terraform/plugin/discovery/meta_set.go

196 lines
5.4 KiB
Go

package discovery
// A PluginMetaSet is a set of PluginMeta objects meeting a certain criteria.
//
// Methods on this type allow filtering of the set to produce subsets that
// meet more restrictive criteria.
type PluginMetaSet map[PluginMeta]struct{}
// Add inserts the given PluginMeta into the receiving set. This is a no-op
// if the given meta is already present.
func (s PluginMetaSet) Add(p PluginMeta) {
s[p] = struct{}{}
}
// Remove removes the given PluginMeta from the receiving set. This is a no-op
// if the given meta is not already present.
func (s PluginMetaSet) Remove(p PluginMeta) {
delete(s, p)
}
// Has returns true if the given meta is in the receiving set, or false
// otherwise.
func (s PluginMetaSet) Has(p PluginMeta) bool {
_, ok := s[p]
return ok
}
// Count returns the number of metas in the set
func (s PluginMetaSet) Count() int {
return len(s)
}
// ValidateVersions returns two new PluginMetaSets, separating those with
// versions that have syntax-valid semver versions from those that don't.
//
// Eliminating invalid versions from consideration (and possibly warning about
// them) is usually the first step of working with a meta set after discovery
// has completed.
func (s PluginMetaSet) ValidateVersions() (valid, invalid PluginMetaSet) {
valid = make(PluginMetaSet)
invalid = make(PluginMetaSet)
for p := range s {
if _, err := p.Version.Parse(); err == nil {
valid.Add(p)
} else {
invalid.Add(p)
}
}
return
}
// WithName returns the subset of metas that have the given name.
func (s PluginMetaSet) WithName(name string) PluginMetaSet {
ns := make(PluginMetaSet)
for p := range s {
if p.Name == name {
ns.Add(p)
}
}
return ns
}
// WithVersion returns the subset of metas that have the given version.
//
// This should be used only with the "valid" result from ValidateVersions;
// it will ignore any plugin metas that have a invalid version strings.
func (s PluginMetaSet) WithVersion(version Version) PluginMetaSet {
ns := make(PluginMetaSet)
for p := range s {
gotVersion, err := p.Version.Parse()
if err != nil {
continue
}
if gotVersion.Equal(version) {
ns.Add(p)
}
}
return ns
}
// ByName groups the metas in the set by their Names, returning a map.
func (s PluginMetaSet) ByName() map[string]PluginMetaSet {
ret := make(map[string]PluginMetaSet)
for p := range s {
if _, ok := ret[p.Name]; !ok {
ret[p.Name] = make(PluginMetaSet)
}
ret[p.Name].Add(p)
}
return ret
}
// Newest returns the one item from the set that has the newest Version value.
//
// The result is meaningful only if the set is already filtered such that
// all of the metas have the same Name.
//
// If there isn't at least one meta in the set then this function will panic.
// Use Count() to ensure that there is at least one value before calling.
//
// If any of the metas have invalid version strings then this function will
// panic. Use ValidateVersions() first to filter out metas with invalid
// versions.
//
// If two metas have the same Version then one is arbitrarily chosen. This
// situation should be avoided by pre-filtering the set.
func (s PluginMetaSet) Newest() PluginMeta {
if len(s) == 0 {
panic("can't call NewestStable on empty PluginMetaSet")
}
var first = true
var winner PluginMeta
var winnerVersion Version
for p := range s {
version, err := p.Version.Parse()
if err != nil {
panic(err)
}
if first == true || version.NewerThan(winnerVersion) {
winner = p
winnerVersion = version
first = false
}
}
return winner
}
// ConstrainVersions takes a set of requirements and attempts to
// return a map from name to a set of metas that have the matching
// name and an appropriate version.
//
// If any of the given requirements match *no* plugins then its PluginMetaSet
// in the returned map will be empty.
//
// All viable metas are returned, so the caller can apply any desired filtering
// to reduce down to a single option. For example, calling Newest() to obtain
// the highest available version.
//
// If any of the metas in the set have invalid version strings then this
// function will panic. Use ValidateVersions() first to filter out metas with
// invalid versions.
func (s PluginMetaSet) ConstrainVersions(reqd PluginRequirements) map[string]PluginMetaSet {
ret := make(map[string]PluginMetaSet)
for p := range s {
name := p.Name
allowedVersions, ok := reqd[name]
if !ok {
continue
}
if _, ok := ret[p.Name]; !ok {
ret[p.Name] = make(PluginMetaSet)
}
version, err := p.Version.Parse()
if err != nil {
panic(err)
}
if allowedVersions.Allows(version) {
ret[p.Name].Add(p)
}
}
return ret
}
// OverridePaths returns a new set where any existing plugins with the given
// names are removed and replaced with the single path given in the map.
//
// This is here only to continue to support the legacy way of overriding
// plugin binaries in the .terraformrc file. It treats all given plugins
// as pre-versioning (version 0.0.0). This mechanism will eventually be
// phased out, with vendor directories being the intended replacement.
func (s PluginMetaSet) OverridePaths(paths map[string]string) PluginMetaSet {
ret := make(PluginMetaSet)
for p := range s {
if _, ok := paths[p.Name]; ok {
// Skip plugins that we're overridding
continue
}
ret.Add(p)
}
// Now add the metadata for overriding plugins
for name, path := range paths {
ret.Add(PluginMeta{
Name: name,
Version: VersionZero,
Path: path,
})
}
return ret
}