Dynamic Header Injection & Removal
There are multiple interceptors available for manipulating headers, either injection or regex based removal.
This demo will run you through some of these use cases step-by-step.
View the full demo in realtime
Review the docker compose environment
As can be seen from docker-compose.yaml
the demo environment consists of the following services:
- gateway1
- gateway2
- kafka-client
- kafka1
- kafka2
- kafka3
- schema-registry
- zookeeper
- Command
- File Content
cat docker-compose.yaml
version: '3.7'
services:
zookeeper:
image: confluentinc/cp-zookeeper:latest
hostname: zookeeper
container_name: zookeeper
environment:
ZOOKEEPER_CLIENT_PORT: 2801
ZOOKEEPER_TICK_TIME: 2000
healthcheck:
test: nc -zv 0.0.0.0 2801 || exit 1
interval: 5s
retries: 25
kafka1:
hostname: kafka1
container_name: kafka1
image: confluentinc/cp-kafka:latest
ports:
- 19092:19092
environment:
KAFKA_BROKER_ID: 1
KAFKA_ZOOKEEPER_CONNECT: zookeeper:2801
KAFKA_LISTENERS: INTERNAL://:9092,EXTERNAL_SAME_HOST://:19092
KAFKA_ADVERTISED_LISTENERS: INTERNAL://kafka1:9092,EXTERNAL_SAME_HOST://localhost:19092
KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: INTERNAL:PLAINTEXT,EXTERNAL_SAME_HOST:PLAINTEXT
KAFKA_INTER_BROKER_LISTENER_NAME: INTERNAL
KAFKA_GROUP_INITIAL_REBALANCE_DELAY_MS: 0
KAFKA_LOG4J_LOGGERS: kafka.authorizer.logger=INFO
KAFKA_LOG4J_ROOT_LOGLEVEL: WARN
KAFKA_AUTO_CREATE_TOPICS_ENABLE: false
depends_on:
zookeeper:
condition: service_healthy
healthcheck:
test: nc -zv kafka1 9092 || exit 1
interval: 5s
retries: 25
kafka2:
hostname: kafka2
container_name: kafka2
image: confluentinc/cp-kafka:latest
ports:
- 19093:19093
environment:
KAFKA_BROKER_ID: 2
KAFKA_ZOOKEEPER_CONNECT: zookeeper:2801
KAFKA_LISTENERS: INTERNAL://:9093,EXTERNAL_SAME_HOST://:19093
KAFKA_ADVERTISED_LISTENERS: INTERNAL://kafka2:9093,EXTERNAL_SAME_HOST://localhost:19093
KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: INTERNAL:PLAINTEXT,EXTERNAL_SAME_HOST:PLAINTEXT
KAFKA_INTER_BROKER_LISTENER_NAME: INTERNAL
KAFKA_GROUP_INITIAL_REBALANCE_DELAY_MS: 0
KAFKA_LOG4J_LOGGERS: kafka.authorizer.logger=INFO
KAFKA_LOG4J_ROOT_LOGLEVEL: WARN
KAFKA_AUTO_CREATE_TOPICS_ENABLE: false
depends_on:
zookeeper:
condition: service_healthy
healthcheck:
test: nc -zv kafka2 9093 || exit 1
interval: 5s
retries: 25
kafka3:
image: confluentinc/cp-kafka:latest
hostname: kafka3
container_name: kafka3
ports:
- 19094:19094
environment:
KAFKA_BROKER_ID: 3
KAFKA_ZOOKEEPER_CONNECT: zookeeper:2801
KAFKA_LISTENERS: INTERNAL://:9094,EXTERNAL_SAME_HOST://:19094
KAFKA_ADVERTISED_LISTENERS: INTERNAL://kafka3:9094,EXTERNAL_SAME_HOST://localhost:19094
KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: INTERNAL:PLAINTEXT,EXTERNAL_SAME_HOST:PLAINTEXT
KAFKA_INTER_BROKER_LISTENER_NAME: INTERNAL
KAFKA_GROUP_INITIAL_REBALANCE_DELAY_MS: 0
KAFKA_LOG4J_LOGGERS: kafka.authorizer.logger=INFO
KAFKA_LOG4J_ROOT_LOGLEVEL: WARN
KAFKA_AUTO_CREATE_TOPICS_ENABLE: false
depends_on:
zookeeper:
condition: service_healthy
healthcheck:
test: nc -zv kafka3 9094 || exit 1
interval: 5s
retries: 25
schema-registry:
image: confluentinc/cp-schema-registry:latest
hostname: schema-registry
container_name: schema-registry
ports:
- 8081:8081
environment:
SCHEMA_REGISTRY_HOST_NAME: schema-registry
SCHEMA_REGISTRY_KAFKASTORE_BOOTSTRAP_SERVERS: kafka1:9092,kafka2:9093,kafka3:9094
SCHEMA_REGISTRY_LOG4J_ROOT_LOGLEVEL: WARN
SCHEMA_REGISTRY_LISTENERS: http://0.0.0.0:8081
SCHEMA_REGISTRY_KAFKASTORE_TOPIC: _schemas
SCHEMA_REGISTRY_SCHEMA_REGISTRY_GROUP_ID: schema-registry
volumes:
- type: bind
source: .
