Class RoutingRule.Builder (2.40.0)

Specifies the routing information that should be sent along with the request in the form of routing header. NOTE: All service configuration rules follow the "last one wins" order.

The examples below will apply to an RPC which has the following request type:

Message Definition:

 message Request {
   // The name of the Table
   // Values can be of the following formats:
   // - <code>projects/&lt;project&gt;/tables/&lt;table&gt;</code>
   // - <code>projects/&lt;project&gt;/instances/&lt;instance&gt;/tables/&lt;table&gt;</code>
   // - <code>region/&lt;region&gt;/zones/&lt;zone&gt;/tables/&lt;table&gt;</code>
   string table_name = 1;

   // This value specifies routing for replication.
   // It can be in the following formats:
   // - <code>profiles/&lt;profile_id&gt;</code>
   // - a legacy <code>profile_id</code> that can be any string
   string app_profile_id = 2;
 }

Example message:

 {
   table_name: projects/proj_foo/instances/instance_bar/table/table_baz,
   app_profile_id: profiles/prof_qux
 }

The routing header consists of one or multiple key-value pairs. Every key and value must be percent-encoded, and joined together in the format of key1=value1&key2=value2. In the examples below I am skipping the percent-encoding for readablity.

Example 1

Extracting a field from the request to put into the routing header unchanged, with the key equal to the field name.

annotation:

 option (google.api.routing) = {
   // Take the <code>app_profile_id</code>.
   routing_parameters {
     field: "app_profile_id"
   }
 };

result:

 x-goog-request-params: app_profile_id=profiles/prof_qux

Example 2

Extracting a field from the request to put into the routing header unchanged, with the key different from the field name.

annotation:

 option (google.api.routing) = {
   // Take the <code>app_profile_id</code>, but name it <code>routing_id</code> in the header.
   routing_parameters {
     field: "app_profile_id"
     path_template: "{routing_id=**}"
   }
 };

result:

 x-goog-request-params: routing_id=profiles/prof_qux

Example 3

Extracting a field from the request to put into the routing header, while matching a path template syntax on the field's value.

NB: it is more useful to send nothing than to send garbage for the purpose of dynamic routing, since garbage pollutes cache. Thus the matching.

Sub-example 3a

The field matches the template.

annotation:

 option (google.api.routing) = {
   // Take the <code>table_name</code>, if it's well-formed (with project-based
   // syntax).
   routing_parameters {
     field: "table_name"
     path_template: "{table_name=projects/&#42;&#47;instances/&#42;&#47;&#42;*}"
   }
 };

result:

 x-goog-request-params:
 table_name=projects/proj_foo/instances/instance_bar/table/table_baz

Sub-example 3b

The field does not match the template.

annotation:

 option (google.api.routing) = {
   // Take the <code>table_name</code>, if it's well-formed (with region-based
   // syntax).
   routing_parameters {
     field: "table_name"
     path_template: "{table_name=regions/&#42;&#47;zones/&#42;&#47;&#42;*}"
   }
 };

result:

 <no routing header will be sent>

Sub-example 3c

Multiple alternative conflictingly named path templates are specified. The one that matches is used to construct the header.

annotation:

 option (google.api.routing) = {
   // Take the <code>table_name</code>, if it's well-formed, whether
   // using the region- or projects-based syntax.

   routing_parameters {
     field: "table_name"
     path_template: "{table_name=regions/&#42;&#47;zones/&#42;&#47;&#42;*}"
   }
   routing_parameters {
     field: "table_name"
     path_template: "{table_name=projects/&#42;&#47;instances/&#42;&#47;&#42;*}"
   }
 };

result:

 x-goog-request-params:
 table_name=projects/proj_foo/instances/instance_bar/table/table_baz

Example 4

Extracting a single routing header key-value pair by matching a template syntax on (a part of) a single request field.

annotation:

 option (google.api.routing) = {
   // Take just the project id from the <code>table_name</code> field.
   routing_parameters {
     field: "table_name"
     path_template: "{routing_id=projects/&#42;}/&#42;*"
   }
 };

result:

 x-goog-request-params: routing_id=projects/proj_foo

Example 5

Extracting a single routing header key-value pair by matching several conflictingly named path templates on (parts of) a single request field. The last template to match "wins" the conflict.

annotation:

 option (google.api.routing) = {
   // If the <code>table_name</code> does not have instances information,
   // take just the project id for routing.
   // Otherwise take project + instance.

   routing_parameters {
     field: "table_name"
     path_template: "{routing_id=projects/&#42;}/&#42;*"
   }
   routing_parameters {
     field: "table_name"
     path_template: "{routing_id=projects/&#42;&#47;instances/&#42;}/&#42;*"
   }
 };

result:

 x-goog-request-params:
 routing_id=projects/proj_foo/instances/instance_bar

Example 6

Extracting multiple routing header key-value pairs by matching several non-conflicting path templates on (parts of) a single request field.

