LDAP Organizational Data · Backstage Software Catalog and Developer Platform

The Backstage catalog can be set up to ingest organizational data - users and groups - directly from an LDAP compatible service. The result is a hierarchy of User and Group kind entities that mirror your org setup.

Installation

This guide will use the Entity Provider method. If you for some reason prefer the Processor method (not recommended), it is described separately below.

The provider is not installed by default, therefore you have to add a dependency to @backstage/plugin-catalog-backend-module-ldap to your backend package.

# From your Backstage root directory
yarn add --cwd packages/backend @backstage/plugin-catalog-backend-module-ldap

Note: When configuring to use a Provider instead of a Processor you do not need to add a location pointing to your LDAP server

Update the catalog plugin initialization in your backend to add the provider and schedule it:

 // packages/backend/src/plugins/catalog.ts
+import { Duration } from 'luxon';
+import { LdapOrgEntityProvider } from '@backstage/plugin-catalog-backend-module-ldap';

 export default async function createPlugin(
   env: PluginEnvironment,
 ): Promise<Router> {
   const builder = await CatalogBuilder.create(env);

+  // The target parameter below needs to match the ldap.providers.target
+  // value specified in your app-config.
+  builder.addEntityProvider(
+    LdapOrgEntityProvider.fromConfig(env.config, {
+      id: 'our-ldap-master',
+      target: 'ldaps://ds.example.net',
+      logger: env.logger,
+      schedule: env.scheduler.createScheduledTaskRunner({
+        frequency: { minutes: 60 },
+        timeout: { minutes: 15 },
+      }),
+    }),
+  );

After this, you also have to add some configuration in your app-config that describes what you want to import for that target.

Configuration

The following configuration is a small example of how a setup could look for importing groups and users from a corporate LDAP server.

ldap:
  providers:
    - target: ldaps://ds.example.net
      bind:
        dn: uid=ldap-reader-user,ou=people,ou=example,dc=example,dc=net
        secret: ${LDAP_SECRET}
      users:
        dn: ou=people,ou=example,dc=example,dc=net
        options:
          filter: (uid=*)
        map:
          description: l
        set:
          metadata.customField: 'hello'
      groups:
        dn: ou=access,ou=groups,ou=example,dc=example,dc=net
        options:
          filter: (&(objectClass=some-group-class)(!(groupType=email)))
        map:
          description: l
        set:
          metadata.customField: 'hello'

There may be many providers, each targeting a specific target which is supposed to match the target of a dedicated provider instance - i.e., you will add one entity provider class instance per target to ingest from.

These config blocks have a lot of options in them, so we will describe each "root" key within the block separately.

target

This is the URL of the targeted server, typically on the form ldaps://ds.example.net for SSL enabled servers or ldap://ds.example.net without SSL.

bind

The bind block specifies how the plugin should bind (essentially, to authenticate) towards the server. It has the following fields.

dn: uid=ldap-reader-user,ou=people,ou=example,dc=example,dc=net
secret: ${LDAP_SECRET}

The dn is the full LDAP Distinguished Name for the user that the plugin authenticates itself as. At this point, only regular user based authentication is supported.

The secret is the password of the same user. In this example, it is given in the form of an environment variable LDAP_SECRET, that has to be set when the backend starts.

users

The users block defines the settings that govern the reading and interpretation of users. Its fields are explained in separate sections below.

users.dn

The DN under which users are stored, e.g. ou=people,ou=example,dc=example,dc=net.

users.options

The search options to use when sending the query to the server, when reading all users. All the options are shown below, with their default values, but they are all optional.

options:
  # One of 'base', 'one', or 'sub'.
  scope: one
  # The filter is the one that you commonly will want to specify explicitly. It
  # is a string on the standard LDAP query format. Use it to select out the set
  # of users that are of actual interest to ingest. For example, you may want
  # to filter out disabled users.
  filter: (uid=*)
  # The attribute selectors for each item, as passed to the LDAP server.
  attributes: ['*', '+']
  # This field is either 'false' to disable paging when reading from the
  # server, or an object on the form '{ pageSize: 100, pagePause: true }' that
  # specifies the details of how the paging shall work.
  paged: false

users.set

This optional piece lets you specify a number of JSON paths (on a.b.c form) and hard coded values to set on those paths. This can be useful for example if you want to hard code a namespace or similar on the generated entities.

set:
  # Just an example; the key and value can be anything
  metadata.namespace: 'ldap'

users.map

Mappings from well known entity fields, to LDAP attribute names. This is where you are able to define how to interpret the attributes of each LDAP result item, and to move them into the corresponding entity fields. All the options are shown below, with their default values, but they are all optional.