target: /clientConfig
read_only: true
depends_on:
kafka1:
condition: service_healthy
kafka2:
condition: service_healthy
kafka3:
condition: service_healthy
healthcheck:
test: nc -zv schema-registry 8081 || exit 1
interval: 5s
retries: 25
gateway1:
image: conduktor/conduktor-gateway:3.0.3
hostname: gateway1
container_name: gateway1
environment:
KAFKA_BOOTSTRAP_SERVERS: kafka1:9092,kafka2:9093,kafka3:9094
GATEWAY_ADVERTISED_HOST: localhost
GATEWAY_MODE: VCLUSTER
GATEWAY_SECURITY_PROTOCOL: SASL_PLAINTEXT
GATEWAY_FEATURE_FLAGS_ANALYTICS: false
depends_on:
kafka1:
condition: service_healthy
kafka2:
condition: service_healthy
kafka3:
condition: service_healthy
ports:
- 6969:6969
- 6970:6970
- 6971:6971
- 8888:8888
healthcheck:
test: curl localhost:8888/health
interval: 5s
retries: 25
gateway2:
image: conduktor/conduktor-gateway:3.0.3
hostname: gateway2
container_name: gateway2
environment:
KAFKA_BOOTSTRAP_SERVERS: kafka1:9092,kafka2:9093,kafka3:9094
GATEWAY_ADVERTISED_HOST: localhost
GATEWAY_MODE: VCLUSTER
GATEWAY_SECURITY_PROTOCOL: SASL_PLAINTEXT
GATEWAY_FEATURE_FLAGS_ANALYTICS: false
GATEWAY_START_PORT: 7969
depends_on:
kafka1:
condition: service_healthy
kafka2:
condition: service_healthy
kafka3:
condition: service_healthy
ports:
- 7969:7969
- 7970:7970
- 7971:7971
- 8889:8888
healthcheck:
test: curl localhost:8888/health
interval: 5s
retries: 25
kafka-client:
image: confluentinc/cp-kafka:latest
hostname: kafka-client
container_name: kafka-client
command: sleep infinity
volumes:
- type: bind
source: .
target: /clientConfig
read_only: true
networks:
demo: null
Starting the docker environment
Start all your docker processes, wait for them to be up and ready, then run in background
--wait
: Wait for services to berunning|healthy
. Implies detached mode.--detach
: Detached mode: Run containers in the background
- Command
- Output
- Recording
docker compose up --detach --wait
Network header-injection_default Creating
Network header-injection_default Created
Container zookeeper Creating
Container kafka-client Creating
Container zookeeper Created
Container kafka1 Creating
Container kafka3 Creating
Container kafka2 Creating
Container kafka-client Created
Container kafka2 Created
Container kafka3 Created
Container kafka1 Created
Container schema-registry Creating
Container gateway2 Creating
Container gateway1 Creating
Container gateway2 Created
Container gateway1 Created
Container schema-registry Created
Container zookeeper Starting
Container kafka-client Starting
Container kafka-client Started
Container zookeeper Started
Container zookeeper Waiting
Container zookeeper Waiting
Container zookeeper Waiting
Container zookeeper Healthy
Container kafka2 Starting
Container zookeeper Healthy
Container kafka1 Starting
Container zookeeper Healthy
Container kafka3 Starting
Container kafka2 Started
Container kafka3 Started
Container kafka1 Started
Container kafka1 Waiting
Container kafka2 Waiting
Container kafka3 Waiting
Container kafka2 Waiting
Container kafka3 Waiting
Container kafka1 Waiting
Container kafka1 Waiting
Container kafka2 Waiting
Container kafka3 Waiting
Container kafka3 Healthy
Container kafka3 Healthy
Container kafka2 Healthy
Container kafka1 Healthy
Container kafka1 Healthy
Container kafka1 Healthy
Container kafka2 Healthy
Container gateway1 Starting
Container kafka3 Healthy
Container schema-registry Starting
Container kafka2 Healthy
Container gateway2 Starting
Container schema-registry Started
Container gateway2 Started
Container gateway1 Started
Container gateway1 Waiting
Container gateway2 Waiting
Container kafka-client Waiting
Container zookeeper Waiting
Container kafka1 Waiting
Container kafka2 Waiting
Container kafka3 Waiting
Container schema-registry Waiting
Container kafka1 Healthy
Container kafka2 Healthy
Container kafka-client Healthy
Container kafka3 Healthy
Container zookeeper Healthy
Container gateway1 Healthy
