db-ctl-base: Allow record UUIDs to be abbreviated.

This makes it easier to type ovs-vsctl, ovn-sbctl, ovn-nbctl, and vtep-ctl
commands without cut-and-paste.

Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Andy Zhou <azhou@ovn.org>

NEWS

@@ -12,6 +12,8 @@ Post-v2.7.0
        still can be configured via extra arguments for DPDK EAL.
    - New support for multiple VLANs (802.1ad or "QinQ"), including a new
      "dot1q-tunnel" port VLAN mode.
+   - In ovn-vsctl and vtep-ctl, record UUIDs in commands may now be
+     abbreviated to 4 hex digits.
    - OVN:
      * IPAM for IPv4 can now exclude user-defined addresses from assignment.
      * IPAM can now assign IPv6 addresses.
@@ -20,6 +22,8 @@ Post-v2.7.0
      * Allow ovn-controller SSL configuration to be obtained from vswitchd
        database.
      * ovn-trace now has basic support for tracing distributed firewalls.
+     * In ovn-nbctl and ovn-sbctl, record UUIDs in commands may now be
+       abbreviated to 4 hex digits.
    - Add the command 'ovs-appctl stp/show' (see ovs-vswitchd(8)).
    - OpenFlow:
      * Increased support for OpenFlow 1.6 (draft).

lib/db-ctl-base.c

@@ -300,6 +300,14 @@ get_row_by_id(struct ctl_context *ctx,
     return final;
 }
 
+static bool
+is_partial_uuid_match(const struct uuid *uuid, const char *match)
+{
+    char uuid_s[UUID_LEN + 1];
+    snprintf(uuid_s, sizeof uuid_s, UUID_FMT, UUID_ARGS(uuid));
+    return !strncmp(uuid_s, match, strlen(match));
+}
+
 static const struct ovsdb_idl_row *
 get_row(struct ctl_context *ctx,
         const struct ovsdb_idl_table_class *table, const char *record_id,
@@ -330,6 +338,26 @@ get_row(struct ctl_context *ctx,
             }
         }
     }
+    if (!row
+        && record_id[uuid_is_partial_string(record_id)] == '\0'
+        && strlen(record_id) >= 4) {
+        for (const struct ovsdb_idl_row *r = ovsdb_idl_first_row(ctx->idl,
+                                                                 table);
+             r != NULL;
+             r = ovsdb_idl_next_row(r)) {
+            if (is_partial_uuid_match(&r->uuid, record_id)) {
+                if (!row) {
+                    row = r;
+                } else {
+                    ctl_fatal("%s contains 2 or more rows whose UUIDs begin "
+                              "with %s: at least "UUID_FMT" and "UUID_FMT,
+                              table->name, record_id,
+                              UUID_ARGS(&row->uuid),
+                              UUID_ARGS(&r->uuid));
+                }
+            }
+        }
+    }
     if (must_exist && !row) {
         ctl_fatal("no row \"%s\" in table %s", record_id, table->name);
     }

ovn/utilities/ovn-nbctl.8.xml

@@ -674,7 +674,8 @@
     <p>Each of these commands has a <var>table</var> parameter to identify a table
     within the database.  Many of them also take a <var>record</var> parameter
     that identifies a particular record within a table.  The <var>record</var>
-    parameter may be the UUID for a record, and many tables offer
+    parameter may be the UUID for a record, which may be abbreviated to its
+    first 4 (or more) hex digits, as long as that is unique.  Many tables offer
     additional ways to identify records.  Some commands also take
     <var>column</var> parameters that identify a particular field within the
     records in a table.</p>
@@ -737,6 +738,16 @@
 
     </dl>
 
+    <p>
+      Record names must be specified in full and with correct capitalization,
+      except that UUIDs may be abbreviated to their first 4 (or more) hex
+      digits, as long as that is unique within the table.  Names of tables and
+      columns are not case-sensitive, and <code>-</code> and <code>_</code> are
+      treated interchangeably.  Unique abbreviations of table and column names
+      are acceptable, e.g. <code>d</code> or <code>dhcp</code> is sufficient
+      to identify the <code>DHCP_Options</code> table.
+    </p>
+
     <xi:include href="lib/db-ctl-base.xml" xmlns:xi="http://www.w3.org/2003/XInclude"/>
 
