Forbid delete of default NAT instance

NAT instances are mapped to VPP's VRFs.
Default NAT instance (id=0) is mapped to default VRF,
which is allways present in VPP.

This patch forbids deleteion of default instance
to be consistent with VPP behaviour
and NAT instance reader implementation.

Change-Id: I71aa6986395e4ba67baaa75d90905b450434aca4
Signed-off-by: Marek Gradzki <mgradzki@cisco.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/nat/nat2vpp/src/main/java/io/fd/hc2vpp/nat/write/NatInstaceCustomizer.java b/nat/nat2vpp/src/main/java/io/fd/hc2vpp/nat/write/NatInstaceCustomizer.java
index fa5cfa8e2..8e5673003 100644
--- a/nat/nat2vpp/src/main/java/io/fd/hc2vpp/nat/write/NatInstaceCustomizer.java
+++ b/nat/nat2vpp/src/main/java/io/fd/hc2vpp/nat/write/NatInstaceCustomizer.java
@@ -42,5 +42,12 @@ final class NatInstaceCustomizer implements ListWriterCustomizer<NatInstance, Na
                                         @Nonnull final NatInstance dataBefore, @Nonnull final WriteContext writeContext)
             throws WriteFailedException {
         LOG.trace("Deleting nat-instance: {}", id);
+
+        // For consistency with reader, forbid removing default NAT instance:
+        final Long vrfId = id.firstKeyOf(NatInstance.class).getId();
+        if (vrfId == 0) {
+            throw new WriteFailedException.DeleteFailedException(id,
+                new UnsupportedOperationException("Removing default NAT instance (vrf=0) is not supported."));
+        }
     }
 }