Summarizing the findings thus far:

• karaf has many commands that help with detecting and solving errors, such as "import" and "export", which list packages being exported from or imported into various bundles
• unix commands such as "grep" and "wc -l" are supported, making debugging faster and easier
• the framework does not appear to contain service component infrastructure needed by this project

In the previous comment, I said "the framework does not appear to contain service component infrastructure needed by this project."

This seems very strange!

I found a Web page on karaf that mentioned some useful commands, include "feature:list".

There are 174 "features" listed! One of these is "scr", with Description "Declarative Service support." Its current "State" is "Uninstalled."

Maybe, if I somehow "install" this feature, I would not need to install the "org.osgi:org.osgi.service.component" bundle from my local "mvn" repository?

So, I tried to install it with:

karaf@root()> feature:install scr

After this, the "scr" feature State changed to "Started."

I then uninstalled the previously installed bundles. Freshly attempting to re-install and re-start bundle org.wso2.carbon/org.wso2.carbon.book.provider/1.0-SNAPSHOT succeeded without any error.

I then quit and restarted karaf with a fresh, clean environment with "karaf clean".
I confirmed that the "scr" feature was not active. I then activated it as before with "feature:install scr" and then tried to load the "provider" bundle.

This time, it loaded without any error.

Thus, karaf actually does contain support declarative services. You just have to install that feature within the framework to activate it, I guess.

Trying now to figure out which version of declarative services / scr is used in this tutorial.

I was able to build it using JDK 11 and run it in the latest version (4.3.9) of karaf, also running in JDK 11. This suggests that maybe the most up-to-date system for declarative services is being used?

Upon consultation with Nowlan Freese, we realized that the only way to be truly sure about this is to look at the package import statements in the code.

Investigating the code:

package org.wso2.carbon.book.provider.internal;

import org.osgi.framework.BundleContext;
import org.osgi.service.component.ComponentContext;
import org.osgi.service.component.annotations.Activate;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Deactivate;
import org.wso2.carbon.book.provider.BookProvider;
import org.wso2.carbon.book.provider.BookProviderImpl;

import java.util.logging.Logger;

@Component(
        name = "org.wso2.carbon.book.provider",
        immediate = true
)

Now, looking at Component imports in an IGB project (master branch, jdk 1.8 build):

• ./core/igb-services-api/src/main/java/org/lorainelab/igb/services/search/SearchModeRegistry.java

imports and Component annotation:

import aQute.bnd.annotation.component.Component;
import aQute.bnd.annotation.component.Reference;
...
@Component(name = SearchModeRegistry.COMPONENT_NAME, immediate = true, provide = SearchModeRegistry.class)

Our project (IGB) does not appear to be using felix scr but instead is using something perhaps even older - annotations from package aQute.bnd.annotation.component.