module openconfig-messages {
  yang-version 1;
  namespace "http://openconfig.net/yang/messages";
  prefix oc-messages;

  import openconfig-extensions {
    prefix oc-ext;
  }
  import openconfig-system-logging {
    prefix oc-log;
  }

  organization
    "OpenConfig working group";
  contact
    "OpenConfig working group
     www.openconfig.net";
  description
    "This module defines configuration and operational state data
     related to Syslog messages that a device may generate.

     These messages are historically obtained through the Syslog
     transport, however this module allows for obtaining them through
     an alternative transport, such as a Subscribe operation over an
     RPC.

     This module does not usurp traditional syslog servers, which may
     still be configured through the
     /yang/system/openconfig-system.yang model, rather it provies the
     Operator with an alternative method of consuming messages.";

  revision 2018-08-13 {
    description
      "Initial draft.";
    reference
      "0.0.1";
  }

  oc-ext:openconfig-version "0.0.1";

  identity DEBUG_SERVICE {
    description
      "Base identity for debug services. Identities within this base
       identity are to be augmented in by vendors.";
  }

  grouping messages-config {
    description
      "Configuration data for defining Syslog message severity.";
    leaf severity {
      type oc-log:syslog-severity;
      description
        "Specifies that only messages of the given severity (or
         greater severity) are sent over the RPC.

         This is analogous to differentiating which severity is to be
         sent to legacy Syslog servers, as opposed to local buffer or
         files.";
    }
  }

  grouping messages-state {
    description
      "Operational state data for Syslog messages.";
    container message {
      oc-ext:telemetry-atomic;
      config false;
      description
        "Syslog messages the client is Subscribing to. This is all
         messages currently configured to be sent according to
         syslog-severity.";
      reference
        "IETF RFC 5424 - The Syslog Protocol";
      leaf msg {
        type string;
        description
          "Message payload. If other leafs within this container not
           supported, this leaf MAY include the entire message,
           inclding pri, procid, app-name etc..";
      }
      leaf priority {
        type uint8;
        description
          "The Priority value (PRIVAL) represents both the
           Facility and Severity.";
        reference
          "IETF RFC 5424, Section 6.2.1";
      }
      leaf app-name {
        type string;
        description
          "The APP-NAME field SHOULD identify the device or
           application that originated the message.";
        reference
          "IETF RFC 5424, Section 6.2.5.";
      }
      leaf procid {
        type string;
        description
          "PROCID is a value that is included in the message, having
           no interoperable meaning, except that a change in the value
           indicates there has been a discontinuity in syslog
           reporting.";
        reference
          "IETF RFC 5424, Section 6.2.6.";
      }
      leaf msgid {
        type string;
        description
          "The MSGID SHOULD identify the type of message. For
           example, a firewall might use the MSGID 'TCPIN' for
           incoming TCP traffic and the MSGID 'TCPOUT' for outgoing
           TCP traffic.";
        reference
          "IETF RFC 5424, Section 6.2.7.";
      }
    }
  }

  grouping debug-messages-config {
    description
      "Configuration data for enabling debug messages.";
    leaf service {
      type identityref {
        base DEBUG_SERVICE;
      }
      description
        "Enumeration of all services which can have debugging enabled.
         Vendors are to augment this base identity with their platform
         or OS specific debug options.";
    }
    leaf enabled {
      type boolean;
      default "false";
      description
        "Enable and disable debugging.";
    }
  }

  grouping debug-messages-top {
    description
      "Configuration data for enabling Syslog debug messages.";
    container debug-entries {
      description
        "Enclosing container for list of debugs to enable.";
      list debug-service {
        key "service";
        description
          "List of debugging entries.";
        leaf service {
          type leafref {
            path "../config/service";
          }
          description
            "Reference to the debug-enable service key.";
        }
        container config {
          description
            "Configuration data for debug service entries.";
          uses debug-messages-config;
        }
        container state {
          config false;
          description
            "Operational state data for enabled debugs.";
          uses debug-messages-config;
        }
      }
    }
  }

  grouping messages-top {
    description
      "Top-level grouping for Syslog messages.";
    container messages {
      description
        "Top-level container for Syslog messages.";
      container config {
        description
          "Configuration data for Syslog messages.";
        uses messages-config;
      }
      container state {
        config false;
        description
          "Operational state data for a Syslog messages.";
        uses messages-config;
        uses messages-state;
      }
      uses debug-messages-top;
    }
  }

  uses messages-top;
}