interface.go

// Copyright 2022 Namespace Labs Inc; All rights reserved.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.

package runtime

import (
	"context"
	"fmt"
	"io"
	"net"
	"strings"
	"time"

	specs "github.com/opencontainers/image-spec/specs-go/v1"
	"namespacelabs.dev/foundation/internal/artifacts/oci"
	"namespacelabs.dev/foundation/internal/artifacts/registry"
	"namespacelabs.dev/foundation/internal/console/termios"
	"namespacelabs.dev/foundation/internal/fnerrors"
	"namespacelabs.dev/foundation/internal/runtime/rtypes"
	"namespacelabs.dev/foundation/internal/secrets"
	"namespacelabs.dev/foundation/schema"
	runtimepb "namespacelabs.dev/foundation/schema/runtime"
	"namespacelabs.dev/foundation/schema/storage"
	"namespacelabs.dev/foundation/std/cfg"
	"namespacelabs.dev/foundation/std/resources"
)

const (
	FnServiceLivez  = "foundation.namespacelabs.dev/livez"
	FnServiceReadyz = "foundation.namespacelabs.dev/readyz"
)

// A runtime class represents a runtime implementation type, e.g. "kubernetes".
// The codebase seldom interacts with Class, but instead of Cluster instances
// obtained from a runtime class.
type Class interface {
	// Attaches to an existing cluster. Fails if the cluster doesn't exist or
	// the provider used would have instantiated a new cluster.
	AttachToCluster(context.Context, cfg.Configuration) (Cluster, error)

	// Attaches to an existing cluster (if not is specified in the
	// configuration), or creates a new cluster as needed.
	EnsureCluster(context.Context, cfg.Context, string) (Cluster, error)

	// Planner produces a planner for this runtime class. This may instantiate a
	// new cluster, but will attempt to do so lazily.
	Planner(context.Context, cfg.Context, string) (Planner, error)
}

// A cluster represents a cluster where Namespace is capable of deployment one
// or more applications.
type Cluster interface {
	// Returns a namespace'd cluster -- one for a particular application use,
	// bound to the workspace identified by the cfg.Context.
	Bind(context.Context, cfg.Context) (ClusterNamespace, error)

	// Fetch diagnostics of a particular container reference.
	FetchDiagnostics(context.Context, *runtimepb.ContainerReference) (*runtimepb.Diagnostics, error)

	// Fetch logs of a specific container reference.
	FetchLogsTo(ctx context.Context, container *runtimepb.ContainerReference, opts FetchLogsOpts, callback func(ContainerLogLine)) error

	// Attaches to a running container.
	AttachTerminal(ctx context.Context, container *runtimepb.ContainerReference, io TerminalIO) error

	// Exposes the cluster's ingress, in the specified local address and port.
	// This is used to create stable localhost-bound ingress addresses (for e.g.
	// nslocal.host).
	ForwardIngress(ctx context.Context, localAddrs []string, localPort int, notify PortForwardedFunc) (io.Closer, error)

	// EnsureState ensures that a cluster-specific bit of initialization is done once per instance.
	EnsureState(context.Context, string) (any, error)

	// EnsureState ensures that a cluster-specific bit of initialization is done once per instance.
	EnsureKeyedState(context.Context, string, string) (any, error)

	// Deletes any runtime resource deployed by this runtime, regardless of
	// environment. If wait is true, waits until the target resources have been
	// removed. Returns true if resources were deleted.
	DeleteAllRecursively(ctx context.Context, wait bool, progress io.Writer) (bool, error)
}

type ContainerLogLine struct {
	Timestamp        time.Time
	MissingTimestamp bool
	LogLine          []byte
	Event            ContainerLogLineEvent
	ResumeErr        error
}

type ContainerLogLineEvent string

const (
	ContainerLogLineEvent_LogLine   ContainerLogLineEvent = "ns.logline"
	ContainerLogLineEvent_Connected ContainerLogLineEvent = "ns.connected"
	ContainerLogLineEvent_Resuming  ContainerLogLineEvent = "ns.resuming"
)

