akvorado/console/data/docs/02-configuration.md

Configuration

The orchestrator service is configured through a YAML file and includes the configuration of the other services. Other services are expected to query the orchestrator through HTTP on start to retrieve their configuration.

The default configuration can be obtained with docker-compose exec akvorado-orchestrator akvorado orchestrator --dump --check /dev/null. Note that some sections are generated from the configuration of another section. Notably, all Kafka configuration comes from upper-level kafka key. Durations must be written using strings like 10h20m or 5s. Valid time units are ms, s, m, and h.

It is also possible to override configuration settings using environment variables. You need to remove any - from key names and use _ to handle nesting. Then, put AKVORADO_ORCHESTRATOR_ as a prefix. For example, let's consider the following configuration file:

http:
  listen: 127.0.0.1:8081
kafka:
  topic: test-topic
  brokers:
    - 192.0.2.1:9092
    - 192.0.2.2:9092

It can be translated to:

AKVORADO_ORCHESTRATOR_HTTP_LISTEN=127.0.0.1:8081
AKVORADO_ORCHESTRATOR_KAFKA_TOPIC=test-topic
AKVORADO_ORCHESTRATOR_KAFKA_BROKERS=192.0.2.1:9092,192.0.2.2:9092

The orchestrator service has its own configuration, as well as the configuration for the other services under the key matching the service name (inlet and console). For each service, it is possible to provide a list of configuration. A service can query the configuration it wants by appending an index to the configuration URL. If the index does not match a provided configuration, the first configuration is provided.

Each service is split into several functional components. Each of them gets a section of the configuration file matching its name.

Inlet service

This service is configured under the inlet key. The main components of the inlet services are flow, kafka, and core.

Flow

The flow component handles incoming flows. It accepts the inputs key to define the list of inputs to receive incoming flows and the rate-limit key to have an hard-limit on the number of flows/second accepted per exporter. When set, the provided rate limit will be enforced for each exporter and the sampling rate of the surviving flows will be adapted.

Each input has a type and a decoder. For decoder, both netflow or sflow are supported. As for the type, both udp and file are supported.

For the UDP input, the supported keys are listen to set the listening endpoint, workers to set the number of workers to listen to the socket, receive-buffer to set the size of the kernel's incoming buffer for each listening socket, and queue-size to define the number of messages to buffer inside each worker. For example:

flow:
  inputs:
    - type: udp
      decoder: netflow
      listen: 0.0.0.0:2055
      workers: 3
    - type: udp
      decoder: sflow
      listen: 0.0.0.0:6343
      workers: 3
  workers: 2

The file input should only be used for testing. It supports a paths key to define the files to read from. These files are injected continuously in the pipeline. For example:

flow:
  inputs:
    - type: file
      decoder: netflow
      paths:
       - /tmp/flow1.raw
       - /tmp/flow2.raw
    - type: file
      decoder: sflow
      paths:
       - /tmp/flow1.raw
       - /tmp/flow2.raw
  workers: 2

Without configuration, Akvorado will listen for incoming Netflow/IPFIX and sFlow flows on a random port (check the logs to know which one).

BMP

The BMP component handles incoming BMP connections from routers. The information received can be used to fetch source and destination AS numbers, as well as the AS paths and communities. Not all exporters need to send their tables with BMP. Akvorado will try to select the best route using the next hop advertised in the flow and fallback to any next hop if not found.

The following keys are accepted:

• listen specifies the IP address and port to listen for incoming connections (default port is 10179)
• rds specifies a list of route distinguisher to accept (0 is meant to accept routes without an associated route distinguisher)
• collect-asns tells if origin AS numbers should be collected
• collect-aspaths tells if AS paths should be collected
• collect-communities tells if communities should be collected (both regular communities and large communities; extended communities are not supported)
• keep tells how much time the routes sent from a terminated BMP connection should be kept

If you are not interested in AS paths and communities, disabling them will decrease the memory usage of Akvorado, as well as the disk space used in ClickHouse.

