From 719062e800ef64b2a95552e0ca2fd936f1b096be Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=81lex=20Ruiz?= <alejandro.ruiz.becerra@wazuh.com>
Date: Thu, 2 Nov 2023 19:29:47 +0100
Subject: [PATCH] Add a script to configure the rollover policy

---
 scripts/indexer-ism-init.sh | 208 ++++++++++++++++++++++++++++++++++++
 1 file changed, 208 insertions(+)
 create mode 100644 scripts/indexer-ism-init.sh

diff --git a/scripts/indexer-ism-init.sh b/scripts/indexer-ism-init.sh
new file mode 100644
index 0000000000000..5b77addc44e16
--- /dev/null
+++ b/scripts/indexer-ism-init.sh
@@ -0,0 +1,208 @@
+#!/bin/bash
+# Wazuh Copyright (C) 2023 Wazuh Inc. (License GPLv2)
+# Wazuh - Indexer set rollover policy and templates
+
+# Policy settings
+MIN_SHARD_SIZE=${MIN_SHARD_SIZE:-25}
+MIN_INDEX_AGE=${MIN_INDEX_AGE:-"7d"}
+MIN_DOC_COUNT=${MIN_DOC_COUNT:-200000000}
+ISM_INDEX_PATTERNS=${ISM_INDEX_PATTERNS:-'["wazuh-alerts-*", "wazuh-archives-*", "-wazuh-alerts-4.x-sample*"]'}
+ISM_PRIORITY=${ISM_PRIORITY:-50}
+
+POLICY_NAME="rollover_policy"
+
+INDEXER_URL="https://localhost:9200"
+
+# curl settings shortcuts
+C_AUTH="-u admin:admin"
+
+#########################################################################
+# Creates the rollover_policy ISM policy.
+# Globals:
+#   MIN_SHARD_SIZE: The minimum shard size in GB.
+#   MIN_INDEX_AGE: The minimum index age.
+#   MIN_DOC_COUNT: The minimum document count.
+#   ISM_INDEX_PATTERNS: The index patterns to apply the policy.
+#   ISM_PRIORITY: The policy priority.
+# Arguments:
+#   None.
+# Returns:
+#   The rollover policy as a JSON string
+#########################################################################
+function generate_rollover_policy() {
+  cat <<EOF
+  {
+    "policy": {
+      "description": "Wazuh rollover and alias policy",
+      "default_state": "active",
+      "states": [
+        {
+          "name": "active",
+          "actions": [
+            {
+              "rollover": {
+                "min_primary_shard_size": "${MIN_SHARD_SIZE}gb",
+                "min_index_age": "${MIN_INDEX_AGE}",
+                "min_doc_count": "${MIN_DOC_COUNT}"
+              }
+            }
+          ]
+        }
+      ],
+      "ism_template": {
+        "index_patterns": $ISM_INDEX_PATTERNS,
+        "priority": "${ISM_PRIORITY}"
+      }
+    }
+  }
+EOF
+}
+
+
+#########################################################################
+# Creates an index template with order 3 to set the rollover alias.
+# Arguments:
+#   - The alias name, a string. Also used as index pattern.
+# Returns:
+#   The index template as a JSON string.
+#########################################################################
+function generate_rollover_template() {
+  cat <<EOF
+  {
+    "order": 3,
+    "index_patterns": ["$1-*"],
+    "settings": {
+      "index.plugins.index_state_management.rollover_alias": "$1"
+    }
+  }
+EOF
+}
+
+
+#########################################################################
+# Loads the index templates for the rollover policy to the indexer.
+#########################################################################
+function load_templates() {
+  # Note: the wazuh-template.json could also be loaded here.
+  for alias in "${aliases[@]}"; do
+    echo "TEMPLATES AND POLICIES - Uploading ${alias} template"
+    generate_rollover_template "${alias}" | curl -s -k ${C_AUTH} \
+      -X PUT "$INDEXER_URL/_template/${alias}-rollover" -o /dev/null \
+      -H 'Content-Type: application/json' -d @-
+  done
+}
+
+
+#########################################################################
+# Uploads the rollover policy.
+#   If the policy does not exist, the policy "${POLICY_NAME}" is created.
+#   If the policy exists, but the rollover conditions are different, the
+#   policy is updated.
+# Arguments:
+#   None.
+#########################################################################
+function upload_rollover_policy() {
+  policy_exists=$(
+    curl -s -k ${C_AUTH} \
+    -X GET "$INDEXER_URL/_plugins/_ism/policies/${POLICY_NAME}" \
+    -o /dev/null \
+    -w "%{http_code}"
+  )
+
+  # Check if the ${POLICY_NAME} ISM policy was loaded (404 error if not found)
+  if [[ $policy_exists == "404" ]]; then
+    echo "TEMPLATES AND POLICIES - Uploading ${POLICY_NAME} ISM policy"
+    generate_rollover_policy | curl -s -k ${C_AUTH} -o /dev/null \
+      -X PUT "$INDEXER_URL/_plugins/_ism/policies/${POLICY_NAME}" \
+      -H 'Content-Type: application/json' -d @-
+  else
+    if [[ $policy_exists == "200" ]]; then
+      echo "TEMPLATES AND POLICIES - ${POLICY_NAME} policy already exists"
+    else
+      echo "TEMPLATES AND POLICIES - Error uploading ${POLICY_NAME} policy"
+    fi
+  fi
+}
+
+
+#########################################################################
+# Check if an alias exists in the indexer.
+# Arguments:
+#   1. The alias to look for. String.
+#########################################################################
+function check_for_write_index() {
+  curl -s -k ${C_AUTH} "$INDEXER_URL/_cat/aliases" | \
+  grep -i "${1}" | \
+  grep -i true | \
+  awk '{print $2}'
+}
+
+
+#########################################################################
+# Creates the settings for the aliased write index.
+# Arguments:
+#   1. The alias. String.
+#########################################################################
+function generate_write_index_alias() {
+  cat << EOF
+  {
+    "aliases": {
+      "$1": {
+        "is_write_index": true
+      }
+    }
+  }
+EOF
+}
+
+
+#########################################################################
+# Creates the initial aliased write index.
+# Arguments:
+#   1. The alias. String.
+#########################################################################
+function create_write_index() {
+  curl -s -k ${C_AUTH} -o /dev/null \
+    -X PUT "$INDEXER_URL/%3C${1}-4.x-%7Bnow%2Fd%7D-000001%3E?pretty" \
+    -H 'Content-Type: application/json' -d "$(generate_write_index_alias "${1}")"
+}
+
+
+#########################################################################
+# Creates the write indices for the aliases given as parameter.
+# Arguments:
+#   1. List of aliases to initialize.
+#########################################################################
+function create_indices() {
+  echo "TEMPLATES AND POLICIES - Creating write indices"
+  for alias in "${aliases[@]}"; do
+    # Check if there are any write indices for the current alias
+    write_index_exists=$(check_for_write_index "${alias}")
+
+    # Create the write index if it does not exist
+    if [[ -z $write_index_exists ]]; then
+      create_write_index "${alias}"
+    fi
+  done
+}
+
+
+#########################################################################
+# Main function.
+#########################################################################
+function main() {
+  # The list should contain every alias which indices implement the
+  # rollover policy
+  aliases=("wazuh-alerts" "wazuh-archives")
+
+  # Load the Wazuh Indexer templates
+  load_templates
+
+  # Upload the rollover policy
+  upload_rollover_policy
+
+  # Create the initial write indices
+  create_indices "${aliases[@]}"
+}
+
+main "$@"
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