func WriteToWriter(w io.Writer) func(ContainerLogLine) {
	return func(cll ContainerLogLine) {
		if cll.Event == ContainerLogLineEvent_LogLine {
			fmt.Fprintf(w, "%s\n", cll.LogLine)
		}
	}
}

func WriteToWriterWithTimestamps(w io.Writer) func(ContainerLogLine) {
	return func(cll ContainerLogLine) {
		if cll.Event == ContainerLogLineEvent_LogLine {
			if cll.MissingTimestamp {
				fmt.Fprintf(w, "? %s\n", cll.LogLine)
			} else {
				fmt.Fprintf(w, "%s %s\n", cll.Timestamp.Format(time.RFC3339Nano), cll.LogLine)
			}
		}
	}
}

// A planner is capable of generating namespace-specific deployment plans. It
// may obtain external data in order to produce a plan, but none of its methods
// mutate outside state in order to do so.
type Planner interface {
	// Plans a deployment, i.e. produces a series of instructions that will
	// instantiate the required deployment resources to run the servers in the
	// specified Deployment. This method is side-effect free; mutations are
	// applied when the generated plan is applied.
	PlanDeployment(context.Context, DeploymentSpec) (*DeploymentPlan, error)

	// Plans an ingress deployment, i.e. produces a series of instructions that
	// will instantiate the required deployment resources to run the servers
	// with the specified Ingresses. This method is side-effect free; mutations
	// are applied when the generated plan is applied.
	PlanIngress(context.Context, *schema.Stack, []*schema.IngressFragment) (*DeploymentPlan, error)

	// PrepareProvision is called before invoking a provisioning tool, to offer
	// the runtime implementation a way to pass runtime-specific information to
	// the tool. E.g. what's the Kubernetes namespace we're working with.
	PrepareProvision(context.Context) (*rtypes.ProvisionProps, error)

	// Returns the set of platforms that the target runtime operates on, e.g. linux/amd64.
	TargetPlatforms(context.Context) ([]specs.Platform, error)

	// The registry we should upload to.
	Registry() registry.Manager

	// The ingress class this runtime implementation uses.
	Ingress() IngressClass

	EnsureClusterNamespace(context.Context) (ClusterNamespace, error)
}

type IngressClass interface {
	Name() string

	// ComputeBaseNaming returns a base naming configuration that is specific
	// to the target runtime (e.g. kubernetes cluster).
	ComputeNaming(*schema.Environment, *schema.Naming) (*schema.ComputedNaming, error)
}

// ClusterNamespace represents a target deployment environment, scoped to an application
// (usually the combination of an environment and workspace).
type ClusterNamespace interface {
	// Returns a reference to the cluster where this namespace exists.
	Cluster() Cluster

	// DeployedConfigImageID retrieves the image reference of the "configuration
	// image" used to deploy the specified server. Configuration images are only
	// generated for production environments for now.
	DeployedConfigImageID(context.Context, Deployable) (oci.ImageID, error)

	// Returns a list of containers that the server has deployed.
	ResolveContainers(context.Context, Deployable) ([]*runtimepb.ContainerReference, error)

	// Fetch environment diagnostics, e.g. event list.
	FetchEnvironmentDiagnostics(context.Context) (*storage.EnvironmentDiagnostics, error)

	// Starts a new shell in the container of a previously deployed server. The
	// image of the server must contain the specified command. For ephemeral
	// containers, see #329.
	StartTerminal(ctx context.Context, server Deployable, io TerminalIO, command string, rest ...string) error

	// Forwards a single port.
	// XXX remove; callers should instead implement their own TCP net.Listener
	// and call DialServer as needed.
	ForwardPort(ctx context.Context, server Deployable, containerPort int32, localAddrs []string, notify SinglePortForwardedFunc) (io.Closer, error)

