This is the script I use for synchronizing data between my machines (and also
to directories on the same machine, externally connected drives, and to and
between ZFS filesystems).

Here is an example set of files for synchronizing my home directory and
`/usr/local` via rsync between two machines: `foo` and `bar`.  First,
`~/.pushme/stores.yml`:

    - Targets:
      - - bar
        - - home
          - local
      HostRe: [Ff]oo
      Name: Foo
      UserName: johnw
      SelfRe: [Ff]oo
      ZfsPool: null
      ZfsPath: null
      IsPrimary: true
      AnnexName: foo
      AnnexFlags: []
    - Targets:
      - - foo
        - - home
          - local
      HostRe: [Bb]ar
      Name: Bar
      UserName: johnw
      SelfRe: [Bb]ar
      ZfsPool: null
      ZfsPath: null
      IsPrimary: false
      AnnexName: bar
      AnnexFlags:
      - - 'foo'
        - - - 'home'
            - - '-\('
              - '--not'
              - '--in'
              - 'foo'
              - '--and'
              - '--not'
              - '--in'
              - 'web'
              - '-\)'

Then, `~/.pushme/filesets.yml`:

    - Priority: 60
      Name: home
      Class: quick,main
      ReportMissing: true
    - Priority: 80
      Name: local
      Class: system,main
      ReportMissing: false

And finally, `~/.pushme/containers.yml`:

    - Store: foo,bar
      Recurse: false
      Fileset: home
      PoolPath: null
      IsAnnex: false
      LastRev: null
      LastSync: null
      Path: ~/
    - Store: foo,bar
      Recurse: false
      Fileset: local
      PoolPath: null
      IsAnnex: false
      LastRev: null
      LastSync: null
      Path: /usr/local/

Now I can run the following command:

    foo $ pushme bar
    15:18:44 - [NOTICE] Synchronizing Foo -> Bar
    15:18:44 - [NOTICE] Sending Foo/home → Bar
    15:18:52 - [NOTICE] Sent 151.0M in 131 files (out of 1.37G in 12,418)
    15:20:26 - [NOTICE] Sending Foo/local → Bar
    15:21:02 - [NOTICE] Sent 0b in 0 files (out of 6.45G in 207,453)

If you are wondering about the complexity of keeping filesets separate from
containers, it's because I use pushme for several different scenarios:
rsync'ing between machines, rsync'ing into ZFS filesystems, and sending ZFS
filesystems as snapshot stream between servers.  Pushme is able to handle all
of these scenarios, but doing so required a bit more abstraction than a simple
rsync-only tool would have needed.

Some common options include:

    $ pushme -c quick bar       # only sync filesets with the "quick" class
    $ pushme -f home bar        # only sync the "home" fileset
    $ pushme -n bar             # don't do anything, just scan
    $ pushme -N bar             # don't even scan
    $ pushme -v bar             # show commands being executed
    $ pushme -D bar             # show more info than you want to see