flux

README

Flux

We believe in GitOps:

• You declaratively describe the entire desired state of your system in git. This includes the apps, config, dashboards, monitoring and everything else.
• What can be described can be automated. Use YAMLs to enforce conformance of the system. You don't need to run kubectl, all changes go through git. Use diff tools to detect divergence between observed and desired state and get notifications.
• You push code not containers. Everything is controlled through pull requests. There is no learning curve for new devs, they just use your standard git PR process. The history in git allows you to recover from any snapshot as you have an sequence of transactions. It is much more transparent to make operational changes by pull request, e.g. fix a production issue via a pull request instead of making changes to the running system.

Flux is a tool that automatically ensures that the state of a cluster matches the config in git. It uses an operator in the cluster to trigger deployments inside Kubernetes, which means you don't need a separate CD tool. It monitors all relevant image repositories, detects new images, triggers deployments and updates the desired running configuration based on that (and a configurable policy).

The benefits are: you don't need to grant your CI access to the cluster, every change is atomic and transactional, git has your audit log. Each transaction either fails or succeeds cleanly. You're entirely code centric and don't need new infrastructure.

What Flux does

Flux is most useful when used as a deployment tool at the end of a Continuous Delivery pipeline. Flux will make sure that your new container images and config changes are propagated to the cluster.

Features

Its major features are:

• Automated git → cluster synchronisation
• Automated deployment of new container images
• Integrations with other devops tools (Helm and more)
• No additional service or infrastructure needed - Flux lives inside your cluster
• Straight-forward control over the state of deployments in the cluster (rollbacks, lock a specific version of a workload, manual deployments)
• Observability: git commits are an audit trail, and you can record e.g., why a given deployment was locked.

Relation to Weave Cloud

Weave Cloud is a SaaS product by Weaveworks that includes Flux, as well as:

• a UI and alerts for deployments: nicely integrated overview, all flux operations just a click away.
• full observability and insights into your cluster: Instantly start using monitoring dashboards for your cluster, hosted 13 months of history, use a realtime map of your cluster to debug and analyse its state.

If you want to learn more about Weave Cloud, you can see it in action on its homepage.

Get started with Flux

Get started by browsing through the documentation below:

• Background about Flux
  • Introduction to Flux
  • FAQ and frequently encountered issues
  • How it works
  • Considerations regarding installing Flux
• Get Started with Flux
  • Standalone Flux
  • Flux using Helm
• Operating Flux
  • Using Flux
  • Troubleshooting
  • Frequently encountered issues
  • Upgrading to Flux v1

Developer information

Build documentation

Release documentation

Contribution

Flux follows a typical PR workflow. All contributions should be made as PRs that satisfy the guidelines below.

Guidelines

• All code must abide Go Code Review Comments
• Names should abide What's in a name
• Code must build on both Linux and Darwin, via plain go build
• Code should have appropriate test coverage, invoked via plain go test

In addition, several mechanical checks are enforced. See the lint script for details.

Getting Help

If you have any questions about Flux and continuous delivery:

• Read the Weave Flux docs.
• Invite yourself to the Weave community slack.
• Ask a question on the #flux slack channel.
• Join the Weave User Group and get invited to online talks, hands-on training and meetups in your area.
• Send an email to weave-users@weave.works
• File an issue.

Your feedback is always welcome!

Documentation

Index

• Variables
• type ResourceID
  • func MakeResourceID(namespace, kind, name string) ResourceID
  • func MustParseResourceID(s string) ResourceID
  • func ParseResourceID(s string) (ResourceID, error)
  • func ParseResourceIDOptionalNamespace(namespace, s string) (ResourceID, error)
  • func (id ResourceID) Components() (namespace, kind, name string)
  • func (id ResourceID) MarshalJSON() ([]byte, error)
  • func (id ResourceID) MarshalText() (text []byte, err error)
  • func (id *ResourceID) UnmarshalJSON(data []byte) (err error)
  • func (id *ResourceID) UnmarshalText(text []byte) error
• type ResourceIDSet
  • func (s ResourceIDSet) Add(ids []ResourceID)
  • func (s ResourceIDSet) Contains(id ResourceID) bool
  • func (s ResourceIDSet) Intersection(others ResourceIDSet) ResourceIDSet
  • func (s ResourceIDSet) String() string
  • func (s ResourceIDSet) ToSlice() ResourceIDs
  • func (s ResourceIDSet) Without(others ResourceIDSet) ResourceIDSet
• type ResourceIDs
  • func (ids ResourceIDs) Contains(id ResourceID) bool
  • func (ids ResourceIDs) Intersection(others ResourceIDSet) ResourceIDSet
  • func (p ResourceIDs) Len() int
  • func (p ResourceIDs) Less(i, j int) bool
  • func (p ResourceIDs) Sort()
  • func (p ResourceIDs) Swap(i, j int)
  • func (ids ResourceIDs) Without(others ResourceIDSet) (res ResourceIDs)

