Prerequisites for Docker on Synology

[rheckly]

My cronmaster runs in my docker environment - so far so good.
But I had issues to save cron-jobs - nsenter and crontab commands were not available on synology.
So I had to search for and found I have to install those commands from entware.
Looking on Marius Hosting it seems just to install the docker - also looking the video here https://www.youtube.com/watch?v=NF7U8Jelono seems very easy - but doing exactly the steps will not end in a running solution on synology.
Does anybody has a guide with step by step to install prerequisites etc.?

My problem at the moment is, that I don't see the tasks from my task scheduler.
As soon as I enable "Logging" for a job, the job crashes - no log information why.
Bash was also not available - so my execution of the script would be with full path information, because crontab runs on the host and must find the files there:
/opt/bin/bash /volume3/docker/cronmaster/scripts/photoprismindex.sh

just bash /app/scripts/photoprismindex.sh would not work

If somebody went through all this - and has also Photoprism scripts - how to check if an index is already running - script like mentioned here: photoprism/photoprism#1952
Help is very welcome!

[fccview]

My cronmaster runs in my docker environment - so far so good.
But I had issues to save cron-jobs - nsenter and crontab commands were not available on synology.
So I had to search for and found I have to install those commands from entware.
Looking on Marius Hosting it seems just to install the docker - also looking the video here https://www.youtube.com/watch?v=NF7U8Jelono seems very easy - but doing exactly the steps will not end in a running solution on synology.
Does anybody has a guide with step by step to install prerequisites etc.?

My problem at the moment is, that I don't see the tasks from my task scheduler.
As soon as I enable "Logging" for a job, the job crashes - no log information why.
Bash was also not available - so my execution of the script would be with full path information, because crontab runs on the host and must find the files there:
/opt/bin/bash /volume3/docker/cronmaster/scripts/photoprismindex.sh

just bash /app/scripts/photoprismindex.sh would not work

If somebody went through all this - and has also Photoprism scripts - how to check if an index is already running - script like mentioned here: photoprism/photoprism#1952
Help is very welcome!

Hi,

This sounds like a permission issues.
First of all, what user are you mapping for your cronjobs? What used uses crontab on your system? As that needs to be what's specified in the docker-compose file

Also do the mapped folders in your compose file have the right permissions? Seems like the app can't write logs at all

[rheckly]

A run this docker on a Synology - DSM 7.3
The User in my docker compose file is: root

This is my docker compose:

For all configuration options, see howto/DOCKER.md

services:
cronmaster:
image: ghcr.io/fccview/cronmaster:latest
container_name: cronmaster
user: "root"
ports:
- "40123:3000"
environment:
- NODE_ENV=production
- DOCKER=true
- NEXT_PUBLIC_CLOCK_UPDATE_INTERVAL=30000
- AUTH_PASSWORD=
- HOST_CRONTAB_USER=root
- MAX_LOG_AGE_DAYS=30
- NEXT_PUBLIC_MAX_LOG_AGE_DAYS=30
- MAX_LOGS_PER_JOB=50
- HOST_PROJECT_DIR= /volume3/docker/cronmaster #not needed as of version 1.5.0 https://github.com/fccview/cronmaster/releases
volumes:
# Docker socket for command execution
- /var/run/docker.sock:/var/run/docker.sock

  - /volume3/docker/cronmaster/scripts:/app/scripts:rw
  - /volume3/docker/cronmaster/data:/app/data:rw
  - /volume3/docker/cronmaster/snippets:/app/snippets:rw
pid: host
privileged: true
restart: always
init: true
#platform: linux/amd64

first of all:
As of version 1.5.0 the host_project_dir is not needed anymore. So I'm wondering how the log files will be written. As I understand - the docker executes a job on the host. The host doesn't know the folder "/app/data/logs" - without this environment variable host_project_dir - how does the host know where to write the log files? Only after mapping on the host a folder with
mkdir -p /app
ln -s /volum3/docker/cronmaster/app/data

Now the job writes the log files.

Also I had to install on my synology packages from entware - nsenter, cron and bash

Also the scripts are in app/scripts - only when I enter full path to the script with the host folders then it works:
/opt/bin/bash /volume3/docker/cronmaster/scripts/photoprism.sh

For me this seems a problem between docker and host environment. Not a permission.

[fccview]

how does the host know where to write the log file

Hey, so instead of having an env variable I let the docker image read the docker-compose mapping. So in your case volume3/docker/cronmaster/data:/app/data:rw, the image will know that /app/data corresponds to volume3/docker/cronmaster/data.

This happens here:

cronmaster/app/_server/actions/global/index.ts

Line 38 in f098ded

export const getHostDataPath = async (): Promise<string | null> => {

And here for scripts:

cronmaster/app/_server/actions/global/index.ts

Line 63 in f098ded

export const getHostScriptsPath = async (): Promise<string | null> => {

I am not sure why on synology this is not behaving as it should..

I'll try and investigate, however unfortunately I don't own one, so I'll need to try and simulate a similar setup, which may not be as accurate.

I am glad you eventually got it working, I think a lot of users will find this discussion very helpful, thank you SO much for persisting and I hope you like the new branding ♥️

[rheckly]

Let me know if I can test anything for you - or if you need any information.

[juergenbarth]

My 5 cents: you should rather not install Cronmaster on Synology since on this platform you have the Task Planner which does exactly the same and ist properly aligned with everything Synology/DSM.