config: parse provider version constraints into a constraint map

This commit is contained in:
Martin Atkins 2017-04-14 19:34:12 -07:00
parent 0b14c2cdb3
commit 32a5c62639
1 changed files with 103 additions and 0 deletions

103
config/providers.go Normal file
View File

@ -0,0 +1,103 @@
package config
import "github.com/blang/semver"
// ProviderVersionConstraint presents a constraint for a particular
// provider, identified by its full name.
type ProviderVersionConstraint struct {
Constraint string
ProviderType string
}
// ProviderVersionConstraints is a map from provider full name to its associated
// ProviderVersionConstraint, as produced by Config.RequiredProviders.
type ProviderVersionConstraints map[string]ProviderVersionConstraint
// RequiredProviders returns the ProviderVersionConstraints for this
// module.
//
// This includes both providers that are explicitly requested by provider
// blocks and those that are used implicitly by instantiating one of their
// resource types. In the latter case, the returned semver Range will
// accept any version of the provider.
func (c *Config) RequiredProviders() ProviderVersionConstraints {
ret := make(ProviderVersionConstraints, len(c.ProviderConfigs))
configs := c.ProviderConfigsByFullName()
// In order to find the *implied* dependencies (those without explicit
// "provider" blocks) we need to walk over all of the resources and
// cross-reference with the provider configs.
for _, rc := range c.Resources {
providerName := rc.ProviderFullName()
var providerType string
// Default to (effectively) no constraint whatsoever, but we might
// override if there's an explicit constraint in config.
constraint := ">=0.0.0"
config, ok := configs[providerName]
if ok {
if config.Version != "" {
constraint = config.Version
}
providerType = config.Name
} else {
providerType = providerName
}
ret[providerName] = ProviderVersionConstraint{
ProviderType: providerType,
Constraint: constraint,
}
}
return ret
}
// RequiredRanges returns a semver.Range for each distinct provider type in
// the constraint map. If the same provider type appears more than once
// (e.g. because aliases are in use) then their respective constraints are
// combined such that they must *all* apply.
//
// The result of this method can be passed to the
// PluginMetaSet.ConstrainVersions method within the plugin/discovery
// package in order to filter down the available plugins to those which
// satisfy the given constraints.
//
// This function will panic if any of the constraints within cannot be
// parsed as semver ranges. This is guaranteed to never happen for a
// constraint set that was built from a configuration that passed validation.
func (cons ProviderVersionConstraints) RequiredRanges() map[string]semver.Range {
ret := make(map[string]semver.Range, len(cons))
for _, con := range cons {
spec := semver.MustParseRange(con.Constraint)
if existing, exists := ret[con.ProviderType]; exists {
ret[con.ProviderType] = existing.AND(spec)
} else {
ret[con.ProviderType] = spec
}
}
return ret
}
// ProviderConfigsByFullName returns a map from provider full names (as
// returned by ProviderConfig.FullName()) to the corresponding provider
// configs.
//
// This function returns no new information than what's already in
// c.ProviderConfigs, but returns it in a more convenient shape. If there
// is more than one provider config with the same full name then the result
// is undefined, but that is guaranteed not to happen for any config that
// has passed validation.
func (c *Config) ProviderConfigsByFullName() map[string]*ProviderConfig {
ret := make(map[string]*ProviderConfig, len(c.ProviderConfigs))
for _, pc := range c.ProviderConfigs {
ret[pc.FullName()] = pc
}
return ret
}