mbentley/timemachine

docker image to run Samba or AFP (netatalk) to provide a compatible Time Machine for MacOS

Image Tags

Multi-arch Tags

The following tags have multi-arch support for amd64, armv7l, and arm64 and will automatically pull the correct tag based on your system's architecture:

latest, smb

Note: The afp tag has been deprecated in terms of new feature updates and is only available for amd64.

Date Specific Tags

The smb tags also have unique manifests that are generated daily. These are in the format smb-YYYYMMDD (e.g. - smb-20210730) and can be viewed on Docker Hub. Each one of these tags will be generated daily and is essentially a point in time snapshot of the smb tag's manifest that you can pin to if you wish. Please note that these tags will remain available on Docker Hub for 6 months and will not receive security fixes. You will need to update to newer tags as they are published in order to get updated images. If you do not care about specific image digests to pin to, I would suggest just using the smb tag.

Explicit Architecture Tags

These tags will explicitly pull the image for the listed architecture and are bit for bit identical to the multi-arch tags images.

amd64

• latest-smb-amd64, smb-amd64 - SMB image based off of alpine:latest
• afp, afp-amd64 - AFP image based off of debian:jessie
  • Deprecated but still available; not being regularly built - This image may have unpatched security vulnerabilities

armv7l

• latest-smb-armv7l, smb-armv7l - SMB image based off of alpine:latest for the armv7l architecture

arm64

• latest-smb-arm64, smb-arm64 - SMB image based off of alpine:latest for the arm64 architecture

Warning: I would strongly suggest migrating to the SMB image as AFP is being deprecated by Apple and I've found it to be much more stable. I do not plan on adding any new features to the AFP based config and I switched the default image in the latest tag to the SMB variant on October 15, 2020.

To pull this image: docker pull mbentley/timemachine:smb

Example usage for SMB

Note: If you update the TM_USERNAME value, that will change the path for the persistent volume. See persistent data path for more details.

Example usage with --net=host to allow Avahi discovery; with commonly used environment variables set to their default values:

docker run -d --restart=always \
  --name timemachine \
  --net=host \
  -e TM_USERNAME="timemachine" \
  -e TM_GROUPNAME="timemachine" \
  -e PASSWORD="timemachine" \
  -e TM_UID="1000" \
  -e TM_GID="1000" \
  -e SET_PERMISSIONS="false" \
  -e VOLUME_SIZE_LIMIT="0" \
  -v /path/on/host/to/backup/to/for/timemachine:/opt/timemachine \
  --tmpfs /run/samba \
  mbentley/timemachine:smb

Example usage with exposing ports without Avahi discovery; with commonly used environment variables set to their default values:

docker run -d --restart=always \
  --name timemachine \
  --hostname timemachine \
  -p 137:137/udp \
  -p 138:138/udp \
  -p 139:139 \
  -p 445:445 \
  -e TM_USERNAME="timemachine" \
  -e TM_GROUPNAME="timemachine" \
  -e PASSWORD="timemachine" \
  -e TM_UID="1000" \
  -e TM_GID="1000" \
  -e SET_PERMISSIONS="false" \
  -e VOLUME_SIZE_LIMIT="0" \
  -v /path/on/host/to/backup/to/for/timemachine:/opt/timemachine \
  --tmpfs /run/samba \
  mbentley/timemachine:smb

Kubernetes support

The images are also compatible with Kubernetes. Checkout timemachine-k3s.yaml as an example for running a TimeMachine backup server on a single-node k3s cluster running (on a Raspberry Pi 4).

Tips for Automatic Discovery w/Avahi

This works best with --net=host so that discovery can be broadcast. Otherwise, you will need to expose the above ports and then you must manually map the share in Finder for it to show up (open Finder, click Shared, and connect as smb://hostname-or-ip/TimeMachine with your TimeMachine credentials). Using --net=host only works if you do not already run Samba or Avahi on the host! Alternatively, you can use the SMB_PORT option to change the port that Samba uses. See below for another workaround if you do not wish to change the Samba port.

Known Issues

Processes fail to start; container has high CPU usage

If the container isn't starting and you're seeing logs like Failed to start message bus: Failed to bind socket, and possibly have other symptoms like seeing high CPU usage from the container, it could be that your are hitting the nofile ulimit. Make sure your compose file or docker run command have the nofile ulimits adjusted to increase the defaults. Check the examples in the README or the example compose files in this repository.

