The following command creates a container instance of elasticsearch:latest image:
$ az container create --image elasticsearch:latest --name es -g rg-es --ip-address public --memory 4 --cpu 2
According to:
$ az container show --name es -g rg-es -o table
the instance is running yet when I browse to the assigned IP the browser responds with: "can't open the page because the server where this page is located isn't responding".
Creating the container from the azure portal doesn't make any difference.
Has anyone come across this problem?
Elastic search doesn't expose port 80 by default. But you can pass port
—port 9200 to expose the default port. This is probably the issue you're hitting.
Thanks!
Related
We have an application which uses SSH to copy artifact from one node to other. While creating the Docker image (Linux Centos 8 based), I have installed the Openssh server and client, when I run the image from Docker command and exec into it, I am successfully able to run the SSH command and I also see the port 22 enabled and listening ( $ lsof -i -P -n | grep LISTEN).
But if I start a POD/Container using the same image in the Kubernetes cluster, I do not see port 22 enabled and listening inside the container. Even if I try to start the sshd from inside the k8s container then it gives me below error:
Redirecting to /bin/systemctl start sshd.service Failed to get D-Bus connection: Operation not permitted.
Is there any way to start the K8s container with SSH enabled?
There are three things to consider:
Like David said in his comment:
I'd redesign your system to use a communication system that's easier
to set up, like with HTTP calls between pods.
If you put a service in front of your deployment, it is not going to relay any SSH connections. So you have to point to the pods directly, which might be pretty inconvenient.
In case you have missed that: you need to declare port 22 in your deployment template.
Please let me know if that helped.
I'm in a team where some of us use docker toolbox and some user docker desktop. We're writing an application that needs to communicate to a docker container in development.
On docker toolbox, I know the docker-machine env command sets the docker host environment variable and I can use that to get the ip of the virtual machine that's running the docker engine. From there I just access the exposed ports.
What's the equivalent way to get that information on docker desktop? (I do not have a machine that has docker desktop, only docker toolbox but I'm writing code that should be able to access the docker container on both)
On windows OS, after installed docker, there is an entry added by docker inside your hosts file (C:\Windows\System32\drivers\etc\hosts), which states the IP as:
Added by Docker Desktop
10.xx.xx.xx host.docker.internal
Below section got added in my /etc/hosts:
# Added by Docker Desktop
192.168.99.1 host.docker.internal
192.168.99.1 gateway.docker.internal
Then I was able to access by adding the port to which the app was bind to.
This command should display the IP
ping -q -c 1 docker.local | sed -En "s/^.*\((.+)\).*$/\1/p"
ipconfig can get you this information as well
I'm working with Docker to create AEM (Adobe Experience Manager) images on the basis of the following repository https://github.com/AdobeAtAdobe/aem_6-1_docker
I just can't figure out how to open a debug mode for AEM.
I have tried adding a port to EXPOSE EXPOSE 4502 30311 and adding a start file with the new JVM_OPTS CQ_JVM_OPTS="-debug -Xnoagent -Djava.compiler=none -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=30311,server=y,suspend=n ${CQ_JVM_OPTS}"
and I have also tried changing the START_OPTS START_OPTS="${START_OPTS} -debug 30311"
I'm not really comfortable with Docker yet so I'm not sure what I'm missing to startup the debug mode. Do I need to open a port in Docker via ENV or RUN?
You have to bind your host ports to container ports.
So, in your docker run add flag -p 4502:4502 -p 30311:30311
I have a question regarding Docker. That container's concept being totally new to me and I am sure that I haven't grasped how things work (Containers, Dockerfiles, ...) and how they could work, yet.
Let's say, that I would like to host small websites on the same VM that consist of Apache, PHP-FPM, MySQL and possibly Memcache.
This is what I had in mind:
1) One image that contains Apache, PHP, MySQL and Memcache
2) One or more images that contains my websites files
I must find a way to tell in my first image, in the apache, where are stored the websites folders for the hosted websites. Yet, I don't know if the first container can read files inside another container.
Anyone here did something similar?
Thank you
Your container setup should be:
MySQL Container
Memcached Container
Apache, PHP etc
Data Conatainer (Optional)
Run MySQL and expose its port using the -p command:
docker run -d --name mysql -p 3306:3306 dockerfile/mysql
Run Memcached
docker run -d --name memcached -p 11211:11211 borja/docker-memcached
Run Your web container and mount the web files from the host file system into the container. They will be available at /container_fs/web_files/ inside the container. Link to the other containers to be able to communicate with them over tcp.
docker run -d --name web -p 80:80 \
-v /host_fs/web_files:/container_fs/web_files/ \
--link mysql:mysql \
--link memcached:memcached \
your/docker-web-container
Inside your web container
look for the environment variables MYSQL_PORT_3306_TCP_ADDR and MYSQL_PORT_3306_TCP_PORT to tell you where to conect to the mysql instance and similarly MEMCACHED_PORT_11211_TCP_ADDR and MEMCACHED_PORT_11211_TCP_PORT to tell you where to connect to memcacheed.
