Moving to Docker

[akbooer]

@rhcpng

Ooh, super – another Docker expert.

I'm really stuck. I think that there's a vital piece of documentation that I haven't found/read. Whether this is Synology, or Docker, or GitHub/vwout, I'm not sure...

• I have Docker installed in Synology
• I have the (alpine) version of openLuup installed and running (apparently)
• but I can't access it at all or work out where the openLuup files go.

I think this is something to do with the method of persisting data:

docker-compose.yml

and whilst I understand that there are (probably) some commands to be run:

docker run -d \
       -v openluup-env:/etc/cmh-ludl/ \
       -v openluup-logs:/etc/cmh-ludl/logs/ \
       -v openluup-backups:/etc/cmh-ludl/backup/ \
       -p 3480:3480
       vwout/openluup:alpine

I don't know where that goes either.

So I feel stupid, and stuck. (Nice, in fact, to understand how others feel when approaching something new.)

Any pointers, anyone?

[RHCPNG]

@akbooer
I'm far from an expert, but have some experience with it yes. I haven't composed a container through yaml yet.

You first need to define/create the volumes, that's when you can state where the volumes should be "placed" and where the data resides. This can be a local directory or a nfs mount for example. Default, it creates a dir in the docker dir.

If you are not a Linux expert, like me (although I can manage), I would advise installing Portainer first. It gives you a nice GUI for managing your dockers. Far easier than doing everything through command line.

[kfxo]

@akbooer said in Moving to Docker:

• but I can't access it at all or work out where the openLuup files go.

You are using the synology docker package to create and deploy your container, correct? At minimum, to get the container accessible, change the port settings to 3480(local):3480(container). Then you should be able access it at http://YourSynologyIP:3480/

[akbooer]

@kfxo said in Moving to Docker:

You are using the synology docker package to create and deploy your container, correct?

Yes, that's correct for now. I need also to investigate Portainer, apparently.

@kfxo said in Moving to Docker:

change the port settings to 3480(local):3480(container).

OK, I was looking for where to do that, but I guess, I'll look harder. Thanks.

[akbooer]

... Oh, THOSE settings!

Thanks again.

[akbooer]

It's MAGIC !

I particularly like the look of this...

This instills a sense of wonder in me... I mean, I know (almost) exactly how openLuup works, but to see it wrapped in a container running on a NAS, seems rather special. "Hats off" ("chapeau?") to those who have engineered this, not least @vwout.

One is never quite finished, however.

I understand that to make any changes last across container/NAS restarts, I need to make the volumes external to the container, as per the above yaml. So this is my next step.

Any further insights welcomed. Perhaps Portainer is that next step?

[RHCPNG]

I'm not familiar with the docker GUI of Synology, maybe that's good enough. But Portainer is widely used for managing docker containers. I like it. It is quite easy to create volumes and the sorts.

[kfxo]

@akbooer said in Moving to Docker:

I understand that to make any changes last across container/NAS restarts, I need to make the volumes external to the container, as per the above yaml. So this is my next step.

Any further insights welcomed. Perhaps Portainer is that next step?

You cannot create named volumes through the synology GUI. You will need to use portainer or you can ssh into your synology and run the manual commands as outlined by vwout/openluup

You can also do this manually. Start by creating docker volumes:

docker volume create openluup-env
docker volume create openluup-logs
docker volume create openluup-backups

Create an openLuup container, e.g. based on Alpine linux and mount the created (still empty) volumes:

docker run -d
-v openluup-env:/etc/cmh-ludl/
-v openluup-logs:/etc/cmh-ludl/logs/
-v openluup-backups:/etc/cmh-ludl/backup/
-p 3480:3480
vwout/openluup:alpine

[kfxo]

@akbooer
I have been messing with this today. I do not currently run openluup through docker so this may not even be the best way to do this but it is what I did to get it up and running and with the ability to easily see and manipulate all openluup files within "File Station" on the synology.

