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 *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 } // 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 } // 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. } } 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...) } 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) }