182 lines
9.2 KiB
Markdown
182 lines
9.2 KiB
Markdown
# Project Description
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Every organization has unique policies that affect the entire stack. These policies are vital to long term success because they codify
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important requirements around cost, performance, security, legal regulation, and more. At the same time, organizations often rely on
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tribal knowledge and documentation to ensure that policies are enforced correctly. While these approaches are known to be error prone,
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they exist because systems frequently lack the flexibility and expressiveness required to automate policy enforcement.
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The Open Policy Agent (OPA) is a general-purpose policy engine that enables unified, context-aware policy enforcement across the stack.
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OPA empowers administrators with greater control and flexibility so that organizations can automate policy enforcement at any layer.
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At the core of OPA is a high-level declarative language (and runtime) that allows administrators to enforce policies across multiple
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domains such as API authorization, admission control, workload placement, storage, and networking. OPA’s language is purpose-built for
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expressing policy decisions. The language has rich support for processing complex data structures as well as performing search and
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aggregation across context required for policy decisions. The language also provides support for encapsulation and composition so that
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complex policies can be shared and re-used. Finally, the language includes a standard library of built-in functions for performing math
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operations, string manipulation, date/time parsing, and more.
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With OPA, policy decisions are decoupled from applications and services so that policy logic can be modified easily and upgraded
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on-the-fly without requiring expensive, time consuming development and release cycles.
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OPA provides simple APIs to offload policy decisions from applications and services. Policy decisions are computed by OPA and returned
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to callers as structured data. Callers integrate with OPA by executing policy queries that can include arbitrary input values. For
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example, an API gateway might supply incoming API requests as input and expect boolean values (representing allow/deny decisions) as
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output. On the other hand, a container orchestrator might supply workload resources as input and expect a map of clusters and weights
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to drive workload placement as output. See the appendix for sample policies that cover these use cases.
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OPA itself is written in Go and can be integrated as a library, host-level daemon, or sidecar container. OPA provides APIs to load and
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manage policies as well as external data. Finally, OPA provides rich tooling to support the development, testing, and debugging of
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policies.
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Since the initial release in July 2016, OPA’s mission has been to provide a powerful building block that enables policy-based control
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across the stack. OPA’s roadmap for the next 12 months includes improvements to the language, integration with Google’s CEL, expansion
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of the standard policy library, as well as continued hardening and performance optimization.
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**Sponsor from TOC:** Ken Owens, Brian Grant
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**Preferred Maturity Level:** Sandbox
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**License:** Apache License v2
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# Source Control
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https://github.com/open-policy-agent/opa
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https://github.com/open-policy-agent/library
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# External Dependencies
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github.com/ghodss/yaml MIT License
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github.com/gorilla/mux BSD 3-clause "New" or "Revised" License
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github.com/mattn/go-runewidth MIT License
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github.com/olekukonko/tablewriter MIT License
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github.com/peterh/liner MIT License
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github.com/pkg/errors BSD 2-clause "Simplified" License
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github.com/sirupsen/logrus MIT License
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github.com/spf13/cobra Apache License 2.0
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github.com/spf13/pflag BSD 3-clause "New" or "Revised" License
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golang.org/x/crypto/ssh/terminal BSD 3-clause "New" or "Revised" License
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golang.org/x/sys/unix BSD 3-clause "New" or "Revised" License
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gopkg.in/fsnotify.v1 BSD 3-clause "New" or "Revised" License
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gopkg.in/yaml.v2 Apache License 2.0
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**Initial Committers:** Torin Sandall and Tim Hinrichs from Styra (since creation), Tristan Swadell from Google (since May 2017)
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**Infrastructure Requests:** None initially. CI is currently hosted on Travis and covered by the free tier for open source projects. In
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the future, we would like to leverage CNCF test clusters for system testing integrations built as part of the OPA project.
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**Communication Channels:**
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Slack: http://slack.openpolicyagent.org
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**Issue Tracker:** https://github.com/open-policy-agent/opa/issues
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**Website:** http://www.openpolicyagent.org
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# Release Methodology and Mechanics
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We currently use numbered releases with the changelog and binaries published to https://github.com/open-policy-agent/opa/releases.
