schema-registry-cli

#!/usr/bin/env bash

# Check required binaries: curl
if [[ -z $(which curl) ]]; then
  echo "curl not installed; exit."
  exit 1
fi

ProgName=$(basename $0)

# functions:

# _run
# _help

# _schema
# _schema_help
# _schema_types
# _schema_show
# _schema_version

# _subject
# _subject_help
# _subject_version
# _subject_version_help
# _subject_version_list
# _subject_version_show
# _subject_version_delete
# _subject_version_ref

# _subject_schema
# _subject_schema_help
# _subject_schema_show
# _subject_schema_create

# _subject_list
# _subject_create
# _subject_delete

# _config

function _run {
  if [ "${DRY_RUN}" = "1" ]; then
    echo $1
  else
    eval $1
  fi
}

function _help {
  echo "Usage: $ProgName <subcommand> [options]"
  echo ""
  echo "Subcommands:"
  echo ""
  echo "  schema     schema commands."
  echo "  subject    subject commands."
  echo "  config     show config."
  echo ""
  echo "For help with each subcommand, run:"
  echo ""
  echo "  $ProgName <subcommand> -h|--help"
  echo ""
  echo "For Rest API documentation, see:"
  echo ""
  echo "  https://docs.confluent.io/current/schema-registry/develop/api.html"
  echo ""
}

function _schema {
  subcommand=$1
  case $subcommand in
    "" | "-h" | "--help")
      _schema_help
      ;;
    *)
      shift
      _schema_${subcommand} $@
      if [ $? = 127 ]; then
        echo "Error: '$subcommand' is not a known subcommand of $ProgName schema." >&2
        echo "Run '$ProgName schema --help' for a list of known subcommands." >&2
        return 1
      fi
      ;;
  esac
}

function _schema_help {
  echo "Usage: $ProgName schema <subcommand> [options]"
  echo ""
  echo "Subcommands:"
  echo "  types     Get the schema types that are registered with Schema Registry."
  echo "  show      Get the schema string identified by the input ID."
  echo "  version   Get the subject-version pairs identified by the input ID."
  echo ""
}

function _schema_types {
  _run "curl -s -X GET -H \"Content-Type: application/vnd.schemaregistry.v1+json\" http://$SCHEMA_REGISTRY_URL/schemas/types"
}

function _schema_show {
  [[ -z $1 ]] && echo "Usage: $ProgName schema show {schema-id}" && return 1

  _run "curl -s -X GET -H \"Content-Type: application/vnd.schemaregistry.v1+json\" http://$SCHEMA_REGISTRY_URL/schemas/ids/$1"
}

function _schema_version {
  [[ -z $1 ]] && echo "Usage: $ProgName schema version {schema-id}" && return 1
  
  _run "curl -s -X GET -H \"Content-Type: application/vnd.schemaregistry.v1+json\" http://$SCHEMA_REGISTRY_URL/schemas/ids/$1/versions"
}

function _subject {
  subcommand=$1
  case $subcommand in
    "" | "-h" | "--help")
      _subject_help
      ;;
    *)
      shift
      _subject_${subcommand} $@
      if [ $? = 127 ]; then
        echo "Error: '$subcommand' is not a known subcommand of $ProgName subject." >&2
        echo "Run '$ProgName subject --help' for a list of known subcommands." >&2
        return 1
      fi
      ;;
  esac
}

function _subject_help {
  echo "Usage: $ProgName subject <subcommand> [options]"
  echo ""
  echo "Subcommands:"
  echo "  version    version management."
  echo "  schema     schema management."
  echo "  list       Get the subject-version pairs identified by the input ID."
  echo "  create     Register a new schema under the specified subject. (Essentially, create a new schema.)"
  echo "  delete     Deletes the specified subject and its associated compatibility level if registered."
  echo ""
}

function _subject_version {
  subcommand=$1
  case $subcommand in
    "" | "-h" | "--help")
      _subject_version_help
      ;;
    *)
      shift
      _subject_version_${subcommand} $@
      if [ $? = 127 ]; then
        echo "Error: '$subcommand' is not a known subcommand of $ProgName subject version." >&2
        echo "Run '$ProgName subject version --help' for a list of known subcommands." >&2
        return 1
      fi
      ;;
  esac
}

function _subject_version_help {
  echo "Usage: $ProgName subject version <subcommand> [options]"
  echo ""
  echo "Subcommands:"
  echo "  list   Get a list of versions registered under the specified subject."
  echo "  show   Get a specific version of the schema registered under this subject."
  echo "  delete Deletes a specific version of the schema registered under this subject."
  echo "  ref    Get a list of IDs of schemas that reference the schema with the given subject and version."
  echo ""
}

function _subject_version_list {
  [[ -z $1 ]] && echo "Usage: $ProgName subject version list {subject}" && return 1

  _run "curl -s -X GET -H \"Content-Type: application/vnd.schemaregistry.v1+json\" http://$SCHEMA_REGISTRY_URL/subjects/$1/versions"
}

function _subject_version_show {
  [[ -z $1 ]] && echo "Usage: $ProgName subject version show {subject} {version}" && return 1
  [[ -z $2 ]] && echo "Usage: $ProgName subject version show {subject} {version}" && return 1

