Sling RepoInit: a Handy Tool to Manage Content and Users in AEM

Tech Tips

Exadel Marketing Technology Team Jan 6, 2021

#AEM #AEM tips #content migration #Sling

Managing the initial repository state can be hard because it involves setting up code, configuration, content, and more. This is a lot to cope with when we need to complete several tasks in advance, such as creating service users, creating groups, setting up ACL permissions, and pre-creating/updating content. Repoinit (Apache Sling Repository Initialization) is a tool to help configure all of this in one place.

The advantages of Repoinit include:

Keeping the environments in sync in terms of initial and basic configuration
Speeding up local environment setup for developers
Creating resources at startup so they’re built into the logic from the beginning

Enable Repoinit in AEM

To enable Repoinit, OSGi configuration for factory PID org.apache.sling.jcr.repoinit.RepositoryInitializer in one of the project’s configuration folders. Since it’s an OSGi configuration, it is easy to have a set of scripts for author and publish run modes, along with different environments such as Stage and Production. For example, config.author, config.publish, config.author.prod, and config.publish.stage, etc. use a descriptive name for the configuration like org.apache.sling.jcr.repoinit.RepositoryInitializer~init.

These configurations have two optional fields:

A multi-value references field with each value providing the URL (as a String) of raw Repoinit statements
A multi-value scripts field with each value providing Repoinit statements as plain text in a String

Apache Repo

Note 1: this service presents a challenge when you’re resolving the references. Each reference is expected to be in the form of a URL, and OSGi supports exposing bundles as URLs. However, when Apache Felix resolves a bundle’s URL in the URLHandlersBundleStreamHandler, it expects the URL host to be the UUID of the bundle, not a stable ID such as the Bundle’s Symbolic Name. You can find out how to resolve this issue here.

Note 2: When configuring script properties, it is easier to define them in the .config file than it is to define in the JSON-based .cfg.json format, since scripts are typically multiline.

Configuration file example: /apps/my-app/config.author/org.apache.sling.jcr.repoinit.RepositoryInitializer-init.config

scripts=["
    create service user my-data-reader-service

    set ACL on /var/my-data
        allow jcr:read for my-data-reader-service
    end

    create path (sling:Folder) /conf/my-app/settings
"]

scripts=["

create service user my-data-reader-service

set ACL on /var/my-data

allow jcr:read for my-data-reader-service

end

create path (sling:Folder) /conf/my-app/settings

Repoinit vs. Ensure Authorizable

Ensure Service User config:
/ui.apps/src/main/content/jcr_root/apps/site-com/config/com.adobe.acs.commons.users.impl.EnsureServiceUser-user-1.xml (this is the config for user-1 only; for user-2 we will need to create a separate xml config)

<!--?xml version="1.0" encoding="UTF-8"?-->
<jcr:root xmlns:sling="http://sling.apache.org/jcr/sling/1.0" xmlns:jcr="http://www.jcp.org/jcr/1.0" jcr:primarytype="sling:OsgiConfig" principalname="user-1" operation="add" ensure-immediately="{Boolean}true" aces="[type=allow;privileges=jcr:read;path=/content/dam]">
</jcr:root>

<jcr:root xmlns:sling="http://sling.apache.org/jcr/sling/1.0" xmlns:jcr="http://www.jcp.org/jcr/1.0" jcr:primarytype="sling:OsgiConfig" principalname="user-1" operation="add" ensure-immediately="{Boolean}true" aces="[type=allow;privileges=jcr:read;path=/content/dam]">

</jcr:root>

Equivalent Repoinit script:

create service user user-1, user-2

set ACL on /content/dam
    allow jcr:read for user-1,user-2
end

set ACL on /content/dam

allow jcr:read for user-1,user-2

end

Content Management: Repoinit vs. OnDeploy Scripts

Imagine that we need to create a “/path/A” resource and update the existing one under “/path/B”.

The OnDeplyScript might look something like this:

public class PrecreateContentScript extends OnDeployScriptBase {

    @Override
    protected void execute() throws Exception {
        Resource parent = this.getResourceResolver().resolve("/path");
        this.getResourceResolver().create(parent, "A",
                ImmutableMap.of(
                        "sling:ResourceType", "x/y/z",
                        "someInteger", 42,
                        "someBoolean", true,
                        "someDate", new Date()));

        Resource b = this.getResourceResolver().resolve("/path/B");
        ValueMap map = b.adaptTo(ModifiableValueMap.class);

        map.putIfAbsent("sling:ResourceType", "x/y/z");
        map.putIfAbsent("someInteger", 42);
        map.putIfAbsent("someBoolean", true);
        map.putIfAbsent("someDate", new Date());
    }
}

public class PrecreateContentScript extends OnDeployScriptBase {

@Override

protected void execute() throws Exception {

Resource parent = this.getResourceResolver().resolve("/path");

this.getResourceResolver().create(parent, "A",

ImmutableMap.of(

"sling:ResourceType", "x/y/z",

"someInteger", 42,

"someBoolean", true,

"someDate", new Date()));

Resource b = this.getResourceResolver().resolve("/path/B");

ValueMap map = b.adaptTo(ModifiableValueMap.class);

map.putIfAbsent("sling:ResourceType", "x/y/z");

map.putIfAbsent("someInteger", 42);

map.putIfAbsent("someBoolean", true);

map.putIfAbsent("someDate", new Date());

}

And this is a script which does the same thing:

create path (nt:unstructured) /path/A
set properties on /path/A, /path/B
  set sling:ResourceType{String} to /x/y/z
  default someInteger{Long} to 42
  set someFlag{Boolean} to true
  default someDate{Date} to "2020-03-19T11:39:33.437+05:30"
end

create path (nt:unstructured) /path/A

set properties on /path/A, /path/B

set sling:ResourceType{String} to /x/y/z

default someInteger{Long} to 42

set someFlag{Boolean} to true

default someDate{Date} to "2020-03-19T11:39:33.437+05:30"

end

These are just a few examples of how we used Repoinit for our project; find more ideas about what you can do using Repoinit here.

Author: Iryna Ason

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