Questions tagged [containers]
Use for generic questions on containers that do not fall under a specific container technology, like Docker, LXC, FreeBSD Jails, OpenBSD sysjails, Solaris Containers, WPARs, etc. Also use where the specific technology is not relevant to the question.
178
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12
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PreStop container hook on Pod termination
I have two containers in my Pod (one main app container and another one is just a simple nginx reverse proxy)
containers:
- name: my-app
- name: my-nginx
lifecycle:
...
- 546
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votes
0
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11
views
How are containers secured with MACVLAN networks?
Containers cannot be connected both to an internal bridge and to the host network at the same time, according to this question. However, this is what I need; I want a set of containers to be connected ...
- 1
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2
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55
views
Creating container image without docker
Is it possible to build a container image as a simple user account on a system which does not have docker or podman installed? In other words, is there a user-space tool/application which can build an ...
- 103
4
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2
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73
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Docker vs Virtualisation
I am trying to understand the underlining architecture of Docker. The diagram that's been shown everywhere claims that in contrast with Virtualisation technologies such as "VirtualBox", ...
- 143
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30
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install helm chart package without public container registry (offline,locally)
When I want to install a package in kubernetes cluster with helm chart, for example install gitlab with helm, during installation there is need to download docker image from a public registry and I ...
- 1
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22
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Duplicate docker layers should not count twice in quota
On my machine, I have a 1 Gb docker image with several layers.
I tag it many times with different tags. On my machine it still takes 1 Gb, as shown by "docker system df".
But when I push ...
- 101
2
votes
1
answer
29
views
Container deployment sync problem with Ansible
Imagine the following situation after you have switched from docker-compose to Ansible:
You start a DB container which needs time to boot up
You want to load data dump into it
(could be also you ...
- 6,702
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23
views
Access AWS Secret inside docker file
I have a docker file running on AWS that looks like the following:
FROM ubuntu:latest
RUN apt-get update
RUN apt-get install -y python3
RUN apt-get install -y git
RUN git init
RUN git clone https://&...
- 11
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19
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Azure Devops build and deployment process for .NET Core app - excessive disk space use on servers by Docker
My Azure Virtual Machine Scaleset instances, used for hosting of an application, are filling up due to excessive disk space usage by Docker.
The deployment of the application is based on an Azure ...
- 101
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0
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12
views
Private certificate authority and container images
We have a internal domain name, let's say "mycompany.net" with a private CA which delivers all our internal application HTTPS certificates for this domain like "myapp.mycompany.net"...
- 111
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17
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Best Practice for Managing Ephemeral Storage on Bare Metal Kubernetes Instance?
Host OS: Ubuntu 20.04
Kubernetes: 1.23
RAM: 64g
HDD: 3.7Tb
Containers are failing and rescheduling due to low ephemeral storage. Ex. The node was low on resource: ephemeral-storage. Container <...
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2
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32
views
How to create a container from an image
I have this following image:
REPOSITORY TAG IMAGE ID CREATED SIZE
nvcr.io/nvidia/pytorch 18.04-py3 c3555fec4fe6 3 years ago 5.9GB
The goal is to use Ubuntu ...
- 107
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16
views
How to containerise developement of GUI apps (C++, C#)
I'm looking for a solution to virtualise the environment for the development of C++/C# Windows apps that have a UI that display live video.
The apps needs to run native on the local machine during ...
- 101
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8
views
Commit and Push Container Running in Azure Container Group?
My question has to do with the posture of Azure container groups. I'm comfortable working with Docker images and and deploying those in a Kubernetes environment. I'm new to Azure. I have a ...
- 161
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44
views
Access API on a container from another container
I have 2 containers A and B which both contains webapps
A is listening on 443 (apache2)
B is listening on 4000 (node.js)
Since I need to access to both services with https from my machine (win10), I ...
- 101
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26
views
What is the difference between `gitlab-runner start` and `gitlab-runner run`? What is the purpose of `run`?
What is the difference between gitlab-runner start and gitlab-runner run?
The documentation is not very clear on this:
gitlab-runner run
This is main command that is executed when GitLab Runner is ...
- 101
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answers
25
views
Where can I set the restart policy for a Azure Linux (container) App Service from the portal?