The idiomatic way of using Docker is to try to keep to one process per container. So, Apache and MySQL etc should be in separate containers.
You can then create a data-container to hold your website files and simply mount the volume in the Webserver container using --volumes-from. For more information see https://docs.docker.com/userguide/dockervolumes/, specifically "Creating and mounting a Data Volume Container".
I want to run rabbitmq-server in one docker container and connect to it from another container using celery (http://celeryproject.org/)
I have rabbitmq running using the below command...
sudo docker run -d -p :5672 markellul/rabbitmq /usr/sbin/rabbitmq-server
and running the celery via
sudo docker run -i -t markellul/celery /bin/bash
When I am trying to do the very basic tutorial to validate the connection on http://docs.celeryproject.org/en/latest/getting-started/first-steps-with-celery.html
I am getting a connection refused error:
consumer: Cannot connect to amqp://guest#127.0.0.1:5672//: [Errno 111]
Connection refused.
When I install rabbitmq on the same container as celery it works fine.
What do I need to do to have container interacting with each other?
[edit 2016]
Direct links are deprecated now. The new way to do link containers is docker network connect. It works quite similar to virtual networks and has a wider feature set than the old way of linking.
First you create your named containers:
docker run --name rabbitmq -d -p :5672 markellul/rabbitmq /usr/sbin/rabbitmq-server
docker run --name celery -it markellul/celery /bin/bash
Then you create a network (last parameter is your network name):
docker network create -d bridge --subnet 172.25.0.0/16 mynetwork
Connect the containers to your newly created network:
docker network connect mynetwork rabbitmq
docker network connect mynetwork celery
Now, both containers are in the same network and can communicate with each other.
A very detailed user guide can be found at Work with networks: Connect containers.
[old answer]
There is a new feature in Docker 0.6.5 called linking, which is meant to help the communication between docker containers.
First, create your rabbitmq container as usual. Note that i also used the new "name" feature which makes life a litte bit easier:
docker run --name rabbitmq -d -p :5672 markellul/rabbitmq /usr/sbin/rabbitmq-server
You can use the link parameter to map a container (we use the name here, the id would be ok too):
docker run --link rabbitmq:amq -i -t markellul/celery /bin/bash
Now you have access to the IP and Port of the rabbitmq container because docker automatically added some environmental variables:
$AMQ_PORT_5672_TCP_ADDR
$AMQ_PORT_5672_TCP_PORT
In addition Docker adds a host entry for the source container to the /etc/hosts file. In this example amq will be a defined host in the container.
From Docker documentation:
Unlike host entries in the /etc/hosts file, IP addresses stored in the environment variables are not automatically updated if the source container is restarted. We recommend using the host entries in /etc/hosts to resolve the IP address of linked containers.
Just get your container ip, and connect to it from another container:
CONTAINER_IP=$(sudo docker inspect --format '{{ .NetworkSettings.IPAddress }}' $CONTAINER_ID)
echo $CONTAINER_IP
When you specify -p 5672, What docker does is open up a new port, such as 49xxx on the host and forwards it to port 5672 of the container.
you should be able to see which port is forwarding to the container by running:
sudo docker ps -a
From there, you can connect directly to the host IP address like so:
amqp://guest#HOST_IP:49xxx
You can't use localhost, because each container is basically its own localhost.
Create Image:
docker build -t "imagename1" .
docker build -t "imagename2" .
Run Docker image:
docker run -it -p 8000:8000 --name=imagename1 imagename1
docker run -it -p 8080:8080 --name=imagename2 imagename2
Create Network:
docker network create -d bridge "networkname"
Connect the network with container(imagename) created after running the image:
docker network connect "networkname" "imagename1"
docker network connect "networkname" "imagename2"
We can add any number of containers to the network.
docker network inspect ''networkname"
I think you can't connect to another container directly by design - that would be the responsibility of the host. An example of sharing data between containers using Volumes is given here http://docs.docker.io/en/latest/examples/couchdb_data_volumes/, but I don't think that that is what you're looking for.
I recently found out about https://github.com/toscanini/maestro - that might suit your needs. Let us know if it does :), I haven't tried it myself yet.
Edit. Note that you can read here that native "Container wiring and service discovery" is on the roadmap. I guess 7.0 or 8.0 at the latest.
You can get the docker instance IP with...
CID=$(sudo docker run -d -p :5672 markellul/rabbitmq /usr/sbin/rabbitmq-server); sudo docker inspect $CID | grep IPAddress
But that's not very useful.
You can use pipework to create a private network between docker containers.
This is currently on the 0.8 roadmap:
https://github.com/dotcloud/docker/issues/1143