	// Dials a TCP port to one of the replicas of the target server. The
	// lifecycle of the connection is bound to the specified context.
	DialServer(ctx context.Context, server Deployable, port *schema.Endpoint_Port) (net.Conn, error)

	// Observes lifecyle events of the specified server. Unless OneShot is set,
	// Observe runs until the context is cancelled.
	Observe(context.Context, Deployable, ObserveOpts, func(ObserveEvent) (bool, error)) error

	// WaitUntilReady blocks until the target deployable reports ready. If the
	// deployable represents a collection of replicas, readiness waits for all
	// replicas to become ready.
	WaitUntilReady(ctx context.Context, object Deployable) error

	// Waits until the specified deployable is no longer running (typically a one-shot).
	WaitForTermination(ctx context.Context, object Deployable) ([]ContainerStatus, error)

	// Deletes a previously deployed DeployableSpec.
	DeleteDeployable(ctx context.Context, deployable Deployable) error

	// Deletes the scoped environment, and all of its associated resources (e.g.
	// after a test invocation). If wait is true, waits until the target
	// resources have been removed. Returns true if resources were deleted.
	DeleteRecursively(ctx context.Context, wait bool) (bool, error)
}

type Deployable interface {
	GetPackageRef() *schema.PackageRef

	GetId() string

	GetName() string

	// Returns a string to be compatible with the proto API.
	GetDeployableClass() string // schema.DeployableClass
}

type DeploymentSpec struct {
	Specs []DeployableSpec
}

type DeployableSpec struct {
	ErrorLocation fnerrors.Location

	PackageRef *schema.PackageRef
	Focused    bool // Set to true if the user explicitly asked for this object to be deployed.
	Attachable AttachableKind

	Description string
	Class       schema.DeployableClass
	Id          string // Must not be empty.
	Name        string // Can be empty.
	Volumes     []*schema.Volume
	Permissions *schema.ServerPermissions
	Replicas    int32
	Tolerations []*schema.Server_Toleration

	MainContainer ContainerRunOpts
	Sidecars      []SidecarRunOpts
	Inits         []SidecarRunOpts

	ConfigImage         *oci.ImageID
	RuntimeConfig       *runtimepb.RuntimeConfig
	BuildVCS            *runtimepb.BuildVCS
	ResourceDeps        []*resources.ResourceDependency
	PlannedResourceDeps []*resources.ResourceDependency
	ComputedResources   []ComputedResource

	Secrets secrets.GroundedSecrets

	// The list of primitive std/runtime:Secret that this deployable depends on.
	// These are treated in a special way: each one of them is mounted under
	// /namespace/secrets automatically, and the corresponding SecretInstance
	// entries are generated by the runtime-specific planner.
	SecretResources []SecretResourceDependency

	// Where to mount the runtime configuration; if unset, the runtime
	// configuration is not persisted, and not mounted.
	MountRuntimeConfigPath string

	SetContainerField []*runtimepb.SetContainerField

	Extensions []*schema.DefExtension

	Endpoints         []*schema.Endpoint         // Owned by this deployable.
	InternalEndpoints []*schema.InternalEndpoint // Owned by this deployable.

	Probes []*schema.Probe
}

// A resource whose instance is known.
type ComputedResource struct {
	ResourceInstanceID     string
	InstanceType           *schema.ResourceType
	InstanceSerializedJSON []byte
}

type SecretResourceDependency struct {
	SecretRef   *schema.PackageRef
	ResourceRef *schema.PackageRef
}

type AttachableKind string

const (
	AttachableKind_WITH_STDIN_ONLY AttachableKind = "stdin-only"
	AttachableKind_WITH_TTY        AttachableKind = "with-tty"
)

var _ Deployable = DeployableSpec{}

func (d DeployableSpec) GetId() string                     { return d.Id }
func (d DeployableSpec) GetName() string                   { return d.Name }
func (d DeployableSpec) GetDeployableClass() string        { return string(d.Class) }
func (d DeployableSpec) GetPackageRef() *schema.PackageRef { return d.PackageRef }
func (d DeployableSpec) GetPackageName() string            { return d.PackageRef.GetPackageName() }