Sub-example 6a

Make the templates strict, so that if the table_name does not have an instance information, nothing is sent.

annotation:

 option (google.api.routing) = {
   // The routing code needs two keys instead of one composite
   // but works only for the tables with the "project-instance" name
   // syntax.

   routing_parameters {
     field: "table_name"
     path_template: "{project_id=projects/*}/instances/*/**"
   }
   routing_parameters {
     field: "table_name"
     path_template: "projects/*/{instance_id=instances/*}/**"
   }
 };

result:

 x-goog-request-params:
 project_id=projects/proj_foo&instance_id=instances/instance_bar

Sub-example 6b

Make the templates loose, so that if the table_name does not have an instance information, just the project id part is sent.

annotation:

 option (google.api.routing) = {
   // The routing code wants two keys instead of one composite
   // but will work with just the <code>project_id</code> for tables without
   // an instance in the <code>table_name</code>.

   routing_parameters {
     field: "table_name"
     path_template: "{project_id=projects/&#42;}/&#42;*"
   }
   routing_parameters {
     field: "table_name"
     path_template: "projects/&#42;&#47;{instance_id=instances/&#42;}/&#42;*"
   }
 };

result (is the same as 6a for our example message because it has the instance information):

 x-goog-request-params:
 project_id=projects/proj_foo&instance_id=instances/instance_bar

Example 7

Extracting multiple routing header key-value pairs by matching several path templates on multiple request fields.

NB: note that here there is no way to specify sending nothing if one of the fields does not match its template. E.g. if the table_name is in the wrong format, the project_id will not be sent, but the routing_id will be. The backend routing code has to be aware of that and be prepared to not receive a full complement of keys if it expects multiple.

annotation:

 option (google.api.routing) = {
   // The routing needs both <code>project_id</code> and <code>routing_id</code>
   // (from the <code>app_profile_id</code> field) for routing.

   routing_parameters {
     field: "table_name"
     path_template: "{project_id=projects/&#42;}/&#42;*"
   }
   routing_parameters {
     field: "app_profile_id"
     path_template: "{routing_id=**}"
   }
 };

result:

 x-goog-request-params:
 project_id=projects/proj_foo&routing_id=profiles/prof_qux

Example 8

Extracting a single routing header key-value pair by matching several conflictingly named path templates on several request fields. The last template to match "wins" the conflict.

annotation:

 option (google.api.routing) = {
   // The <code>routing_id</code> can be a project id or a region id depending on
   // the table name format, but only if the <code>app_profile_id</code> is not set.
   // If <code>app_profile_id</code> is set it should be used instead.

   routing_parameters {
     field: "table_name"
     path_template: "{routing_id=projects/&#42;}/&#42;*"
   }
   routing_parameters {
      field: "table_name"
      path_template: "{routing_id=regions/&#42;}/&#42;*"
   }
   routing_parameters {
     field: "app_profile_id"
     path_template: "{routing_id=**}"
   }
 };

result:

 x-goog-request-params: routing_id=profiles/prof_qux

Example 9

Bringing it all together.

annotation:

 option (google.api.routing) = {
   // For routing both <code>table_location</code> and a <code>routing_id</code> are needed.
   //
   // table_location can be either an instance id or a region+zone id.
   //
   // For <code>routing_id</code>, take the value of <code>app_profile_id</code>
   // - If it's in the format <code>profiles/&lt;profile_id&gt;</code>, send
   // just the <code>&lt;profile_id&gt;</code> part.
   // - If it's any other literal, send it as is.
   // If the <code>app_profile_id</code> is empty, and the <code>table_name</code> starts with
   // the project_id, send that instead.

   routing_parameters {
     field: "table_name"
     path_template: "projects/&#42;&#47;{table_location=instances/&#42;}/tables/&#42;"
   }
   routing_parameters {
     field: "table_name"
     path_template: "{table_location=regions/&#42;&#47;zones/&#42;}/tables/&#42;"
   }
   routing_parameters {
     field: "table_name"
     path_template: "{routing_id=projects/&#42;}/&#42;*"
   }
   routing_parameters {
     field: "app_profile_id"
     path_template: "{routing_id=**}"
   }
   routing_parameters {
     field: "app_profile_id"
     path_template: "profiles/{routing_id=*}"
   }
 };

result:

 x-goog-request-params:
 table_location=instances/instance_bar&routing_id=prof_qux

Protobuf type google.api.RoutingRule

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

repeated .google.api.RoutingParameter routing_parameters = 2;