Container gateway2 Healthy
Container schema-registry Healthy
Creating virtual cluster teamA
Creating virtual cluster teamA
on gateway gateway1
and reviewing the configuration file to access it
- Command
- Output
- Recording
# Generate virtual cluster teamA with service account sa
token=$(curl \
--request POST "http://localhost:8888/admin/vclusters/v1/vcluster/teamA/username/sa" \
--header 'Content-Type: application/json' \
--user 'admin:conduktor' \
--silent \
--data-raw '{"lifeTimeSeconds": 7776000}' | jq -r ".token")
# Create access file
echo """
bootstrap.servers=localhost:6969
security.protocol=SASL_PLAINTEXT
sasl.mechanism=PLAIN
sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required username='sa' password='$token';
""" > teamA-sa.properties
# Review file
cat teamA-sa.properties
bootstrap.servers=localhost:6969
security.protocol=SASL_PLAINTEXT
sasl.mechanism=PLAIN
sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required username='sa' password='eyJhbGciOiJIUzI1NiJ9.eyJ1c2VybmFtZSI6InNhIiwidmNsdXN0ZXIiOiJ0ZWFtQSIsImV4cCI6MTcyMDQ3NjQ3MH0.hoxPqEUpXmMu_zwYCZVZlK5_NWDVoREkUtvxjeJoTZA';
Creating topic users on teamA
Creating on teamA
:
- Topic
users
with partitions:1 and replication-factor:1
- Command
- Output
- Recording
Adding interceptor inject-headers
Let's create the interceptor to inject various headers
- Command
- Output
- Recording
cat step-07-inject-headers.json | jq
curl \
--request POST "http://localhost:8888/admin/interceptors/v1/vcluster/teamA/interceptor/inject-headers" \
--header 'Content-Type: application/json' \
--user 'admin:conduktor' \
--silent \
--data @step-07-inject-headers.json | jq
{
"pluginClass": "io.conduktor.gateway.interceptor.DynamicHeaderInjectionPlugin",
"priority": 100,
"config": {
"headers": {
"X-MY-KEY": "my own value",
"X-USER": "{{user}}",
"X-INTERPOLATED": "User {{user}} via ip {{userIp}}"
}
}
}
{
"message": "inject-headers is created"
}
Send tom and laura into users
Producing 2 messages in users
in cluster teamA
- Command
- Output
- Recording
Sending 2 events
{
"name" : "tom",
"username" : "tom@conduktor.io",
"password" : "motorhead",
"visa" : "#abc123",
"address" : "Chancery lane, London"
}
{
"name" : "laura",
"username" : "laura@conduktor.io",
"password" : "kitesurf",
"visa" : "#888999XZ",
"address" : "Dubai, UAE"
}
with
echo '{"name":"tom","username":"tom@conduktor.io","password":"motorhead","visa":"#abc123","address":"Chancery lane, London"}' | \
kafka-console-producer \
--bootstrap-server localhost:6969 \
--producer.config teamA-sa.properties \
--topic users
echo '{"name":"laura","username":"laura@conduktor.io","password":"kitesurf","visa":"#888999XZ","address":"Dubai, UAE"}' | \
kafka-console-producer \
--bootstrap-server localhost:6969 \
--producer.config teamA-sa.properties \
--topic users
Verify tom and laura have the corresponding headers
Verify tom and laura have the corresponding headers in cluster teamA
- Command
- Output
- Recording
kafka-console-consumer \
--bootstrap-server localhost:6969 \
--consumer.config teamA-sa.properties \
--topic users \
--from-beginning \
--max-messages 2 \
--timeout-ms 10000 \
--property print.headers=true | jq
returns 2 events
{
"headers" : {
"X-INTERPOLATED" : "User sa via ip 192.168.65.1",
"X-MY-KEY" : "my own value",
"X-USER" : "sa"
},
"value" : {
"name" : "tom",
"username" : "tom@conduktor.io",
"password" : "motorhead",
"visa" : "#abc123",
"address" : "Chancery lane, London"
}
}
{
"headers" : {
"X-INTERPOLATED" : "User sa via ip 192.168.65.1",
"X-MY-KEY" : "my own value",
"X-USER" : "sa"
},
"value" : {
"name" : "laura",
"username" : "laura@conduktor.io",
"password" : "kitesurf",
"visa" : "#888999XZ",
"address" : "Dubai, UAE"
}
}
jq: parse error: Invalid numeric literal at line 1, column 15
Processed a total of 2 messages
Adding interceptor remove-headers
Let's create the interceptor remove-headers
to remove headers that match X-MY-.*
