DOC-5601 Transform functions (#163)

* setup to incorporate transform function docs

* source blocks missing quotes

* intro sentence

* move transform function content from streamlearn

* integrate content from stream learn

* move sink option to own section

* remove collapsibles in prep for migration

* remove tabs in prep for migration

* fix some issues

* typos

Author: aimurphy

modules/ROOT/nav.adoc

@@ -19,7 +19,9 @@
 ** xref:ROOT:astream-subscriptions-shared.adoc[]
 ** xref:ROOT:astream-subscriptions-failover.adoc[]
 ** xref:ROOT:astream-subscriptions-keyshared.adoc[]
-* xref:developing:astream-functions.adoc[]
+* {pulsar-short} functions
+** xref:developing:astream-functions.adoc[]
+** xref:developing:astream-functions-transform.adoc[]
 * xref:developing:starlight.adoc[]
 * xref:developing:astream-cdc.adoc[]
 * xref:developing:gpt-schema-translator.adoc[]

modules/ROOT/partials/functions-ui-common-steps-pt1.adoc

@@ -0,0 +1,7 @@
+. In the {astra-ui-link} header, click icon:grip[name="Applications"], and then select *Streaming*.
+
+. Click the name of the tenant where you want to deploy a function.
+
+. On the *Functions* tab, click *Create Function*.
+
+. Enter a function name.

modules/ROOT/partials/functions-ui-common-steps-pt2.adoc

@@ -0,0 +1,37 @@
+. Select the namespace and one or more input topics for the function.
+
+. If needed, select an output namespace and topics.
++
+Whether you need to specify an output topic depends on the function's logic.
+For example, the `cast` xref:developing:astream-functions-transform.adoc[transform function] needs an output topic to receive the transformed messages.
+
+. Optional: Select a log topic.
++
+The log topic is a separate output topic for messages containing additional `loglevel`, `fqn`, and `instance` properties.
+
+. Optional: Configure advanced settings:
++
+* *Instances*: Enter a number of sink instances to run.
+* *Processing Guarantee*: Select one of the following:
+** *ATLEAST_ONCE* (default): Each message sent to the function can be processed one or more times.
+** *ATMOST_ONCE*: Each message sent to the function is processed 0 or 1 times.
+This means there is a change that a message is not processed.
+** *EFFECTIVELY_ONCE*: Each message sent to the function has only one output associated with it.
+* *Timeout*: Set a timeout limit.
+* *Auto Acknowledge*: Enable or disable automatic message acknowledgment.
+
+. If needed, provide a JSON-formatted config key for your function.
+This configuration depends on your function code.
+
+. Click *Create*.
+
+. Confirm your function was created on the *Functions* tab.
++
+You can also verify the function deployment with the {pulsar-short} CLI:
++
+[source,shell]
+----
+./bin/pulsar-admin functions list --tenant $TENANT
+----
+
+Once created, the function starts processing messages from the input topics according to its logic.