23-udf-example.yaml

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: "clickhouse-initdb-udf"
data:
  # todo think about arm64 and hash sum calculation
  load_jq_udf.sh: |
    #!/usr/bin/env bash
    if [ ! -f /opt/user_scripts/jq ]; then
      clickhouse-client --echo -q "INSERT INTO FUNCTION file('./jq', RawBLOB) SELECT value FROM url('https://github.com/stedolan/jq/releases/latest/download/jq-linux64', RawBLOB, 'value String') SETTINGS max_http_get_redirects=5"
      mv -vf /var/lib/clickhouse/user_files/jq /opt/user_scripts/
    
    cat > /opt/user_scripts/jq-wrapper.sh << EOL
      while IFS='$\n' read -r line; do
        json=\$(echo "\$line" | awk '{print \$1}')
        expression=\$(echo "\$line" | awk '{\$1=""; print \$0}')
        echo "\$json" | /opt/user_scripts/jq -c -r "\$expression"
      done
    EOL
    
      chmod -v +x /opt/user_scripts/jq*
    fi

---
apiVersion: "clickhouse.altinity.com/v1"
kind: "ClickHouseInstallation"
metadata:
  name: "udf-executable-example"
spec:
  troubleshoot: "no"
  templates:
    volumeClaimTemplates:
      - name: udf-volume
        spec:
          accessModes:
            - ReadWriteOnce
          resources:
            requests:
              storage: 1Gi
      - name: data-volume
        spec:
          accessModes:
            - ReadWriteOnce
          resources:
            requests:
              storage: 10Gi
      - name: log-volume
        spec:
          accessModes:
            - ReadWriteOnce
          resources:
            requests:
              storage: 1Gi

    podTemplates:
      - name: pod-template-with-udf
        spec:
          volumes:
            - name: initdb-volume
              configMap:
                name: clickhouse-initdb-udf
                defaultMode: 0555
          
          containers:
            - name: clickhouse
              image: clickhouse/clickhouse-server:latest
              env:
                - name: CLICKHOUSE_ALWAYS_RUN_INITDB_SCRIPTS
                  value: "true"
              volumeMounts:
                - name: initdb-volume
                  mountPath: /docker-entrypoint-initdb.d
                  readOnly: true
                - name: udf-volume
                  mountPath: /opt/user_scripts
                - name: data-volume
                  mountPath: /var/lib/clickhouse
                - name: log-volume
                  mountPath: /var/log/clickhouse-server
  defaults:
    templates:
      podTemplate: pod-template-with-udf
  configuration:
    settings:
      user_scripts_path: /opt/user_scripts
      user_defined_executable_functions_config: config.d/*_function.xml
    files:
      config.d/jq_udf_function.xml: |
        <!--
        look documentation https://clickhouse.com/docs/en/sql-reference/functions/#executable-user-defined-functions
        
        SELECT jq('{"a":111}','.a'), jq('{"foo":222}','.foo')
          
        ┌─jq('{"a":111}','.a')─┬─jq('{"foo":222}','.foo')─┐
        │ 111                  │ 222                      │
        └──────────────────────┴──────────────────────────┘        
        -->
        <clickhouse>
        	<function>
        		<type>executable_pool</type>
        		<execute_direct>0</execute_direct>
        		<name>jq</name>
        		<return_type>String</return_type>
        		<argument>
                    <name>json</name>
        			<type>String</type>
        		</argument>
        		<argument>
                    <name>query</name>
        			<type>String</type>
        		</argument>
        		<format>TabSeparated</format>
        		<command>/opt/user_scripts/jq-wrapper.sh</command>
        	</function>
        </clickhouse>