terraform/configs/config.go

270 lines
8.9 KiB
Go

package configs
import (
"fmt"
"sort"
version "github.com/hashicorp/go-version"
"github.com/hashicorp/hcl/v2"
"github.com/hashicorp/terraform/addrs"
)
// A Config is a node in the tree of modules within a configuration.
//
// The module tree is constructed by following ModuleCall instances recursively
// through the root module transitively into descendent modules.
//
// A module tree described in *this* package represents the static tree
// represented by configuration. During evaluation a static ModuleNode may
// expand into zero or more module instances depending on the use of count and
// for_each configuration attributes within each call.
type Config struct {
// RootModule points to the Config for the root module within the same
// module tree as this module. If this module _is_ the root module then
// this is self-referential.
Root *Config
// ParentModule points to the Config for the module that directly calls
// this module. If this is the root module then this field is nil.
Parent *Config
// Path is a sequence of module logical names that traverse from the root
// module to this config. Path is empty for the root module.
//
// This should only be used to display paths to the end-user in rare cases
// where we are talking about the static module tree, before module calls
// have been resolved. In most cases, an addrs.ModuleInstance describing
// a node in the dynamic module tree is better, since it will then include
// any keys resulting from evaluating "count" and "for_each" arguments.
Path addrs.Module
// ChildModules points to the Config for each of the direct child modules
// called from this module. The keys in this map match the keys in
// Module.ModuleCalls.
Children map[string]*Config
// Module points to the object describing the configuration for the
// various elements (variables, resources, etc) defined by this module.
Module *Module
// CallRange is the source range for the header of the module block that
// requested this module.
//
// This field is meaningless for the root module, where its contents are undefined.
CallRange hcl.Range
// SourceAddr is the source address that the referenced module was requested
// from, as specified in configuration.
//
// This field is meaningless for the root module, where its contents are undefined.
SourceAddr string
// SourceAddrRange is the location in the configuration source where the
// SourceAddr value was set, for use in diagnostic messages.
//
// This field is meaningless for the root module, where its contents are undefined.
SourceAddrRange hcl.Range
// Version is the specific version that was selected for this module,
// based on version constraints given in configuration.
//
// This field is nil if the module was loaded from a non-registry source,
// since versions are not supported for other sources.
//
// This field is meaningless for the root module, where it will always
// be nil.
Version *version.Version
}
// NewEmptyConfig constructs a single-node configuration tree with an empty
// root module. This is generally a pretty useless thing to do, so most callers
// should instead use BuildConfig.
func NewEmptyConfig() *Config {
ret := &Config{}
ret.Root = ret
ret.Children = make(map[string]*Config)
ret.Module = &Module{}
return ret
}
// Depth returns the number of "hops" the receiver is from the root of its
// module tree, with the root module having a depth of zero.
func (c *Config) Depth() int {
ret := 0
this := c
for this.Parent != nil {
ret++
this = this.Parent
}
return ret
}
// DeepEach calls the given function once for each module in the tree, starting
// with the receiver.
//
// A parent is always called before its children and children of a particular
// node are visited in lexicographic order by their names.
func (c *Config) DeepEach(cb func(c *Config)) {
cb(c)
names := make([]string, 0, len(c.Children))
for name := range c.Children {
names = append(names, name)
}
for _, name := range names {
c.Children[name].DeepEach(cb)
}
}
// AllModules returns a slice of all the receiver and all of its descendent
// nodes in the module tree, in the same order they would be visited by
// DeepEach.
func (c *Config) AllModules() []*Config {
var ret []*Config
c.DeepEach(func(c *Config) {
ret = append(ret, c)
})
return ret
}
// Descendent returns the descendent config that has the given path beneath
// the receiver, or nil if there is no such module.
//
// The path traverses the static module tree, prior to any expansion to handle
// count and for_each arguments.
//
// An empty path will just return the receiver, and is therefore pointless.
func (c *Config) Descendent(path addrs.Module) *Config {
current := c
for _, name := range path {
current = current.Children[name]
if current == nil {
return nil
}
}
return current
}
// DescendentForInstance is like Descendent except that it accepts a path
// to a particular module instance in the dynamic module graph, returning
// the node from the static module graph that corresponds to it.
