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.
201
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0
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12
views
How to add packages to the micro and mini suse base images
I want to install tar and zstd packages to the base image of registry.suse.com/bci/bci-minimal:15.5 and registry.suse.com/bci/bci-micro:15.5 (taken from https://registry.suse.com/) but none of the ...
- 123
2
votes
0
answers
103
views
How to run nerdctl run inside a container?
This is not for building inside a container, this is for running containerized CLI tools in a Job. I know the security implications. This is a lateral move security wise from DooD just to get us to ...
- 133
0
votes
0
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22
views
How do you distinguish between a timeshare system, a VM, and a container?
A time-share system, a virtual machine and a container all seem very similar. How do you materially and meaningfully distinguish between them? What are the merits, benefits and drawbacks of each ...
- 3,724
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42
views
Docker build reset file ownership after each layer built
I've noticed a new strange thing where file permissions reset while building a docker image.
Consider the following Dockerfile:
FROM ubuntu
RUN mkdir -p /home/user && \
useradd -l -u ...
- 101
0
votes
1
answer
156
views
Processes in "podman build" have lower file descriptor limit than processes in "podman run", how can I increase this?
I'm running podman 3.4.4 on Ubuntu 22.04 LTS server.
I have been having podman build issues that are not reproducible if I do those steps after the container build using podman run.
Eventually I ...
- 101
0
votes
0
answers
79
views
Change memlock limit in a Docker container; is it possible?
I'm running a container from vast.ai, Ubuntu 20.04 LTS.
I'd like to change memlock limit in the Docker container. Is it possible?
What I've already tried:
Changing the memlock limits in /etc/security/...
0
votes
1
answer
53
views
What is best practice for passing files and directories as command line arguments to a containerized program?
I am working to containerize a program. The program requires a configuration file and directories for its operation, which are passed as command line arguments, e.g. something like this:
$ myprog -c /...
- 101
0
votes
0
answers
18
views
Run Docker container with user who started it
I have two users on host machine usera, userb. I have added these users to the Dockerfile as below.
FROM ubuntu:latest
ENV DEBIAN_FRONTEND=noninteractive \
TERM=xterm
RUN groupadd -g 1111 ...
0
votes
1
answer
30
views
Way to detect base container version for pods
I am trying to understand how companies detect that a Kuberentes pod is running a container that is based on a container image that is out of date.
So, for example, say I have an application called ...
- 206
0
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0
answers
70
views
Error registering container in Gitlab
I'm trying to register a container in a project, I thought it was a passing problem, but it persisted. I created a new project still holds. I never got around to using Gitlab's registry for containers....
- 1
0
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0
answers
17
views
Why does k8s by design uses 3 ports for NodePort's services instead of just 2
I am seeing that to create a nodePort service using a yaml manifest there are three port parameters to enter: port, targetport and NodePort.
To give an example, I have this hypothethical manifest:
Now ...
1
vote
1
answer
596
views
How can I make an image out of a k8s specific pod container
I have made a pod, and it has only one container, I've been able to connect ot it by using kubectl exec -it -c <container_name> <pod_name> bash
And I've installed and done several stuff on ...
0
votes
0
answers
669
views
Why k8s with minikube NodePort are not working?
I am using minikube on my windows 11 machine just to start testing k8s. And my NodePorts are not giving an URL, and even when I recover the service's I.P and ports by using kubectl describe and I use ...
1
vote
1
answer
515
views
Why does running a nginx image in docker interactive mode makes nginx not working
I have made a docker container from nginx running in background this way:
docker run -d --name nginx1 -p 49699:80 nginx
When I go to localhost:49699 on a browser with cleared cache it works properly ...
1
vote
1
answer
595
views
Azure DevOps Pipeline failure - Program does not contain a static 'Main' method suitable for an entry point
I have been tasked with deploying an email service to an Azure tenant using Windows Containers. In my Pipeline (Azure DevOps), I am receiving the following error when in the build step:
CSC : error ...
- 11
0
votes
0
answers
29
views
How do I schedule to run a docker python app hosted on Azure Container Registry with timed tasks?
I have pushed a docker python app to ACR already and I would like to be able to set up and manage "cron" tasks in order to run the image with custom run commands. For instance:
Take image A ...
- 1
0
votes
1
answer
307
views
How to delete an existing label in a deployment with helm upgrade
I have an existing deployment that has the label importance: normal in spec/template/metadata/labels (all the pods spawned from this deployment have that label in them).
The current deployment yaml ...
