InnerSource is the term for the emerging practice of organizations adopting the open source methodology, albeit to develop proprietary software. This blog discusses the building of a model InnerSource ecosystem that leverages multiple AWS services, such as CodeBuild, CodeCommit, CodePipeline, CodeArtifact, and CodeGuru, along with other AWS services and open source tools.

What is InnerSource and why is it gaining traction?

Most software companies leverage open source software (OSS) in their products, as it is a great mechanism for standardizing software and bringing in cost effectiveness via the re-use of high quality, time-tested code. Some organizations may allow its use as-is, while others may utilize a vetting mechanism to ensure that the OSS adheres to the organization standards of security, quality, etc. This confidence in OSS stems from how these community projects are managed and sustained, as well as the culture of openness, collaboration, and creativity that they nurture.

Many organizations building closed source software are now trying to imitate these development principles and practices. This approach, which has been perhaps more discussed than adopted, is popularly called “InnerSource”. InnerSource serves as a great tool for collaborative software development within the organization perimeter, while keeping its concerns for IP & Legality in check. It provides collaboration and innovation avenues beyond the confines of organizational silos through knowledge and talent sharing. Organizations reap the benefits of better code quality and faster time-to-market, yet at only a fraction of the cost.

What constitutes an InnerSource ecosystem?

Infrastructure and processes that harbor collaboration stand at the heart of InnerSource ecology. These systems (refer Figure 1) would typically include tools supporting features such as code hosting, peer reviews, Pull Request (PR) approval flow, issue tracking, documentation, communication & collaboration, continuous integration, and automated testing, among others. Another major component of this system is an entry portal that enables the employees to discover the InnerSource projects and join the community, beginning as ordinary users of the reusable code and later graduating to contributors and committers.

A typical InnerSource ecosystem

Figure 1: A typical InnerSource ecosystem

More to InnerSource than meets the eye

This blog focuses on detailing a technical solution for establishing the required tools for an InnerSource system primarily to enable a development workflow and infrastructure. But the secret sauce of an InnerSource initiative in an enterprise necessitates many other ingredients.

InnerSource Roles & Use Cases

Figure 2: InnerSource Roles & Use Cases

InnerSource thrives on community collaboration and a low entry barrier to enable adoptability. In turn, that demands a cultural makeover. While strategically deciding on the projects that can be inner sourced as well as the appropriate licensing model, enterprises should bootstrap the initiative with a seed product that draws the community, with maintainers and the first set of contributors. Many of these users would eventually be promoted, through a meritocracy-based system, to become the trusted committers.

Over a set period, the organization should plan to move from an infra specific model to a project specific model. In a Project-specific InnerSource model, the responsibility for a particular software asset is owned by a dedicated team funded by other business units. Whereas in the Infrastructure-based InnerSource model, the organization provides the necessary infrastructure to create the ecosystem with code & document repositories, communication tools, etc. This enables anybody in the organization to create a new InnerSource project, although each project initiator maintains their own projects. They could begin by establishing a community of practice, and designating a core team that would provide continuing support to the InnerSource projects’ internal customers. Having a team of dedicated resources would clearly indicate the organization’s long-term commitment to sustaining the initiative. The organization should promote this culture through regular boot camps, trainings, and a recognition program.

Lastly, the significance of having a modular architecture in the InnerSource projects cannot be understated. This architecture helps developers understand the code better, as well as aids code reuse and parallel development, where multiple contributors could work on different code modules while avoiding conflicts during code merges.

A model InnerSource solution using AWS services

This blog discusses a solution that weaves various services together to create the necessary infrastructure for an InnerSource system. While it is not a full-blown solution, and it may lack some other components that an organization may desire in its own system, it can provide you with a good head start.

The ultimate goal of the model solution is to enable a developer workflow as depicted in Figure 3.

Typical developer workflow at InnerSource

Figure 3: Typical developer workflow at InnerSource

At the core of the InnerSource-verse is the distributed version control (AWS CodeCommit in our case). To maintain system transparency, openness, and participation, we must have a discovery mechanism where users could search for the projects and receive encouragement to contribute to the one they prefer (Step 1 in Figure 4).

Architecture diagram for the model InnerSource system

Figure 4: Architecture diagram for the model InnerSource system

For this purpose, the model solution utilizes an open source reference implementation of InnerSource Portal. The portal indexes data from AWS CodeCommit by using a crawler, and it lists available projects with associated metadata, such as the skills required, number of active branches, and average number of commits. For CodeCommit, you can use the crawler implementation that we created in the open source code repo at

The major portal feature is providing an option to contribute to a project by using a “Contribute” link. This can present a pop-up form to “apply as a contributor” (Step 2 in Figure 4), which when submitted sends an email (or creates a ticket) to the project maintainer/committer who can create an IAM (Step 3 in Figure 4) user with access to the particular repository. Note that the pop-up form functionality is built into the open source version of the portal. However, it would be trivial to add one with an associated action (send an email, cut a ticket, etc.).

