pulumi/pkg/resource/provider.go
2017-05-18 14:51:52 -07:00

61 lines
3.4 KiB
Go

// Licensed to Pulumi Corporation ("Pulumi") under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// Pulumi licenses this file to You under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package resource
import (
"io"
"github.com/pulumi/lumi/pkg/tokens"
)
// Provider presents a simple interface for orchestrating resource create, reead, update, and delete operations. Each
// provider understands how to handle all of the resource types within a single package.
//
// This interface hides some of the messiness of the underlying machinery, since providers are behind an RPC boundary.
//
// It is important to note that provider operations are not transactional. (Some providers might decide to offer
// transactional semantics, but such a provider is a rare treat.) As a result, failures in the operations below can
// range from benign to catastrophic (possibly leaving behind a corrupt resource). It is up to the provider to make a
// best effort to ensure catastrophies do not occur. The errors returned from mutating operations indicate both the
// underlying error condition in addition to a bit indicating whether the operation was successfully rolled back.
type Provider interface {
// Closer closes any underlying OS resources associated with this provider (like processes, RPC channels, etc).
io.Closer
// Pkg fetches this provider's package.
Pkg() tokens.Package
// Check validates that the given property bag is valid for a resource of the given type.
Check(t tokens.Type, props PropertyMap) ([]CheckFailure, error)
// Name names a given resource. Sometimes this will be assigned by a developer, and so the provider
// simply fetches it from the property bag; other times, the provider will assign this based on its own algorithm.
// In any case, resources with the same name must be safe to use interchangeably with one another.
Name(t tokens.Type, props PropertyMap) (tokens.QName, error)
// Create allocates a new instance of the provided resource and returns its unique ID afterwards.
Create(t tokens.Type, props PropertyMap) (ID, PropertyMap, State, error)
// Get reads the instance state identified by id/t, and returns a bag of properties.
Get(id ID, t tokens.Type) (PropertyMap, error)
// InspectChange checks what impacts a hypothetical update will have on the resource's properties.
InspectChange(id ID, t tokens.Type, olds PropertyMap, news PropertyMap) ([]string, PropertyMap, error)
// Update updates an existing resource with new values.
Update(id ID, t tokens.Type, olds PropertyMap, news PropertyMap) (State, error)
// Delete tears down an existing resource.
Delete(id ID, t tokens.Type) (State, error)
}
// CheckFailure indicates that a call to check failed; it contains the property and reason for the failure.
type CheckFailure struct {
Property PropertyKey // the property that failed checking.
Reason string // the reason the property failed to check.
}