  _run "curl -s -X GET -H \"Content-Type: application/vnd.schemaregistry.v1+json\" http://$SCHEMA_REGISTRY_URL/subjects/$1/versions/$2"
}

function _subject_version_delete {
  [[ -z $1 ]] && echo "Usage: $ProgName subject version delete {subject} {version}" && return 1
  [[ -z $2 ]] && echo "Usage: $ProgName subject version delete {subject} {version}" && return 1

  _run "curl -s -X DELETE -H \"Content-Type: application/vnd.schemaregistry.v1+json\" http://$SCHEMA_REGISTRY_URL/subjects/$1/versions/$2"
}

function _subject_version_ref {
  [[ -z $1 ]] && echo "Usage: $ProgName subject version ref {subject} {version}" && return 1
  [[ -z $2 ]] && echo "Usage: $ProgName subject version ref {subject} {version}" && return 1

  _run "curl -s -X GET -H \"Content-Type: application/vnd.schemaregistry.v1+json\" http://$SCHEMA_REGISTRY_URL/subjects/$1/versions/$2/referencedby"
}

function _subject_schema {
  subcommand=$1
  case $subcommand in
    "" | "-h" | "--help")
      _subject_schema_help
      ;;
    *)
      shift
      _subject_schema_${subcommand} $@
      if [ $? = 127 ]; then
        echo "Error: '$subcommand' is not a known subcommand of $ProgName subject schema." >&2
        echo "Run '$ProgName subject schema --help' for a list of known subcommands." >&2
        return 1
      fi
      ;;
  esac
}

function _subject_schema_help {
  echo "Usage: $ProgName subject schema <subcommand> [options]"
  echo ""
  echo "Subcommands:"
  echo "  show   Get the schema for the specified version of this subject."
  echo "  create Register a new schema under the specified subject. (Essentially, create a new schema.)"
  echo ""
}

function _subject_schema_show {
  [[ -z $1 ]] && echo "Usage: $ProgName subject schema show {subject} {version}" && return 1
  [[ -z $2 ]] && echo "Usage: $ProgName subject schema show {subject} {version}" && return 1

  _run "curl -s -X GET -H \"Content-Type: application/vnd.schemaregistry.v1+json\" http://$SCHEMA_REGISTRY_URL/subjects/$1/versions/$2/schema"
}

function _subject_schema_create {
  [[ -z $1 ]] && echo "Usage: $ProgName subject schema create {subject} {schema-json}" && return 1

  if [[ -z $2 ]]; then
    # schema-json is not provided; read from stdin.
    if [[ -p /proc/self/fd/0 ]]; then
      schema_json=$(cat /dev/stdin | tr -d '\n' | tr -d ' ')
    else
      echo "Usage: $ProgName subject schema create {subject} {schema-json}"
      return 1
    fi
  else
    # schema-json is provided
    schema_json=$(echo $2 | tr -d '\n' | tr -d ' ')
  fi

  _run "curl -s -X POST -H \"Content-Type: application/vnd.schemaregistry.v1+json\" -d '{\"schema\":\"$(echo $schema_json | sed -e 's/"/\\"/g')\"}' http://$SCHEMA_REGISTRY_URL/subjects/$1/versions"
}

function _subject_list {
  _run "curl -s -X GET -H \"Content-Type: application/vnd.schemaregistry.v1+json\" http://$SCHEMA_REGISTRY_URL/subjects"
}

function _subject_create {
  [[ -z $1 ]] && echo "Usage: $ProgName subject create {subject} {schema-json}" && return 1

  if [[ -z $2 ]]; then
    # schema-json is not provided; read from stdin.
    if [[ -p /proc/self/fd/0 ]]; then
      schema_json=$(cat /dev/stdin | tr -d '\n' | tr -d ' ')
    else
      echo "Usage: $ProgName subject schema create {subject} {schema-json}"
      return 1
    fi
  else
    # schema-json is provided
    schema_json=$(echo $2 | tr -d '\n' | tr -d ' ')
  fi

  _run "curl -s -X POST -H \"Content-Type: application/vnd.schemaregistry.v1+json\" -d '{\"schema\":\"$(echo $schema_json | sed -e 's/"/\\"/g')\"}' http://$SCHEMA_REGISTRY_URL/subjects/$1"
}

function _subject_delete {
  [[ -z $1 ]] && echo "Usage: $ProgName subject delete {subject}" && return 1

  _run "curl -s -X DELETE -H \"Content-Type: application/vnd.schemaregistry.v1+json\" http://$SCHEMA_REGISTRY_URL/subjects/$1"
}

function _config {
  _run "curl -s -X GET -H \"Content-Type: application/vnd.schemaregistry.v1+json\" http://$SCHEMA_REGISTRY_URL/config"
}

SCHEMA_REGISTRY_HOST=${KAFKA_CONNECT_HOST:-localhost}
SCHEMA_REGISTRY_PORT=${KAFKA_CONNECT_PORT:8080}
KAFKA_CONNECT_URL=${KAFKA_CONNECT_URL:-${SCHEMA_REGISTRY_HOST}:${SCHEMA_REGISTRY_PORT}}

DRY_RUN=${DRY_RUN:0}

subcommand=$1
case $subcommand in
  "" | "-h" | "--help")
    _help
    ;;
  *)
    shift
    _${subcommand} $@
    if [ $? = 127 ]; then
      echo "Error: '$subcommand' is not a known subcommand." >&2
      echo "Run '$ProgName --help' for a list of known subcommands." >&2
      exit 1
    fi
    ;;
esac