Error updating mastercontainer on Docker rootless (cannot connect to Docker daemon at unix:///var/run/docker.sock)

[daks]

I tried to update mastercontainer running on Docker container and it doesn't work.
The logs are

2024-11-19T08:57:51.978341255Z time="2024-11-19T08:57:51Z" level=debug msg="Sleeping for a second to ensure the docker api client has been properly initialized."
2024-11-19T08:57:52.978739412Z time="2024-11-19T08:57:52Z" level=debug msg="Making sure everything is sane before starting"
2024-11-19T08:57:52.978812445Z time="2024-11-19T08:57:52Z" level=info msg="Watchtower 1.7.1"
2024-11-19T08:57:52.978835270Z time="2024-11-19T08:57:52Z" level=info msg="Using no notifications"
2024-11-19T08:57:52.978852750Z time="2024-11-19T08:57:52Z" level=info msg="Only checking containers which name matches \"nextcloud-aio-mastercontainer\""
2024-11-19T08:57:52.978871065Z time="2024-11-19T08:57:52Z" level=info msg="Running a one time update."
2024-11-19T08:57:52.979130508Z time="2024-11-19T08:57:52Z" level=debug msg="Checking containers for updated images"
2024-11-19T08:57:52.979188591Z time="2024-11-19T08:57:52Z" level=debug msg="Retrieving running containers"
2024-11-19T08:57:52.979987976Z time="2024-11-19T08:57:52Z" level=error msg="Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?"
2024-11-19T08:57:52.982250623Z panic: runtime error: invalid memory address or nil pointer dereference
2024-11-19T08:57:52.982290329Z [signal SIGSEGV: segmentation violation code=0x1 addr=0x30 pc=0x9fa4e2]
2024-11-19T08:57:52.982312672Z 
2024-11-19T08:57:52.982332760Z goroutine 1 [running]:
2024-11-19T08:57:52.982432454Z github.com/containrrr/watchtower/pkg/metrics.NewMetric({0x0, 0x0})
2024-11-19T08:57:52.982470836Z 	/home/runner/work/watchtower/watchtower/pkg/metrics/metrics.go:31 +0x22
2024-11-19T08:57:52.982493857Z github.com/containrrr/watchtower/cmd.runUpdatesWithNotifications(0xc00039f490)
2024-11-19T08:57:52.982512283Z 	/home/runner/work/watchtower/watchtower/cmd/root.go:377 +0x171
2024-11-19T08:57:52.982530070Z github.com/containrrr/watchtower/cmd.Run(0xc00039a300?, {0xc0003b2080?, 0x4?, 0x4?})
2024-11-19T08:57:52.982551153Z 	/home/runner/work/watchtower/watchtower/cmd/root.go:168 +0x658
2024-11-19T08:57:52.982599797Z github.com/spf13/cobra.(*Command).execute(0xc00039a300, {0xc000180060, 0x4, 0x4})
2024-11-19T08:57:52.982706211Z 	/home/runner/go/pkg/mod/github.com/spf13/[email protected]/command.go:987 +0xaa7
2024-11-19T08:57:52.982743507Z github.com/spf13/cobra.(*Command).ExecuteC(0xc00039a300)
2024-11-19T08:57:52.982766099Z 	/home/runner/go/pkg/mod/github.com/spf13/[email protected]/command.go:1115 +0x417
2024-11-19T08:57:52.982784112Z github.com/spf13/cobra.(*Command).Execute(...)
2024-11-19T08:57:52.982802072Z 	/home/runner/go/pkg/mod/github.com/spf13/[email protected]/command.go:1039
2024-11-19T08:57:52.982824760Z github.com/containrrr/watchtower/cmd.Execute()
2024-11-19T08:57:52.982843011Z 	/home/runner/work/watchtower/watchtower/cmd/root.go:75 +0x52
2024-11-19T08:57:52.982864799Z main.main()
2024-11-19T08:57:52.982882592Z 	/home/runner/work/watchtower/watchtower/main.go:13 +0x17

You can see the line "Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?" even if in compose.yaml I have

services:
  nextcloud-aio-mastercontainer:
    volumes:
      [...]
      - /var/run/user/1100/docker.sock:/var/run/docker.sock:ro

Is there any way to manually update the container so I can start the nextcloud server?

[daks]

I finally found the information on... the doc! (shame on me!) https://github.com/nextcloud/all-in-one/blob/f7de6f6704bde77cd0f0753a42fa3d078d566ecc/docker-rootless.md. The compose.yaml needs a specific a specific environment value for the watchtower container which handles the update, see WATCHTOWER_DOCKER_SOCKET_PATH