Akvorado supports receiving the AdjRIB-in, with or without filtering. It may also work with a LocRIB.

Kafka

Received flows are exported to a Kafka topic using the protocol buffers format. The definition file is flow/flow-*.proto. Each flow is written in the length-delimited format.

The following keys are accepted:

• topic, brokers, tls, and version keys are described in the configuration for the orchestrator service (the values of these keys come from the orchestrator configuration)
• flush-interval defines the maximum flush interval to send received flows to Kafka
• flush-bytes defines the maximum number of bytes to store before flushing flows to Kafka
• max-message-bytes defines the maximum size of a message (it should be equal or smaller to the same setting in the broker configuration)
• compression-codec defines the compression codec to use to compress messages (none, gzip, snappy, lz4 and zstd)
• queue-size defines the size of the internal queues to send messages to Kafka. Increasing this value will improve performance, at the cost of losing messages in case of problems.

The topic name is suffixed by the version of the schema. For example, if the configured topic is flows and the current schema version is 1, the topic used to send received flows will be flows-v2.

Core

The core component queries the geoip and the snmp component to enriches the flows with additional information. It also classifies exporters and interfaces into groups with a set of classification rules.

The following configuration keys are accepted:

• workers key define how many workers should be spawned to process incoming flows
• exporter-classifiers is a list of classifier rules to define a group for exporters
• interface-classifiers is a list of classifier rules to define connectivity type, network boundary and provider for an interface
• classifier-cache-duration defines how long to keep the result of a previous classification in memory to reduce CPU usage.
• default-sampling-rate defines the default sampling rate to use when the information is missing. If not defined, flows without a sampling rate will be rejected. Use this option only if your hardware is unable to advertise a sampling rate. This can either be a single value or a map from subnets to sampling rates.
• override-sampling-rate defines the sampling rate instead of the one received in the flows. This is useful if a device lie about its sampling rate. This is a map from subnets to sampling rates (but it would also accept a single value).
• asn-providers defines the source list for AS numbers. The available sources are flow, flow-except-private (use information from flow except if the ASN is private), geoip, bmp, and bmp-except-private. The default value is flow, bmp, and geoip.

Classifier rules are written using expr.

Exporter classifiers gets the classifier IP address and its hostname. If they can make a decision, they should invoke one of the Classify() functions with the target element as an argument. Once classification is done for an element, it cannot be changed by a subsequent rule. All strings are normalized (down case, special chars removed).

• Exporter.IP for the exporter IP address
• Exporter.Name for the exporter name
• ClassifyGroup() to classify the exporter to a group
• ClassifyRole() to classify the exporter for a role (edge, core)
• ClassifySite() to classify the exporter to a site (paris, berlin, newyork)
• ClassifyRegion() to classify the exporter to a region (france, italy, caraibes)
• ClassifyTenant() to classify the exporter to a tenant (team-a, team-b)

As a compatibility Classify() is an alias for ClassifyGroup(). Here is an example, assuming routers are named th2-ncs55a1-1.example.fr or milan-ncs5k8-2.example.it:

exporter-classifiers:
  - ClassifySiteRegex(Exporter.Name, "^([^-]+)-", "$1")
  - Exporter.Name endsWith ".it" && ClassifyRegion("italy")
  - Exporter.Name matches "^(washington|newyork).*" && ClassifyRegion("usa")
  - Exporter.Name endsWith ".fr" && ClassifyRegion("france")

Interface classifiers gets the following information and, like exporter classifiers, should invoke one of the Classify() functions to make a decision:

• Exporter.IP for the exporter IP address
• Exporter.Name for the exporter name
• Interface.Name for the interface name
• Interface.Description for the interface description
• Interface.Speed for the interface speed
• ClassifyConnectivity() to classify for a connectivity type (transit, PNI, PPNI, IX, customer, core, ...)
• ClassifyProvider() to classify for a provider (Cogent, Telia, ...)
• ClassifyExternal() to classify the interface as external
• ClassifyInternal() to classify the interface as internal

Once an interface is classified for a given criteria, it cannot be changed by later rule. Once an interface is classified for all criteria, remaining rules are skipped. Connectivity and provider are normalized (down case, special chars removed).

