lensesio / schema-registry

A CLI and Go client for Kafka Schema Registry. This repository is deprecated and no longer maintained.

Schema Registry CLI and client

This repository contains a Command Line Interface (CLI) and a Go client for the REST API of Confluent's Kafka Schema Registry.

CLI

To install the CLI, assuming a properly setup Go installation, do:

go get -u github.com/landoop/schema-registry/schema-registry-cli

After that, the CLI is found in $GOPATH/bin/schema-registry-cli. Running schema-registry-cli without arguments gives:

A command line interface for the Confluent schema registry

Usage:
  schema-registry-cli [command]

Available Commands:
  add         registers the schema provided through stdin
  compatible  tests compatibility between a schema from stdin and a given subject
  exists      checks if the schema provided through stdin exists for the subject
  get         retrieves a schema specified by id or subject
  get-config  retrieves global or suject specific configuration
  subjects    lists all registered subjects
  versions    lists all available versions

Flags:
  -h, --help         help for schema-registry-cli
  -n, --no-color     dont color output
  -e, --url string   schema registry url, overrides SCHEMA_REGISTRY_URL (default "http://localhost:8081")
  -v, --verbose      be verbose

Use "schema-registry-cli [command] --help" for more information about a command.

The schema registry url can be configured through the SCHEMA_REGISTRY_URL environment variable, and overridden through --url. When none is provided, http://localhost:8081 is used as default.

Client

The client package provides a client to deal with the registry from code. It is used by the CLI internally. Usage looks like:

import "github.com/landoop/schema-registry"

client, _ := schemaregistry.NewClient(schemaregistry.DefaultUrl)
client.Subjects()

Or, to use with a Schema Registry endpoint listening on HTTPS:

import (
    "crypto/tls"
    "crypto/x509"
    "io/ioutil"

    "github.com/landoop/schema-registry"
)

// Create a TLS config to use to connect to Schema Registry. This config will permit TLS connections to an endpoint
// whose TLS cert is signed by the given caFile.
caCert, err := ioutil.ReadFile("/path/to/ca/file")
if err != nil {
    panic(err)
}

caCertPool := x509.NewCertPool()
caCertPool.AppendCertsFromPEM(caCert)

tlsConfig :=  &tls.Config{
    RootCAs:            caCertPool,
    InsecureSkipVerify: true,
}

httpsClientTransport := &http.Transport{
  TLSClientConfig: tlsConfig,
}

httpsClient := &http.Client{
  Transport: httpsClientTransport,
}

// Create the Schema Registry client
client, _ := schemaregistry.NewClient(baseurl, UsingClient(httpsClient))
client.Subjects()

The documentation of the package can be found here:

schema-registry's Issues

Provide/document schema registry url environment variable

Not sure if Viper already provides this, and what the name is then. Is convenient though.

Sub schema reference support?

I am interested to know if the current release offers to define sub-schemas? Schemas can get very complex and I believe having separate nested schemas that can be referenced into the main schema can improve the maintainability?

Is that something currently offered or planned to include in future releases?

Regards
Bhupinder

Fix linter warnings

Pretty print json output (avsc)

Controllable through some -flag

Support compatibility testing

http://docs.confluent.io/3.0.0/schema-registry/docs/api.html#id1

License?

I noticed there was once an Apache 2.0 license in one of the files, but no license information anywhere else. Could you add a LICENSE file, or clarify what the license is for this project?

Expose schema registry errors

Hello,

Thanks for this great library!
I was wondering if there's a simple way to check for "subject not found" errors.

I can see that in the IsRegistered method, there's a check for schema not found error:

if ce, confluentErr := err.(confluentError); confluentErr && ce.ErrorCode == schemaNotFound {
	return false, fs, nil
}

But the const subjectNotFound is not used on the project. Is there any reason behind that?

Thanks!

Client interface

Hi,

We're using this project and thought it might benefit from Client being an interface rather then a struct.

This allows one to mock the Client, among other possibilities.

Currently, we're using a fork with this change, but I figured I might as well suggest it here in case there's interest.

If there is, please let me know and I can submit a PR.

Does it support caching the response?

We do not want to query the registry every time but want to do only when required or in some interval. Does it support caching?

Support compatibility configuration

per subject: http://docs.confluent.io/3.0.0/schema-registry/docs/api.html#put--config-(string- subject)
globally:
http://docs.confluent.io/3.0.0/schema-registry/docs/api.html#put--config
http://docs.confluent.io/3.0.0/schema-registry/docs/api.html#get--config
http://docs.confluent.io/3.0.0/schema-registry/docs/api.html#get--config-(string- subject)

Is this repo still active?

No commits for a year and no releases since 2017. No go.mod support. Is this still maintained?

Encoding support

In order to use this client library with kafka for sending messages under the correct encoding, it would be beneficial to have a method like encode_record_with_schema like the Python Kafka schema registry library:

https://github.com/verisign/python-confluent-schemaregistry