Unable to start the armv7l image

If you are running the armv7l image, you may see and error when trying to start the container:

s6-svscan: warning: unable to iopause: Operation not permitted

This is due to an issue with the libseccomp2 package. You have two options:

1. Disable seccomp for the container by adding the --security-opt seccomp=unconfined argument (this has security implications)

2. Install a backported version of libseccomp2:

   wget http://ftp.us.debian.org/debian/pool/main/libs/libseccomp/libseccomp2_2.5.1-1~bpo10+1_armhf.deb
   sudo dpkg -i libseccomp2_2.5.1-1~bpo10+1_armhf.deb
   

This issue has been observed on Raspberry Pi OS (formerly known as Raspbian) based on Debian 10 (Buster) but may also be found on other distros as they may commonly use the libseccomp2 package version 2.3.3-4.

Conflicts with Samba and/or Avahi on the Host

Note: If you are already running Samba/Avahi on your Docker host (or you're wanting to run this on your NAS), you should be aware that using --net=host will cause a conflict with the Samba/Avahi install. Raspberry Pi users: be aware that there is already an mDNS responder running on the stock Raspberry Pi OS image that will conflict with the mDNS responder in the container.

If your host is running Avahi, you can configure it to act as a reflector, and the container advertisements will be broadcast to your host network without using --net=host. To do this, edit the avahi config (/etc/avahi/avahi-daemon.conf) on the host:

• set enable-reflector=yes
• set cache-entries-max=0 - this prevents issues with Apple devices reporting duplicate names and adding/incrementing numbers in their name (references: https://blogs.thismonkey.com/?p=33 and https://community.ui.com/questions/mdns-reflector-help-computer-name-keeps-changing/180dd51f-a5b2-465c-88c2-6e85ab03c38a#answer/4732ed77-37aa-4f30-b992-cf99752e4f6a)

Then set the ADVERTISED_HOSTNAME environment variable in your container config to the mDNS hostname of your host, without the .local suffix.

As an alternative, you can use the macvlan driver in Docker which will allow you to map a static IP address to your container. If you have issues setting up Time Machine with the configuration, feel free to open an issue and I can assist - this is how I persoanlly run time machine.

1. Create a macvlan Docker network (assuming your local subnet is 192.168.1.0/24, the default gateway is 192.168.1.1, and eth0 for the host's network interface):

docker network create -d macvlan --subnet=192.168.1.0/24 --gateway=192.168.1.1 -o parent=eth0 macvlan1

On devices such as Synology DSM, the primary network interface may be ovs_eth0 due to the usage of Open vSwitch. If you are unsure of your primary network interface, this command may help:

$ route | grep ^default | awk '{print $NF}'
eth0

The macvlan driver can use another network interface as the documentation states above but in cases where multiple network interfaces may exist and they might not all be connected, choosing the primary network interface is generally safe.

1. Add --network macvlan1 and --ip 192.168.1.x to your docker run command where 192.168.1.x is a static IP to assign to Time Machine

Example macvlan setup using docker-compose

services:
  timemachine:
    hostname: timemachine
    mac_address: "AA:BB:CC:DD:EE:FF"
    networks:
      timemachine:
        ipv4_address: 192.168.1.x

networks:
  timemachine:
    driver: macvlan
    driver_opts:
      parent: eth0
    ipam:
      config:
        - subnet: 192.168.1.0/24
          ip_range: 192.168.1.0/24
          gateway: 192.168.1.1

1. hostname, mac_address, and ipv4_address are optional, but can be used to control how it is configured on the network. If not defined, random values will be used.
2. This config requires docker-compose version 1.27.0+ which implements the compose specification.

Volume & File system Permissions

If you're using an external volume like in the example above, you will need to set the filesystem permissions on disk. By default, the timemachine user is 1000:1000.

The backing data store for your persistent time machine data must support extended file attributes (xattr). Remote file systems, such as NFS, will very likely not support xattrs. See #61 for more details. This image will check and try to set xattrs to a test file in /opt/${TM_USERNAME} to warn the user if they are not supported but this will not prevent the image from running.

Persistent Data Path

If you change the TM_USERNAME value, it will change the persistent data path from /opt/timemachine to /opt/<value-of-TM_USERNAME>. Failure to map this appropriately will lead to data being stored inside the container and not in the volume you have specified!