Variables

var (
	ErrInvalidServiceID = errors.New("invalid service ID")

	LegacyServiceIDRegexp = regexp.MustCompile("^([a-zA-Z0-9_-]+)/([a-zA-Z0-9_-]+)$")
	// The namespace and name commponents are (apparently
	// non-normatively) defined in
	// https://github.com/kubernetes/community/blob/master/contributors/design-proposals/architecture/identifiers.md
	// In practice, more punctuation is used than allowed there;
	// specifically, people use underscores as well as dashes and dots, and in names, colons.
	ResourceIDRegexp            = regexp.MustCompile("^([a-zA-Z0-9_-]+):([a-zA-Z0-9_-]+)/([a-zA-Z0-9_.:-]+)$")
	UnqualifiedResourceIDRegexp = regexp.MustCompile("^([a-zA-Z0-9_-]+)/([a-zA-Z0-9_.:-]+)$")
)

Types

type ResourceID

type ResourceID struct {
	// contains filtered or unexported fields
}

ResourceID is an opaque type which uniquely identifies a resource in an orchestrator.

func MakeResourceID

func MakeResourceID(namespace, kind, name string) ResourceID

MakeResourceID constructs a ResourceID from constituent components.

func MustParseResourceID

func MustParseResourceID(s string) ResourceID

MustParseResourceID constructs a ResourceID from a string representation, panicing if the format is invalid.

func ParseResourceID

func ParseResourceID(s string) (ResourceID, error)

ParseResourceID constructs a ResourceID from a string representation if possible, returning an error value otherwise.

func ParseResourceIDOptionalNamespace

func ParseResourceIDOptionalNamespace(namespace, s string) (ResourceID, error)

ParseResourceIDOptionalNamespace constructs a ResourceID from either a fully qualified string representation, or an unqualified kind/name representation and the supplied namespace.

func (ResourceID) Components

func (id ResourceID) Components() (namespace, kind, name string)

Components returns the constituent components of a ResourceID

func (ResourceID) MarshalJSON

func (id ResourceID) MarshalJSON() ([]byte, error)

MarshalJSON encodes a ResourceID as a JSON string. This is done to maintain backwards compatibility with previous flux versions where the ResourceID is a plain string.

func (ResourceID) MarshalText

func (id ResourceID) MarshalText() (text []byte, err error)

MarshalText encodes a ResourceID as a flat string; this is required because ResourceIDs are sometimes used as map keys.

func (*ResourceID) UnmarshalJSON

func (id *ResourceID) UnmarshalJSON(data []byte) (err error)

UnmarshalJSON decodes a ResourceID from a JSON string. This is done to maintain backwards compatibility with previous flux versions where the ResourceID is a plain string.

func (*ResourceID) UnmarshalText

func (id *ResourceID) UnmarshalText(text []byte) error

MarshalText decodes a ResourceID from a flat string; this is required because ResourceIDs are sometimes used as map keys.

type ResourceIDSet

type ResourceIDSet map[ResourceID]struct{}

func (ResourceIDSet) Add

func (s ResourceIDSet) Add(ids []ResourceID)

func (ResourceIDSet) Contains

func (s ResourceIDSet) Contains(id ResourceID) bool

func (ResourceIDSet) Intersection

func (s ResourceIDSet) Intersection(others ResourceIDSet) ResourceIDSet

func (ResourceIDSet) String

func (s ResourceIDSet) String() string

func (ResourceIDSet) ToSlice

func (s ResourceIDSet) ToSlice() ResourceIDs

func (ResourceIDSet) Without

func (s ResourceIDSet) Without(others ResourceIDSet) ResourceIDSet

type ResourceIDs

type ResourceIDs []ResourceID

func (ResourceIDs) Contains

func (ids ResourceIDs) Contains(id ResourceID) bool

func (ResourceIDs) Intersection

func (ids ResourceIDs) Intersection(others ResourceIDSet) ResourceIDSet

func (ResourceIDs) Len

func (p ResourceIDs) Len() int

func (ResourceIDs) Less

func (p ResourceIDs) Less(i, j int) bool

func (ResourceIDs) Sort

func (p ResourceIDs) Sort()

func (ResourceIDs) Swap

func (p ResourceIDs) Swap(i, j int)

func (ResourceIDs) Without

func (ids ResourceIDs) Without(others ResourceIDSet) (res ResourceIDs)