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The release process is partially automated with manual portions assisted by scripts. The current release process is documented here:
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https://github.com/open-policy-agent/opa/blob/master/docs/devel/RELEASE.md. The release schedule is somewhat ad-hoc, aligned around
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large feature boundaries.
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**Social Media Accounts:**
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Twitter: https://twitter.com/openpolicyagent
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# Community Size and any Existing Sponsorship
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Adopters:
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Netflix
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Medallia
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Schuberg Phillis
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Huawei
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More: At least one large financial institution and one large online retailer is testing OPA
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Integrations:
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Kubernetes (Use cases: federated resource placement, admission control)
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Docker (Use cases: Docker engine authorization)
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Istio (Use cases: microservice API authorization)
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Linkerd (Use cases: microservice API authorization)
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OpenSDS (Use cases: storage scheduling)
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Terraform (Use cases: risk management on terraform plans)
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PAM (Use cases: SSH and sudo authorization)
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Cloud Foundry buildpack to enable microservice API authorization
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**Sponsors**
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https://www.styra.com
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https://www.firebase.com (Google)
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**Numbers:**
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3 active contributors currently (2 from Styra, 1 from Google), with 8 other contributors over past 12 months.
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80 stars
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49 members on Slack
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31 releases
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# Statement of Alignment with CNCF Mission
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As cloud native technology matures and enterprise adoption increases, the need for policy-based control has become apparent. OPA
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provides a powerful building-block that enables fine-grained, expressive policy enforcement. As such, we think that OPA would be a
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great for fit for the CNCF
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# Benefits to the CNCF
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The ecosystem must provide solutions to control who can do what across microservice deployments because legacy approaches to access
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control do not satisfy the requirements of modern environments. OPA provides a purpose-built language and runtime that can be used to
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author and enforce authorization policy. As such, we feel that OPA will complement the CNCF’s portfolio and help accelerate adoption of
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cloud native technology in enterprises. In the longer term, we think that enterprises will benefit from a unified approach to policy
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enforcement can be applied across the stack.
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# What does OPA need from the CNCF
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OPA needs a well respected, vendor-neutral home that can help serve as a rallying point around policy as code. In addition to increased
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visibility, we hope that inclusion in the CNCF will foster communication between OPA and other projects in the ecosystem. As the project
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grows, we would want to leverage the CNCF’s expertise around project governance and community standards as those are fundamental to the
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long term success of the project.
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The project does not have any infrastructure requests at this time. CI is currently hosted on Travis and covered by the free tier for
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open source projects. In the future, we would like to leverage CNCF test clusters for system testing integrations built as part of the
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OPA project.
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# Appendix A: REST API Authorization Example
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This sample shows two simple rules that enforce an authorization policy on an API that serves salary data. In English, the policy says
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that employees can see their own salary and the salary of any of their reports.
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allow {
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input.method = "GET"
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input.path = ["salary", employee_id]
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input.user = employee_id
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}
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allow {
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input.method = "GET"
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input.path = ["salary", employee_id]
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input.user = data.management_chain[employee_id][_]
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}
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The first rule allows employees to GET their own salary. The rule shows how you can use variables in rules. In that rule, employee_id is
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a variable that will be bound to the same value across the last two expressions.
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The second rule allow employees to GET the salary of their reports. The rule shows how you can access arbirary context (e.g., JSON data)
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inside the policy. The data may loaded into the policy engine (and cached) or it may be external and fetched dynamically.
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# Appendix B: Cluster Placement Example
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This sample shows a simple rule that generates a set of clusters that a workload may be deployed to. The workload is provided as input
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to policy. In English, the policy says that workloads must be placed on clusters that satisfy the workload’s jurisdiction requirements.
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desired_clusters = {name |
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cluster = data.clusters[name]
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satisfies_jurisdiction(input.deployment, cluster)
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}
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satisfies_jursidiction(deployment, cluster) {
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deployment.jurisdiction = "europe"
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startswith(cluster.region, "eu")
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} else {
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not deployment.jurisdiction
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}
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This example shows how logic can be composed across rules and functions.
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