//
// All instances created by a particular module call share the same
// configuration, so the keys within the given path are disregarded.
func (c *Config) DescendentForInstance(path addrs.ModuleInstance) *Config {
current := c
for _, step := range path {
current = current.Children[step.Name]
if current == nil {
return nil
}
}
return current
}
// ProviderTypes returns the FQNs of each distinct provider type referenced
// in the receiving configuration.
//
// This is a helper for easily determining which provider types are required
// to fully interpret the configuration, though it does not include version
// information and so callers are expected to have already dealt with
// provider version selection in an earlier step and have identified suitable
// versions for each provider.
func (c *Config) ProviderTypes() []addrs.Provider {
m := make(map[addrs.Provider]struct{})
c.gatherProviderTypes(m)
ret := make([]addrs.Provider, 0, len(m))
for k := range m {
ret = append(ret, k)
}
sort.Slice(ret, func(i, j int) bool {
return ret[i].String() < ret[j].String()
})
return ret
}
func (c *Config) gatherProviderTypes(m map[addrs.Provider]struct{}) {
if c == nil {
return
}
for _, pc := range c.Module.ProviderConfigs {
fqn := c.Module.ProviderForLocalConfig(addrs.LocalProviderConfig{LocalName: pc.Name})
m[fqn] = struct{}{}
}
for _, rc := range c.Module.ManagedResources {
providerAddr := rc.ProviderConfigAddr()
fqn := c.Module.ProviderForLocalConfig(providerAddr)
m[fqn] = struct{}{}
}
for _, rc := range c.Module.DataResources {
providerAddr := rc.ProviderConfigAddr()
fqn := c.Module.ProviderForLocalConfig(providerAddr)
m[fqn] = struct{}{}
}
// Must also visit our child modules, recursively.
for _, cc := range c.Children {
cc.gatherProviderTypes(m)
}
}
// ResolveAbsProviderAddr returns the AbsProviderConfig represented by the given
// ProviderConfig address, which must not be nil or this method will panic.
//
// If the given address is already an AbsProviderConfig then this method returns
// it verbatim, and will always succeed. If it's a LocalProviderConfig then
// it will consult the local-to-FQN mapping table for the given module
// to find the absolute address corresponding to the given local one.
//
// The module address to resolve local addresses in must be given in the second
// argument, and must refer to a module that exists under the receiver or
// else this method will panic.
func (c *Config) ResolveAbsProviderAddr(addr addrs.ProviderConfig, inModule addrs.ModuleInstance) addrs.AbsProviderConfig {
switch addr := addr.(type) {
case addrs.AbsProviderConfig:
return addr
case addrs.LocalProviderConfig:
// Find the descendent Config that contains the module that this
// local config belongs to.
mc := c.DescendentForInstance(inModule)
if mc == nil {
panic(fmt.Sprintf("ResolveAbsProviderAddr with non-existent module %s", inModule.String()))
}
var provider addrs.Provider
if providerReq, exists := c.Module.ProviderRequirements[addr.LocalName]; exists {
provider = providerReq.Type
} else {
// FIXME: For now we're returning a _legacy_ address as fallback here,
// but once we remove legacy addresses this should actually be a
// _default_ provider address.
provider = addrs.NewLegacyProvider(addr.LocalName)
}
return addrs.AbsProviderConfig{
Module: inModule,
Provider: provider,
Alias: addr.Alias,
}
default:
panic(fmt.Sprintf("cannot ResolveAbsProviderAddr(%v, ...)", addr))
}
}
// ProviderForConfigAddr returns the FQN for a given addrs.ProviderConfig, first
// by checking for the provider in module.ProviderRequirements and falling
// back to addrs.NewLegacyProvider if it is not found.
func (c *Config) ProviderForConfigAddr(addr addrs.LocalProviderConfig) addrs.Provider {
if provider, exists := c.Module.ProviderRequirements[addr.LocalName]; exists {
return provider.Type
}
return c.ResolveAbsProviderAddr(addr, addrs.RootModuleInstance).Provider
}