1. docker
  2. Commit 91ae7ea8c8c8e6877f69029df58af4986f202b88
Browse code

dockerversion: un-export UAStringKey, add WithUpstreamUserAgent

Add a WithUpstreamUserAgent utility instead of exporting the context-key
used.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Sebastiaan van Stijn authored on 2026/05/12 21:29:29
Showing 3 changed files
daemon/server/server.go
History View file @ 91ae7ea
... ... 
@@ -61,7 +61,7 @@ func (s *Server) makeHTTPHandler(route router.Route) http.HandlerFunc {
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 		// use intermediate variable to prevent "should not use basic type
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 		// string as key in context.WithValue" golint errors
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 		ua := r.Header.Get("User-Agent")
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-		ctx := baggage.ContextWithBaggage(context.WithValue(r.Context(), dockerversion.UAStringKey{}, ua), otelutil.MustNewBaggage(
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+		ctx := baggage.ContextWithBaggage(dockerversion.WithUpstreamUserAgent(r.Context(), ua), otelutil.MustNewBaggage(
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 			otelutil.MustNewMemberRaw(otelutil.TriggerKey, "api"),
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 		))
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dockerversion/useragent.go
History View file @ 91ae7ea
... ... 
@@ -10,8 +10,17 @@ import (
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 	"github.com/moby/moby/v2/pkg/useragent"
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 )
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-// UAStringKey is used as key type for user-agent string in net/context struct
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-type UAStringKey struct{}
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+// uaStringKey is used as key type for user-agent string in net/context struct
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+type uaStringKey struct{}
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+
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+// WithUpstreamUserAgent returns a new context carrying the upstream client's
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+// User-Agent string.
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+func WithUpstreamUserAgent(ctx context.Context, ua string) context.Context {
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+	if ua == "" {
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+		return ctx
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+	}
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+	return context.WithValue(ctx, uaStringKey{}, ua)
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+}
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 // DockerUserAgent is the User-Agent used by the daemon.
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 //
... ... 
@@ -71,7 +80,7 @@ func getDaemonUserAgent() string {
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 //
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 // It returns an empty string if no user-agent is present in the context.
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 func getUpstreamUserAgent(ctx context.Context) string {
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-	upstreamUA, ok := ctx.Value(UAStringKey{}).(string)
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+	upstreamUA, ok := ctx.Value(uaStringKey{}).(string)
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 	if !ok || upstreamUA == "" {
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 		return ""
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 	}
dockerversion/useragent_test.go
History View file @ 91ae7ea
... ... 
@@ -32,12 +32,12 @@ func TestDockerUserAgent(t *testing.T) {
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 		},
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 		{
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 			doc:      "daemon user-agent with upstream",
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-			ctx:      context.WithValue(t.Context(), UAStringKey{}, "Magic-Client/1.2.3 (linux)"),
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+			ctx:      WithUpstreamUserAgent(t.Context(), "Magic-Client/1.2.3 (linux)"),
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 			expected: getDaemonUserAgent() + ` UpstreamClient(Magic-Client/1.2.3 \(linux\))`,
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 		},
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 		{
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 			doc: "daemon user-agent with upstream and custom metadata",
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-			ctx: context.WithValue(t.Context(), UAStringKey{}, "Magic-Client/1.2.3 (linux)"),
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+			ctx: WithUpstreamUserAgent(t.Context(), "Magic-Client/1.2.3 (linux)"),
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 			metadata: []useragent.VersionInfo{
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 				{Name: "hello", Version: "world"},
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 				{Name: "foo", Version: "bar"},
... ... 
@@ -46,12 +46,12 @@ func TestDockerUserAgent(t *testing.T) {
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 		},
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 		{
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 			doc:      "daemon user-agent with upstream special chars",
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-			ctx:      context.WithValue(t.Context(), UAStringKey{}, `Magic-Client/1.2.3 (linux); \ test`),
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+			ctx:      WithUpstreamUserAgent(t.Context(), `Magic-Client/1.2.3 (linux); \ test`),
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 			expected: getDaemonUserAgent() + ` UpstreamClient(Magic-Client/1.2.3 \(linux\)\; \\ test)`,
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 		},
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 		{
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 			doc:      "daemon user-agent with upstream control chars",
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-			ctx:      context.WithValue(t.Context(), UAStringKey{}, "Magic-Client/1.2.3\r\nInjected: evil"),
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+			ctx:      WithUpstreamUserAgent(t.Context(), "Magic-Client/1.2.3\r\nInjected: evil"),
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 			expected: getDaemonUserAgent() + ` UpstreamClient(Magic-Client/1.2.3Injected: evil)`,
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 		},
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 	}