Is it possible to set the restart policy for a Azure Linux container from the portal? I build, push and deploy my application from the Azure Pipeline portal, but I need to change the restart policy ...
- 101
3
votes
1
answer
50
views
How to dockerize a jupyer notebooks project?
I have a project composed of 6 different Jupyter Notebooks and 4 CSV files. I would like also my colleagues can try to use this project, even if they don't have python installed and maybe with another ...
- 31
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votes
1
answer
23
views
Check TZ in Container Image without creating instance?
I have a requirement to assure that the container image we build runs in UTC only. I'd like to avoid starting it up just to check the link on /etc/localtime. I thought maybe a tool like dive that ...
- 273
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0
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11
views
Tools for "scanning" container (hardening) vulnerabilities vs tools for "performing" the hardening
Container hardening is the process of fixing the vulnerabilities.
CIS has published a list of container vulnerabilities which should be addressed to complete the hardening process.
Q1. Are there ...
- 225
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answers
26
views
Launching VM instances only when needed
I am looking for the right tool to launch VM instances on a cloud platform only when I need them. Once launched, they should run a containerized script (let's call it a job) that runs for about 5 to ...
- 111
2
votes
2
answers
115
views
Restart container if its application hangs
I have a critical container application which task consist of polling sensors and taking consequent action on some external hardware.
If the application of the container crashes it's fine. restart: ...
- 121
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vote
1
answer
93
views
Docker Swarm stop working with redeploy service, require system reboot
I got a Docker Swarm with 3 nodes, and contain around 40-50 stack on it, now its random stop working to redeploy my new changes its just say in new mode, and really don't know what going one here.
ID ...
2
votes
1
answer
2k
views
How to communicate between AWS ECS containers
Problem
How do ECS containers communicate between each others?
Situation
I use docker compose ecs integration.
In AWS docker context, docker compose up did a deploy correctly.
But reverse proxy doesn'...
- 21
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vote
2
answers
168
views
Best Practice for Container Image Versioning
I'm looking for some guidance on best practices for container image versioning and despite reading a number of the best practice guides they leave some ambiguity.
I understand that most container ...
- 113
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votes
1
answer
102
views
How can I deal with container "patching" in a strict release process?
I am building a new Container and Kubernetes system for my company. Overall it is going well, but container patching has me a bit confused.
We follow a fairly strict release process. New versions ...
- 172
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votes
1
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260
views
Difference between Docker container with Debian vs VM with Debian?
What is the difference between running a Docker container with Debian (eg. https://hub.docker.com/_/debian/) and then running a virtual machine with Debian? And why is it still an advantage if any?
I'...
- 101
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votes
1
answer
42
views
When do I run applications on a server in a pod and when to run them directly on the base operating system?
I am trying to get started in the DevOps Field by setting up a small server currently with Virtualbox, later on for a small team. For my basic setup I plan to use gitea as self-hosted git and Jenkins ...
- 101
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vote
1
answer
32
views
Testing docker image builds when low level libraries change
Background
In our organization we have many small repos for shared libraries used among our applications. Particularly, we have many Python libraries and Python applications. We have a structures like:...
- 121
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2
answers
60
views
Service to service communication - through proxy or direct?
A common scenario is two or more services behind a reverse proxy, typically each deployed in a container:
| service 1 | | service 2 |
\ /
\ /
...
- 101
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votes
1
answer
1k
views
How to build, package and deploy a react-native-web app in a Docker container?
Given there is a react-native-web solution, what needs to be done to build it and run inside a Docker container?
What is the build environment/toolchain?
Which environment is required to run?
From ...
- 6,702
2
votes
2
answers
846
views
Container Image Promotion across environments in ECR/ECS
We have started doing some initial work on deploying containers on ECS Fargate service.
However we are not yet completely figured out how to manage our image promotion across different environments.
...
- 121
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vote
1
answer
103
views
How to create a local network mapping in linux
I'm deploying nextcloud via docker, however the way the configuration is set up, it creates a subnetwork at 10.10.10.0/24 on the system it's running on instead of running it on 127.0.0.1. Then the ...
- 21
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1
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178
views
How can I use a buildah script for image generation using GitHub Actions?
Buildah scripts typically use shell. You can see an example of a script here,
#!/bin/sh
ctr=$(buildah from alpine:3)
buildah commit "$ctr" myAlpineImage
Let's say I have such a shell script ...