- Command
- Output
- Recording
cat step-10-remove-headers.json | jq
curl \
--request POST "http://localhost:8888/admin/interceptors/v1/vcluster/teamA/interceptor/remove-headers" \
--header 'Content-Type: application/json' \
--user 'admin:conduktor' \
--silent \
--data @step-10-remove-headers.json | jq
{
"pluginClass": "io.conduktor.gateway.interceptor.safeguard.MessageHeaderRemovalPlugin",
"priority": 100,
"config": {
"headerKeyRegex": "X-MY-.*"
}
}
{
"message": "remove-headers is created"
}
Verify tom and laura have the corresponding headers
Verify tom and laura have the corresponding headers in cluster teamA
- Command
- Output
- Recording
kafka-console-consumer \
--bootstrap-server localhost:6969 \
--consumer.config teamA-sa.properties \
--topic users \
--from-beginning \
--max-messages 2 \
--timeout-ms 10000 \
--property print.headers=true | jq
returns 2 events
{
"headers" : {
"X-INTERPOLATED" : "User sa via ip 192.168.65.1",
"X-USER" : "sa"
},
"value" : {
"name" : "tom",
"username" : "tom@conduktor.io",
"password" : "motorhead",
"visa" : "#abc123",
"address" : "Chancery lane, London"
}
}
{
"headers" : {
"X-INTERPOLATED" : "User sa via ip 192.168.65.1",
"X-USER" : "sa"
},
"value" : {
"name" : "laura",
"username" : "laura@conduktor.io",
"password" : "kitesurf",
"visa" : "#888999XZ",
"address" : "Dubai, UAE"
}
}
jq: parse error: Invalid numeric literal at line 1, column 15
Processed a total of 2 messages
Remove interceptor remove-headers
Let's delete the interceptor remove-headers
so we can access all our headers again
- Command
- Output
- Recording
Verify tom and laura have X-MY-KEY back
Verify tom and laura have X-MY-KEY back in cluster teamA
- Command
- Output
- Recording
kafka-console-consumer \
--bootstrap-server localhost:6969 \
--consumer.config teamA-sa.properties \
--topic users \
--from-beginning \
--max-messages 2 \
--timeout-ms 10000 \
--property print.headers=true | jq
returns 2 events
{
"headers" : {
"X-INTERPOLATED" : "User sa via ip 192.168.65.1",
"X-MY-KEY" : "my own value",
"X-USER" : "sa"
},
"value" : {
"name" : "tom",
"username" : "tom@conduktor.io",
"password" : "motorhead",
"visa" : "#abc123",
"address" : "Chancery lane, London"
}
}
{
"headers" : {
"X-INTERPOLATED" : "User sa via ip 192.168.65.1",
"X-MY-KEY" : "my own value",
"X-USER" : "sa"
},
"value" : {
"name" : "laura",
"username" : "laura@conduktor.io",
"password" : "kitesurf",
"visa" : "#888999XZ",
"address" : "Dubai, UAE"
}
}
jq: parse error: Invalid numeric literal at line 1, column 15
Processed a total of 2 messages
Tearing down the docker environment
Remove all your docker processes and associated volumes
--volumes
: Remove named volumes declared in the "volumes" section of the Compose file and anonymous volumes attached to containers.
- Command
- Output
- Recording
docker compose down --volumes
Container kafka-client Stopping
Container gateway2 Stopping
Container schema-registry Stopping
Container gateway1 Stopping
Container gateway1 Stopped
Container gateway1 Removing
Container gateway1 Removed
Container gateway2 Stopped
Container gateway2 Removing
Container gateway2 Removed
Container schema-registry Stopped
Container schema-registry Removing
Container schema-registry Removed
Container kafka2 Stopping
Container kafka1 Stopping
Container kafka3 Stopping
Container kafka3 Stopped
Container kafka3 Removing
Container kafka3 Removed
Container kafka2 Stopped
Container kafka2 Removing
Container kafka2 Removed
Container kafka-client Stopped
Container kafka-client Removing
Container kafka-client Removed
Container kafka1 Stopped
Container kafka1 Removing
Container kafka1 Removed
Container zookeeper Stopping
Container zookeeper Stopped
Container zookeeper Removing
Container zookeeper Removed
Network header-injection_default Removing
Network header-injection_default Removed
Conclusion
Leveraging headers in Kafka is of tremendous help!