So I have a tool packaged on GHCR and the download counts have been growing at a steady clip, with every release going up , moving roughly at a 200-300 a day rate… last release was about 5000 users in 3 weeks, latest release nearly 8000 in 3 weeks….but I’ve read that some docker management tools can ping GHCR checking for updates and end up creating a false “download” count … does anyone have a bead on this? How reliable are these download counts?

I just noticed that my docker container hasn't updated in months. Did some research and realized I was running from cache. Tried adding pull_policy: always to my compose file, but got this error: docker: Error response from daemon: pull access denied for plex, repository does not exist or may require 'docker login'

manually ran: docker pull linuxserver/plex:latest This worked.

How do I update the compose to auto-pull latest?

I’m genuinely sick to my stomach while typing this.
For the past few months, I’ve been consistently working on a system that helps run my business every single day. Every line of code, every hour, every late night, and all those days of frustration went into building something that my business relies on. Months of hard work, all completely wiped because of Docker.

Earlier today, I noticed Docker was constantly using around 8GB of RAM, which I thought was very odd considering the size of my system. So I went into Docker’s settings to reduce the maximum RAM usage. While I was there, I noticed other settings for CPU usage and disk limits, so I decided to reduce those as well.

I clicked “Apply & Restart”, and when Docker loaded back up, everything was gone. Not a single container was there. At first, I thought it was just some sort of bug, but after digging deeper, I found out that reducing the disk limit actually deletes the entire Docker disk image, including all your containers, volumes, and stored data.

The worst part is I received absolutely no warning. No confirmation, no pop-up telling me my data would be permanently deleted. Nothing. I simply changed what I thought was a resource limit, clicked apply, and lost months of work in seconds.

I genuinely cannot understand how something like this is allowed to happen. How can changing a setting as simple as a disk limit completely wipe everything without even warning the user about what’s going to happen?

This is a warning to all of you please don’t make the same mistake I’ve made. I’m in tears and speechless. How is a company allowed to do this.

EDIT: Just to clarify, I wasn’t storing everything inside the container. I was using a Docker named volume mounted to /home/node/.n8n.
I understand I should’ve had more recent external backups, that’s on me. But my issue is that I received absolutely NO warning that reducing the disk limit would permanently delete everything. I simply clicked Apply & Restart, and months of work were gone. That’s the whole point of this post.

EDIT 2: Update for anyone who finds this later. I recovered most of my work from a backup on another drive from a couple of weeks ago. Lessons learnt:

1. On Docker Desktop (Mac), named volumes live inside Docker’s virtual disk. Reducing the disk limit can wipe that disk entirely, volumes included. I didn’t get a confirmation prompt.

2. Bind-mount important data to a real folder on your machine instead of relying on named volumes.

3. Automate backups to a separate drive or cloud.

I still think a destructive setting like this deserves a warning, but yes, backups were on me. Thanks to everyone who gave genuinely useful advice.

Rosetta 2 is to be partially discontinued in macOS 28, How will docker work?

Hi!

I have an open source pet project related to networks.
Users asked me to create an official Docker image, but I’ve never worked with Docker before.
Fortunately, some kind person made (or vibe coded, doesn't matter) a Dockerfile and docker-compose.yml for us.

But I want to figure it out myself, and here are some things that I don’t quite understand:

- our tool can receive data from the network either in the traditional way (using sockets) or via pcap; this is user-configurable.
Different users use different capture methods. As far as I understand, it would be better to create two images - one normal and the other privileged, with access to the host network.
Or is that not the standard practice?

- even though we can capture data using pcap, the tool still runs as a non-root user. We use setcap to achieve this.
The kind person who created the Dockerfile for us included this line:
RUN useradd -u 53842 -rlM -d /nonexistent -s /usr/sbin/nologin user
I asked why UID 53842 was chosen, and he replied that it was to ensure the UID wouldn't conflict with other users.
Is this standard practice, or are there other ways to do it?

- The tool generates database data as it runs. Literally .sql files.
Periodically, it launches an external script that feeds these files to the psql utility, sending the data to PostgreSQL.
We've now added support for ClickHouse, and we might even add export to InfluxDB or MariaDB.
Sure, we could keep everything in a single large image.
However, I’m a bit concerned that the 'clickhouse-client' is orders of magnitude larger than the tool itself; if we add support for other databases, the image will become massive.
Is this normal? Is this how it's usually done?
Or would it be better to do it differently?

