Rules

Describes the rules used to configure Mixer’s policy and telemetry features.

Action

Action describes which Handler to invoke and what data to pass to it for processing.

The following example instructs Mixer to invoke ‘prometheus-handler’ handler and pass it the object constructed using the instance ‘RequestCountByService’.

  handler: prometheus-handler
  instances:
  - RequestCountByService
FieldTypeDescriptionRequired
handlerstring

Fully qualified name of the handler to invoke. Must match the name of a Handler.

Yes
instancesstring[]

Each value must match the fully qualified name of the Instances. Referenced instances are evaluated by resolving the attributes/literals for all the fields. The constructed objects are then passed to the handler referenced within this action.

Yes
namestring

A handle to refer to the results of the action.

No

AttributeManifest

AttributeManifest describes a set of Attributes produced by some component of an Istio deployment.

FieldTypeDescriptionRequired
revisionstring

The revision of this document. Assigned by server.

No
namestring

Name of the component producing these attributes. This can be the proxy (with the canonical name istio-proxy) or the name of an attributes kind adapter in Mixer.

Yes
attributesmap<string, AttributeInfo>

The set of attributes this Istio component will be responsible for producing at runtime. We map from attribute name to the attribute’s specification. The name of an attribute, which is how attributes are referred to in aspect configuration, must conform to:

Name = IDENT { SEPARATOR IDENT };

Where IDENT must match the regular expression *a-z*+ and SEPARATOR must match the regular expression [\.-].

Attribute names must be unique within a single Istio deployment. The set of canonical attributes are described at here. Attributes not in that list should be named with a component-specific suffix such as request.count-my.component.

No

AttributeManifest.AttributeInfo

AttributeInfo describes the schema of an Istio Attribute.

Istio Attributes

Istio uses attributes to describe runtime activities of Istio services. An Istio attribute carries a specific piece of information about an activity, such as the error code of an API request, the latency of an API request, or the original IP address of a TCP connection. The attributes are often generated and consumed by different services. For example, a frontend service can generate an authenticated user attribute and pass it to a backend service for access control purpose.

To simplify the system and improve developer experience, Istio uses shared attribute definitions across all components. For example, the same authenticated user attribute will be used for logging, monitoring, analytics, billing, access control, auditing. Many Istio components provide their functionality by collecting, generating, and operating on attributes. For example, the proxy collects the error code attribute, and the logging stores it into a log.

Design

Each Istio attribute must conform to an AttributeInfo in an AttributeManifest in the current Istio deployment at runtime. An AttributeInfo is used to define an attribute’s metadata: the type of its value and a detailed description that explains the semantics of the attribute type. Each attribute’s name is globally unique; in other words an attribute name can only appear once across all manifests.

The runtime presentation of an attribute is intentionally left out of this specification, because passing attribute using JSON, XML, or Protocol Buffers does not change the semantics of the attribute. Different implementations can choose different representations based on their needs.

HTTP Mapping

Because many systems already have REST APIs, it makes sense to define a standard HTTP mapping for Istio attributes that are compatible with typical REST APIs. The design is to map one attribute to one HTTP header, the attribute name and value becomes the HTTP header name and value. The actual encoding scheme will be decided later.

FieldTypeDescriptionRequired
descriptionstring

A human-readable description of the attribute’s purpose.

No
valueTypeValueType

The type of data carried by this attribute.

Yes

Authentication

Authentication allows the operator to specify the authentication of connections to out-of-process infrastructure backend.

FieldTypeDescriptionRequired
tlsTls (oneof)

Originate a TLS connection to the adapter and present an auth token in each call for client authentication.

Yes
mutualMutual (oneof)

Secure connections to the adapter using mutual TLS by presenting client certificates for authentication.

Yes

Connection

Connection allows the operator to specify the endpoint for out-of-process infrastructure backend. Connection is part of the handler custom resource and is specified alongside adapter specific configuration.

FieldTypeDescriptionRequired
addressstring

The address of the backend.

No
timeoutDuration

Timeout for remote calls to the backend.

No
authenticationAuthentication

Auth config for the connection to the backend. If omitted, plain text will be used.

No

DNSName

An instance field of type DNSName denotes that the expression for the field must evaluate to ValueType.DNS_NAME

Objects of type DNSName are also passed to the adapters during request-time for the instance fields of type DNSName

FieldTypeDescriptionRequired
valuestring

DNSName encoded as string.

No

DirectHttpResponse

Direct HTTP response for a client-facing error message which can be attached to an RPC error.

FieldTypeDescriptionRequired
codeHttpStatusCode

HTTP status code. If not set, RPC error code is used.

No
bodystring

HTTP response body.

No
headersmap<string, string>

HTTP response headers.

