[client, management, misc] expose VCS revision in dev build version output (#6263)

* Refactor to use a common checker for development version

* Adds commit sha to development version for cobra command only

Leave dashboard unaffected

* Adjust for "v0.31.1-dev" test case

which must be considered pre-release

* Drop synthetic "dev"/"0.50.0-dev" firewall feature-gate fixtures

These test cases encoded the loose strings.Contains(v, "dev")
semantics inherited from peerSupportedFirewallFeatures, but
NetbirdVersion() never produces those values — only the literal
"development" (and now "development-<sha>[-dirty]") ever flows
through the wire. The agent owns the semantics of an ephemeral
development build, so the tests should exercise the strings we
actually emit.

Replaced with development, development-<sha> and
development-<sha>-dirty cases that match the HasPrefix("development")
predicate introduced upstream.

* Remove unexistent tests on wire format

The sha / dirty flag are added only when the CLI asks the version.
Account versions is unaffacted and can only strictly match "development"

* Adds tests for IsDevelopmentVersion

version/version.go

@@ -2,19 +2,75 @@ package version
 
 import (
 	"regexp"
+	"runtime/debug"
+	"strings"
 
 	v "github.com/hashicorp/go-version"
 )
 
+// DevelopmentVersion is the value of NetbirdVersion() for non-release builds.
+// Wire-format consumers (management server, dashboard) match against this
+// string, so it must not change without coordinating those consumers.
+const DevelopmentVersion = "development"
+
 // will be replaced with the release version when using goreleaser
-var version = "development"
+var version = DevelopmentVersion
 
 var (
 	VersionRegexp = regexp.MustCompile("^" + v.VersionRegexpRaw + "$")
 	SemverRegexp  = regexp.MustCompile("^" + v.SemverRegexpRaw + "$")
 )
 
-// NetbirdVersion returns the Netbird version
+// NetbirdVersion returns the Netbird version. For non-release builds the
+// value is the literal DevelopmentVersion constant; the VCS revision is
+// exposed separately via NetbirdCommit so the wire format stays stable.
 func NetbirdVersion() string {
 	return version
 }
+
+// NetbirdCommit returns the VCS revision (truncated to 12 chars) of the
+// build, with a "-dirty" suffix when the working tree was modified.
+// Returns an empty string when no build info is embedded (e.g. release
+// builds compiled by goreleaser without -buildvcs).
+func NetbirdCommit() string {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return ""
+	}
+
+	var revision string
+	var modified bool
+	for _, s := range info.Settings {
+		switch s.Key {
+		case "vcs.revision":
+			revision = s.Value
+		case "vcs.modified":
+			modified = s.Value == "true"
+		}
+	}
+
+	if revision == "" {
+		return ""
+	}
+
+	if len(revision) > 12 {
+		revision = revision[:12]
+	}
+
+	if modified {
+		revision += "-dirty"
+	}
+	return revision
+}
+
+// IsDevelopmentVersion reports whether the given version string identifies
+// a non-release / development build. It is the single source of truth for
+// "is this a dev build" checks across the codebase; use it instead of
+// comparing against the "development" literal or ad-hoc substring checks.
+//
+// Matches the bare DevelopmentVersion constant as well as any future
+// extension such as "development-<sha>" or "development-<sha>-dirty",
+// while excluding tagged prereleases like "v0.31.1-dev".
+func IsDevelopmentVersion(v string) bool {
+	return strings.HasPrefix(v, DevelopmentVersion)
+}

version/version_test.go

@@ -0,0 +1,26 @@
+package version
+
+import "testing"
+
+func TestIsDevelopmentVersion(t *testing.T) {
+	tests := []struct {
+		version string
+		want    bool
+	}{
+		{"development", true},
+		{"development-0823f3ff9ab1", true},
+		{"development-0823f3ff9ab1-dirty", true},
+		{"0.50.0", false},
+		{"v0.31.1-dev", false},
+		{"1.0.0-dev", false},
+		{"dev", false},
+		{"", false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.version, func(t *testing.T) {
+			if got := IsDevelopmentVersion(tt.version); got != tt.want {
+				t.Errorf("IsDevelopmentVersion(%q) = %v, want %v", tt.version, got, tt.want)
+			}
+		})
+	}
+}