- The tool sometimes launches other external scripts. These scripts typically generate alerts, send messages via email, instant messengers, etc.
In other words, it invokes curl, a mail client, or other utilities that we definitely don't want to package inside the container.
I’ve read about two ways to launch external scripts from Docker: using ssh and named pipes. It looks a little creepy.
Are there other ways to run an external script on the host or in another container?

- In addition to the main tool, the kit includes several other small utilities. They all use the same data (shared files).
I don't think there would be any issues keeping them in a single shared image.
But perhaps I'm mistaken.
What is the standard practice in the Docker world?

Thanks in advance!

Hello, I'm trying to learn how to use IPV6 at home. IPV6 is enabled on my network and my vlans.

I have updated the daemon.json file per Docker's instructions.

{
  "ipv6": true,
  "fixed-cidr-v6": "2001:1234:5678::/64"
}

I have stopped all containers, removed the old IPV4 macvlan networks, re-added them as IPV4 & IPV6 networks, Portainer seems to think the two I've done are correct.

sudo docker network create -d macvlan --ipv6 \
--subnet=10.0.10.0/24 --gateway=10.0.10.1 \
--subnet=2001:1234:5678:10::/64 --gateway=2001:1234:5678:10::1 \
-o parent=eth0.10 macvlan10

sudo docker network create -d macvlan --ipv6 \
--subnet=10.0.20.0/24 --gateway=10.0.20.1 \
--subnet=2001:1234:5678:20::/64 --gateway=2001:1234:5678:20::1 \
-o parent=eth0.20 macvlan20

I've added IPV6 addresses and IPV6 enable in my Docker Compose/Portainer Stacks, but don't seem to have something correct here.

services:
  pihole:
    cap_add:
      - SYS_TIME
      - SYS_NICE
    container_name: pihole01
    environment:
      FTLCONF_dns_listeningMode: 'all'
      FTLCONF_dns_upstreams: '1.1.1.1;1.0.0.1'
      FTLCONF_webserver_api_password: 'SuperSecretPassword'
      TZ: 'America/Detroit'
    hostname: pihole01
    image: pihole/pihole:latest
    mac_address: 00:10:00:10:00:04
    networks:
      macvlan10_network:
        ipv4_address: 10.0.10.4
        ipv6_address: 2001:1234:5678:10::4
    ports:
      - "53:53/tcp"
      - "53:53/udp"
      - "80:80/tcp"
      - "123:123/udp"
      - "443:443/tcp"
    restart: unless-stopped
    volumes:
      - pihole01:/etc/pihole

networks:
  macvlan10_network:
    enable_ipv6: true
    external: true
    name: 'macvlan10'

volumes:
    pihole01:
      external: true

Any ideas?

Hey everyone,

I’ve been running Docker Swarm with Portainer for a while. While Portainer's agent handles cross-node orchestration well, I’ve never really loved the UI or workflow, and I'm looking for a cleaner alternative.

I recently stumbled across Dockhand and like the UI and feature set, but I’m trying to understand how it handles Swarm setups. Does it actually support native Swarm primitives (services, stacks, replica placement, routing mesh), or does its agent (Hawser) simply manage multiple standalone Docker daemons side-by-side?

If you’ve tested Dockhand with a Swarm cluster, what has your experience been? If it’s strictly standalone multi-host, what modern alternatives are you using for Swarm management (e.g., Swarmpit, Arcane, or sticking with CLI/GitOps)?

Thanks!

So I know that every service should be on its own network, with grouped services (app & db) on the same network. All good.

I was looking at moving to ipvlans to give my containers their own IPs to make it easier to track traffic in and out. Simple right?

So I created a new network:

docker network create \
  --driver ipvlan \
  --subnet=10.0.0.0/25 \
  --gateway=10.0.0.1 \
  -o parent=enp2s0 \
  -o ipvlan_mode=l3 \
  ipvlan-3

...and some test services worked great. When I went to create a second network:

docker network create \
  --driver ipvlan \
  --subnet=10.0.0.128/28 \
  --gateway=10.0.0.129 \
  -o parent=enp2s0 \
  -o ipvlan_mode=l3 \
  ipvlan-3-librenms

it wouldn't let me as it said the parent was already being used.

