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CoreDNS

Collect logs from CoreDNS instances with Elastic Agent.

What is an Elastic integration?
Version
0.6.1 (View all)
Compatible Kibana version(s)
8.0.0 or higher
Supported Serverless project types

What's this?
Security
Observability
Subscription level
What's this?
Basic
Level of support
What's this?
Elastic

This integration parses logs from CoreDNS instances.

Compatibility

This integration is designed to read CoreDNS logs running within a Kubernetes cluster or via systemd with logs output to journald. The CoreDNS datasets were tested with version 1.9.3 and 1.10.0.

Logs

The log data stream expects logs from the CoreDNS errors plugin and the log plugin. Query logs from the log plugin can be in either the common or combined format (see log format for details). An example configuration with logging enabled is:

. {
  forward . 8.8.8.8
  errors
  log
}

Exported fields

FieldDescriptionType
@timestamp
Event timestamp.
date
cloud.account.id
The cloud account or organization id used to identify different entities in a multi-tenant environment. Examples: AWS account id, Google Cloud ORG Id, or other unique identifier.
keyword
cloud.availability_zone
Availability zone in which this host is running.
keyword
cloud.image.id
Image ID for the cloud instance.
keyword
cloud.instance.id
Instance ID of the host machine.
keyword
cloud.instance.name
Instance name of the host machine.
keyword
cloud.machine.type
Machine type of the host machine.
keyword
cloud.project.id
Name of the project in Google Cloud.
keyword
cloud.provider
Name of the cloud provider. Example values are aws, azure, gcp, or digitalocean.
keyword
cloud.region
Region in which this host is running.
keyword
container.id
Unique container id.
keyword
container.image.name
Name of the image the container was built on.
keyword
container.labels
Image labels.
object
container.name
Container name.
keyword
coredns.log.buffer_size
The EDNS0 buffer size advertised in the query
long
coredns.log.dnssec_ok
The DO bit is included in a DNS query and is an abbreviation for "DNSSEC OK". If the DO bit is set (DO=1), then the client is DNSSEC-aware, and it is OK for the DNS server to return DNSSEC data in a response. If the DO bit is not set (DO=0), then the client is not DNSSEC-aware, and the DNS server must not include any DNSSEC data in a DNS response.
boolean
coredns.log.error.message
The error message
text
data_stream.dataset
Data stream dataset.
constant_keyword
data_stream.namespace
Data stream namespace.
constant_keyword
data_stream.type
Data stream type.
constant_keyword
destination.bytes
Bytes sent from the destination to the source.
long
dns.header_flags
Array of 2 letter DNS header flags.
keyword
dns.id
The DNS packet identifier assigned by the program that generated the query. The identifier is copied to the response.
keyword
dns.op_code
The DNS operation code that specifies the kind of query in the message. This value is set by the originator of a query and copied into the response.
keyword
dns.question.class
The class of records being queried.
keyword
dns.question.name
The name being queried. If the name field contains non-printable characters (below 32 or above 126), those characters should be represented as escaped base 10 integers (\DDD). Back slashes and quotes should be escaped. Tabs, carriage returns, and line feeds should be converted to \t, \r, and \n respectively.
keyword
dns.question.registered_domain
The highest registered domain, stripped of the subdomain. For example, the registered domain for "foo.example.com" is "example.com". This value can be determined precisely with a list like the public suffix list (http://publicsuffix.org). Trying to approximate this by simply taking the last two labels will not work well for TLDs such as "co.uk".
keyword
dns.question.subdomain
The subdomain is all of the labels under the registered_domain. If the domain has multiple levels of subdomain, such as "sub2.sub1.example.com", the subdomain field should contain "sub2.sub1", with no trailing period.
keyword
dns.question.top_level_domain
The effective top level domain (eTLD), also known as the domain suffix, is the last part of the domain name. For example, the top level domain for example.com is "com". This value can be determined precisely with a list like the public suffix list (http://publicsuffix.org). Trying to approximate this by simply taking the last label will not work well for effective TLDs such as "co.uk".
keyword
dns.question.type
The type of record being queried.
keyword
dns.resolved_ip
Array containing all IPs seen in answers.data. The answers array can be difficult to use, because of the variety of data formats it can contain. Extracting all IP addresses seen in there to dns.resolved_ip makes it possible to index them as IP addresses, and makes them easier to visualize and query for.
ip
dns.response_code
The DNS response code.
keyword
ecs.version
ECS version this event conforms to. ecs.version is a required field and must exist in all events. When querying across multiple indices -- which may conform to slightly different ECS versions -- this field lets integrations adjust to the schema version of the events.
keyword
error.message
Error message.
match_only_text
event.category
This is one of four ECS Categorization Fields, and indicates the second level in the ECS category hierarchy. event.category represents the "big buckets" of ECS categories. For example, filtering on event.category:process yields all events relating to process activity. This field is closely related to event.type, which is used as a subcategory. This field is an array. This will allow proper categorization of some events that fall in multiple categories.
keyword
event.dataset
Event dataset
constant_keyword
event.duration
Duration of the event in nanoseconds. If event.start and event.end are known this value should be the difference between the end and start time.
long
event.kind
This is one of four ECS Categorization Fields, and indicates the highest level in the ECS category hierarchy. event.kind gives high-level information about what type of information the event contains, without being specific to the contents of the event. For example, values of this field distinguish alert events from metric events. The value of this field can be used to inform how these kinds of events should be handled. They may warrant different retention, different access control, it may also help understand whether the data coming in at a regular interval or not.
keyword