No

Duration

An instance field of type Duration denotes that the expression for the field must evaluate to ValueType.DURATION

Objects of type Duration are also passed to the adapters during request-time for the instance fields of type Duration

FieldTypeDescriptionRequired
valueDuration

Duration encoded as google.protobuf.Duration.

No

EmailAddress

DO NOT USE !! Under Development An instance field of type EmailAddress denotes that the expression for the field must evaluate to ValueType.EMAIL_ADDRESS

Objects of type EmailAddress are also passed to the adapters during request-time for the instance fields of type EmailAddress

FieldTypeDescriptionRequired
valuestring

EmailAddress encoded as string.

No

FractionalPercent.DenominatorType

Fraction percentages support several fixed denominator values.

NameDescription
HUNDRED

100.

Example: 1100 = 1%.

TEN_THOUSAND

10,000.

Example: 110000 = 0.01%.

Handler

Handler allows the operator to configure a specific adapter implementation. Each adapter implementation defines its own params proto.

In the following example we define a metrics handler for the prometheus adapter. The example is in the form of a Kubernetes resource: * The metadata.name is the name of the handler * The kind refers to the adapter name * The spec block represents adapter-specific configuration as well as the connection information

### Sample-1: No connection specified (for compiled in adapters)
### Note: if connection information is not specified, the adapter configuration is directly inside
### `spec` block. This is going to be DEPRECATED in favor of Sample-2
apiVersion: "config.istio.io/v1alpha2"
kind: handler
metadata:
  name: requestcount
  namespace: istio-system
spec:
  compiledAdapter: prometheus
  params:
    metrics:
    - name: request_count
      instance_name: requestcount.metric.istio-system
      kind: COUNTER
      label_names:
      - source_service
      - source_version
      - destination_service
      - destination_version
---
### Sample-2: With connection information (for out-of-process adapters)
### Note: Unlike sample-1, the adapter configuration is parallel to `connection` and is nested inside `param` block.
apiVersion: "config.istio.io/v1alpha2"
kind: handler
metadata:
  name: requestcount
  namespace: istio-system
spec:
  compiledAdapter: prometheus
  params:
    param:
      metrics:
      - name: request_count
        instance_name: requestcount.metric.istio-system
        kind: COUNTER
        label_names:
        - source_service
        - source_version
        - destination_service
        - destination_version
    connection:
      address: localhost:8090
---
FieldTypeDescriptionRequired
namestring

Must be unique in the entire Mixer configuration. Used by Actions to refer to this handler.

Yes
compiledAdapterstring

The name of the compiled in adapter this handler instantiates. For referencing non compiled-in adapters, use the adapter field instead.

The value must match the name of the available adapter Mixer is built with. An adapter’s name is typically a constant in its code.

Yes
adapterstring

The name of a specific adapter implementation. For referencing compiled-in adapters, use the compiled_adapter field instead.

An adapter’s implementation name is typically a constant in its code.

No
paramsStruct

Depends on adapter implementation. Struct representation of a proto defined by the adapter implementation; this varies depending on the value of field adapter.

No
connectionConnection

Information on how to connect to the out-of-process adapter. This is used if the adapter is not compiled into Mixer binary and is running as a separate process.

No

HttpStatusCode

HTTP response codes. For more details: http://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml

NameDescription
Empty

Empty - This code not part of the HTTP status code specification, but it is needed for proto enum type.

Continue
OK
Created
Accepted
NonAuthoritativeInformation
NoContent
ResetContent
PartialContent
MultiStatus
AlreadyReported
IMUsed
MultipleChoices
MovedPermanently
Found
SeeOther
NotModified
UseProxy
TemporaryRedirect
PermanentRedirect
BadRequest
Unauthorized
PaymentRequired
Forbidden
NotFound
MethodNotAllowed
NotAcceptable
ProxyAuthenticationRequired
RequestTimeout
Conflict
Gone
LengthRequired
PreconditionFailed
PayloadTooLarge
URITooLong
UnsupportedMediaType
RangeNotSatisfiable
ExpectationFailed
MisdirectedRequest
UnprocessableEntity
Locked
FailedDependency
UpgradeRequired
PreconditionRequired
TooManyRequests
RequestHeaderFieldsTooLarge
InternalServerError
NotImplemented
BadGateway
ServiceUnavailable
GatewayTimeout
HTTPVersionNotSupported
VariantAlsoNegotiates
InsufficientStorage
LoopDetected
NotExtended
NetworkAuthenticationRequired

IPAddress

An instance field of type IPAddress denotes that the expression for the field must evaluate to ValueType.IP_ADDRESS

Objects of type IPAddress are also passed to the adapters during request-time for the instance fields of type IPAddress

FieldTypeDescriptionRequired
valuebytes

IPAddress encoded as bytes.