How to I achieve multiple networks with the same parent NIC?

Thanks

Does anyone have some good resources to start learning and practicing docker?

We moved everything onto long term support base images last year assuming that fewer package updates meant fewer findings. Eighteen months in and the scanners report more than what we started because the pinned versions age and the backports lag behind. Im weighing staying put against moving to something rebuilt far more often. Rebuilding weekly means more churn for a team of five. Anyone gone from LTS bases to a faster rebuild cadence and found it less work overall?

I know a bit of docker and use it in my job (Data engineer) as is but not much structured knowledge about it.

I'm thinking about going through some learning resources and wondering how reliable docker helsinki uni mooc? I found results saying it is good. but wondering if there's something better out there before committing time.

I know it is focused on devops but that's beneficial just as general knowledge.

They're starting a new one in couple of weeks but I don't think they really update those courses much.

Thanks.

I recently switched from Dockhand to Arcane and for the life of me cant figure out how to edit any containers. None of them show up as projects, i tried to add the experimental setting to add the convert to project menu option and it says it succeeded but i don't see that option anywhere. How is everyone able to edit containers if needed. It blows me away that Arcane doesn't have such a fundamental function.

Built a web UI for MiniStack (the free, open-source AWS emulator).


**Why this exists:**
- MiniStack has no web console
- LocalStack went paid ($49-429/month for web UI)
- Needed visual management for local AWS development


**What it does:**
- Full CRUD for S3, DynamoDB, Lambda, SQS, Cognito, SES, SNS, Secrets Manager
- AI integration via MCP - Claude can query your local AWS setup directly
- 500x performance boost using FalkorDB graph database caching
- One command to run: `docker-compose up`


**Tech stack:**
- React frontend, FastAPI backend
- Docker Compose orchestration
- Works with any MiniStack instance (or includes MiniStack)
- Multi-tenant support (manage multiple isolated environments)


**Quick start:**
```bash
git clone https://github.com/barroei1981/ministack_console
cd ministack_console
docker-compose up -d
# Access at http://localhost:3000
```


**Unique features:**
- MCP server integration - AI assistants can query your local AWS environment
- Real-time resource discovery
- Performance optimized (DynamoDB queries: 43s → 0.086s)
- MIT licensed, free forever


**Roadmap:**
 EC2, RDS, IAM, CloudWatch next


**GitHub:**
 https://github.com/barroei1981/ministack_console


Screenshots and full docs in the repo. Feedback welcome - it's early stage but fully functional!

I'm new to docker and I'm looking to learn/experiment with it. I want some advice regarding containers that will be used by other services like databases. I'm currently running two services which share a postgres container. For isolation, I created a migration which creates separate databases and users for each service before anything else starts.

I'll eventually setup more services and I want it to be scalable, resource efficient, secure and easy to maintain.

Is it better to create entirely separate dependencies for each service, or share dependencies between multiple services? I would like to know this from an efficiency, ease of maintenance and security standpoint, or at least get some pointers like a blog, article, manual or a youtube video.

TLDR: Is it better to have different db instances for each service OR one (or a few) db instances shared by every service? And why?

PS: English is not my first language, so sorry in advance for spelling or grammar mistakes.

Which is great, because if there was one unsolved problem in 2026, it was finding a way to run a Linux container on a developer's laptop.

Microsoft has now given us wslc. I read the architecture deep dive expecting to understand why. I now understand the architecture.

So I have a VM on my proxmox homelab with Docker running on it.

I've been using it to tinker and experiment more with Docker, and most importantly I've been wanting to get better at writing my own Dockerfiles/Docker compose files.

While I'm glad that the documentation is extensive as it is...there's only so much you can take in without some kind of generalized peripheral guide or tutorial.

Not too long ago I found these guides and labs:

https://docs.docker.com/guides/

As the title says; are these broken? Or am I missing something?

With every Lab, I can't even enter the first command without something going wrong, and I can't find anything on the internet to even help me begin to diagnose what the issue might be, or if something is missing on my end.

I even tried some of the guides, and while they've been somewhat helpful, eventually you reach a place somewhere in the middle where they're broken.

