I am running ejabberd using this docker image "https://github.com/processone/docker-ejabberd/tree/master/ecs".
Wondering which is the path for .erlang.cookie inside the container? I was trying to setup cluster in different host.
I can't find it in /home/ejabberd location. Tried setting environment variable ERLANG_COOKIE while running docker still can't find it in /home/ejabberd location.
You already found where the erlang cookie file is generated and available.
Alternatively, you can use the ERLANG_COOKIE environment variable to set the cookie value, and don't care about the file. See https://github.com/processone/docker-ejabberd/tree/master/ecs#clustering-example
It is in $HOME directory when login to the container as root user, In my case /home/ejabberd. The file is hidden use ls -a to list it.
To login as root user to the container use --user root while docker exec
Related
I have problem installing CYGNUS using docker as source, simply i cannot understand where i should map what specific agent.conf.
Image i am using is from here.
When i try to map agent.conf witch have my specific setup to container it starts and run but fail to copy, and not only that any change i made to file inside container wont stay it returns to previous default state.
While i have no issues with grouping_rules.conf using same approach.
I used docker and docker compose both same results.
Path on witch i try to copy opt/apache-flume/conf/agent.conf
docker run -v /home/igor/Documents/cygnus/agent.conf:/opt/apache-flume/conf/agent.conf fiware/cygnus-ngsi
Can some who managed to run it using his config tell me if i misunderstood location of agent.conf or something because this is weird, i used many docker images and never had issue where i was not able to copy from my machine to docker container.
Thanks in advance.
** EDIT **
Link of agent.conf
Did you copy the agent.conf file to your directory before start the container?
As you can see here, when you define a volume with "-v" option, docker copies the content of the host directory, inside the container directory using the mount point. Therefore, you must first provide the agent.conf file on your host.
The reason is that when using a "bind mounted" directory from the
host, you're telling docker that you want to take a file or directory
from your host and use it in your container. Docker should not modify
those files/directories, unless you explicitly do so. For example, you
don't want -v /home/user/:/var/lib/mysql to result in your
home-directory being replaced with a MySQL database.
If you do not have access to the agent.conf file, you can download the template in the source code from the official cygnus github repo here. You can also copy it once the docker container is running, using the docker cp option:
docker cp <containerId>:/file/path/within/container /host/path/target
Keep in mind, that you will have to edit the agent.conf file to configure it according to the database you are using. You can find in the official doc how to configure cygnus to use differents sinks like MongoDB, MySQL, etc.
I hope I have been helpful.
Best regards!
I want to see folder structure in OpenShift 3. Is it possible to ssh in? I see with rsync can copy in / out, but how to list content?
To access the container which is running your application use the oc rsh command. This will give you an interactive shell and you can use normal Unix commands to change directory, list files etc.
Consider reading the free eBook at https://www.openshift.com/promotions/for-developers.html and work through exercises at https://learn.openshift.com to learn more about using OpenShift. You can also find various blog posts at blog.openshift.com
If your container doesn't include a shell, you can also use oc exec to run commands directly. Example for a specific container and a command with arguments (note the double dash) :
oc exec -it POD -c CONTAINER -- ls -lrt /tmp/
I want to move containers from one host to another. The containers have updated data in their filesystem, so I do not want to move the original images (docker save) but containers (using docker export).
So I use
docker export l4bnode > l4bnode.tar
on the old host, copy the file to new host, and import image
cat l4bnode.tar | docker import - andi/l4bnode
on the new one. But.. it looks like all the configuration data I had in the Dockerfile (and that I also could specify/had specified in the command line when running the container) is lost. I tried
docker run andi/l4bnode
and get
docker: Error response from daemon: No command specified.
Using docker inspect, I see that all data on the imported image is empty, though it is set on the exported running container. I mainly am missing startup command, working directory, environment variables and exposed ports (some of which I have to change then due to the migration and new environment).
How can I apply the original configuration on the new host, or preferrably, migrate it properly?
You can commit the current container state as new image. Then use save/load on the new image.
That being said this is something you generally should try to avoid. Runtime data should be kept in volumes, any configuration changes should happen via Dockerfile rebuilds.
I am on my virtual machine and I must find a way to connect to the container and verify if there is a specific file. How can I do that?
If you have enabled SSH in your container, then you should be able to login to it from anywhere (even from the VM).
ssh usernae#lxc-hostname
Once logged in you can search for the file. There are various tools, but I like to use the locate command line tool.
locate <filename>
Hope this was useful.
Without SSH you can view the files and directory of the LXC containers; For this we need to find the pid (process identifier) of the container.
$>lxc-info -pHn <container-name-C1>
The above command will return you the pid number of the container launched by name C1
Now go to /proc/'{pid}'/root/; From this place you can view all the files of the lxc container by name C1; The beauty of LXC :)
I'm using the mysql image as an example, but the question is generic.
The password used to launch mysqld in docker is not visible in docker ps however it's visible in docker inspect:
sudo docker run --name mysql-5.7.7 -e MYSQL_ROOT_PASSWORD=12345 -d mysql:5.7.7
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
b98afde2fab7 mysql:5.7.7 "/entrypoint.sh mysq 6 seconds ago Up 5 seconds 3306/tcp mysql-5.7.7
sudo docker inspect b98afde2fab75ca433c46ba504759c4826fa7ffcbe09c44307c0538007499e2a
"Env": [
"MYSQL_ROOT_PASSWORD=12345",
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
"MYSQL_MAJOR=5.7",
"MYSQL_VERSION=5.7.7-rc"
]
Is there a way to hide/obfuscate environment parameters passed when launching containers. Alternatively, is it possible to pass sensitive parameters by reference to a file?
Weirdly, I'm just writing an article on this.
I would advise against using environment variables to store secrets, mainly for the reasons Diogo Monica outlines here; they are visible in too many places (linked containers, docker inspect, child processes) and are likely to end up in debug info and issue reports. I don't think using an environment variable file will help mitigate any of these issues, although it would stop values getting saved to your shell history.
Instead, you can pass in your secret in a volume e.g:
$ docker run -v $(pwd)/my-secret-file:/secret-file ....
If you really want to use an environment variable, you could pass it in as a script to be sourced, which would at least hide it from inspect and linked containers (e.g. CMD source /secret-file && /run-my-app).
The main drawback with using a volume is that you run the risk of accidentally checking the file into version control.
A better, but more complicated solution is to get it from a key-value store such as etcd (with crypt), keywhiz or vault.
You say "Alternatively, is it possible to pass sensitive parameters by reference to a file?", extract from the doc http://docs.docker.com/reference/commandline/run/ --env-file=[] Read in a file of environment variables.