No

Instance

An Instance tells Mixer how to create instances for particular template.

Instance is defined by the operator. Instance is defined relative to a known template. Their purpose is to tell Mixer how to use attributes or literals to produce instances of the specified template at runtime.

The following example instructs Mixer to construct an instance associated with template ‘istio.mixer.adapter.metric.Metric’. It provides a mapping from the template’s fields to expressions. Instances produced with this instance can be referenced by Actions using name ‘RequestCountByService’

- name: RequestCountByService
  template: istio.mixer.adapter.metric.Metric
  params:
    value: 1
    dimensions:
      source: source.name
      destination_ip: destination.ip
FieldTypeDescriptionRequired
namestring

The name of this instance

Must be unique amongst other Instances in scope. Used by Action to refer to an instance produced by this instance.

Yes
compiledTemplatestring

The name of the compiled in template this instance creates instances for. For referencing non compiled-in templates, use the template field instead.

The value must match the name of the available template Mixer is built with.

Yes
templatestring

The name of the template this instance creates instances for. For referencing compiled-in templates, use the compiled_template field instead.

The value must match the name of the available template in scope.

No
paramsStruct

Depends on referenced template. Struct representation of a proto defined by the template; this varies depending on the value of field template.

Yes
attributeBindingsmap<string, string>

Defines attribute bindings to map the output of attribute-producing adapters back into the attribute space. The variable output refers to the output template instance produced by the adapter. The following example derives source.namespace from source.uid in the context of Kubernetes:

params:
  # Pass the required attribute data to the adapter
  source_uid: source.uid | ""
attribute_bindings:
  # Fill the new attributes from the adapter produced output
  source.namespace: output.source_namespace
No

Mutual

Mutual let operator specify TLS configuration for Mixer as client if mutual TLS is used to secure connection to adapter backend.

FieldTypeDescriptionRequired
privateKeystring

The path to the file holding the private key for mutual TLS. If omitted, the default Mixer private key will be used.

No
clientCertificatestring

The path to the file holding client certificate for mutual TLS. If omitted, the default Mixer certificates will be used.

No
caCertificatesstring

The path to the file holding additional CA certificates that are needed to verify the presented adapter certificates. By default Mixer should already include Istio CA certificates and system certificates in cert pool.

No
serverNamestring

Used to configure mixer mutual TLS client to supply server name for SNI. It is not used to verify the hostname of the peer certificate, since Istio verifies whitelisted SAN fields in mutual TLS.

No

OAuth

OAuth let operator specify config to fetch access token via oauth when using TLS for connection to the backend.

FieldTypeDescriptionRequired
clientIdstring

OAuth client id for mixer.

Yes
clientSecretstring

The path to the file holding the client secret for oauth.

Yes
tokenUrlstring

The Resource server’s token endpoint URL.

Yes
scopesstring[]

List of requested permissions.

No
endpointParamsmap<string, string>

Additional parameters for requests to the token endpoint.

No

Rule

A Rule is a selector and a set of intentions to be executed when the selector is true

The following example instructs Mixer to invoke prometheus-handler handler for all services and pass it the instance constructed using the ‘RequestCountByService’ instance.

- match: match(destination.service.host, "*")
  actions:
  - handler: prometheus-handler
    instances:
    - RequestCountByService
FieldTypeDescriptionRequired
matchstring

Match is an attribute based predicate. When Mixer receives a request it evaluates the match expression and executes all the associated actions if the match evaluates to true.

A few example match:

  • an empty match evaluates to true
  • true, a boolean literal; a rule with this match will always be executed
  • match(destination.service.host, "ratings.*") selects any request targeting a service whose name starts with “ratings”
  • attr1 == "20" && attr2 == "30" logical AND, OR, and NOT are also available
No
actionsAction[]

The actions that will be executed when match evaluates to true.

No
requestHeaderOperationsHeaderOperationTemplate[]

Templatized operations on the request headers using values produced by the rule actions. Require the check action result to be OK.

No
responseHeaderOperationsHeaderOperationTemplate[]

Templatized operations on the response headers using values produced by the rule actions. Require the check action result to be OK.

No

Rule.HeaderOperationTemplate

A template for an HTTP header manipulation. Values in the template are expressions that may reference action outputs by name. For example, if an action x produces an output with a field f, then the header value expressions may use attribute x.output.f to reference the field value:

request_header_operations:
- name: x-istio-header
  values:
  - x.output.f

If the header value expression evaluates to an empty string, and the operation is to either replace or append a header, then the operation is not applied. This permits conditional behavior on behalf of the adapter to optionally modify the headers.

