Kafka topics


The CLI can view, create and modify topics. The commands for these actions are shown in the table below.

CommandsDescription
createCreate a new topic.
deleteDelete a specific topic.
updateUpdate the topic

View all topics 

The optional names flag wil display only the names of the topics. If you use the –unwrap flag, each topic name will be displayed on a new line as text:

# list all topics
lenses-cli topics

# list only the metadata
lenses-cli topics metadata

# list only the keys
lenses-cli topics keys

View a specific topic 

lenses-cli topic --name=cc_payments

Create topics 

lenses-cli topic create \
    --name="topicName" \
    --replication=1 \
    --partitions=1 \
    --configs="{\"max.message.bytes\": \"1000010\"}"

Update from a file:

lenses-cli topic create ./topic.yml

Example file:

name: topicName
replication: 1
partitions: 1
configs:
  max.message.bytes: "1000010"

Update a topic’s configuration 

lenses-cli topic update \
    --name="topicName" \
    --configs="{\"max.message.bytes\": \"1000020\"}"

Update from a file:

lenses-cli topic update ./topic.yaml

Example file:

name: topicName
configs:
  max.message.bytes: "2000010"

Update a topic’s metadata configuration 

# first change the key/value type
lenses-cli topics metadata set \
    --name=topicName \
    --key-type=json \
    --value-type=json

# now you may change its schema
lenses-cli topics metadata set \
    --name=topicName \
    --key-type=json \
    --key-schema="{\"type\":\"record\",\"name\":\"lenses_record\",\"namespace\":\"lenses\",\"fields\":[{\"name\":\"keyField\",\"type\":\"string\"}]}" \
    --value-type=json \
    --value-schema="{\"type\":\"record\",\"name\":\"lenses_record\",\"namespace\":\"lenses\",\"fields\":[{\"name\":\"valueField\",\"type\":\"string\"}]}"

Update from a file:

lenses-cli topic update ./topic.yaml

Example file:

name: topicName
keyType: bytes
valueType: xml
valueSchema: "{\"type\":\"record\",\"name\":\"lenses_record\",\"namespace\":\"lenses\",\"fields\":[{\"name\":\"heading3\",\"type\":\"string\"}]}"

Delete topics 

lenses-cli topic delete --name="topicName"
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Last modified: May 28, 2024