opentofu/internal/configs/module.go
Martin Atkins 6b8e103d6a configs: Include "moved" blocks when merging multiple files into a module
An earlier commit added logic to decode "moved" blocks and do static
validation of them. Here we now include that result also in modules
produced from those files, which we can then use in Terraform Core to
actually implement the moves.

This also places the feature behind an active experiment keyword called
config_driven_move. For now activating this doesn't actually achieve
anything except let you include moved blocks that Terraform will summarily
ignore, but we'll expand the scope of this in later commits to eventually
reach the point where it's really usable.
2021-07-01 08:28:02 -07:00

549 lines
19 KiB
Go

package configs
import (
"fmt"
"github.com/hashicorp/hcl/v2"
"github.com/hashicorp/terraform/internal/addrs"
"github.com/hashicorp/terraform/internal/experiments"
)
// Module is a container for a set of configuration constructs that are
// evaluated within a common namespace.
type Module struct {
// SourceDir is the filesystem directory that the module was loaded from.
//
// This is populated automatically only for configurations loaded with
// LoadConfigDir. If the parser is using a virtual filesystem then the
// path here will be in terms of that virtual filesystem.
// Any other caller that constructs a module directly with NewModule may
// assign a suitable value to this attribute before using it for other
// purposes. It should be treated as immutable by all consumers of Module
// values.
SourceDir string
CoreVersionConstraints []VersionConstraint
ActiveExperiments experiments.Set
Backend *Backend
ProviderConfigs map[string]*Provider
ProviderRequirements *RequiredProviders
ProviderLocalNames map[addrs.Provider]string
ProviderMetas map[addrs.Provider]*ProviderMeta
Variables map[string]*Variable
Locals map[string]*Local
Outputs map[string]*Output
ModuleCalls map[string]*ModuleCall
ManagedResources map[string]*Resource
DataResources map[string]*Resource
Moved []*Moved
}
// File describes the contents of a single configuration file.
//
// Individual files are not usually used alone, but rather combined together
// with other files (conventionally, those in the same directory) to produce
// a *Module, using NewModule.
//
// At the level of an individual file we represent directly the structural
// elements present in the file, without any attempt to detect conflicting
// declarations. A File object can therefore be used for some basic static
// analysis of individual elements, but must be built into a Module to detect
// duplicate declarations.
type File struct {
CoreVersionConstraints []VersionConstraint
ActiveExperiments experiments.Set
Backends []*Backend
ProviderConfigs []*Provider
ProviderMetas []*ProviderMeta
RequiredProviders []*RequiredProviders
Variables []*Variable
Locals []*Local
Outputs []*Output
ModuleCalls []*ModuleCall
ManagedResources []*Resource
DataResources []*Resource
Moved []*Moved
}
// NewModule takes a list of primary files and a list of override files and
// produces a *Module by combining the files together.
//
// If there are any conflicting declarations in the given files -- for example,
// if the same variable name is defined twice -- then the resulting module
// will be incomplete and error diagnostics will be returned. Careful static
// analysis of the returned Module is still possible in this case, but the
// module will probably not be semantically valid.
func NewModule(primaryFiles, overrideFiles []*File) (*Module, hcl.Diagnostics) {
var diags hcl.Diagnostics
mod := &Module{
ProviderConfigs: map[string]*Provider{},
ProviderLocalNames: map[addrs.Provider]string{},
Variables: map[string]*Variable{},
Locals: map[string]*Local{},
Outputs: map[string]*Output{},
ModuleCalls: map[string]*ModuleCall{},
ManagedResources: map[string]*Resource{},
DataResources: map[string]*Resource{},
ProviderMetas: map[addrs.Provider]*ProviderMeta{},
}
// Process the required_providers blocks first, to ensure that all
// resources have access to the correct provider FQNs
for _, file := range primaryFiles {
for _, r := range file.RequiredProviders {
if mod.ProviderRequirements != nil {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Duplicate required providers configuration",
Detail: fmt.Sprintf("A module may have only one required providers configuration. The required providers were previously configured at %s.", mod.ProviderRequirements.DeclRange),
Subject: &r.DeclRange,
})
continue
}
mod.ProviderRequirements = r
}
}
// If no required_providers block is configured, create a useful empty
// state to reduce nil checks elsewhere
if mod.ProviderRequirements == nil {
mod.ProviderRequirements = &RequiredProviders{
RequiredProviders: make(map[string]*RequiredProvider),
}
}
// Any required_providers blocks in override files replace the entire
// block for each provider
for _, file := range overrideFiles {
for _, override := range file.RequiredProviders {
for name, rp := range override.RequiredProviders {
mod.ProviderRequirements.RequiredProviders[name] = rp
}
}
}
for _, file := range primaryFiles {
fileDiags := mod.appendFile(file)
diags = append(diags, fileDiags...)