FieldTypeDescriptionRequired
namestring

Header name literal value.

Yes
valuesstring[]

Header value expressions.

No
operationOperation

Header operation type. Default operation is to replace the value of the header by name.

No

Rule.HeaderOperationTemplate.Operation

Header operation type.

NameDescription
REPLACE

Replace a header by name.

REMOVE

Remove a header by name. Values are ignored.

APPEND

Append values to the existing header values.

StringMap

An instance field of type StringMap denotes that the expression for the field must evaluate to ValueType.STRING_MAP

Objects of type StringMap are also passed to the adapters during request-time for the instance fields of type StringMap

FieldTypeDescriptionRequired
valuemap<string, string>

StringMap encoded as a map of strings

No

TimeStamp

An instance field of type TimeStamp denotes that the expression for the field must evaluate to ValueType.TIMESTAMP

Objects of type TimeStamp are also passed to the adapters during request-time for the instance fields of type TimeStamp

FieldTypeDescriptionRequired
valueTimestamp

TimeStamp encoded as google.protobuf.Timestamp.

No

Tls

Tls let operator specify client authentication setting when TLS is used for connection to the backend.

FieldTypeDescriptionRequired
caCertificatesstring

The path to the file holding additional CA certificates to well known public certs.

No
tokenPathstring (oneof)

The path to the file holding the auth token (password, jwt token, api key, etc).

Yes
oauthOAuth (oneof)

Oauth config to fetch access token from auth provider.

Yes
authHeaderAuthHeader (oneof)

Access token is passed as authorization header.

Yes
customHeaderstring (oneof)

Customized header key to hold access token, e.g. x-api-key. Token will be passed as what it is.

Yes
serverNamestring

Used to configure mixer TLS client to verify the hostname on the returned certificates. It is also included in the client’s handshake to support SNI.

No

Tls.AuthHeader

AuthHeader specifies how to pass access token with authorization header.

NameDescription
PLAIN

Access token is passed in authorization header as what it is (authorization: some-token).

BEARER

Access token is passed to adapter as bearer token (i.e. authorization: bearer some-token).

Uri

DO NOT USE !! Under Development An instance field of type Uri denotes that the expression for the field must evaluate to ValueType.URI

Objects of type Uri are also passed to the adapters during request-time for the instance fields of type Uri

FieldTypeDescriptionRequired
valuestring

Uri encoded as string.

No

Value

An instance field of type Value denotes that the expression for the field is of dynamic type and can evaluate to any ValueType enum values. For example, when authoring an instance configuration for a template that has a field data of type istio.policy.v1beta1.Value, both of the following expressions are valid data: source.ip | ip("0.0.0.0"), data: request.id | ""; the resulting type is either ValueType.IP_ADDRESS or ValueType.STRING for the two cases respectively.

Objects of type Value are also passed to the adapters during request-time. There is a 1:1 mapping between oneof fields in Value and enum values inside ValueType. Depending on the expression’s evaluated ValueType, the equivalent oneof field in Value is populated by Mixer and passed to the adapters.

FieldTypeDescriptionRequired
stringValuestring (oneof)

Used for values of type STRING

Yes
int64Valueint64 (oneof)

Used for values of type INT64

Yes
doubleValuedouble (oneof)

Used for values of type DOUBLE

Yes
boolValuebool (oneof)

Used for values of type BOOL

Yes
ipAddressValueIPAddress (oneof)

Used for values of type IPAddress

Yes
timestampValueTimeStamp (oneof)

Used for values of type TIMESTAMP

Yes
durationValueDuration (oneof)

Used for values of type DURATION

Yes
emailAddressValueEmailAddress (oneof)

Used for values of type EmailAddress

Yes
dnsNameValueDNSName (oneof)

Used for values of type DNSName

Yes
uriValueUri (oneof)

Used for values of type Uri

Yes
stringMapValueStringMap (oneof)

Used for values of type STRING_MAP

Yes

ValueType

ValueType describes the types that values in the Istio system can take. These are used to describe the type of Attributes at run time, describe the type of the result of evaluating an expression, and to describe the runtime type of fields of other descriptors.

NameDescription
VALUE_TYPE_UNSPECIFIED

Invalid, default value.

STRING

An undiscriminated variable-length string.

INT64

An undiscriminated 64-bit signed integer.

DOUBLE

An undiscriminated 64-bit floating-point value.

BOOL

An undiscriminated boolean value.

TIMESTAMP

A point in time.

IP_ADDRESS

An IP address.

EMAIL_ADDRESS

An email address.

URI

A URI.

DNS_NAME

A DNS name.

DURATION

A span between two points in time.

STRING_MAP

A map string -> string, typically used by headers.