Each Classify() function, with the exception of ClassifyExternal() and ClassifyInternal() have a variant ending with Regex which takes a string and a regex before the original string and do a regex match. The original string is expanded using the matching parts of the regex. The syntax is the one from Go. If you want to use Perl character classes, such as \d or \w, you need to escape the backslash character: \\d and \\w. To test your regex, you can use a site like regular expressions 101. Be sure to use the "Golang" flavor. You can use the substition function. In this case, append .* to your regex to get the expected result (you can keep it in the final regex if you prefer).

Here is an example, assuming interface descriptions for external facing interfaces look like Transit: Cogent 1-3834938493 or PNI: Netflix (WL6-1190).

interface-classifiers:
  - |
    ClassifyConnectivityRegex(Interface.Description, "^(?i)(transit|pni|ppni|ix):? ", "$1") &&
    ClassifyProviderRegex(Interface.Description, "^[^ ]+? ([^ ]+)", "$1") &&
    ClassifyExternal()
  - ClassifyInternal()

GeoIP

The GeoIP component adds source and destination country, as well as the AS number of the source and destination IP if they are not present in the received flows. It needs two databases using the MaxMind DB file format, one for AS numbers, one for countries. If no database is provided, the component is inactive. It accepts the following keys:

• asn-database tells the path to the ASN database
• geo-database tells the path to the geo database (country or city)
• optional makes the presence of the databases optional on start (when not present on start, the component is just disabled)

If the files are updated while Akvorado is running, they are automatically refreshed.

SNMP

Flows only include interface indexes. To associate them with an interface name and description, SNMP is used to poll the exporter sending each flows. A cache is maintained to avoid polling continuously the exporters. The following keys are accepted:

• cache-duration tells how much time to keep data in the cache
• cache-refresh tells how much time to wait before updating an entry by polling it
• cache-check-interval tells how often to check if cached data is about to expire or need an update
• cache-persist-file tells where to store cached data on shutdown and read them back on startup
• communities is a map from subnets to the SNMPv2 community to use for exporters in the provided subnet. Use ::/0 to set the default value. Alternatively, it also accepts a string to use for all exporters.
• security-parameters is a map from subnets to the SNMPv3 USM security parameters. Like for communities, ::/0 can be used to the set the default value. The security paramaters accepts the following keys: user-name, authentication-protocol (can be omitted, otherwise MD5, SHA, SHA224, SHA256, SHA384, and SHA512 are accepted), authentication-passphrase (if the previous value was set), privacy-protocol (can be omitted, otherwise DES, AES, AES192, AES256, AES192C, and AES256C are accepted, the later being Cisco-variant), privacy-passphrase (if the previous value was set), and context-name.
• agents is a map from exporter IPs to agent IPs (when there is no match, the exporter IP is used)
• ports is a map from subnets to the SNMP port to use to poll agents in the provided subnet.
• poller-retries is the number of retries on unsuccessful SNMP requests.
• poller-timeout tells how much time should the poller wait for an answer.
• workers tell how many workers to spawn to handle SNMP polling.

As flows missing interface information are discarded, persisting the cache is useful to quickly be able to handle incoming flows. By default, no persistent cache is configured.

Akvorado will use SNMPv3 if there is a match for the security-parameters configuration option. Otherwise, it will use SNMPv2.

HTTP

The builtin HTTP server serves various pages. Its configuration supports the listen key to specify the address and port to listen. For example:

http:
  listen: 0.0.0.0:8000

It also supports the profiler key. When set to true, various profiling data are made available on the /debug/pprof/ endpoint. This is useful if you wish to optimize CPU or memory usage of one of the components.

Reporting

Reporting encompasses logging and metrics. Currently, as Akvorado is expected to be run inside Docker, logging is done on the standard output and is not configurable. As for metrics, they are reported by the HTTP component on the /api/v0/inlet/metrics endpoint and there is nothing to configure either.