I created three folders on my synology:
/docker/openLuup/cmh-ludl
/docker/openLuup/logs
/docker/openLuup/backups

Then I created three volumes with a bind to the created folders
'openluup-env' bound to '/volume1/docker/openLuup/cmh-ludl'
'openluup-logs' bound to '/volume1/docker/openLuup/logs'
'openluup-backups' bound to '/volume1/docker/openLuup/backup'

I used portianer but you can ssh into your synology and use the command line to create these volumes with the binds, see this

Then I created the container using portainer making sure to set the correct ports and volume mappings, which can also be done in the command line with

docker run -d \
       -v openluup-env:/etc/cmh-ludl/ \
       -v openluup-logs:/etc/cmh-ludl/logs/ \
       -v openluup-backups:/etc/cmh-ludl/backup/ \
       -p 3480:3480
       vwout/openluup:alpine

Hope this helps.

Edit: The binds are not necessary, I only did it to make it easy to access the files. Without the bindings, the volumes are somewhat hidden on synology that is not easily accessible for example at '/volume1/@docker/volumes/openluup-env/_data'

[RHCPNG]

Good explanation, this is where it comes down to. But in the end, you probably want the bind to make your data persistent and, more important, easy acccessible.

[akbooer]

I'm still struggling with this. I've manually created some external folders, but can't get the multi-line command to work.

@vwout, following my new experience with AlpineWSL on a PC (which I assume to be something very similar to Docker) I created the whole of the cmh-ludl folder as one single external volume. This is really convenient. Is it possible to make the same configuration for a Docker image?

[mrFarmer]

Hi @vwout, can your docker image also be used on the arm64 platform (Pi4)? If not, how would I go about building one? I think with an Unbutu docker and then use the same setup as on a plain Pi.

I am setting up some new things on a Pi4 and came along this (https://github.com/SensorsIot/IOTstack) to use Dockers on a Pi. Looks like a very quick way to (re)build an environment from a basic starting point. Especially the split between user data and all else looks attractive.

Cheers Rene

[akbooer]

Why would you want to do that? It’s not as though installing Lua is difficult. What am I missing?

[RHCPNG]

@akbooer said in Moving to Docker:

I'm still struggling with this. I've manually created some external folders, but can't get the multi-line command to work.

@vwout, following my new experience with AlpineWSL on a PC (which I assume to be something very similar to Docker) I created the whole of the cmh-ludl folder as one single external volume. This is really convenient. Is it possible to make the same configuration for a Docker image?

I don't know what AlpineWSL is, but you can make a volume for your cmh-ludl folder and map it in vwout's docker container.

This is what it looks like in portainer, like a mapping. Really convenient, like you said.

[akbooer]

@rhcpng

Thanks for that. I guess my question is why these have to be done separately, rather than just making cmh-ludl/ (and all its sub folders) external (which, effectively is what I’ve done for WSL.)

I was trying to do it on the command line, since Portainer seemed to be several hundreds of megabytes, which seemed a bit of overkill just for this task (which, I think, is all I need it for.)

[RHCPNG]

You mean not splitting it up in backup, log and cmh-ludl? That's a choice of vwout. To be able to be flexible with what you store where, probably. You can do it with the command line too, but I'm not familiar with that. I don't think you have to do all mappings. Probably the cmh-ludl is enough, but I'm not sure.

[mrFarmer]

@akbooer Well, if I have a complete openLuup setup, except my data, in a Docker and I need to rebuild a system from scratch I can just run a script, restore my data and be back up and running. Creating a complete new system from scratch takes a lot more. Especially if you need to do Grafana, DB, webserver, ... All the packages I need to install again (i never document that well for the next time) etc.

[akbooer]

@mrfarmer

Ah, I see. More of a backup, than anything else, then.

[mrFarmer]

@akbooer a quick restore from a fatal crash of the Pi (SD/SSD) yes.

[vwout]

@akbooer As @RHCPNG said, you can easily do this, once you have a running setup by copying the contents of /etc/cmh-ludl/ to a local folder, restart the container with that folder mounted to /etc/cmh-ludl/.

The difference between using a volume and a folder mount is (amongst other details) how Docker handles this at first startup. When using a volume, Docker copies the contents of e.g. /etc/cmh-ludl/ when it is started with a empty new volume, to that volume. As of that moment all changes are kept in the volume and survive container restarts and updates.
A mounted folder also preserves all settings, but in contrary to volumes, Docker does not copy the original contents of the mount target to the folder at first startup. This means you need to store create the files needed in /etc/cmh-ludl/ yourself, which makes it harder to initially get start (except for one who masters openLuup ).