type ContainerRunOpts struct {
	WorkingDir         string
	Image              oci.ImageID
	Command            []string
	Args               []string
	Env                []*schema.BinaryConfig_EnvEntry
	RunAs              *RunAs
	ReadOnlyFilesystem bool
	Privileged         bool
	HostNetwork        bool
	Mounts             []*schema.Mount
	AllocatedPorts     []*schema.Endpoint_Port
}

type ContainerStatus struct {
	Reference        *runtimepb.ContainerReference
	TerminationError error
}

type RunAs struct {
	UserID  string
	FSGroup *string
}

type SidecarRunOpts struct {
	Name      string
	BinaryRef *schema.PackageRef
	ContainerRunOpts
}

type FetchLogsOpts struct {
	TailLines        int // Only used if it's a positive value.
	Follow           bool
	FetchLastFailure bool
}

type ObserveOpts struct {
}

type ObserveEvent struct {
	Deployable         *runtimepb.Deployable
	ContainerReference *runtimepb.ContainerReference
	Version            string
	Added              bool
	Removed            bool
}

type DeploymentPlan struct {
	Definitions []*schema.SerializedInvocation
	Hints       []string

	// A unique ID that is consistent across invocations, for the same runtime,
	// that represents a tenant namespace.
	NamespaceReference string
}

type TerminalIO struct {
	TTY bool

	Stdin  io.Reader
	Stdout io.Writer
	Stderr io.Writer

	// Optional. If set, a runtime can listen on this channel for terminal resize requests.
	ResizeQueue chan termios.WinSize
}

type ForwardedPortEvent struct {
	Endpoint *schema.Endpoint

	Added   []ForwardedPort
	Removed bool
	Error   error
}

type ForwardedPort struct {
	LocalPort     uint
	ContainerPort uint
}

type PortForwardedFunc func(ForwardedPortEvent)
type SinglePortForwardedFunc func(ForwardedPort)

type EndpointPortForwarder interface {
	io.Closer
	Update([]*schema.Endpoint)
}

type ErrContainerExitStatus struct {
	ExitCode int32
}

func (e ErrContainerExitStatus) Error() string {
	return fmt.Sprintf("container exited with code %d", e.ExitCode)
}

type ErrContainerFailed struct {
	Name     string
	Failures []ErrContainerFailed_Failure
}

type ErrContainerFailed_Failure struct {
	Reference *runtimepb.ContainerReference // A pointer that can be passed to the runtime to fetch logs.
	Reason    string
	Message   string
	ExitCode  int32
}

func (e ErrContainerFailed) Error() string {
	if len(e.Failures) == 0 {
		return fmt.Sprintf("%s: unknown failure", e.Name)
	}

	var labels []string
	for _, failure := range e.Failures {
		labels = append(labels, fmt.Sprintf("%s: failed with %q: exit code %d: last message %q",
			failure.Reference.HumanReference, failure.Reason, failure.ExitCode, failure.Message))
	}

	if len(labels) == 1 {
		return fmt.Sprintf("%s: %s", e.Name, labels[0])
	}

	return fmt.Sprintf("%s: multiple failures:\n%s", e.Name, strings.Join(labels, "\n"))
}

func DeployableToProto(spec Deployable) *runtimepb.Deployable {
	return &runtimepb.Deployable{
		PackageRef:      spec.GetPackageRef(),
		Id:              spec.GetId(),
		Name:            spec.GetName(),
		DeployableClass: spec.GetDeployableClass(),
	}
}

func DeployableCategory(spec Deployable) string {
	return fmt.Sprintf("deployable:%s", spec.GetId())
}

func OwnedByDeployable(spec Deployable) string {
	return fmt.Sprintf("ownedby:%s", spec.GetId())
}