JSON Source Connector for Confluent Platform¶
The Kafka Connect JSON Source connector is used to stream JSON files from an SFTP directory while also converting the data based on the schema supplied in the configuration. If the schema is not supplied in the configuration then the connector can also auto generate the key.schema
and value.schema
at run time when schema.generation.enabled
is true.
To use this connector, use a connector configuration that specifies the name of this connector class in the connector.class
configuration property, as shown below:
connector.class=io.confluent.connect.sftp.SftpJsonSourceConnector
JSON Source Connector Example¶
This example follows the same steps as the Quick Start. Review the Quick Start for help running the Confluent Platform and installing the SFTP connector package.
Generate a JSON dataset using the command below and push it to SFTP server:
echo $'{"id":1,"first_name":"Roscoe","last_name":"Brentnall","email":"rbrentnall0@mediafire.com","gender":"Male","ip_address":"202.84.142.254","last_login":"2018-02-12T06:26:23Z","account_balance":1450.68,"country":"CZ","favorite_color":"#4eaefa"}\n{"id":2,"first_name":"Gregoire","last_name":"Fentem","email":"gfentem1@nsw.gov.au","gender":"Male","ip_address":"221.159.106.63","last_login":"2015-03-27T00:29:56Z","account_balance":1392.37,"country":"ID","favorite_color":"#e8f686"}' > "json-sftp-source.json"
Create an
sftp.properties
file with the following contents:name=JsonSftp tasks.max=1 connector.class=io.confluent.connect.sftp.SftpJsonSourceConnector input.path=/path/to/data error.path=/path/to/error finished.path=/path/to/finished cleanup.policy=NONE input.file.pattern=json-sftp-source.json behavior.on.error=IGNORE sftp.username=username sftp.password=password sftp.host=localhost sftp.port=22 kafka.topic=sftp-json-topic key.schema={\"name\" : \"com.example.users.UserKey\",\"type\" : \"STRUCT\",\"isOptional\" : false,\"fieldSchemas\" : {\"id\" : {\"type\" : \"INT64\",\"isOptional\" : false}}} value.schema={\"name\" : \"com.example.users.User\",\"type\" : \"STRUCT\",\"isOptional\" : false,\"fieldSchemas\" : {\"id\" : {\"type\" : \"INT64\",\"isOptional\" : false},\"first_name\" : {\"type\" : \"STRING\",\"isOptional\" : true},\"last_name\" : {\"type\" : \"STRING\",\"isOptional\" : true},\"email\" : {\"type\" : \"STRING\",\"isOptional\" : true},\"gender\" : {\"type\" : \"STRING\",\"isOptional\" : true},\"ip_address\" : {\"type\" : \"STRING\",\"isOptional\" : true},\"last_login\" : {\"type\" : \"STRING\",\"isOptional\" : true},\"account_balance\" : {\"name\" : \"org.apache.kafka.connect.data.Decimal\",\"type\" : \"BYTES\",\"version\" : 1,\"parameters\" : {\"scale\" : \"2\"},\"isOptional\" : true},\"country\" : {\"type\" : \"STRING\",\"isOptional\" : true},\"favorite_color\" : {\"type\" : \"STRING\",\"isOptional\" : true}}}
Load the SFTP JSON Source Connector.
Caution
You must include a double dash (
--
) between the connector name and your flag. For more information, see this post.confluent local services connect connector load JsonSftp --config sftp.properties
Important
Don’t use the Confluent CLI in production environments.
Configuration Properties¶
Connector-specific configuration properties are described below.
General¶
kafka.topic
The Kafka topic to write the data to.
- Importance: HIGH
- Type: STRING
batch.size
The number of records that should be returned with each batch.
- Importance: LOW
- Type: INT
- Default Value: 1000
empty.poll.wait.ms
The amount of time to wait if a poll returns an empty list of records.
- Importance: LOW
- Type: LONG
- Default Value: 250
- Validator: [1,…,9223372036854775807]
Connection¶
sftp.host
Sftp host to connect with.
- Type: string
- Default: localhost
- Importance: high
sftp.port
Port number of SFTP server.
- Type: int
- Default: 22
- Importance: medium
sftp.username
Username for sftp server.
- Type: string
- Default: foo
- Importance: high
sftp.password
Password for sftp server.
- Type: string
- Default: pass
- Importance: high
Security¶
tls.private.key
Private key that will be used for public-key authentication.