Default credentials

• Username: timemachine
• Password: timemachine

Optional variables for SMB

Variable	Default	Description
ADVERTISED_HOSTNAME	not set	Avahi will advertise the smb services at this hostname instead of the local hostname (useful in Docker without --net=host). Do not set this if you don't know what you're doing!
CUSTOM_SMB_AUTH	no	set to yes, indicates that you want Samba to attempt to authenticate users using the NTLM Encrypted Password Response
CUSTOM_SMB_CONF	false	indicates that you are going to bind mount a custom config to /etc/samba/smb.conf if set to true
CUSTOM_SMB_PROTO	SMB2	indicates that you want to allow another value from Samba Protocol List
CUSTOM_USER	false	indicates that you are going to bind mount /etc/password, /etc/group, and /etc/shadow; and create data directories if set to true
DEBUG_LEVEL	1	sets the debug level for nmbd and smbd
EXTERNAL_CONF	not set	specifies a directory in which individual variable files, ending in .conf, for multiple users; see Adding Multiple Users & Shares for more info
HIDE_SHARES	no	set to yes if you would like only the share(s) a user can access to appear
MIMIC_MODEL	TimeCapsule8,119	sets the value of time machine to mimic
TM_USERNAME	timemachine	sets the username time machine runs as
TM_GROUPNAME	timemachine	sets the group name time machine runs as
TM_UID	1000	sets the UID of the TM_USERNAME user
TM_GID	1000	sets the GID of the TM_GROUPNAME group
PASSWORD	timemachine	sets the password for the timemachine user
SET_PERMISSIONS	false	set to true to have the entrypoint set ownership and permission on the /opt/<username> in the container
SHARE_NAME	TimeMachine	sets the name of the timemachine share to TimeMachine by default
SMB_INHERIT_PERMISSIONS	no	if yes, permissions for new files will be forced to match the parent folder
SMB_NFS_ACES	no	value of fruit:nfs_aces; support for querying and modifying the UNIX mode of directory entries via NFS ACEs
SMB_METADATA	stream	value of fruit:metadata; controls where the OS X metadata stream is stored
SMB_PORT	445	sets the port that Samba will be available on
SMB_VFS_OBJECTS	fruit streams_xattr	value of vfs objects
VOLUME_SIZE_LIMIT	0	sets the maximum size of the time machine backup; a unit can also be passed (e.g. - 1 T). See the Samba docs under the fruit:time machine max size section for more details
WORKGROUP	WORKGROUP	set the Samba workgroup name
IGNORE_DOS_ATTRIBUTES	false	If set to true Samba will ignore DOS attributes. This is accomplished by setting store dos attributes, map hidden, map system, map archive and map readonly to no in the [global] section.

Adding Multiple Users & Shares

In order to add multiple users who have their own shares, you will need to create a file for each user and put them in a directory. The file name must end in .conf or it will not be parsed and the contents must be environment variable formatted proper and include all of the values below in the example. Only VOLUME_SIZE_LIMIT can be empty if you do not want to set a quota.

Example EXTERNAL_CONF File

This is an example to create a user named foo. The EXTERNAL_CONF variable should point to the directory that contains the user definition files. Create multiple files with different attributes to create multiple users and shares.

foo.conf

TM_USERNAME=foo
TM_GROUPNAME=foogroup
PASSWORD=foopass
SHARE_NAME=foo
VOLUME_SIZE_LIMIT="1 T"
TM_UID=1000
TM_GID=1000

Example run command for EXTERNAL_CONF

This run command has the necessary path to where the external user files will be mounted (set in EXTERNAL_CONF) and the volume mount that matches the path specified in EXTERNAL_CONF.

Note: You will need to either bind mount /opt or each SHARE_NAME directory under /opt for each user.

docker run -d --restart=always \
  --name timemachine \
  --net=host \
  --ulimit nofile=65536:65536 \
  -e ADVERTISED_HOSTNAME="" \
  -e CUSTOM_SMB_CONF="false" \
  -e CUSTOM_USER="false" \
  -e DEBUG_LEVEL="1" \
  -e MIMIC_MODEL="TimeCapsule8,119" \
  -e EXTERNAL_CONF="/users" \
  -e HIDE_SHARES="no" \
  -e TM_USERNAME="timemachine" \
  -e TM_GROUPNAME="timemachine" \
  -e TM_UID="1000" \
  -e TM_GID="1000" \
  -e PASSWORD="timemachine" \
  -e SET_PERMISSIONS="false" \
  -e SHARE_NAME="TimeMachine" \
  -e SMB_INHERIT_PERMISSIONS="no" \
  -e SMB_NFS_ACES="no" \
  -e SMB_METADATA="stream" \
  -e SMB_PORT="445" \
  -e SMB_VFS_OBJECTS="fruit streams_xattr" \
  -e VOLUME_SIZE_LIMIT="0" \
  -e WORKGROUP="WORKGROUP" \
  -v /path/on/host/to/backup/to/for/timemachine:/opt \
  -v /path/on/host/to/user/file/directory:/users \
  --tmpfs /run/samba \
  mbentley/timemachine:smb