event.module
Event module
constant_keyword
event.outcome
This is one of four ECS Categorization Fields, and indicates the lowest level in the ECS category hierarchy. event.outcome simply denotes whether the event represents a success or a failure from the perspective of the entity that produced the event. Note that when a single transaction is described in multiple events, each event may populate different values of event.outcome, according to their perspective. Also note that in the case of a compound event (a single event that contains multiple logical events), this field should be populated with the value that best captures the overall success or failure from the perspective of the event producer. Further note that not all events will have an associated outcome. For example, this field is generally not populated for metric events, events with event.type:info, or any events for which an outcome does not make logical sense.
keyword
host.architecture
Operating system architecture.
keyword
host.containerized
If the host is a container.
boolean
host.domain
Name of the domain of which the host is a member. For example, on Windows this could be the host's Active Directory domain or NetBIOS domain name. For Linux this could be the domain of the host's LDAP provider.
keyword
host.hostname
Hostname of the host. It normally contains what the hostname command returns on the host machine.
keyword
host.id
Unique host id. As hostname is not always unique, use values that are meaningful in your environment. Example: The current usage of beat.name.
keyword
host.ip
Host ip addresses.
ip
host.mac
Host mac addresses.
keyword
host.name
Name of the host. It can contain what hostname returns on Unix systems, the fully qualified domain name, or a name specified by the user. The sender decides which value to use.
keyword
host.os.build
OS build information.
keyword
host.os.codename
OS codename, if any.
keyword
host.os.family
OS family (such as redhat, debian, freebsd, windows).
keyword
host.os.kernel
Operating system kernel version as a raw string.
keyword
host.os.name
Operating system name, without the version.
keyword
host.os.name.text
Multi-field of host.os.name.
text
host.os.platform
Operating system platform (such centos, ubuntu, windows).
keyword
host.os.version
Operating system version as a raw string.
keyword
host.type
Type of host. For Cloud providers this can be the machine type like t2.medium. If vm, this could be the container, for example, or other information meaningful in your environment.
keyword
input.type
Input type
keyword
kubernetes.container.name
Kubernetes container name
keyword
kubernetes.labels.*
Kubernetes labels map
object
kubernetes.namespace
Kubernetes namespace
keyword
kubernetes.node.name
Kubernetes node name
keyword
kubernetes.pod.name
Kubernetes pod name
keyword
kubernetes.pod.uid
Kubernetes pod UID
keyword
kubernetes.replicaset.name
Kubernetes replicaset name
keyword
log.file.device_id
ID of the device containing the filesystem where the file resides.
keyword
log.file.fingerprint
The sha256 fingerprint identity of the file when fingerprinting is enabled.
keyword
log.file.idxhi
The high-order part of a unique identifier that is associated with a file. (Windows-only)
keyword
log.file.idxlo
The low-order part of a unique identifier that is associated with a file. (Windows-only)
keyword
log.file.inode
Inode number of the log file.
keyword
log.file.path
Full path to the log file this event came from, including the file name. It should include the drive letter, when appropriate. If the event wasn't read from a log file, do not populate this field.
keyword
log.file.vol
The serial number of the volume that contains a file. (Windows-only)
keyword
log.level
Original log level of the log event. If the source of the event provides a log level or textual severity, this is the one that goes in log.level. If your source doesn't specify one, you may put your event transport's severity here (e.g. Syslog severity). Some examples are warn, err, i, informational.
keyword
log.logger
The name of the logger inside an application. This is usually the name of the class which initialized the logger, or can be a custom name.
keyword
log.offset
Log offset
long
network.bytes
Total bytes transferred in both directions. If source.bytes and destination.bytes are known, network.bytes is their sum.
long
network.iana_number
IANA Protocol Number (https://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml). Standardized list of protocols. This aligns well with NetFlow and sFlow related logs which use the IANA Protocol Number.
keyword
network.protocol
In the OSI Model this would be the Application Layer protocol. For example, http, dns, or ssh. The field value must be normalized to lowercase for querying.
keyword
network.transport
Same as network.iana_number, but instead using the Keyword name of the transport layer (udp, tcp, ipv6-icmp, etc.) The field value must be normalized to lowercase for querying.
keyword
related.hosts
All hostnames or other host identifiers seen on your event. Example identifiers include FQDNs, domain names, workstation names, or aliases.
keyword
related.ip
All of the IPs seen on your event.
ip
source.address
Some event source addresses are defined ambiguously. The event will sometimes list an IP, a domain or a unix socket. You should always store the raw address in the .address field. Then it should be duplicated to .ip or .domain, depending on which one it is.
keyword
source.as.number
Unique number allocated to the autonomous system. The autonomous system number (ASN) uniquely identifies each network on the Internet.
long
source.as.organization.name
Organization name.
keyword
source.as.organization.name.text
Multi-field of source.as.organization.name.
match_only_text
source.bytes
Bytes sent from the source to the destination.
long
source.domain
The domain name of the source system. This value may be a host name, a fully qualified domain name, or another host naming format. The value may derive from the original event or be added from enrichment.
keyword
source.geo.city_name
City name.
keyword
source.geo.continent_name
Name of the continent.
keyword
source.geo.country_iso_code
Country ISO code.
keyword
source.geo.country_name
Country name.
keyword
source.geo.location
Longitude and latitude.
geo_point
source.geo.region_iso_code
Region ISO code.
keyword
source.geo.region_name
Region name.
keyword
source.ip
IP address of the source (IPv4 or IPv6).
ip
source.port
Port of the source.
long
tags
List of keywords used to tag each event.
keyword

