers not to the host vm.

I am able to access the tomcat8 server from the host now. The problem was here:
sudo tomcat8 start && sudo tail -f /var/log/tomcat8/catalina.out
Tomcat8 must be started as a service instead:
sudo service tomcat8 start && sudo tail -f /var/log/tomcat8/catalina.out

Hit given command to find IP address of docker-machine
$ docker-machine ls
The output will be like :
NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS
default * virtualbox Running tcp://192.168.99.100:2376 v1.10.3
Now run your application from host machine as : http://192.168.99.100:8080/myapp

Related

how to config autostart service[nginx] in a running docker container

my docker install my windows10 PC . the below step is which I created the container from the powershell window.
docker run -p 80 --name web -i -t ubuntu /bin/bash
#>apt-get update
#>apt-get install -y nginx
now, I found there are 2 questions when my pc restart.
the container 'web' is not running
when start 'web' container , the 'nginx' service is not running
the first question is resolved:
docker update --restart=always web
but the second question how to do? please help me
The best option in your case is running dedicated container for nginx instead of generic ubuntu with nginx being installed each time.
Use following command to run Nginx alpine release:
docker run -p 80 --name web-Nginx -d --restart always nginx:1.15.8-alpine

docker mysql, send sql commands during exec

i am creating a mysql 5.6 docker using bash script and i would like to change the password.
how can i send sql commands from bash to docker?
build:
sudo docker build -t mysql-5.6 -f ./.Dockerfile .
run.sh:
#!/bin/bash
sudo docker run --name=mysql1 -d mysql-5.6
sudo docker exec -it mysql1 mysql -uroot -p$base_password \
<<< SET PASSWORD FOR 'root'#'localhost' = PASSWORD('new_pass');
You need to bind MySQL-port like descriped here. To keep the port 3306 you can just expose it on your host the following way:
sudo docker run --name=mysql1 -p 3306:3306 -d mysql-5.6
After that you should be able to use mysql -u USER -p PASSWORD on your local host. This will then allow you to send commands to your docker-container.

Expose application that runs under a docker container

I'm trying to expose a nodejs application that runs under a docker
docker run -p 3005:3005 -p 5858:5858 -i -t -v /usuarios centos-nodejs:1.0 /bin/bash
after that command, I access my application
cd usuarios
node index
and then the application is running inside the docker container.
How can I expose a port to access in my browser something like localhost:5858/my_api_here
It seems a nodejs application is bound to localhost:5858 only inside a container. That's why you cannot access it via 127.0.0.1:5858 from the host. You need to find a way to bind it to 0.0.0.0:5858. After that you can access it on 127.0.0.1:5858 from the host.
Following the command below, it works
docker run -p 3005:3005 -p 5858:5858 -i -t -v C:\Users\lgermano\Documents
\Repositorios:/opt/rede/workspace centos-nodejs:1.0 /bin/bash

How to SSH into Docker?

I'd like to create the following infrastructure flow:
How can that be achieved using Docker?
Firstly you need to install a SSH server in the images you wish to ssh-into. You can use a base image for all your container with the ssh server installed.
Then you only have to run each container mapping the ssh port (default 22) to one to the host's ports (Remote Server in your image), using -p <hostPort>:<containerPort>. i.e:
docker run -p 52022:22 container1
docker run -p 53022:22 container2
Then, if ports 52022 and 53022 of host's are accessible from outside, you can directly ssh to the containers using the ip of the host (Remote Server) specifying the port in ssh with -p <port>. I.e.:
ssh -p 52022 myuser#RemoteServer --> SSH to container1
ssh -p 53022 myuser#RemoteServer --> SSH to container2
Notice: this answer promotes a tool I've written.
The selected answer here suggests to install an SSH server into every image. Conceptually this is not the right approach (https://docs.docker.com/articles/dockerfile_best-practices/).
I've created a containerized SSH server that you can 'stick' to any running container. This way you can create compositions with every container. The only requirement is that the container has bash.
The following example would start an SSH server exposed on port 2222 of the local machine.
$ docker run -d -p 2222:22 \
-v /var/run/docker.sock:/var/run/docker.sock \
-e CONTAINER=my-container -e AUTH_MECHANISM=noAuth \
jeroenpeeters/docker-ssh
$ ssh -p 2222 localhost
For more pointers and documentation see: https://github.com/jeroenpeeters/docker-ssh
Not only does this defeat the idea of one process per container, it is also a cumbersome approach when using images from the Docker Hub since they often don't (and shouldn't) contain an SSH server.
These files will successfully open sshd and run service so you can ssh in locally. (you are using cyberduck aren't you?)
Dockerfile
FROM swiftdocker/swift
MAINTAINER Nobody
RUN apt-get update && apt-get -y install openssh-server supervisor
RUN mkdir /var/run/sshd
RUN echo 'root:password' | chpasswd
RUN sed -i 's/PermitRootLogin without-password/PermitRootLogin yes/' /etc/ssh/sshd_config
# SSH login fix. Otherwise user is kicked off after login
RUN sed 's#session\s*required\s*pam_loginuid.so#session optional pam_loginuid.so#g' -i /etc/pam.d/sshd
ENV NOTVISIBLE "in users profile"
RUN echo "export VISIBLE=now" >> /etc/profile
COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
EXPOSE 22
CMD ["/usr/bin/supervisord"]
supervisord.conf
[supervisord]
nodaemon=true
[program:sshd]
command=/usr/sbin/sshd -D
to build / run start daemon / jump into shell.
docker build -t swift3-ssh .
docker run -p 2222:22 -i -t swift3-ssh
docker ps # find container id
docker exec -i -t <containerid> /bin/bash
I guess it is possible. You just need to install a SSH server in each container and expose a port on the host. The main annoyance would be maintaining/remembering the mapping of port to container.
However, I have to question why you'd want to do this. SSH'ng into containers should be rare enough that it's not a hassle to ssh to the host then use docker exec to get into the container.
Create docker image with openssh-server preinstalled:
Dockerfile
FROM ubuntu:16.04
RUN apt-get update && apt-get install -y openssh-server
RUN mkdir /var/run/sshd
RUN echo 'root:screencast' | chpasswd
RUN sed -i 's/PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config
# SSH login fix. Otherwise user is kicked off after login
RUN sed 's#session\s*required\s*pam_loginuid.so#session optional pam_loginuid.so#g' -i /etc/pam.d/sshd
ENV NOTVISIBLE "in users profile"
RUN echo "export VISIBLE=now" >> /etc/profile
EXPOSE 22
CMD ["/usr/sbin/sshd", "-D"]
Build the image using:
$ docker build -t eg_sshd .
Run a test_sshd container:
$ docker run -d -P --name test_sshd eg_sshd
$ docker port test_sshd 22
0.0.0.0:49154
Ssh to your container:
$ ssh root#192.168.1.2 -p 49154
# The password is ``screencast``.
root#f38c87f2a42d:/#
Source: https://docs.docker.com/engine/examples/running_ssh_service/#build-an-eg_sshd-image
It is a short way but not permanent
first create a container
docker run ..... -p 22022:2222 .....
port 22022 on your host machine will map on 2222, we change the ssh port on container later
, then on your container executing the following commands
apt update && apt install openssh-server # install ssh server
passwd #change root password
in file /etc/ssh/sshd_config change these :
uncomment Port and change it to 2222
Port 2222
uncomment PermitRootLogin to
PermitRootLogin yes
and finally restart ssh server
/etc/init.d/ssh start
you can login to your container now
ssh -p 22022 root#HostIP
Remember : if you restart the container you need to restart ssh server again

