Add grammar for platform string

Platform string to be of the form <os>[(<osversion>)]|<arch>|<os>[(<OSVersion>)]/<arch>[/<variant>]
OSVersion is optional only and currently used only by Windows OS.

Signed-off-by: Kirtana Ashok <[email protected]>

database.go

@@ -17,6 +17,7 @@
 package platforms
 
 import (
+ "regexp"
  "runtime"
  "strings"
 )
@@ -59,17 +60,35 @@ func isKnownArch(arch string) bool {
  return false
 }
 
-func normalizeOS(os string) string {
- if os == "" {
- return runtime.GOOS
+func getWindowsOsVersion(OSAndVersion string) string {
+ parts := regexp.MustCompile("[()]").Split(OSAndVersion, -1)
+ if len(parts) > 1 {
+ if parts[1] != "" {
+ return parts[1]
+ }
+ }
+ return ""
+}
+
+// The formart of OS part of the platform specifier is <OS>[(<OSVersion>)]
+// OSVersion is optional only and is currently used only by windows OS.
+// If OsVersion is not specified, empty string is returned.
+func normalizeOS(OSAndVersion string) (string, string) {
+ if OSAndVersion == "" {
+ return runtime.GOOS, ""
  }
- os = strings.ToLower(os)
+ os := strings.Split(strings.ToLower(OSAndVersion), "(")[0]
 
  switch os {
  case "macos":
  os = "darwin"
  }
- return os
+
+ // check for OS verion if OS version is windows. Otherwise, use the host OSVersion
+ if os == "windows" {
+ return "windows", getWindowsOsVersion(OSAndVersion)
+ }
+ return os, ""
 }
 
 // normalizeArch normalizes the architecture.

platforms.go

@@ -121,7 +121,8 @@ import (
 )
 
 var (
- specifierRe = regexp.MustCompile(`^[A-Za-z0-9_-]+$`)
+ specifierRe = regexp.MustCompile(`^[()A-Za-z0-9_.-]+$`)
+ OSAndVersionFormat = "%s(%s)"
 )
 
 // Platform is a type alias for convenience, so there is no need to import image-spec package everywhere.
@@ -174,9 +175,13 @@ func ParseAll(specifiers []string) ([]specs.Platform, error) {
 
 // Parse parses the platform specifier syntax into a platform declaration.
 //
-// Platform specifiers are in the format `<os>|<arch>|<os>/<arch>[/<variant>]`.
+// Platform specifiers are in the format `<os>[(<OSVersion>)]|<arch>|<os>[(<OSVersion>)]/<arch>[/<variant>]`.
 // The minimum required information for a platform specifier is the operating
-// system or architecture. If there is only a single string (no slashes), the
+// system or architecture. The OSVersion can be part of the OS like windows(10.0.17763)
+// Currently, the OS version is only used by windows. Therefore, if the OS is windows
+// and an os version is specified, then specs.Platform.OSVersion is populated. If not it
+// is left empty.
+// If there is only a single string (no slashes), the
 // value will be matched against the known set of operating systems, then fall
 // back to the known set of architectures. The missing component will be
 // inferred based on the local environment.
@@ -197,23 +202,20 @@ func Parse(specifier string) (specs.Platform, error) {
  var p specs.Platform
  switch len(parts) {
  case 1:
- // in this case, we will test that the value might be an OS, then look
- // it up. If it is not known, we'll treat it as an architecture. Since
+ // in this case, we will test that the value might be an OS (with or
+ // without the optional osversion specified) and look it up.
+ // If it is not known, we'll treat it as an architecture. Since
  // we have very little information about the platform here, we are
  // going to be a little more strict if we don't know about the argument
  // value.
- p.OS = normalizeOS(parts[0])
+ p.OS, p.OSVersion = normalizeOS(parts[0])
  if isKnownOS(p.OS) {
  // picks a default architecture
  p.Architecture = runtime.GOARCH
  if p.Architecture == "arm" && cpuVariant() != "v7" {
  p.Variant = cpuVariant()
  }
 
- if p.OS == "windows" {
- p.OSVersion = GetWindowsOsVersion()
- }
-
  return p, nil
  }
 
@@ -228,31 +230,23 @@ func Parse(specifier string) (specs.Platform, error) {
 
  return specs.Platform{}, fmt.Errorf("%q: unknown operating system or architecture: %w", specifier, errInvalidArgument)
  case 2:
- // In this case, we treat as a regular os/arch pair. We don't care
+ // In this case, we treat as a regular os[(osversion)]/arch pair. We don't care
  // about whether or not we know of the platform.
- p.OS = normalizeOS(parts[0])
+ p.OS, p.OSVersion = normalizeOS(parts[0])
  p.Architecture, p.Variant = normalizeArch(parts[1], "")
  if p.Architecture == "arm" && p.Variant == "v7" {
  p.Variant = ""
  }
 
- if p.OS == "windows" {
- p.OSVersion = GetWindowsOsVersion()
- }
-
  return p, nil
  case 3:
  // we have a fully specified variant, this is rare
- p.OS = normalizeOS(parts[0])
+ p.OS, p.OSVersion = normalizeOS(parts[0])
  p.Architecture, p.Variant = normalizeArch(parts[1], parts[2])
  if p.Architecture == "arm64" && p.Variant == "" {
  p.Variant = "v8"
  }
 
- if p.OS == "windows" {
- p.OSVersion = GetWindowsOsVersion()
- }
-
  return p, nil
  }
 
@@ -275,6 +269,11 @@ func Format(platform specs.Platform) string {
  return "unknown"
  }
 
+ if strings.ToLower(platform.OS) == "windows" && platform.OSVersion != "" {
+ windowsOsVersion := fmt.Sprintf(OSAndVersionFormat, platform.OS, platform.OSVersion)
+ return path.Join(windowsOsVersion, platform.Architecture, platform.Variant)
+ }
+
  return path.Join(platform.OS, platform.Architecture, platform.Variant)
 }
 
@@ -283,7 +282,7 @@ func Format(platform specs.Platform) string {
 // For example, if "Aarch64" is encountered, we change it to "arm64" or if
 // "x86_64" is encountered, it becomes "amd64".
 func Normalize(platform specs.Platform) specs.Platform {
- platform.OS = normalizeOS(platform.OS)
+ platform.OS, platform.OSVersion = normalizeOS(platform.OS)
  platform.Architecture, platform.Variant = normalizeArch(platform.Architecture, platform.Variant)
 
  return platform

platforms_test.go

@@ -290,6 +290,36 @@ func TestParseSelector(t *testing.T) {
  },
  formatted: path.Join("darwin", defaultArch, defaultVariant),
  },
+ {
+ input: "windows",
+ expected: specs.Platform{
+ OS: "windows",
+ OSVersion: "",
+ Architecture: defaultArch,
+ Variant: defaultVariant,
+ },
+ formatted: path.Join("windows", defaultArch, defaultVariant),
+ },
+ {
+ input: "windows()",
+ expected: specs.Platform{
+ OS: "windows",
+ OSVersion: "",
+ Architecture: defaultArch,
+ Variant: defaultVariant,
+ },
+ formatted: path.Join("windows", defaultArch, defaultVariant),
+ },
+ {
+ input: "windows(10.0.17763)",
+ expected: specs.Platform{
+ OS: "windows",
+ OSVersion: "10.0.17763",
+ Architecture: defaultArch,
+ Variant: defaultVariant,
+ },
+ formatted: path.Join("windows(10.0.17763)", defaultArch, defaultVariant),
+ },
  } {
  t.Run(testcase.input, func(t *testing.T) {
  if testcase.skip {