}
for _, file := range overrideFiles {
fileDiags := mod.mergeFile(file)
diags = append(diags, fileDiags...)
}
diags = append(diags, checkModuleExperiments(mod)...)
// Generate the FQN -> LocalProviderName map
mod.gatherProviderLocalNames()
return mod, diags
}
// ResourceByAddr returns the configuration for the resource with the given
// address, or nil if there is no such resource.
func (m *Module) ResourceByAddr(addr addrs.Resource) *Resource {
key := addr.String()
switch addr.Mode {
case addrs.ManagedResourceMode:
return m.ManagedResources[key]
case addrs.DataResourceMode:
return m.DataResources[key]
default:
return nil
}
}
func (m *Module) appendFile(file *File) hcl.Diagnostics {
var diags hcl.Diagnostics
// If there are any conflicting requirements then we'll catch them
// when we actually check these constraints.
m.CoreVersionConstraints = append(m.CoreVersionConstraints, file.CoreVersionConstraints...)
m.ActiveExperiments = experiments.SetUnion(m.ActiveExperiments, file.ActiveExperiments)
for _, b := range file.Backends {
if m.Backend != nil {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Duplicate backend configuration",
Detail: fmt.Sprintf("A module may have only one backend configuration. The backend was previously configured at %s.", m.Backend.DeclRange),
Subject: &b.DeclRange,
})
continue
}
m.Backend = b
}
for _, pc := range file.ProviderConfigs {
key := pc.moduleUniqueKey()
if existing, exists := m.ProviderConfigs[key]; exists {
if existing.Alias == "" {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Duplicate provider configuration",
Detail: fmt.Sprintf("A default (non-aliased) provider configuration for %q was already given at %s. If multiple configurations are required, set the \"alias\" argument for alternative configurations.", existing.Name, existing.DeclRange),
Subject: &pc.DeclRange,
})
} else {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Duplicate provider configuration",
Detail: fmt.Sprintf("A provider configuration for %q with alias %q was already given at %s. Each configuration for the same provider must have a distinct alias.", existing.Name, existing.Alias, existing.DeclRange),
Subject: &pc.DeclRange,
})
}
continue
}
m.ProviderConfigs[key] = pc
}
for _, pm := range file.ProviderMetas {
provider := m.ProviderForLocalConfig(addrs.LocalProviderConfig{LocalName: pm.Provider})
if existing, exists := m.ProviderMetas[provider]; exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Duplicate provider_meta block",
Detail: fmt.Sprintf("A provider_meta block for provider %q was already declared at %s. Providers may only have one provider_meta block per module.", existing.Provider, existing.DeclRange),
Subject: &pm.DeclRange,
})
}
m.ProviderMetas[provider] = pm
}
for _, v := range file.Variables {
if existing, exists := m.Variables[v.Name]; exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Duplicate variable declaration",
Detail: fmt.Sprintf("A variable named %q was already declared at %s. Variable names must be unique within a module.", existing.Name, existing.DeclRange),
Subject: &v.DeclRange,
})
}
m.Variables[v.Name] = v
}
for _, l := range file.Locals {
if existing, exists := m.Locals[l.Name]; exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Duplicate local value definition",
Detail: fmt.Sprintf("A local value named %q was already defined at %s. Local value names must be unique within a module.", existing.Name, existing.DeclRange),
Subject: &l.DeclRange,
})
}
m.Locals[l.Name] = l
}
for _, o := range file.Outputs {
if existing, exists := m.Outputs[o.Name]; exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Duplicate output definition",
Detail: fmt.Sprintf("An output named %q was already defined at %s. Output names must be unique within a module.", existing.Name, existing.DeclRange),
Subject: &o.DeclRange,
})
}
m.Outputs[o.Name] = o
}
for _, mc := range file.ModuleCalls {
if existing, exists := m.ModuleCalls[mc.Name]; exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Duplicate module call",
Detail: fmt.Sprintf("A module call named %q was already defined at %s. Module calls must have unique names within a module.", existing.Name, existing.DeclRange),
Subject: &mc.DeclRange,
})
}
m.ModuleCalls[mc.Name] = mc
}
for _, r := range file.ManagedResources {
key := r.moduleUniqueKey()
if existing, exists := m.ManagedResources[key]; exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: fmt.Sprintf("Duplicate resource %q configuration", existing.Type),
Detail: fmt.Sprintf("A %s resource named %q was already declared at %s. Resource names must be unique per type in each module.", existing.Type, existing.Name, existing.DeclRange),
Subject: &r.DeclRange,
})
continue
}
m.ManagedResources[key] = r
// set the provider FQN for the resource
if r.ProviderConfigRef != nil {
r.Provider = m.ProviderForLocalConfig(r.ProviderConfigAddr())
} else {
// an invalid resource name (for e.g. "null resource" instead of
// "null_resource") can cause a panic down the line in addrs:
// https://github.com/hashicorp/terraform/issues/25560
implied, err := addrs.ParseProviderPart(r.Addr().ImpliedProvider())
if err == nil {
r.Provider = m.ImpliedProviderForUnqualifiedType(implied)
}
// We don't return a diagnostic because the invalid resource name
// will already have been caught.