How to use docker container as apache server?

I just started using docker and followed following tutorial: https://docs.docker.com/engine/admin/using_supervisord/
FROM ubuntu:14.04
RUN apt-get update && apt-get upgrade
RUN apt-get install -y openssh-server apache2 supervisor
RUN mkdir -p /var/lock/apache2 /var/run/apache2 /var/run/sshd /var/log/supervisor
COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
EXPOSE 22 80
CMD ["/usr/bin/supervisord"]
and
[supervisord]
nodaemon=true
[program:sshd]
command=/usr/sbin/sshd -D
[program:apache2]
command=/bin/bash -c "source /etc/apache2/envvars && exec /usr/sbin/apache2 -DFOREGROUND"
Build and run:
sudo docker build -t <yourname>/supervisord .
sudo docker run -p 22 -p 80 -t -i <yourname>/supervisord
My question is, when docker runs on my server with IP http://88.xxx.x.xxx/, how can I access the apache localhost running inside the docker container from the browser on my computer? I would like to use a docker container as a web server.
You will have to use port forwarding to be able to access your docker container from the outside world.
From the Docker docs:
By default Docker containers can make connections to the outside world, but the outside world cannot connect to containers.
But if you want containers to accept incoming connections, you will need to provide special options when invoking docker run.
So, what does this mean? You will have to specify a port on your host machine (typically port 80) and forward all connections on that port to the docker container. Since you are running Apache in your docker container you probably want to forward the connection to port 80 on the docker container as well.
This is best done via the -p option for the docker run command.
sudo docker run -p 80:80 -t -i <yourname>/supervisord
The part of the command that says -p 80:80 means that you forward port 80 from the host to port 80 on the container.
When this is set up correctly you can use a browser to surf onto http://88.x.x.x and the connection will be forwarded to the container as intended.
The Docker docs describes the -p option thoroughly. There are a few ways of specifying the flag:
# Maps the provided host_port to the container_port but only
# binds to the specific external interface
-p IP:host_port:container_port
# Maps the provided host_port to the container_port for all
# external interfaces (all IP:s)
-p host_port:container_port
Edit: When this question was originally posted there was no official docker container for the Apache web server. Now, an existing version exists.
The simplest way to get Apache up and running is to use the official Docker container. You can start it by using the following command:
$ docker run -p 80:80 -dit --name my-app -v "$PWD":/usr/local/apache2/htdocs/ httpd:2.4
This way you simply mount a folder on your file system so that it is available in the docker container and your host port is forwarded to the container port as described above.
There is an official image for apache. The image documentation contains instructions in how you can use this official images as a base for a custom image.
To see how it's done take a peek at the Dockerfile used by the official image:
https://github.com/docker-library/httpd/blob/master/2.4/Dockerfile
Example
Ensure files are accessible to root
sudo chown -R root:root /path/to/html_files
Host these files using official docker image
docker run -d -p 80:80 --name apache -v /path/to/html_files:/usr/local/apache2/htdocs/ httpd:2.4
Files are accessible on port 80.

Resources