InnerSource portal indexes CodeCommit repos and provides a bird’s eye view

Figure 5: InnerSource portal indexes CodeCommit repos and provides a bird’s eye view

The contributor, upon receiving access, logs in to CodeCommit, clones the mainline branch of the InnerSource project (Step 4 in Figure 4) into a fix or feature branch, and starts altering/adding the code. Once completed, the contributor commits the code to the branch and raises a PR (Step 5 in Figure 4). A Pull Request is a mechanism to offer code to an existing repository, which is then peer-reviewed and tested before acceptance for inclusion.

The PR triggers a CodeGuru review (Step 6 in Figure 4) that adds the recommendations as comments on the PR. Furthermore, it triggers a CodeBuild process (Steps 7 to 10 in Figure 4) and logs the build result in the PR. At this point, the code can be peer reviewed by Trusted Committers or Owners of the project repository. The number of approvals would depend on the approval template rule configured in CodeCommit. The Committer(s) can approve the PR (Step 12 in Figure 4) and merge the code to the mainline branch – that is once they verify that the code serves its purpose, has passed the required tests, and doesn’t break the build. They could also rely on the approval vote from a sanity test conducted by a CodeBuild process. Optionally, a build process could deploy the latest mainline code (Step 14 in Figure 4) on the PR merge commit.

To maintain transparency in all communications related to progress, bugs, and feature requests to downstream users and contributors, a communication tool may be needed. This solution does not show integration with any Issue/Bug tracking tool out of the box. However, multiple of these tools are available at the AWS marketplace, with some offering forum and Wiki add-ons in order to elicit discussions. Standard project documentation can be kept within the repository by using the constructs of the file to provide project mission details and the file to guide the potential code contributors.

An overview of the AWS services used in the model solution

The model solution employs the following AWS services:

  • Amazon CodeCommit: a fully managed source control service to host secure and highly scalable private Git repositories.
  • Amazon CodeBuild: a fully managed build service that compiles source code, runs tests, and produces software packages that are ready to deploy.
  • Amazon CodeDeploy: a service that automates code deployments to any instance, including EC2 instances and instances running on-premises.
  • Amazon CodeGuru: a developer tool providing intelligent recommendations to improve code quality and identify an application’s most expensive lines of code.
  • Amazon CodePipeline: a fully managed continuous delivery service that helps automate release pipelines for fast and reliable application and infrastructure updates.
  • Amazon CodeArtifact: a fully managed artifact repository service that makes it easy to securely store, publish, and share software packages utilized in their software development process.
  • Amazon S3: an object storage service that offers industry-leading scalability, data availability, security, and performance.
  • Amazon EC2: a web service providing secure, resizable compute capacity in the cloud. It is designed to ease web-scale computing for developers.
  • Amazon EventBridge: a serverless event bus that eases the building of event-driven applications at scale by using events generated from applications and AWS services.
  • Amazon Lambda: a serverless compute service that lets you run code without provisioning or managing servers.

The journey of a thousand miles begins with a single step

InnerSource might not be the right fit for every organization, but is a great step for those wanting to encourage a culture of quality and innovation, as well as purge silos through enhanced collaboration. It requires backing from leadership to sponsor the engineering initiatives, as well as champion the establishment of an open and transparent culture granting autonomy to the developers across the organization to contribute to projects outside of their teams. The organizations best-suited for InnerSource have already participated in open source initiatives, have engineering teams that are adept with CI/CD tools, and are willing to adopt OSS practices. They should start small with a pilot and build upon their successes.


Ever more enterprises are adopting the open source culture to develop proprietary software by establishing an InnerSource. This instills innovation, transparency, and collaboration that result in cost effective and quality software development. This blog discussed a model solution to build the developer workflow inside an InnerSource ecosystem, from project discovery to PR approval and deployment. Additional features, like an integrated Issue Tracker, Real time chat, and Wiki/Forum, can further enrich this solution.

If you need helping hands, AWS Professional Services can help adapt and implement this model InnerSource solution in your enterprise. Moreover, our Advisory services can help establish the governance model to accelerate OSS culture adoption through Experience Based Acceleration (EBA) parties.


About the authors

Debashish Chakrabarty

Debashish Chakrabarty

Debashish is a Senior Engagement Manager at AWS Professional Services, India managing complex projects on DevOps, Security and Modernization and help ProServe customers accelerate their adoption of AWS Services. He loves to keep connected to his technical roots. Outside of work, Debashish is a Hindi Podcaster and Blogger. He also loves binge-watching on Amazon Prime, and spending time with family.

Akash Verma

Akash Verma

Akash works as a Cloud Consultant for AWS Professional Services, India. He enjoys learning new technologies and helping customers solve complex technical problems and drive business outcomes by providing solutions using AWS products and services. Outside of work, Akash loves to travel, interact with new people and try different cuisines. He also enjoy gardening, watching Stand-up comedy, and listening to poetry.

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