An example event for log looks as following:

{
    "@timestamp": "2023-09-27T18:59:58.096Z",
    "agent": {
        "ephemeral_id": "bbb180b6-3756-4f5b-81d5-6e333e740796",
        "id": "86a82f91-ff66-4d28-ab7c-eb9350f317ed",
        "name": "docker-fleet-agent",
        "type": "filebeat",
        "version": "8.10.1"
    },
    "coredns": {
        "log": {
            "buffer_size": 1232,
            "dnssec_ok": false
        }
    },
    "data_stream": {
        "dataset": "coredns.log",
        "namespace": "ep",
        "type": "logs"
    },
    "destination": {
        "bytes": 65
    },
    "dns": {
        "header_flags": [
            "RD",
            "RA"
        ],
        "id": "58521",
        "question": {
            "class": "IN",
            "name": "google.com",
            "registered_domain": "google.com",
            "top_level_domain": "com",
            "type": "A"
        },
        "response_code": "NOERROR"
    },
    "ecs": {
        "version": "8.5.1"
    },
    "elastic_agent": {
        "id": "86a82f91-ff66-4d28-ab7c-eb9350f317ed",
        "snapshot": false,
        "version": "8.10.1"
    },
    "event": {
        "agent_id_status": "verified",
        "category": [
            "network"
        ],
        "created": "2023-09-27T18:59:58.096Z",
        "dataset": "coredns.log",
        "duration": 32133957.999999996,
        "ingested": "2023-09-27T18:59:59Z",
        "kind": "event",
        "original": "[INFO] 192.168.112.3:45632 - 58521 \"A IN google.com. udp 51 false 1232\" NOERROR qr,rd,ra 65 0.032133958s",
        "outcome": "success",
        "type": [
            "protocol"
        ]
    },
    "host": {
        "architecture": "aarch64",
        "containerized": false,
        "hostname": "docker-fleet-agent",
        "id": "ddbe644fa129402e9d5cf6452db1422d",
        "ip": [
            "172.31.0.7"
        ],
        "mac": [
            "02-42-AC-1F-00-07"
        ],
        "name": "docker-fleet-agent",
        "os": {
            "codename": "focal",
            "family": "debian",
            "kernel": "5.15.49-linuxkit",
            "name": "Ubuntu",
            "platform": "ubuntu",
            "type": "linux",
            "version": "20.04.6 LTS (Focal Fossa)"
        }
    },
    "input": {
        "type": "filestream"
    },
    "log": {
        "file": {
            "device_id": 141,
            "inode": 18614042,
            "path": "/tmp/service_logs/coredns.log"
        },
        "level": "info",
        "offset": 67
    },
    "network": {
        "bytes": 116,
        "iana_number": "17",
        "protocol": "dns",
        "transport": "udp"
    },
    "related": {
        "hosts": [
            "google.com"
        ],
        "ip": [
            "192.168.112.3"
        ]
    },
    "source": {
        "address": "192.168.112.3",
        "bytes": 51,
        "ip": "192.168.112.3",
        "port": 45632
    },
    "tags": [
        "preserve_original_event",
        "coredns-log"
    ]
}

Changelog

VersionDetailsKibana version(s)

0.6.1

Bug fix View pull request
Add null and ignore_missing check to handle event.original field.

—

0.6.0

Enhancement View pull request
Update the package format_version to 3.0.0.

—

0.5.0

Enhancement View pull request
Adapt fields for changes in file system info

—

0.4.0

Enhancement View pull request
Rename ownership from obs-service-integrations to obs-infraobs-integrations

—

0.3.0

Enhancement View pull request
Migrate Overview dashboard visualizations to lens.

—

0.2.2

Bug fix View pull request
Fix reference error in Overview dashboard.

—

0.2.1

Enhancement View pull request
Added categories and/or subcategories.

—

0.2.0

Enhancement View pull request
Update ECS version to 8.5.1

—

0.1.0

Enhancement View pull request
Initial draft of the package

—

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