- Type: password
- Default: [hidden]
- Importance: low
tls.public.key
Public key that will be used to decrypt the private key if the given private key is encrypted.
- Type: password
- Default: [hidden]
- Importance: low
tls.passphrase
Passphrase that will be used to decrypt the private key if the given private key is encrypted.
- Type: password
- Default: [hidden]
- Importance: low
tls.pemfile
Path to pemfile.
- Type: string
- Default: “”
- Importance: low
Kerberos¶
If Kerberos is enabled, the Connector assumes the /etc/krb5.conf
file has been correctly configured and points to a KDC which can issue tickets for SFTP. The connector will refresh its TGT when it expires.
To test if the configuration of the krb5.conf
file and the keytab was successful, the command kinit -k -t /path/to/user.keytab username
may be used.
The connector first looks for a cached ticket on the system, if it does not exist it uses the configured keytab and principal. Note that if there is ticket cached on the system that is for a different application, the cache may need to be cleared temporarily when starting the connector.
kerberos.user.principal
The principal to use when connecting to SFTP with Kerberos. The `` sftp.username`` is still required. Format:
username@REALM
.- Type: string
- Default: “”
- Importance: low
kerberos.keytab.path
The path to the keytab file for the SFTP connector principal. This keytab file should only be readable by the connector.
- Type: string
- Default: “”
- Importance: low
Proxy¶
sftp.proxy.url
Proxy url for sftp connection.
- Type: string
- Default: “”
- Importance: low
proxy.username
Proxy username for sftp server if proxy is being used.
- Type: string
- Default: null
- Importance: low
proxy.password
Proxy password for sftp server if proxy is being used.
- Type: string
- Default: null
- Importance: low
Auto topic creation¶
For more information about Auto topic creation, see Configuring Auto Topic Creation for Source Connectors.
Note
Configuration properties accept regular expressions (regex) that are defined as Java regex.
topic.creation.groups
A list of group aliases that are used to define per-group topic configurations for matching topics. A
default
group always exists and matches all topics.- Type: List of String types
- Default: empty
- Possible Values: The values of this property refer to any additional groups. A
default
group is always defined for topic configurations.
topic.creation.$alias.replication.factor
The replication factor for new topics created by the connector. This value must not be larger than the number of brokers in the Kafka cluster. If this value is larger than the number of Kafka brokers, an error occurs when the connector attempts to create a topic. This is a required property for the
default
group. This property is optional for any other group defined intopic.creation.groups
. Other groups use the Kafka broker default value.- Type: int
- Default: n/a
- Possible Values:
>= 1
for a specific valid value or-1
to use the Kafka broker’s default value.
topic.creation.$alias.partitions
The number of topic partitions created by this connector. This is a required property for the
default
group. This property is optional for any other group defined intopic.creation.groups
. Other groups use the Kafka broker default value.- Type: int
- Default: n/a
- Possible Values:
>= 1
for a specific valid value or-1
to use the Kafka broker’s default value.
topic.creation.$alias.include
A list of strings that represent regular expressions that match topic names. This list is used to include topics with matching values, and apply this group’s specific configuration to the matching topics.
$alias
applies to any group defined intopic.creation.groups
. This property does not apply to thedefault
group.- Type: List of String types
- Default: empty
- Possible Values: Comma-separated list of exact topic names or regular expressions.
topic.creation.$alias.exclude
A list of strings representing regular expressions that match topic names. This list is used to exclude topics with matching values from getting the group’s specfic configuration.
$alias
applies to any group defined intopic.creation.groups
. This property does not apply to thedefault
group. Note that exclusion rules override any inclusion rules for topics.- Type: List of String types
- Default: empty
- Possible Values: Comma-separated list of exact topic names or regular expressions.
topic.creation.$alias.${kafkaTopicSpecificConfigName}
Any of the Changing Broker Configurations Dynamically for the version of the Kafka broker where the records will be written. The broker’s topic-level configuration value is used if the configuration is not specified for the rule.
$alias
applies to thedefault
group as well as any group defined intopic.creation.groups
.- Type: property values
- Default: Kafka broker value
File System¶
input.path
The directory where Kafka Connect reads files that are processed. This directory must exist and be writable by the user running Connect.