}
}
for _, r := range file.DataResources {
key := r.moduleUniqueKey()
if existing, exists := m.DataResources[key]; exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: fmt.Sprintf("Duplicate data %q configuration", existing.Type),
Detail: fmt.Sprintf("A %s data resource named %q was already declared at %s. Resource names must be unique per type in each module.", existing.Type, existing.Name, existing.DeclRange),
Subject: &r.DeclRange,
})
continue
}
m.DataResources[key] = r
// set the provider FQN for the resource
if r.ProviderConfigRef != nil {
r.Provider = m.ProviderForLocalConfig(r.ProviderConfigAddr())
} else {
// an invalid data source name (for e.g. "null resource" instead of
// "null_resource") can cause a panic down the line in addrs:
// https://github.com/hashicorp/terraform/issues/25560
implied, err := addrs.ParseProviderPart(r.Addr().ImpliedProvider())
if err == nil {
r.Provider = m.ImpliedProviderForUnqualifiedType(implied)
}
// We don't return a diagnostic because the invalid resource name
// will already have been caught.
}
}
// "Moved" blocks just append, because they are all independent
// of one another at this level. (We handle any references between
// them at runtime.)
m.Moved = append(m.Moved, file.Moved...)
return diags
}
func (m *Module) mergeFile(file *File) hcl.Diagnostics {
var diags hcl.Diagnostics
if len(file.CoreVersionConstraints) != 0 {
// This is a bit of a strange case for overriding since we normally
// would union together across multiple files anyway, but we'll
// allow it and have each override file clobber any existing list.
m.CoreVersionConstraints = nil
m.CoreVersionConstraints = append(m.CoreVersionConstraints, file.CoreVersionConstraints...)
}
if len(file.Backends) != 0 {
switch len(file.Backends) {
case 1:
m.Backend = file.Backends[0]
default:
// An override file with multiple backends is still invalid, even
// though it can override backends from _other_ files.
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Duplicate backend configuration",
Detail: fmt.Sprintf("Each override file may have only one backend configuration. A backend was previously configured at %s.", file.Backends[0].DeclRange),
Subject: &file.Backends[1].DeclRange,
})
}
}
for _, pc := range file.ProviderConfigs {
key := pc.moduleUniqueKey()
existing, exists := m.ProviderConfigs[key]
if pc.Alias == "" {
// We allow overriding a non-existing _default_ provider configuration
// because the user model is that an absent provider configuration
// implies an empty provider configuration, which is what the user
// is therefore overriding here.
if exists {
mergeDiags := existing.merge(pc)
diags = append(diags, mergeDiags...)
} else {
m.ProviderConfigs[key] = pc
}
} else {
// For aliased providers, there must be a base configuration to
// override. This allows us to detect and report alias typos
// that might otherwise cause the override to not apply.
if !exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Missing base provider configuration for override",
Detail: fmt.Sprintf("There is no %s provider configuration with the alias %q. An override file can only override an aliased provider configuration that was already defined in a primary configuration file.", pc.Name, pc.Alias),
Subject: &pc.DeclRange,
})
continue
}
mergeDiags := existing.merge(pc)
diags = append(diags, mergeDiags...)