Orchestrator service

The two main components of the orchestrator service are clickhouse and kafka. It also uses the HTTP and reporting component from the inlet service and accepts the same configuration settings.

Kafka

The Kafka component creates or updates the Kafka topic to receive flows. It accepts the following keys:

• brokers specifies the list of brokers to use to bootstrap the connection to the Kafka cluster
• tls defines the TLS configuration to connect to the cluster
• version tells which minimal version of Kafka to expect
• topic defines the base topic name
• topic-configuration describes how the topic should be configured

The following keys are accepted for the TLS configuration:

• enable should be set to true to enable TLS.
• verify can be set to false to skip checking server certificate (not recommended).
• ca-file gives the location of the file containing the CA certificate in PEM format to check the server certificate. If not provided, the system certificates are used instead.
• cert-file and key-file defines the location of the client certificate pair in PEM format to authenticate to the broker. If the first one is empty, no client certificate is used. If the second one is empty, the key is expected to be in the certificate file.
• sasl-username and sasl-password enables SASL authentication with the provided user and password.
• sasl-algorithm tells which SASL mechanism to use for authentication. This can be none, plain, scram-sha256, or scram-sha512. This should not be set to none when SASL is used.

The following keys are accepted for the topic configuration:

• num-partitions for the number of partitions
• replication-factor for the replication factor
• config-entries is a mapping from configuration names to their values

For example:

kafka:
  topic: test-topic
  topic-configuration:
    num-partitions: 1
    replication-factor: 1
    config-entries:
      segment.bytes: 1073741824
      retention.ms: 86400000
      cleanup.policy: delete

Another useful setting is retention.bytes to limit the size of a partition in bytes too (divide it by the number of partitions to have a limit for the topic).

Currently, the orchestrator service won't update the replication factor. The configuration entries are kept in sync with the content of the configuration file.

ClickHouse

The ClickHouse component exposes some useful HTTP endpoints to configure a ClickHouse database. It also provisions and keep up-to-date a ClickHouse database. The following keys should be provided:

• servers defines the list of ClickHouse servers to connect to
• username is the username to use for authentication
• password is the password to use for authentication
• database defines the database to use to create tables
• kafka defines the configuration for the Kafka consumer. Currently, the only interesting key is consumers which defines the number of consumers to use to consume messages from the Kafka topic. It is silently bound by the maximum number of threads ClickHouse will use (by default, the number of CPUs). It should also be less than the number of partitions: the additional consumers will stay idle.
• resolutions defines the various resolutions to keep data
• max-partitions defines the number of partitions to use when creating consolidated tables
• networks maps subnets to attributes. Attributes are name, role, site, region, and tenant. They are exposed as SrcNetName, DstNetName, SrcNetRole, DstNetRole, etc.
• network-sources fetch a remote source mapping subnets to attributes. This is similar to networks but the definition is fetched through HTTP. It accepts a map from source names to sources. Each source accepts the following attributes:
  • url is the URL to fetch
  • proxy says if we should use a proxy (defined through environment variables like http_proxy)
  • timeout defines the timeout for fetching and parsing
  • interval is the interval at which the source should be refreshed
  • transform is a jq expression to transform the received JSON into a set of network attributes represented as objects. Each object must have a prefix attribute and, optionally, name, role, site, region, and tenant. See the example provided in the shipped akvorado.yaml configuration file.
• asns maps AS number to names (overriding the builtin ones)
• orchestrator-url defines the URL of the orchestrator to be used by Clickhouse (autodetection when not specified)

The resolutions setting contains a list of resolutions. Each resolution has two keys: interval and ttl. The first one is the consolidation interval. The second is how long to keep the data in the database. If ttl is 0, then the data is kept forever. If interval is 0, it applies to the raw data (the one in the flows table). For each resolution, a materialized view flows_XXXX is created with the specified interval. It should be noted that consolidated tables do not contain information about source/destination IP addresses and ports. That's why you may want to keep the interval-0 table data a bit longer. Akvorado will still use the consolidated tables if the query do not require the raw table, for performance reason.

