I am planning to use cAdvisor to monitor performance of running docker container on multiple VMs, do I need to install cAdvisor on all VMs, or there is any other way?
Yes, you need it on each host seeing as it uses the local mounts to get the data it exports
Related
I've managed to run Docker Swam mode with multiple hosts with Docker Toolbox, but I am unable to create a swarm with Docker Desktop since it apparently only offers single node swarm.
Is there any way to get this working with Docker Desktop or is it not supported?
No. But yes. But actually no. But technically yes.
No. Docker Desktop does not support this. It manages a single docker node in a vm and has no capability to manage multiple dockers.
But yes. docker:dind is an image you can easily use to deploy multiple docker nodes as containers, and then swarm init / swarm join to create a swarm cluster hosted on docker. You can even swarm join the docker-desktop node to be the swarm manager which means you can communicate with your local docker desktop node to control the swarm.
But actually, no.
Unless your use case is a very limited hello-world on swarm tutorial, there is no support for exposing ports from the dind-swarm to the host. Even if the host docker acts as the manager, overlay networking that is required for ingress will require communications over :2377, :4789/udp, and :7946, and as the host is not part of its own overlay networks, this will never work.
So, communicating with tasks running on the swarm is basically impossible.
But technically yes. play-with-docker apparently runs docker swarms using dind. They do some heavy lifting to expose a restricted set of ports via l7 loadbalancers. Pretty cool. but not at all easy to do at home. If you have a spare Dell PowerEdge or equivalent blade server with 120+ cores just laying around, and want to expose it as a docker swarm rather than split it into VMS... perhaps this is a viable approach.
I have a windows service within a Docker container that needs to access a MySQL database in a Linux container on the same machine (dev machine currently).
I thought of creating an overlay network on the two "nodes" on the same machine but this isn't possible as creating the swarm worker fails on windows after creating the swarm master on linux.
Is this possible, if not what is the easiest way of doing this? The purpose of the windows container is simply to deploy to a test environment to gather data. Do I need to deploy the linux to the cloud or another machine maybe, so the windows container can communicate?
You can simply use docker compose, it will create the network automatically. Replace the MySQL host with the MySQL service name you defined in the compose yaml file. Detailed information please refer to docker-compose.
I need to monitor OpenVZ containers using TICK stack. But it must be done without install anything inside of containers. Is there any plugins for Telegraf to collect metric (cpu, bandwidth, iops) from OpenVZ container?
OpenVZ is deprecated since long time. Try this new thing named Docker, or at least LXC.
Telegraf uses cgroups for collecting metrics from containers, Docker, LXC use cgroups.
Is there a way to run a cAdvisor container in a Monitoring server and monitor docker containers in a separate server? Is there a command I can include when running cAdvisor?
Because I want to be able to monitor containers in a separate server but I’m not sure how to achieve that…
Any suggestions or shared knowledge would be very helpful. Thank you.
To take measurements from different machines, you will have to deploy cAdvisor to every separate server.
My source is:
A monitoring solution for Docker hosts, containers and containerized services
Extending the monitoring system
Dockprom Grafana dashboards can be easily extended to cover more then one Docker host. In order to monitor more hosts, all you need to do is to deploy a node-exporter and a cAdvisor container on each host and point the Prometheus server to scrape those.
On how to create and start a container by using the remote api, you can check this answer: How to use docker remote api to create container?
I have a silly question regarding docker swarm.
I am thinking I can start a web application image in two containers, either in same server or two vm servers, then I start a load balance container, pointing to two web app containers through IP and port.
In this case, why do I need docker swarm for clustering management? What benefits can docker swarm bring?
I have read from docker documentation, they only introduce what is swarm and how to use swarm. But I can not find out answer for why I have to use swarm.
Thanks
What is swarming managing? turns a pool of Docker hosts into a single, virtual Docker host.
Can swarm auto-start the container if the container died? Yes it can, so can the Docker daemon on each host.
Can swarm auto-create more nodes if the resource is not enough? No it cannot. It does not aims on providing this service. Nevertheless you can program a node that start and run containers when needed.
Which mean, if traffic grows fast, do we still manually create more node and deploy more containers? Yes, unfortunately.
update
If needed, here is an answer that details how to deploy a Swarm cluster.