- Importance: HIGH
- Type: STRING
- Validator: Absolute path to a sftp directory that exists and is writable.
input.file.pattern
Regular expression to check input file names against. This expression must match the entire filename. The equivalent of
Matcher.matches()
.- Importance: HIGH
- Type: STRING
finished.path
The directory where Connect puts files that are successfully processed. This directory must exist and be writable by the user running Connect.
- Importance: HIGH
- Type: STRING
- Validator: Absolute path to a sftp directory that exists and is writable.
error.path
The directory to place files that have errors. This directory must exist and be writable by the user running Kafka Connect.
- Importance: HIGH
- Type: STRING
- Validator: Absolute path to a sftp directory that exists and is writable.
behavior.on.error
Sets how the connector should behave when error are encountered while processing records.
FAIL
stops the connector when any error occurs.IGNORE
ignores the current file and continues to the next file for processing.LOG
after logging the error message, it continues to the next file for processing.- Importance: HIGH
- Type: STRING
- Default Value: FAIL
- Validator: Matches:
FAIL
,IGNORE
,LOG
cleanup.policy
Sets how the connector should clean up files that are successfully processed.
NONE
leaves the files in place. Files left in place may be reprocessed if the connector is restarted.DELETE
removes the file from the filesystem.MOVE
(the default) moves the file to thefinished.path
directory.- Importance: MEDIUM
- Type: STRING
- Default Value: MOVE
- Validator: Matches:
NONE
,DELETE
,MOVE
file.minimum.age.ms
The amount of time in milliseconds after the file was last written to before the file can be processed.
- Importance: LOW
- Type: LONG
- Default Value: 0
- Validator: [0,…]
processing.file.extension
Before a file is processed, it is renamed to indicate that it is currently being processed. This setting is appended to the end of the file.
- Importance: LOW
- Type: STRING
- Default Value: .PROCESSING
- Validator: Matches regex( ^.*..+$ )
Schema¶
key.schema
The schema for the key written to Kafka.
- Importance: HIGH
- Type: STRING
value.schema
The schema for the value written to Kafka.
- Importance: HIGH
- Type: STRING
Schema Generation¶
schema.generation.enabled
Flag to determine if schemas should be dynamically generated. If set to true,
key.schema
andvalue.schema
can be omitted, butschema.generation.key.name
andschema.generation.value.name
must be set.- Importance: MEDIUM
- Type: BOOLEAN
- Default Value: false
schema.generation.key.fields
Field(s) use to build key schema. This is only used during schema generation. If
schema.generation.enabled
is true andschema.generation.key.fields
is set to empty list as[]
thenkey.schema
will be of type Struct with empty fields. Ifschema.generation.enabled
is true andschema.generation.key.fields
is set to list of field names then thekey.schema
will be generated by extracting the fields present in the list fromvalue.schema
.- Importance: MEDIUM
- Type: LIST
- Default Value: []
schema.generation.key.name
The name of the generated key schema.
- Importance: MEDIUM
- Type: STRING
- Default Value: defaultkeyschemaname
schema.generation.value.name
The name of the generated value schema.
- Importance: MEDIUM
- Type: STRING
- Default Value: defaultvalueschemaname
timestamp.field
The field in the value schema that contains the parsed timestamp for the record. This field cannot be marked as optional and must be a Timestamp.
- Importance: MEDIUM
- Type: STRING
- Default Value: “”
Timestamps¶
timestamp.mode
Determines how the connector sets the timestamp for the ConnectRecord. If set to
Field
, the timestamp is read from a field in the value. This field cannot be optional and must be a Timestamp. Specify the field intimestamp.field
. If set toFILE_TIME
, the last time the file was modified is used. If set toPROCESS_TIME
(the default), the time the record is read is used.- Importance: MEDIUM
- Type: STRING
- Default Value: PROCESS_TIME
- Validator: Matches:
FIELD
,FILE_TIME
,PROCESS_TIME
timestamp.field
The field in the value schema that contains the parsed timestamp for the record. This field cannot be marked as optional and must be a Timestamp.
- Importance: MEDIUM
- Type: STRING
parser.timestamp.date.formats
The date formats that are expected in the file. This is a list of strings that are used to parse the date fields in order. The most accurate date format should be first in the list. See the Java documentation for more information.
- Importance: LOW
- Type: LIST
- Default Value: [yyyy-MM-dd’T’HH:mm:ss, yyyy-MM-dd’ ‘HH:mm:ss]
parser.timestamp.timezone
The time zone used for all parsed dates.
- Importance: LOW
- Type: STRING
- Default Value: UTC