Build a CI/CD pipeline by using Oracle Cloud Infrastructure DevOps service and Oracle Cloud Infrastructure Functions
Rapid delivery of software is essential for efficiently running your applications in the cloud. Oracle DevOps service provides a continuous integration and deployment (CI/CD) platform for developers. You can use the DevOps service to easily build, test, and deploy software and applications on Oracle Cloud. DevOps build and deployment pipelines reduce change-driven errors and decrease the time customers spend on building and deploying releases.
The service also provides private Git repositories to store your code and it supports connections to external code repositories. Whether you're migrating workloads to Oracle Cloud Infrastructure (OCI)—from on-premises or other clouds—or developing new applications on OCI, you can use the DevOps service to simplify your software delivery lifecycle.
Architecture
In this reference architecture, you will build and deploy python application by using OCI DevOps and OCI Function services.
The application source code is hosted on a DevOps code repository. The end user commits the code into the code repository. A new commit to the code repository will trigger the start of a build pipeline. The build pipeline follows a user-defined flow to build the function artifacts to deploy to OCI Function services. The output of the build is stored in the container registry as Docker images. The deployment pipeline then uses the built image from the container registry to deploy to the OCI Functions environment. The following architecture diagram shows how an application is built and deployed by using a default image and a custom image (by using a Dockerfile).
To simplify the setup of this example CI/CD workflow, this sample application uses Terraform to automate creation and configuration of DevOps resources.
The following diagram illustrates this reference architecture.
Description of the illustration cicd-pipe-devops-functions-arch.png
cicd-pipe-devops-functions-arch-oracle.zip
- Region
An OCI region is a localized geographic area that contains one or more data centers, called availability domains. Regions are independent of other regions, and vast distances can separate them (across countries or even continents). The architecture uses a single region.
- DevOps project
A logical grouping of DevOps resources needed to implement a CI/CD workflow. DevOps resources can be artifacts, build pipelines, deployment pipelines, external connections, triggers, and environments. DevOps projects make it easy to enable logging, monitoring, and notifications for all your DevOps resources.
- Build pipeline
A build pipeline takes a commit ID from your source code repositories and uses that source code to run your build instructions. Build pipelines define a set of stages for the build process: building, testing and compiling software artifacts, delivering artifacts to OCI repositories, and optionally triggering a deployment. You define the flow and instructions of your build run in the build spec file.
- Code repository
Private Git repositories hosted by the DevOps service. You can store, manage, develop source code with our DevOps Code Repositories.
- Deployment pipeline
A sequence of steps for delivering and deploying a set of artifacts to a target environment. The flow and logic of your software release can be controlled by defining stages that can run in serial or parallel.
- Deployment stages
Stages are individual actions that take place during a run of a pipeline. The DevOps deployment pipeline includes the following predefined stage types for you to use in your release process:
- Rolling deployment: An incremental release to Oracle Container Engine for Kubernetes (OKE), Functions, or instance groups
- Wait: Wait N seconds
- Manual approval: Proceed if an approval is given; stop if an approval is rejected.
- Invoke function: Perform custom tasks or integrations by calling a Function and pass an artifact of request parameters.
- DevOps artifact
A DevOps artifact is a reference or pointer to any file, binary, package, manifest, or image that makes up your application. When creating an artifact, inform Oracle DevOps of the source location of the actual artifact. DevOps supports OCI Container Image Registry and OCI Artifact Registry repositories.
- Artifact repository
Artifact repository creates repositories to group similar artifacts. When the repository is created, you can upload artifacts to it. These artifacts are a collection of text files, binaries, and deployment manifests that are delivered to the target deployment environment. Each artifact has a name, which is made of its path: version. The path is a string to organize the artifacts.
- OCI Logging and Notification services
OCI Logging service stores logs related to the deployment. The deployment runtime output and the final results of the deployment are shown as log entries. OCI Notifications service provides visibility into the latest state of the deployment project and its resources and takes any necessary action. For example, you're notified when an important event, such as a stage in a deploy pipeline waiting for approval. When you receive the notification message, you can go to DevOps deployment pipelines and approve the stage.
- Deployment environments
An environment is a collection of a customer’s computing resources where artifacts are deployed. Environments can be a function, Compute virtual machine (VM) or bare metal instance, or an OKE cluster.
- Oracle Kubernetes cluster: OCI Container Engine for Kubernetes (OKE) is a fully managed, scalable, and highly available service that you can use to deploy your containerized applications to the cloud.
- Compute instances: The OCI Compute service enables you provision and manage Compute hosts in the cloud. You can deploy Compute instances with shapes that meet your resource requirements for CPU, memory, network bandwidth, and storage.
- Functions: Oracle Functions is a fully managed, multitenant, highly scalable, on-demand, functions-as-a-service platform. The service is built on enterprise-grade Oracle Cloud Infrastructure and powered by the Fn Project open source engine.
Recommendations
- Memory allocation and time out for functions
We can alter the configuration by updating func.yaml file, per the following settings:
Parameter Description Settings Maximum time a function will be allowed to run - Default Value: 30
- Units: Seconds
- func.yaml Parameter: timeout
- Environment Variable: n/a
- Fn CLI Option: n/a
- Notes:
- Maximum value: 300
- Best practice is to specify a timeout that is close to that likely to be required, rather than significantly more.
Maximum memory threshold for a function - Default Value: 128
- Units: MB
- func.yaml Parameter: memory
- Environment Variable: FN_MEMORY
- Fn CLI Option: n/a
- Notes:
One of:
- 128
- 256
- 512
- 1024
- Virtual Cloud Network (VCN)
When you create a VCN, determine the number of CIDR blocks required and the size of each block based on the number of resources that you plan to attach to subnets in the VCN. Use CIDR blocks that are within the standard private IP address space.
After you create a VCN, you can change, add, and remove its CIDR blocks.
This architecture uses a public VCN to host OKE. You can also use a private VCN. In that case, use a NAT gateway to give the cluster access over the public internet.
- Container Image Registry
This architecture deploys registry as a private Docker registry for internal use. Docker images are pushed to and pulled from the registry. You can also use registry as a public Docker registry, enabling any user with internet access and knowledge of the appropriate URL to pull images from public repositories in OCI.
Considerations
When building and deploying Python applications by using OCI DevOps and OCI Function services, consider:
- DevOps supports deployments to OKE, Compute hosts, and Functions.
- When deploying an instance group to Compute, only Linux hosts are supported.
- Artifacts deployed with DevOps must be in an OCI artifact registry or container image registry repository.
- The best practice is to group each application and all its microservices into a single project.
Deploy
The code required to deploy this reference architecture is available in GitHub. You can pull the code into Oracle Cloud Infrastructure Resource Manager with a single click, create the stack, and deploy it. Alternatively, download the code from GitHub to your computer, customize the code, and deploy the architecture by using the Terraform CLI.
- Deploy using the sample stack in Oracle Cloud Infrastructure Resource
Manager:
- Click
If you aren't already signed in, enter the tenancy and user credentials.
- Select the region where you want to deploy the stack.
- Follow the on-screen prompts and instructions to create the stack.
- After creating the stack, click Terraform Actions, and select Plan.
- Wait for the job to be completed, and review the plan.
To make any changes, return to the Stack Details page, click Edit Stack, and make the required changes. Then, run the Plan action again.
- If no further changes are necessary, return to the Stack Details page, click Terraform Actions, and select Apply.
- Click
- Deploy using the Terraform code in GitHub:
- Go to GitHub.
- Clone or download the repository to your local computer.
- Follow the instructions in the
READMEdocument.