- 379
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votes
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353
views
kubernetes quota vs limit. What are they? How are they different? When should I use one or the other?
I have been reading through the docs but it still is not clear as to why I should use one or the other. They have great examples of how to configure them but don't answer the why for quotes or limits ...
- 101
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votes
1
answer
36
views
Does RAM Come Into The Container vs VM Decision?
I am currently running a Java trading system on a VM that needs ~32 GB RAM and runs (almost) 24/7.
There are a couple of engines linked to it that require 4GB + 8BG respectively.
I am considering ...
- 481
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vote
1
answer
5k
views
Docker Build Ending Up `returned a non-zero code: 1`
Running mktexlsr /var/lib/texmf ... done.
Building format(s) --all.
This may take some time... done.
build.sh: line 81: -: No such file or directory
The command '/bin/sh -c bash build.sh' ...
- 11
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vote
1
answer
390
views
kubelet connecting to docker.sock instead of containerd.sock
Kubernetes version: latest
Installation method: kubeadm
Host OS: debian9
container runtime: containerd
Kubelet fails when starting and after inspecting the logs using journalctl -xeu kubelet i see ...
- 11
0
votes
1
answer
48
views
Increase concurrent users by limiting container resources with docker-swarm
Consider the scenario where I have:
4 replicas of an app
4 cores
On load, the app consumes 100% for a single core
Can I tell each replica to only use 50% of the core and if so, would this allow at ...
- 101
0
votes
1
answer
31
views
How to redirect the request to a different node when there is an unexpected exception and one of the pods gets restarted
We are deploying the application in a Kubernetes cluster and when we face an unexpected error and the pod gets restarted or goes down we are getting a 502 Gateway error even though there is another ...
- 21
4
votes
1
answer
335
views
Change docker container’s log PATH
Team:
All my container logs are under /var/log/containers..
Where in kubelet or docker config can I specify this path such that logs are instead created under new path?
Ex : /shared ? Instead of /var/...
- 151
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1
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210
views
Why is it necessary to have virtual machines to run multiple server instances?
I'm trying to learn about virtualization and containers. In an educational video it is said that the introduction of virtual machines was a big deal because it made companies available to run multiple ...
- 43
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2
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2k
views
How to get the IDs of Docker Containers that belong to a Service, given the Service name or id
Background
I'm trying to maintain some websites running in a Docker Swarm. I want to do security updates on them.
In a non-Docker environment, like a VPS, my simple process is that I would connect in ...
- 265
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votes
1
answer
26
views
Helm Repo: can it host dockerfiles and other image-building artifacts
I have a service that I want to port to Helm. It's a django application that requires memcached and postgresql and a forward proxy like nginx.
I would ideally like to have one repository with all that ...
- 379
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2
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2k
views
Can I upgrade a docker image/container from buntu 18.04 to ubuntu 20.04?
I have a host ubuntu 20.04 running my software on docker with a container derivated from ubuntu 18.04. I would like to use ubuntu 20.04 for several reasons (like the better software on 20.04).
If I ...
0
votes
1
answer
71
views
hello world with flask and redis using docker networking
The sample from Docker, a "hello world" with redis and flask, seems to build fine, but, as an exercise can it be broken into two components?
The redis service uses a public Redis image ...
1
vote
1
answer
2k
views
docker-compose up: Error starting userland proxy: listen tcp 0.0.0.0:443: bind: address already in use
specific error:
ERROR: for traefik Cannot start service traefik: driver failed programming external connectivity on endpoint frappe_docker_traefik_1 (...
0
votes
1
answer
63
views
how to push an image to docker hub?
How do I push this image to docker hub?
root $
root $ docker images helloworld_web
REPOSITORY TAG IMAGE ID CREATED SIZE
helloworld_web latest ...
2
votes
1
answer
88
views
How to Connect Docker Containers?
In "What is a container?" the docker docs show the following nifty image:
For my scenario I have only App A and App B; let's designate them Alice and Bob. How do Alice and Bob communicate, ...
0
votes
1
answer
36
views
How to deploy MySQL server repeatedly
From fifty-thousand feet, how are, for example, multiple MySQL containers handled?
In the context of my limited experience, simply running the container is insufficient, with additional configuration ...