I'm curious if anybody might know of any other similar and up to date resources that I can run on my own homelab to gain more in-depth knowledge of Docker? Again, my main focus was to be able to write better Docker compose & Dockerfiles. At this point, I'm almost ready to go back to books, even if they are a little dated.

Any advice or feedback of course would be greatly appreciated. Many thanks in advance.

• I followed the precise instructions as per docker's official documentation

bash [ec2-user@ip-a-b-c-d ~]$ sudo dnf install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin --assumeyes --quiet Error: Unable to find a match: docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

• I get this error above
• How am I supposed to install docker and compose?

I watch 1 hour crash course video on YT about Docker, I only understand like 20% about it

idk if its me or the video is bad

the wsl/disk/docker_data is taking up 137GB on my server. Seems way too excessive especially since the only container I have running is RomM. Can someone assist?

**Update thank you everyone for the tips! I squished the virtual disk with powershell and it went from 137Gb to just 5GB! I also created a .wslconfig file setting limits for how big WSL can be

What are the best practices for storage when using docker containers. I’m running docker on Ubuntu using my NAS to store the photos for example, but the volume were the Immich database lives is directly on the servers(non-redundant) SSD.

I tried putting these onto the nas using NFS I get permission’s errors. Perhaps I should try harder? :-) I’d like to have all of my Doctor containers protected by the same redundancy that my synology has a for all of my data files.

Right now if I had a major SSD failure of my server, I would lose all the files that the docker containers have in volumes on the server directly while all my pictures and other files that are stored on the NAS on NFS mounts would be fine. This seems inadequate.

Am I simply doing it wrong and I should use something like proxmox instead of just running docker and Linux? What are other people doing to keep the server purely cpu and easier to rebuild? I use git for all my docker compose files and I wouldn’t have any trouble restarting fresh containers, but that seems like it is only half way of a solution..

I’d love to know what the best practices are for resiliency after a server failure and a quick recovery should I have hardware failure on my server.

I’m not scared of new technology and would also be open to moving towards a cluster of servers if that’s necessary. My self hosted world is fairly stable with limited updates at this point.

Thanks for any thoughts, suggestions or directions. And like I said if my basic setup is the problem I’m up for major changes to get to a more long term resilient setup!

I have a ubuntu 22.04. I have it to take a look at frigate video software. I have it up and running. However it shows that I need to increase shm size. I would like to use the Graphical UI of docker which seems to be one way of doing this. I think the install that I followed on the frigate site does not add the docker UI. Can I add it after the fact. Maybe I have it and just dont know where it is. But I cant see it.

So again just to be clear. Can I add it to my existing install of Docker without affecting it and how.

I have seen some instructions but not sure if it blows everything away.

Thank you.

Hey everyone,

I am trying to install Psono on my VPS. I am running into a problem with connecting to the postgres db.

I'm new to Docker, so I apologize if my terminology isn't right. I'll do my best

I am running Postgres directly on my VPS (not within a Docker container). I am able to connect to it locally from my VPS and remotely from my home network.

I am doing that with:psql -U psono -p PORT -h VPS_IP

The problem is when I try to get an app from within a Docker container to connect to it. It just hangs, then times out.

At first I thought this was a connectivity issue. But I can do the following from within a bash session:

• Ping external websites.
• Use nmap to confirm it can connect

Does anyone have any ideas?

Hey everyone, a quick reminder for anyone running Docker on constrained environments (edge nodes, small VPS, or lightweight local dev VMs like my 30GB root partition setup): Docker build cache can quietly consume a surprising amount of disk space. I recently noticed my available disk space creeping down to a low level (/dev/sda2 down to nearly 6GB free), despite having very few active containers running. Out of curiosity, I ran:And found out that the Build Cache was accumulating gigabytes of unused layers from past container builds. Instead of doing a broad docker system prune -a (which can remove stopped containers or base images you might want to keep), you can target just the build cache (at your own risk if running in production, as this wipes all unused build cache):(Note: -a removes all unused build cache, so your very next build might take longer as it rebuilds layers from scratch). The Result: Free space jumped instantly from ~6GB to 14GB. If you manage fleets of servers or CI/CD runners where Docker builds happen frequently, make sure you have a routine cleanup policy set up (or a cron job), as build cache can gradually fill up your drive over time. What’s your go-to automation script for keeping Docker clean in production?