map:
  # The name of the attribute that holds the relative
  # distinguished name of each entry.
  rdn: uid
  # The name of the attribute that shall be used for the value of
  # the metadata.name field of the entity.
  name: uid
  # The name of the attribute that shall be used for the value of
  # the metadata.description field of the entity.
  description: description
  # The name of the attribute that shall be used for the value of
  # the spec.profile.displayName field of the entity.
  displayName: cn
  # The name of the attribute that shall be used for the value of
  # the spec.profile.email field of the entity.
  email: mail
  # The name of the attribute that shall be used for the value of
  # the spec.profile.picture field of the entity.
  picture: <nothing, left out>
  # The name of the attribute that shall be used for the values of
  # the spec.memberOf field of the entity.
  memberOf: memberOf

groups

The groups block defines the settings that govern the reading and interpretation of groups. Its fields are explained in separate sections below.

groups.dn

The DN under which groups are stored, e.g. ou=people,ou=example,dc=example,dc=net.

groups.options

The search options to use when sending the query to the server, when reading all groups. All the options are shown below, with their default values, but they are all optional.

options:
  # One of 'base', 'one', or 'sub'.
  scope: one
  # The filter is the one that you commonly will want to specify explicitly. It
  # is a string on the standard LDAP query format. Use it to select out the set
  # of groups that are of actual interest to ingest. For example, you may want
  # to filter out disabled groups.
  filter: (&(objectClass=some-group-class)(!(groupType=email)))
  # The attribute selectors for each item, as passed to the LDAP server.
  attributes: ['*', '+']
  # This field is either 'false' to disable paging when reading from the
  # server, or an object on the form '{ pageSize: 100, pagePause: true }' that
  # specifies the details of how the paging shall work.
  paged: false

groups.set

set:
  # Just an example; the key and value can be anything
  metadata.namespace: 'ldap'

groups.map

Mappings from well known entity fields, to LDAP attribute names. This is where you are able to define how to interpret the attributes of each LDAP result item, and to move them into the corresponding entity fields. All of the options are shown below, with their default values, but they are all optional.

If you leave out an optional mapping, it will still be copied using that default value. For example, even if you do not put in the field displayName in your config, the provider will still copy the attribute cn into the entity field spec.profile.displayName. If the target field is optional, such as the display name, the importer will accept missing attributes and just leave the target field unset. If the target field is mandatory, such as the name of the entity, validation will fail if the source attribute is missing.

map:
  # The name of the attribute that holds the relative
  # distinguished name of each entry. This value is copied into a
  # well known annotation to be able to query by it later.
  rdn: cn
  # The name of the attribute that shall be used for the value of
  # the metadata.name field of the entity.
  name: cn
  # The name of the attribute that shall be used for the value of
  # the metadata.description field of the entity.
  description: description
  # The name of the attribute that shall be used for the value of
  # the spec.type field of the entity.
  type: groupType
  # The name of the attribute that shall be used for the value of
  # the spec.profile.displayName field of the entity.
  displayName: cn
  # The name of the attribute that shall be used for the value of
  # the spec.profile.email field of the entity.
  email: <nothing, left out>
  # The name of the attribute that shall be used for the value of
  # the spec.profile.picture field of the entity.
  picture: <nothing, left out>
  # The name of the attribute that shall be used for the values of
  # the spec.parent field of the entity.
  memberOf: memberOf
  # The name of the attribute that shall be used for the values of
  # the spec.children field of the entity.
  members: member

Customize the Provider

In case you want to customize the ingested entities, the provider allows to pass transformers for users and groups. Here we will show an example of overriding the group transformer.

Create a transformer:

export async function myGroupTransformer(
  vendor: LdapVendor,
  config: GroupConfig,
  group: SearchEntry,
): Promise<GroupEntity | undefined> {
  // Transformations may change namespace, change entity naming pattern, fill
  // profile with more or other details...

  // Create the group entity on your own, or wrap the default transformer
  return await defaultGroupTransformer(vendor, config, group);
}

Configure the provider with the transformer:

const ldapEntityProvider = LdapOrgEntityProvider.fromConfig(env.config, {
  id: 'our-ldap-master',
  target: 'ldaps://ds.example.net',
  logger: env.logger,
  groupTransformer: myGroupTransformer,
});

Using a Processor instead of a Provider

An alternative to using the Provider for ingesting LDAP entries is to use a Processor. This is the old way that's based on registering locations with the proper type and target, triggering the processor to run.

The drawback of this method is that it will leave orphaned Group/User entities whenever they are deleted on your LDAP server, and you cannot control the frequency with which they are refreshed, separately from other processors.

Processor Installation

The LdapOrgReaderProcessor is not registered by default, so you have to register it in the catalog plugin:

// packages/backend/src/plugins/catalog.ts
builder.addProcessor(
  LdapOrgReaderProcessor.fromConfig(env.config, {
    logger: env.logger,
  }),
);

Driving LDAP Org Processor Ingestion with Locations

Locations point out the specific org(s) you want to import. The type of these locations must be ldap-org, and the target must point to the exact URL (starting with ldap:// or ldaps://) of the targeted LDAP server. You can have several such location entries if you want, but typically you will have just one.

catalog:
  locations:
    - type: ldap-org
      target: ldaps://ds.example.net
      rules:
        - allow: [User, Group]