     <h1>Synchronization Commands</h1>

ovn/utilities/ovn-sbctl.8.in

@@ -257,6 +257,32 @@ This option is only useful if the SSL peer sends its CA certificate
 as part of the SSL certificate chain.  The SSL protocol does not
 require the controller to send the CA certificate.
 .
+.SS "Database Commands"
+.
+These commands query and modify the contents of \fBovsdb\fR tables.
+They are a slight abstraction of the \fBovsdb\fR interface and as such
+they operate at a lower level than other \fBovs\-sbctl\fR commands.
+.PP
+.ST "Identifying Tables, Records, and Columns"
+.PP
+Each of these commands has a \fItable\fR parameter to identify a table
+within the database.  Many of them also take a \fIrecord\fR parameter
+that identifies a particular record within a table.  The \fIrecord\fR
+parameter may be the UUID for a record, and many tables offer
+additional ways to identify records.  Some commands also take
+\fIcolumn\fR parameters that identify a particular field within the
+records in a table.
+.\" It would be kind to list all the tables and their supported identifiers
+.\" here.
+.PP
+Record names must be specified in full and with correct
+capitalization, except that UUIDs may be abbreviated to their first 4
+(or more) hex digits, as long as that is unique within the table.
+Names of tables and columns are not case-sensitive, and \fB\-\fR and
+\fB_\fR are treated interchangeably.  Unique abbreviations of table
+and column names are acceptable, e.g. \fBaddr\fR or \fBa\fR is
+sufficient to identify the \fBAddress_Set\fR table.
+.
 .so lib/db-ctl-base.man
 .SH "EXIT STATUS"
 .IP "0"

ovn/utilities/ovn-sbctl.c

@@ -727,6 +727,9 @@ is_partial_uuid_match(const struct uuid *uuid, const char *match)
     char uuid_s[UUID_LEN + 1];
     snprintf(uuid_s, sizeof uuid_s, UUID_FMT, UUID_ARGS(uuid));
 
+    /* We strip leading zeros because we want to accept cookie values derived
+     * from UUIDs, and cookie values are printed without leading zeros because
+     * they're just numbers. */
     const char *s1 = strip_leading_zero(uuid_s);
     const char *s2 = strip_leading_zero(match);
 

utilities/ovs-vsctl.8.in

@@ -560,10 +560,12 @@ packets on a per-flow basis using OpenFlow \fBsample\fR actions.
 Configuration for Auto Attach within a bridge.
 .PP
 Record names must be specified in full and with correct
-capitalization.  Names of tables and columns are not case-sensitive,
+capitalization, except that UUIDs may be abbreviated to their first 4
-and \fB\-\-\fR and \fB_\fR are treated interchangeably.  Unique
+(or more) hex digits, as long as that is unique within the table.
-abbreviations are acceptable, e.g. \fBnet\fR or \fBn\fR is sufficient
+Names of tables and columns are not case-sensitive, and \fB\-\fR and
-to identify the \fBNetFlow\fR table.
+\fB_\fR are treated interchangeably.  Unique abbreviations of table
+and column names are acceptable, e.g. \fBnet\fR or \fBn\fR is
+sufficient to identify the \fBNetFlow\fR table.
 .
 .so lib/db-ctl-base.man
 .SH "EXAMPLES"

vtep/vtep-ctl.8.in

@@ -394,10 +394,12 @@ encapsulated and forwarded.  Records may be identified by physical
 locator name.
 .PP
 Record names must be specified in full and with correct
-capitalization.  Names of tables and columns are not case-sensitive,
+capitalization, except that UUIDs may be abbreviated to their first 4
-and \fB\-\-\fR and \fB_\fR are treated interchangeably.  Unique
+(or more) hex digits, as long as that is unique within the table.
-abbreviations are acceptable, e.g. \fBman\fR or \fBm\fR is sufficient
+Names of tables and columns are not case-sensitive, and \fB\-\fR and
-to identify the \fBManager\fR table.
+\fB_\fR are treated interchangeably.  Unique abbreviations of table
+and column names are acceptable, e.g. \fBman\fR or \fBm\fR is
+sufficient to identify the \fBManager\fR table.
 .
 .so lib/db-ctl-base.man
 .PP