- 113
0
votes
0
answers
14
views
What feature of Windows used by Docker
I know docker is based on cgroups and namespaces in Linux operating system, but I wanted to know what feature in Windows used by docker to implement containers? Somebody could explain it?
- 101
3
votes
1
answer
48
views
Do docker layers work at file level or block level?
I'm considering using a Docker image as way to snapshot a MySQL database after fixtures have been loaded, in order to quickly restore the snapshot before each acceptance test.
In order for this to be ...
- 198
0
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0
answers
19
views
Print application log in an external directory from Golang application deployed in Kubernetes cluster
I am new to containerization. I have a Golang application deployed in a Kubernetes cluster inside an Ubuntu VM. I can access the application log using k logs -f <pod-name> command. However, I ...
0
votes
1
answer
491
views
How reliable is NFS for using in Kubernetes?
I'm setting up a self-managed Kubernetes cluster where I'm limited by the number of choices for the backend storage for Pods.
I should use a remote storage, so that multiple Pods can read/write at the ...
- 1
0
votes
0
answers
845
views
Access docker container through a fake domain name for better usability, with docker compose
I was developing a docker-compose setup for improving local development.
My intention is that we could access some URL like https://api.testapi.local, instead of using http://localhost:8000.
Is it ...
1
vote
0
answers
237
views
Best practice for database migration with Kubernetes and docker
Is there a best practice for initializing and managing database schema(and seed data) for containerized backend applications?
I'm currently developing an on-premise application deployed at the ...
- 11
4
votes
1
answer
73
views
Rationale for using Docker to containerize applications
I'm trying to get a better understanding of the reasons to use [and not use] Docker based on specific use cases.
From my current understanding, Docker helps to isolate applications and their ...
- 143
1
vote
1
answer
329
views
Why does stripping executables in Docker add ridiculous layer memory overhead?
On this image, I ran the following command to reduce executable sizes:
find -P -O3 /usr/bin/ /usr/local/bin -type f -not -name strip -and -not -name dbus-daemon -execdir strip -v --strip-unneeded '{}' ...
- 170
3
votes
1
answer
382
views
How do I supply a professional license to a Docker image?
I’m using Windows Server Core as part of an image I’m working on. When it's deployed to production, how do I supply a license to it?
Besides that, is this license needed to be bought for each image it'...
- 33
0
votes
1
answer
33
views
How do you securely deploy large number of Kubernetes components in isolation?
Precursor: I am not experienced in the design of large-scale infrastructure deployments for infra applications.
The assumptions for the questions:
I have read that it is a good practice to host ...
0
votes
0
answers
20
views
How do you ensure users do not bypass Kubernetes security and interact with the Container runtimes directly?
You could have Docker and Kubernetes installed on the same host and allow the user to access both binaries. A malicious user can potentially bypass Kubernetes security (e.g. PodSecurityPolicies), by ...
0
votes
0
answers
27
views
How do you isolate Kubernetes components in a network?
When I install Kubernetes on a host, all the core components (etcd, Kube manager, scheduler) are all installed on a host by default.
Is there a use case or need to deploy Kubernetes components ...
0
votes
1
answer
26
views
Continuous deployment question
This question is not in case of kubernetes but when you use servers or docker for deployment using CICD tool like Jenkins or gitlab.
In jenkins or gitlab I've agents/runners and in pipeline stages I'...
- 23
1
vote
2
answers
659
views
Combine Helm charts or leave separate?
I'm new to Helm and my first task was to recreate a simple pipeline. This pipeline is just:
PostgreSQL -> Spark, with ELK monitoring the instances.
Someone mentioned I may be able to combine all of ...
- 11
2
votes
0
answers
158
views
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:
...
- 661
0
votes
1
answer
589
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 ...
- 11
1
vote
2
answers
2k
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 ...
- 113
4
votes
2
answers
240
views
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
2
votes
1
answer
105
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 ...
- 6,802
1
vote
0
answers
88
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://&...
- 111
1
vote
0
answers
35
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
1
vote
0
answers
66
views
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 <...
- 11
0
votes
2
answers
467
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 ...
0
votes
0
answers
553
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
3
votes
1
answer
125
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 ...
- 33
1
vote
1
answer
35
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 ...
- 353
1
vote
0
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
3
votes
2
answers
870
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: ...
- 131
1
vote
1
answer
380
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
5k
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
2
votes
2
answers
2k
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 ...
- 123
0
votes
1
answer
574
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 ...
- 206
0
votes
1
answer
864
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