}
}
for _, v := range file.Variables {
existing, exists := m.Variables[v.Name]
if !exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Missing base variable declaration to override",
Detail: fmt.Sprintf("There is no variable named %q. An override file can only override a variable that was already declared in a primary configuration file.", v.Name),
Subject: &v.DeclRange,
})
continue
}
mergeDiags := existing.merge(v)
diags = append(diags, mergeDiags...)
}
for _, l := range file.Locals {
existing, exists := m.Locals[l.Name]
if !exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Missing base local value definition to override",
Detail: fmt.Sprintf("There is no local value named %q. An override file can only override a local value that was already defined in a primary configuration file.", l.Name),
Subject: &l.DeclRange,
})
continue
}
mergeDiags := existing.merge(l)
diags = append(diags, mergeDiags...)
}
for _, o := range file.Outputs {
existing, exists := m.Outputs[o.Name]
if !exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Missing base output definition to override",
Detail: fmt.Sprintf("There is no output named %q. An override file can only override an output that was already defined in a primary configuration file.", o.Name),
Subject: &o.DeclRange,
})
continue
}
mergeDiags := existing.merge(o)
diags = append(diags, mergeDiags...)
}
for _, mc := range file.ModuleCalls {
existing, exists := m.ModuleCalls[mc.Name]
if !exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Missing module call to override",
Detail: fmt.Sprintf("There is no module call named %q. An override file can only override a module call that was defined in a primary configuration file.", mc.Name),
Subject: &mc.DeclRange,
})
continue
}
mergeDiags := existing.merge(mc)
diags = append(diags, mergeDiags...)
}
for _, r := range file.ManagedResources {
key := r.moduleUniqueKey()
existing, exists := m.ManagedResources[key]
if !exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Missing resource to override",
Detail: fmt.Sprintf("There is no %s resource named %q. An override file can only override a resource block defined in a primary configuration file.", r.Type, r.Name),
Subject: &r.DeclRange,
})
continue
}
mergeDiags := existing.merge(r, m.ProviderRequirements.RequiredProviders)
diags = append(diags, mergeDiags...)
}
for _, r := range file.DataResources {
key := r.moduleUniqueKey()
existing, exists := m.DataResources[key]
if !exists {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Missing data resource to override",
Detail: fmt.Sprintf("There is no %s data resource named %q. An override file can only override a data block defined in a primary configuration file.", r.Type, r.Name),
Subject: &r.DeclRange,
})
continue
}
mergeDiags := existing.merge(r, m.ProviderRequirements.RequiredProviders)
diags = append(diags, mergeDiags...)
}
for _, m := range file.Moved {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Cannot override 'moved' blocks",
Detail: "Records of moved objects can appear only in normal files, not in override files.",
Subject: m.DeclRange.Ptr(),
})
}
return diags
}
// gatherProviderLocalNames is a helper function that populatesA a map of
// provider FQNs -> provider local names. This information is useful for
// user-facing output, which should include both the FQN and LocalName. It must
// only be populated after the module has been parsed.
func (m *Module) gatherProviderLocalNames() {
providers := make(map[addrs.Provider]string)
for k, v := range m.ProviderRequirements.RequiredProviders {
providers[v.Type] = k
}
m.ProviderLocalNames = providers
}
// LocalNameForProvider returns the module-specific user-supplied local name for
// a given provider FQN, or the default local name if none was supplied.
func (m *Module) LocalNameForProvider(p addrs.Provider) string {
if existing, exists := m.ProviderLocalNames[p]; exists {
return existing
} else {
// If there isn't a map entry, fall back to the default:
// Type = LocalName
return p.Type
}
}
// ProviderForLocalConfig returns the provider FQN for a given
// LocalProviderConfig, based on its local name.
func (m *Module) ProviderForLocalConfig(pc addrs.LocalProviderConfig) addrs.Provider {
return m.ImpliedProviderForUnqualifiedType(pc.LocalName)
}
// ImpliedProviderForUnqualifiedType returns the provider FQN for a given type,
// first by looking up the type in the provider requirements map, and falling
// back to an implied default provider.
//
// The intended behaviour is that configuring a provider with local name "foo"
// in a required_providers block will result in resources with type "foo" using
// that provider.
func (m *Module) ImpliedProviderForUnqualifiedType(pType string) addrs.Provider {
if provider, exists := m.ProviderRequirements.RequiredProviders[pType]; exists {
return provider.Type
}
return addrs.ImpliedProviderForUnqualifiedType(pType)
}