terraform/configs/module.go

481 lines
17 KiB
Go

package configs
import (
"fmt"
"github.com/hashicorp/hcl/v2"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/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 map[string]ProviderRequirements
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
}
// 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 []*RequiredProvider
Variables []*Variable
Locals []*Local
Outputs []*Output
ModuleCalls []*ModuleCall
ManagedResources []*Resource
DataResources []*Resource
}
// 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{},
ProviderRequirements: map[string]ProviderRequirements{},
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{},
}
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
for _, constraint := range file.CoreVersionConstraints {
// If there are any conflicting requirements then we'll catch them
// when we actually check these constraints.
m.CoreVersionConstraints = append(m.CoreVersionConstraints, constraint)
}
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 _, reqd := range file.RequiredProviders {
var fqn addrs.Provider
if reqd.Source != "" {
// FIXME: capture errors
fqn, _ = addrs.ParseProviderSourceString(reqd.Source)
} else {
fqn = addrs.NewLegacyProvider(reqd.Name)
}
if existing, exists := m.ProviderRequirements[reqd.Name]; exists {
if existing.Type != fqn {
panic("provider fqn mismatch")
}
existing.VersionConstraints = append(existing.VersionConstraints, reqd.Requirement)
} else {
m.ProviderRequirements[reqd.Name] = ProviderRequirements{Type: fqn, VersionConstraints: []VersionConstraint{reqd.Requirement}}
}
}
for _, pm := range file.ProviderMetas {
// TODO(paddy): pm.Provider is a string, but we need to build an addrs.Provider out of it somehow
if existing, exists := m.ProviderMetas[addrs.NewLegacyProvider(pm.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[addrs.NewLegacyProvider(pm.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("An 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
}
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
}
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
for _, constraint := range file.CoreVersionConstraints {
m.CoreVersionConstraints = append(m.CoreVersionConstraints, constraint)
}
}
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...)
}
}
if len(file.RequiredProviders) != 0 {
mergeProviderVersionConstraints(m.ProviderRequirements, file.RequiredProviders)
}
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)
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)
diags = append(diags, mergeDiags...)
}
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 {
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
func (m *Module) ProviderForLocalConfig(pc addrs.LocalProviderConfig) addrs.Provider {
if provider, exists := m.ProviderRequirements[pc.LocalName]; exists {
return provider.Type
}
return addrs.NewLegacyProvider(pc.LocalName)
}