I am working on a script to extract a specific environment variable - CONFLUENT_SECURITY_MASTER_KEY defined in the unit for the service confluent-server.service and use that value in the script to perform other actions.
I tried systemctl show confluent-server.service --property=Environment but it shows only the first ENVIRONMENT= value - Environment=KAFKA_HEAP_OPTS. There are 5 ENVIRONMENT variables defined for the service. How do I list all 5 and extract the value of CONFLUENT_SECURITY_MASTER_KEY.
I thought the original question was fully explaining the situation, but have added more details.
Below is the output of the command
`systemctl show confluent-server.service --property=Environment`
This is the whole output. Modified the masterkey value, but format is same
Environment=KAFKA_OPTS=-Djdk.tls.ephemeralDHKeySize=2048 -javaagent:/opt/jolokia/jolokia.jar=config=/etc/kafka/kafka_jolokia.properties KAFKA_HEAP_OPTS=-Xms6g -Xmx6g -XX:MetaspaceSize=96m -XX:+UseG1GC -XX:MaxGCPauseMillis=20 -XX:InitiatingHeapOccupancyPercent=35 -XX:G1HeapRegionSize=16M -XX:MinMetaspaceFreeRatio=50 -XX:MaxMetaspaceFreeRatio=80 KAFKA_LOG4J_OPTS=-Dlog4j.configuration=file:/etc/kafka/log4j.properties LOG_DIR=/var/log/kafka CONFLUENT_SECURITY_MASTER_KEY=abcdefghYRkHGYhKM4CRQOBVt9C9wKp8QAZ3i5Nzs=
@Thiru has already provided the answer. And I have accepted it as it resolves the issue
As discussed, here is the solution.
Using awk you can just filter the value you would want like below but note that it works fine only if the variable CONFLUENT_SECURITY_MASTER_KEY output value is at the end of the line.
# systemctl show confluent-server.service --property=Environment | awk -F "CONFLUENT_SECURITY_MASTER_KEY=" '{print $2}'
abcdefghYRkHGYhKM4CRQOBVt9C9wKp8QAZ3i5Nzs=
If the CONFLUENT_SECURITY_MASTER_KEY value comes in the middle of the line. example :
systemctl show confluent-server.service --property=Environment
Environment=KAFKA_OPTS=-Djdk.tls.ephemeralDHKeySize=2048 -javaagent:/opt/jolokia/jolokia.jar=config=/etc/kafka/kafka_jolokia.properties KAFKA_HEAP_OPTS=-Xms6g -Xmx6g -XX:MetaspaceSize=96m -XX:+UseG1GC -XX:MaxGCPauseMillis=20 -XX:InitiatingHeapOccupancyPercent=35 -XX:G1HeapRegionSize=16M -XX:MinMetaspaceFreeRatio=50 -XX:MaxMetaspaceFreeRatio=80 CONFLUENT_SECURITY_MASTER_KEY=abcdefghYRkHGYhKM4CRQOBVt9C9wKp8QAZ3i5Nzs= KAFKA_LOG4J_OPTS=-Dlog4j.configuration=file:/etc/kafka/log4j.properties LOG_DIR=/var/log/kafka
Then the awk result would be as below which is not right . (of course using the awk we can further filter the value like this : awk -F "CONFLUENT_SECURITY_MASTER_KEY=" '{print $2}' | awk '{print $1}')
systemctl show confluent-server.service --property=Environment | awk -F "CONFLUENT_SECURITY_MASTER_KEY=" '{print $2}'
abcdefghYRkHGYhKM4CRQOBVt9C9wKp8QAZ3i5Nzs= KAFKA_LOG4J_OPTS=-Dlog4j.configuration=file:/etc/kafka/log4j.properties LOG_DIR=/var/log/kafka
Simple workaround is that we can simply split the lines using sed (replace space with new line /n) and then we can filter the value
systemctl show confluent-server.service --property=Environment | sed 's/ /\n/g'
Environment=KAFKA_OPTS=-Djdk.tls.ephemeralDHKeySize=2048
-javaagent:/opt/jolokia/jolokia.jar=config=/etc/kafka/kafka_jolokia.properties
KAFKA_HEAP_OPTS=-Xms6g
-Xmx6g
-XX:MetaspaceSize=96m
-XX:+UseG1GC
-XX:MaxGCPauseMillis=20
-XX:InitiatingHeapOccupancyPercent=35
-XX:G1HeapRegionSize=16M
-XX:MinMetaspaceFreeRatio=50
-XX:MaxMetaspaceFreeRatio=80
CONFLUENT_SECURITY_MASTER_KEY=abcdefghYRkHGYhKM4CRQOBVt9C9wKp8QAZ3i5Nzs=
KAFKA_LOG4J_OPTS=-Dlog4j.configuration=file:/etc/kafka/log4j.properties
LOG_DIR=/var/log/kafka
and finally do a grep
systemctl show confluent-server.service --property=Environment | sed 's/ /\n/g' | grep CONFLUENT_SECURITY_MASTER_KEY
CONFLUENT_SECURITY_MASTER_KEY=abcdefghYRkHGYhKM4CRQOBVt9C9wKp8QAZ3i5Nzs=