Simplify CLI by requiring explicit job names.

Job names are derived from job type + user-defined name in config file
CLI now has subcommands corresponding 1:1 to the config file sections:

        push,pull,autosnap,prune

A subcommand always expects a job name, thus executes exactly one job.

Dict-style syntax also used for PullACL and Sink sections.

jobrun package is currently only used for autosnap, all others need to
be invoked repeatedly via external tool.
Plan is to re-integrate jobrun in an explicit daemon-mode (subcommand).

cmd/sampleconf/zrepl.yml

@@ -1,5 +1,5 @@
 pools:
-  - name: offsite_backups
+  offsite_backups:
     transport:
       ssh:
         host: 192.168.122.6
@@ -8,21 +8,26 @@ pools:
         identity_file: /etc/zrepl/identities/offsite_backups
 
 pushs:
-  - to: offsite_backups
+
+  offsite:
+    to: offsite_backups
     filter: {
       "tank/var/db*":"ok",
       "tank/usr/home*":"ok"
     }
 
 pulls:
-  - from: offsite_backups
+
+  offsite:
+    from: offsite_backups
     mapping: {
       # like in sinks
     }
 
   # local replication, only allowed in pull mode
   # the from name 'local' is reserved for this purpose
-  - from: local
+  homemirror:
+    from: local
     repeat:
       interval: 15m
     mapping: {
@@ -35,21 +40,21 @@ sinks:
   #       1:1 mapping of remote dataset to local dataset
   #       We will reject a push request which contains > 0 datasets that do not
   #         match a mapping
-  - from: db1
+  db1:
     mapping: {
       "ssdpool/var/db/postgresql9.6":"zroot/backups/db1/pg_data"
     }
 
   # "|" non-recursive wildcard
   #       the remote must present excatly one dataset, mapped to the rhs
-  - from: cdn_master
+  cdn_master:
     mapping: {
       "|":"tank/srv/cdn" # NOTE: | is currently an invalid character for a ZFS dataset
     }
 
   # "*" recursive wildcard
   #       the remote may present an arbitrary set of marks a recursive wildcard, i.e. map all remotes to a tree under rhs
-  - from: mirror1
+  mirror1:
     mapping: {
       "tank/foo/bar*":"zroot/backups/mirror1" # NOTE: * is currently an invalid character for a ZFS dataset
     }
@@ -60,7 +65,7 @@ sinks:
   #       local dataset (same order) or '!<space>optional reason' on stdout
   #       If the acceptor scripts exits with non-zero status code, the remote's
   #       request will be rejected
-  - from: complex_host
+  complex_host:
     mapping: { #
       "*":"!/path/to/acceptor" # we could just wire the path to the acceptor directly to the mapping
                                # but let's stick with the same type for the mapping field for now'
@@ -70,7 +75,7 @@ sinks:
   # Mixing the rules
   #   Mixing should be possible if there is a defined precedence (direct before *)
   #   and non-recursive wildcards are not allowed in multi-entry mapping objects
-  - from: special_snowflake
+  special_snowflake:
     mapping: { # an explicit mapping mixed with a recursive wildcard
       "sun/usr/home": backups/special_snowflake/homedirs,
       "sun/var/db":   backups/special_snowflake/database,
@@ -79,8 +84,9 @@ sinks:
     }
 
 pull_acls:
+
   # same synatx as in sinks, but the returned mapping does not matter
-  - from: office_backup
+  office_backup:
     mapping: {
       "tank/usr/home":"notnull"
     }
@@ -88,7 +94,7 @@ pull_acls:
 
 prune:
 
-  - name: clean_backups
+  clean_backups:
     policy: grid
     grid: 6x10min | 24x1h | 7x1d | 32 x 1d | 4 x 3mon
     dataset_filter: {
@@ -98,7 +104,7 @@ prune:
       prefix: zrepl_
     }
 
-  - name: hfbak_prune # cleans up after hfbak autosnap job
+  hfbak_prune: # cleans up after hfbak autosnap job
     policy: grid
     grid: 1x1min(keep=all)
     dataset_filter: {
@@ -110,7 +116,7 @@ prune:
 
 autosnap:
 
-  - name: hfbak
+  hfbak:
     prefix: zrepl_hfbak_
     interval: 1s
     dataset_filter: {