terraform/registry/regsrc/module.go

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package regsrc
import (
"errors"
"fmt"
"regexp"
"strings"
)
var (
ErrInvalidModuleSource = errors.New("not a valid registry module source")
// nameSubRe is the sub-expression that matches a valid module namespace or
// name. It's strictly a super-set of what GitHub allows for user/org and
// repo names respectively, but more restrictive than our original repo-name
// regex which allowed periods but could cause ambiguity with hostname
// prefixes. It does not anchor the start or end so it can be composed into
// more complex RegExps below. Alphanumeric with - and _ allowed in non
// leading or trailing positions. Max length 64 chars. (GitHub username is
// 38 max.)
nameSubRe = "[0-9A-Za-z](?:[0-9A-Za-z-_]{0,62}[0-9A-Za-z])?"
// providerSubRe is the sub-expression that matches a valid provider. It
// does not anchor the start or end so it can be composed into more complex
// RegExps below. Only lowercase chars and digits are supported in practice.
// Max length 64 chars.
providerSubRe = "[0-9a-z]{1,64}"
// moduleSourceRe is a regular expression that matches the basic
// namespace/name/provider[//...] format for registry sources. It assumes
// any FriendlyHost prefix has already been removed if present.
moduleSourceRe = regexp.MustCompile(
fmt.Sprintf("^(%s)\\/(%s)\\/(%s)(?:\\/\\/(.*))?$",
nameSubRe, nameSubRe, providerSubRe))
// disallowed is a set of hostnames that have special usage in modules and
// can't be registry hosts
disallowed = map[string]bool{
"github.com": true,
"bitbucket.org": true,
}
)
// Module describes a Terraform Registry Module source.
type Module struct {
// RawHost is the friendly host prefix if one was present. It might be nil
// if the original source had no host prefix which implies
// PublicRegistryHost but is distinct from having an actual pointer to
// PublicRegistryHost since it encodes the fact the original string didn't
// include a host prefix at all which is significant for recovering actual
// input not just normalized form. Most callers should access it with Host()
// which will return public registry host instance if it's nil.
RawHost *FriendlyHost
RawNamespace string
RawName string
RawProvider string
RawSubmodule string
}
// NewModule construct a new module source from separate parts. Pass empty
// string if host or submodule are not needed.
func NewModule(host, namespace, name, provider, submodule string) *Module {
m := &Module{
RawNamespace: namespace,
RawName: name,
RawProvider: provider,
RawSubmodule: submodule,
}
if host != "" {
m.RawHost = NewFriendlyHost(host)
}
return m
}
// ParseModuleSource attempts to parse source as a Terraform registry module
// source. If the string is not found to be in a valid format,
// ErrInvalidModuleSource is returned. Note that this can only be used on
// "input" strings, e.g. either ones supplied by the user or potentially
// normalised but in Display form (unicode). It will fail to parse a source with
// a punycoded domain since this is not permitted input from a user. If you have
// an already normalized string internally, you can compare it without parsing
// by comparing with the normalized version of the subject with the normal
// string equality operator.
func ParseModuleSource(source string) (*Module, error) {
// See if there is a friendly host prefix.
host, rest := ParseFriendlyHost(source)
if host != nil {
if !host.Valid() || disallowed[host.Display()] {
return nil, ErrInvalidModuleSource
}
}
matches := moduleSourceRe.FindStringSubmatch(rest)
if len(matches) < 4 {
return nil, ErrInvalidModuleSource
}
m := &Module{
RawHost: host,
RawNamespace: matches[1],
RawName: matches[2],
RawProvider: matches[3],
}
if len(matches) == 5 {
m.RawSubmodule = matches[4]
}
return m, nil
}
// Display returns the source formatted for display to the user in CLI or web
// output.
func (m *Module) Display() string {
return m.formatWithPrefix(m.normalizedHostPrefix(m.Host().Display()), false)
}
// Normalized returns the source formatted for internal reference or comparison.
func (m *Module) Normalized() string {
return m.formatWithPrefix(m.normalizedHostPrefix(m.Host().Normalized()), false)
}
// String returns the source formatted as the user originally typed it assuming
// it was parsed from user input.
func (m *Module) String() string {
// Don't normalize public registry hostname - leave it exactly like the user
// input it.
hostPrefix := ""
if m.RawHost != nil {
hostPrefix = m.RawHost.String() + "/"
}
return m.formatWithPrefix(hostPrefix, true)
}
// Module returns just the registry ID of the module, without a hostname or
// suffix.
func (m *Module) Module() string {
return fmt.Sprintf("%s/%s/%s", m.RawNamespace, m.RawName, m.RawProvider)
}
// Equal compares the module source against another instance taking
// normalization into account.
func (m *Module) Equal(other *Module) bool {
return m.Normalized() == other.Normalized()
}
// Host returns the FriendlyHost object describing which registry this module is
// in. If the original source string had not host component this will return the
// PublicRegistryHost.
func (m *Module) Host() *FriendlyHost {
if m.RawHost == nil {
return PublicRegistryHost
}
return m.RawHost
}
func (m *Module) normalizedHostPrefix(host string) string {
if m.Host().Equal(PublicRegistryHost) {
return ""
}
return host + "/"
}
func (m *Module) formatWithPrefix(hostPrefix string, preserveCase bool) string {
suffix := ""
if m.RawSubmodule != "" {
suffix = "//" + m.RawSubmodule
}
str := fmt.Sprintf("%s%s/%s/%s%s", hostPrefix, m.RawNamespace, m.RawName,
m.RawProvider, suffix)
// lower case by default
if !preserveCase {
return strings.ToLower(str)
}
return str
}