In older versions of my guides and in practice I was using my main admin users details for all my Docker containers, this is not great for security so it is good practice to setup a unique user with more limited access for you containers.
Creating a User
Navigate into the DSM control panel and open up ‘User’ then click Create.
You can call the user whatever you want, I just kept mine simple and created one called ‘dockerlimited’
It’s also a good idea to generate a very strong random password for the user, while it will be a very limited account you don’t want to give it an easy to guess password. You will never need this password for what we are doing.
Next we are going to add this new user to the ‘users’ group as we don’t want it having any sort of admin access.
Next we are going to allow this user ‘Read/Write’ access to the data and docker folders, if you have any other folders it should default to ‘No Access’
Nothing to change on the User quota settings just click ‘Next’
Our user will not require any application permissions so check the ‘Deny’ button at the top of the screen.
Again we don’t need to set any speed limits for this user so click on ‘Next’
The final screen will just confirm your settings make sure the correct shares are in the ‘Writeable’ list, click on ‘Done’ and your user has been created.
Obtaining the new users PUID and PGID
Now we have created the new user for your containers we need to obtain the PUID (Personal User ID) and PGID (Personal Group ID) as this is passed through in our container setup and ensures all the correct permissions are inherited.
You will need to SSH into your Diskstation using ‘Putty’ or an equivalent program depending on if you are a Windows / Linux /Mac user.
So lets jump into the Control Panel again and enable SSH
Open up Putty, the only thing you need to enter is the IP address of your NAS and select the SSH radio button.
Click on ‘Open’, you will get a prompt asking if you trust the key, if this is the first time you have used SSH, just press OK or accept.
Enter the login information for your main Synology user account, you will not be able to see the password as you type it.
Once logged in type ‘id nameofuser’ without the quotes and the ‘nameofuser’ will be the name of the user you created earlier. This will show the UID (aka PUID) and GID (aka PGID)
In the example screenshot you can see the details for the user I use in the guides
You have now setup the locked down user account, You may also want to disable SSH again.