Using a password file

This is an example to using Docker secrets to pass the password via a file

password.txt

my_secret_password

Example docker-compose file

The follow example shows the key values required for in your compose file.

version: "3.3" # or greater
services:
  timemachine:
    # ...
    environment:
      - PASSWORD_FILE=/run/secrets/password
      # ...
    secrets:
      - password

secrets:
  password:
    file: ./password.txt

AFP Examples and Variables

Click to expand

Example docker-compose usage for AFP

docker compose -f timemachine-compose.yml up -d

Example docker run usage for AFP

Example usage with --net=host to allow Avahi discovery to function:

docker run -d --restart=always \
  --net=host \
  --name timemachine \
  -e CUSTOM_AFP_CONF="false" \
  -e CUSTOM_USER="false" \
  -e LOG_LEVEL="info" \
  -e MIMIC_MODEL="TimeCapsule6,106" \
  -e TM_USERNAME="timemachine" \
  -e TM_GROUPNAME="timemachine" \
  -e TM_UID="1000" \
  -e TM_GID="1000" \
  -e PASSWORD="timemachine" \
  -e SET_PERMISSIONS="false" \
  -e SHARE_NAME="TimeMachine" \
  -e VOLUME_SIZE_LIMIT="0" \
  -v /path/on/host/to/backup/to/for/timemachine:/opt/timemachine \
  -v timemachine-netatalk:/var/netatalk \
  -v timemachine-logs:/var/log/supervisor \
  mbentley/timemachine:afp

Example usage with exposing ports without Avahi discovery:

docker run -d --restart=always \
  --name timemachine \
  --hostname timemachine \
  -p 548:548 \
  -p 636:636 \
  -e CUSTOM_AFP_CONF="false" \
  -e CUSTOM_USER="false" \
  -e LOG_LEVEL="info" \
  -e MIMIC_MODEL="TimeCapsule6,106" \
  -e TM_USERNAME="timemachine" \
  -e TM_GROUPNAME="timemachine" \
  -e TM_UID="1000" \
  -e TM_GID="1000" \
  -e PASSWORD="timemachine" \
  -e SET_PERMISSIONS="false" \
  -e SHARE_NAME="TimeMachine" \
  -e VOLUME_SIZE_LIMIT="0" \
  -v /path/on/host/to/backup/to/for/timemachine:/opt/timemachine \
  -v timemachine-netatalk:/var/netatalk \
  -v timemachine-logs:/var/log/supervisor \
  mbentley/timemachine:afp

This works best with --net=host so that discovery can be broadcast. Otherwise, you will need to expose the above ports and then you must manually map the share in Finder for it to show up (open Finder, click Shared, and connect as afp://hostname-or-ip/TimeMachine with your TimeMachine credentials).

Optional variables for AFP:

Variable	Default	Description
CUSTOM_AFP_CONF	false	indicates that you are going to bind mount a custom config to /etc/netatalk/afp.conf if set to true
CUSTOM_USER	false	indicates that you are going to bind mount /etc/password, /etc/group, and /etc/shadow; and create data directories if set to true
LOG_LEVEL	info	sets the netatalk log level
MIMIC_MODEL	TimeCapsule6,106	sets the value of time machine to mimic
TM_USERNAME	timemachine	sets the username time machine runs as
TM_GROUPNAME	timemachine	sets the group name time machine runs as
TM_UID	1000	sets the UID of the TM_USERNAME user
TM_GID	1000	sets the GID of the TM_GROUPNAME group
PASSWORD	timemachine	sets the password for the timemachine user
SET_PERMISSIONS	false	set to true to have the entrypoint set ownership and permission on /opt/timemachine
SHARE_NAME	TimeMachine	sets the name of the timemachine share to TimeMachine by default
VOLUME_SIZE_LIMIT	0	sets the maximum size of the time machine backup in MiB (mebibyte)

Thanks for odarriba and arve0 for their examples to start from.