terraform/internal/getproviders/multi_source.go

225 lines
7.7 KiB
Go

package getproviders
import (
"fmt"
"strings"
svchost "github.com/hashicorp/terraform-svchost"
"github.com/hashicorp/terraform/addrs"
)
// MultiSource is a Source that wraps a series of other sources and combines
// their sets of available providers and provider versions.
//
// A MultiSource consists of a sequence of selectors that each specify an
// underlying source to query and a set of matching patterns to decide which
// providers can be retrieved from which sources. If multiple selectors find
// a given provider version then the earliest one in the sequence takes
// priority for deciding the package metadata for the provider.
//
// For underlying sources that make network requests, consider wrapping each
// one in a MemoizeSource so that availability information retrieved in
// AvailableVersions can be reused in PackageMeta.
type MultiSource []MultiSourceSelector
var _ Source = MultiSource(nil)
// AvailableVersions retrieves all of the versions of the given provider
// that are available across all of the underlying selectors, while respecting
// each selector's matching patterns.
func (s MultiSource) AvailableVersions(provider addrs.Provider) (VersionList, error) {
if len(s) == 0 { // Easy case: there can be no available versions
return nil, nil
}
// We will return the union of all versions reported by the nested
// sources that have matching patterns that accept the given provider.
vs := make(map[Version]struct{})
for _, selector := range s {
if !selector.CanHandleProvider(provider) {
continue // doesn't match the given patterns
}
thisSourceVersions, err := selector.Source.AvailableVersions(provider)
switch err.(type) {
case nil:
// okay
case ErrProviderNotKnown:
continue // ignore, then
default:
return nil, err
}
for _, v := range thisSourceVersions {
vs[v] = struct{}{}
}
}
if len(vs) == 0 {
return nil, ErrProviderNotKnown{provider}
}
ret := make(VersionList, 0, len(vs))
for v := range vs {
ret = append(ret, v)
}
ret.Sort()
return ret, nil
}
// PackageMeta retrieves the package metadata for the requested provider package
// from the first selector that indicates availability of it.
func (s MultiSource) PackageMeta(provider addrs.Provider, version Version, target Platform) (PackageMeta, error) {
if len(s) == 0 { // Easy case: no providers exist at all
return PackageMeta{}, ErrProviderNotKnown{provider}
}
for _, selector := range s {
if !selector.CanHandleProvider(provider) {
continue // doesn't match the given patterns
}
meta, err := selector.Source.PackageMeta(provider, version, target)
switch err.(type) {
case nil:
return meta, nil
case ErrProviderNotKnown, ErrPlatformNotSupported:
continue // ignore, then
default:
return PackageMeta{}, err
}
}
// If we fall out here then none of the sources have the requested
// package.
return PackageMeta{}, ErrPlatformNotSupported{
Provider: provider,
Version: version,
Platform: target,
}
}
// MultiSourceSelector is an element of the source selection configuration on
// MultiSource. A MultiSource has zero or more of these to configure which
// underlying sources it should consult for a given provider.
type MultiSourceSelector struct {
// Source is the underlying source that this selector applies to.
Source Source
// Include and Exclude are sets of provider matching patterns that
// together define which providers are eligible to be potentially
// installed from the corresponding Source.
Include, Exclude MultiSourceMatchingPatterns
}
// MultiSourceMatchingPatterns is a set of patterns that together define a
// set of providers by matching on the segments of the provider FQNs.
//
// The Provider address values in a MultiSourceMatchingPatterns are special in
// that any of Hostname, Namespace, or Type can be getproviders.Wildcard
// to indicate that any concrete value is permitted for that segment.
type MultiSourceMatchingPatterns []addrs.Provider
// ParseMultiSourceMatchingPatterns parses a slice of strings containing the
// string form of provider matching patterns and, if all the given strings
// are valid, returns the corresponding MultiSourceMatchingPatterns value.
func ParseMultiSourceMatchingPatterns(strs []string) (MultiSourceMatchingPatterns, error) {
if len(strs) == 0 {
return nil, nil
}
ret := make(MultiSourceMatchingPatterns, len(strs))
for i, str := range strs {
parts := strings.Split(str, "/")
if len(parts) < 2 || len(parts) > 3 {
return nil, fmt.Errorf("invalid provider matching pattern %q: must have either two or three slash-separated segments", str)
}
host := defaultRegistryHost
explicitHost := len(parts) == 3
if explicitHost {
givenHost := parts[0]
if givenHost == "*" {
host = svchost.Hostname(Wildcard)
} else {
normalHost, err := svchost.ForComparison(givenHost)
if err != nil {
return nil, fmt.Errorf("invalid hostname in provider matching pattern %q: %s", str, err)
}
// The remaining code below deals only with the namespace/type portions.
host = normalHost
}
parts = parts[1:]
}
if !validProviderNameOrWildcard(parts[1]) {
return nil, fmt.Errorf("invalid provider type %q in provider matching pattern %q: must either be the wildcard * or a provider type name", parts[1], str)
}
if !validProviderNameOrWildcard(parts[0]) {
return nil, fmt.Errorf("invalid registry namespace %q in provider matching pattern %q: must either be the wildcard * or a literal namespace", parts[1], str)
}
ret[i] = addrs.Provider{
Hostname: host,
Namespace: parts[0],
Type: parts[1],
}
if ret[i].Hostname == svchost.Hostname(Wildcard) && !(ret[i].Namespace == Wildcard && ret[i].Type == Wildcard) {
return nil, fmt.Errorf("invalid provider matching pattern %q: hostname can be a wildcard only if both namespace and provider type are also wildcards", str)
}
if ret[i].Namespace == Wildcard && ret[i].Type != Wildcard {
return nil, fmt.Errorf("invalid provider matching pattern %q: namespace can be a wildcard only if the provider type is also a wildcard", str)
}
}
return ret, nil
}
// CanHandleProvider returns true if and only if the given provider address
// is both included by the selector's include patterns and _not_ excluded
// by its exclude patterns.
//
// The absense of any include patterns is treated the same as a pattern
// that matches all addresses. Exclusions take priority over inclusions.
func (s MultiSourceSelector) CanHandleProvider(addr addrs.Provider) bool {
switch {
case s.Exclude.MatchesProvider(addr):
return false
case len(s.Include) > 0:
return s.Include.MatchesProvider(addr)
default:
return true
}
}
// MatchesProvider tests whether the receiving matching patterns match with
// the given concrete provider address.
func (ps MultiSourceMatchingPatterns) MatchesProvider(addr addrs.Provider) bool {
for _, pattern := range ps {
hostMatch := (pattern.Hostname == svchost.Hostname(Wildcard) || pattern.Hostname == addr.Hostname)
namespaceMatch := (pattern.Namespace == Wildcard || pattern.Namespace == addr.Namespace)
typeMatch := (pattern.Type == Wildcard || pattern.Type == addr.Type)
if hostMatch && namespaceMatch && typeMatch {
return true
}
}
return false
}
// Wildcard is a string value representing a wildcard element in the Include
// and Exclude patterns used with MultiSource. It is not valid to use Wildcard
// anywhere else.
const Wildcard string = "*"
// We'll read the default registry host from over in the addrs package, to
// avoid duplicating it. A "default" provider uses the default registry host
// by definition.
var defaultRegistryHost = addrs.DefaultRegistryHost
func validProviderNameOrWildcard(s string) bool {
if s == Wildcard {
return true
}
_, err := addrs.ParseProviderPart(s)
return err == nil
}