add docs on init hooks

Author: HarshCasper

content/en/references/init-hooks/index.md

@@ -0,0 +1,68 @@
+---
+title: "Initialization Hooks"
+linkTitle: "Initialization Hooks"
+weight: 5
+description: >
+  Writing shell or SQL scripts to customize or initialize your Snowflake emulator
+cascade:
+  type: docs
+hide_readingtime: true
+---
+ 
+## Introduction
+
+LocalStack for Snowflake supports automatically executing `*.sf.sql` with [Init Hooks](https://docs.localstack.cloud/references/init-hooks/) when mounted into the Docker container. A script can be added to one of these stages in the lifecycle:
+
+-   `BOOT`: the container is running, but LocalStack hasn’t started
+-   `START`: the Python process is running, and LocalStack is starting
+-   `READY`: LocalStack is ready for requests
+-   `SHUTDOWN`: LocalStack is shutting down
+
+A script can be in one of four states: `UNKNOWN`, `RUNNING`, `SUCCESSFUL`, or `ERROR`. By default, scripts are in the `UNKNOWN` state when first discovered.
+
+## Getting started
+
+To begin, create a script called `test.sf.sql` with the following SQL statements:
+
+```sql
+CREATE DATABASE foobar123;
+CREATE DATABASE test123;
+SHOW DATABASES;
+```
+
+Mount the script into `/etc/localstack/init/ready.d/` using Docker Compose or the `localstack` CLI:
+
+{{< tabpane >}}
+{{< tab header="docker-compose.yml" lang="yml" >}}
+version: "3.8"
+
+services:
+  localstack:
+    container_name: "${LOCALSTACK_DOCKER_NAME:-localstack-main}"
+    image: localstack/snowflake
+    ports:
+      - "127.0.0.1:4566:4566"
+      - "127.0.0.1:4510-4559:4510-4559"
+      - "127.0.0.1:443:443"
+    environment:
+      - LOCALSTACK_AUTH_TOKEN=${LOCALSTACK_AUTH_TOKEN:?}
+      - DEBUG=1
+    volumes:
+      - "/path/to/test.sf.sql:/etc/localstack/init/ready.d/test.sf.sql"  # ready hook
+      - "${LOCALSTACK_VOLUME_DIR:-./volume}:/var/lib/localstack"
+      - "/var/run/docker.sock:/var/run/docker.sock"
+{{< /tab >}}
+{{< tab header="CLI" lang="bash" >}}
+# DOCKER_FLAGS are additional parameters to the `docker run` command of localstack start
+
+DOCKER_FLAGS='-v /path/to/test.sf.sql:/etc/localstack/init/ready.d/test.sf.sql' DEBUG=1 localstack start
+{{< /tab >}}
+{{< /tabpane >}}
+
+Start the Snowflake emulator, and the following logs will appear:
+
+```bash 
+DEBUG --- [et.reactor-0] s.analytics.handler        : REQ: POST /queries/v1/query-request {"sqlText": "CREATE DATABASE foobar123", ...
+DEBUG --- [et.reactor-0] s.analytics.handler        : REQ: POST /queries/v1/query-request {"sqlText": "CREATE DATABASE test123", ...
+DEBUG --- [et.reactor-0] s.analytics.handler        : REQ: POST /queries/v1/query-request {"sqlText": "SHOW DATABASES", ...
+```