Here is the default configuration:

resolutions:
  - interval: 0
    ttl: 360h  # 15 days
  - interval: 1m
    ttl: 168h  # 1 week
  - interval: 5m
    ttl: 2160h # 3 months
  - interval: 1h
    ttl: 8760h # 1 year

Console service

The main components of the console service are http, console, authentication and database. http accepts the same configuration as for the inlet service.

The console itself accepts the following keys:

• default-visualize-options to define default options for the "visualize" tab and the second one defines the widgets to display on the home page (among src-as, dst-as, src-country, dst-country, exporter, protocol, etype, src-port, and dst-port)
• homepage-top-widgets to define the widgets to display on the home page
• dimensions-limit to set the upper limit of the number of returned dimensions

Here is an example:

console:
  homepage-top-widgets: [src-as, src-country, etype]
  default-visualize-options:
    start: 1 day ago
    end: now
    filter: InIfBoundary = external
    dimensions:
      - ExporterName

Authentication

The console does not store user identities and is unable to authenticate them. It expects an authenticating proxy will add some headers to the API endpoints:

• Remote-User is the user login,
• Remote-Name is the user display name,
• Remote-Email is the user email address,
• X-Logout-URL is a link to the logout link.

Only the first header is mandatory. The name of the headers can be changed by providing a different mapping under the headers key. It is also possible to modify the default user (when no header is present) by tweaking the default-user key:

auth:
  headers:
    login: Remote-User
    name: Remote-Name
    email: Remote-Email
    logout-url: X-Logout-URL
  default-user:
    login: default
    name: Default User

To prevent access when not authenticated, the login field for the default-user key should be empty.

There are several systems providing user management with all the bells and whistles, including OAuth2 support, multi-factor authentication and API tokens. Here is a short selection of solutions able to act as an authenticating reverse-proxy for Akvorado:

• Authelia
• Authentik
• Gluu
• Keycloak
• Ory, notably Kratos, Hydra and Oathkeeper

There also exist simpler solutions only providing authentication:

• OAuth2 Proxy, associated with Dex
• Ory, notably Hydra and Oathkeeper

Database

The console stores some data, like per-user filters, into a relational database. When the database is not configured, data is only stored in memory and will be lost on restart. Currently, the only accepted driver is SQLite.

database:
  driver: sqlite
  dsn: /var/lib/akvorado/console.sqlite

The database configuration also accepts a saved-filters key to populate the database with the provided filters. Each filter should have a description and a content:

database:
  saved-filters:
    - description: From Netflix
      content: InIfBoundary = external AND SrcAS = AS2906

Demo exporter service

For testing purpose, it is possible to generate flows using the demo exporter service. It features a NetFlow generator, a simple SNMP agent and a BMP exporter.

snmp:
  name: exporter1.example.com
  interfaces:
    10: "Transit: Telia"
    11: "IX: AMSIX"
    20: "core"
    21: "core"
  listen: 0.0.0.0:161
bmp:
  target: 127.0.0.1:10179
  routes:
    - prefixes: 192.0.2.0/24,2a01:db8:cafe:1::/64
      aspath: 64501
      communities: 65401:10,65401:12
flows:
  samplingrate: 50000
  target: 127.0.0.1:2055
  flows:
    - per-second: 0.2
      in-if-index: 10
      out-if-index: 20
      peak-hour: 16h
      multiplier: 3
      src-port: 0
      dst-port: 80
      protocol: tcp
      size: 1300
      dst-net: 192.0.2.0/24
      dst-as: 64501
      src-net: 198.38.120.0/23
      src-as: 2906

In the snmp section, all fields are mandatory. The interfaces section maps interface indexes to their descriptions. In the bmp session, for each set of prefixes, the aspath is mandatory, but the communities are optional. In the flows section, all fields are mandatory. Have a look at the provided akvorado.yaml configuration file for a more complete example. As generating many flows is quite verbose, it may be useful to rely on YAML anchors to avoid repeating a lot of stuff.