github.com/demonoid81/moby@v0.0.0-20200517203328-62dd8e17c460/dockerversion/useragent.go (about) 1 package dockerversion // import "github.com/demonoid81/moby/dockerversion" 2 3 import ( 4 "context" 5 "fmt" 6 "runtime" 7 8 "github.com/demonoid81/moby/pkg/parsers/kernel" 9 "github.com/demonoid81/moby/pkg/useragent" 10 ) 11 12 // UAStringKey is used as key type for user-agent string in net/context struct 13 type UAStringKey struct{} 14 15 // DockerUserAgent is the User-Agent the Docker client uses to identify itself. 16 // In accordance with RFC 7231 (5.5.3) is of the form: 17 // [docker client's UA] UpstreamClient([upstream client's UA]) 18 func DockerUserAgent(ctx context.Context) string { 19 httpVersion := make([]useragent.VersionInfo, 0, 6) 20 httpVersion = append(httpVersion, useragent.VersionInfo{Name: "docker", Version: Version}) 21 httpVersion = append(httpVersion, useragent.VersionInfo{Name: "go", Version: runtime.Version()}) 22 httpVersion = append(httpVersion, useragent.VersionInfo{Name: "git-commit", Version: GitCommit}) 23 if kernelVersion, err := kernel.GetKernelVersion(); err == nil { 24 httpVersion = append(httpVersion, useragent.VersionInfo{Name: "kernel", Version: kernelVersion.String()}) 25 } 26 httpVersion = append(httpVersion, useragent.VersionInfo{Name: "os", Version: runtime.GOOS}) 27 httpVersion = append(httpVersion, useragent.VersionInfo{Name: "arch", Version: runtime.GOARCH}) 28 29 dockerUA := useragent.AppendVersions("", httpVersion...) 30 upstreamUA := getUserAgentFromContext(ctx) 31 if len(upstreamUA) > 0 { 32 ret := insertUpstreamUserAgent(upstreamUA, dockerUA) 33 return ret 34 } 35 return dockerUA 36 } 37 38 // getUserAgentFromContext returns the previously saved user-agent context stored in ctx, if one exists 39 func getUserAgentFromContext(ctx context.Context) string { 40 var upstreamUA string 41 if ctx != nil { 42 var ki interface{} = ctx.Value(UAStringKey{}) 43 if ki != nil { 44 upstreamUA = ctx.Value(UAStringKey{}).(string) 45 } 46 } 47 return upstreamUA 48 } 49 50 // escapeStr returns s with every rune in charsToEscape escaped by a backslash 51 func escapeStr(s string, charsToEscape string) string { 52 var ret string 53 for _, currRune := range s { 54 appended := false 55 for _, escapableRune := range charsToEscape { 56 if currRune == escapableRune { 57 ret += `\` + string(currRune) 58 appended = true 59 break 60 } 61 } 62 if !appended { 63 ret += string(currRune) 64 } 65 } 66 return ret 67 } 68 69 // insertUpstreamUserAgent adds the upstream client useragent to create a user-agent 70 // string of the form: 71 // $dockerUA UpstreamClient($upstreamUA) 72 func insertUpstreamUserAgent(upstreamUA string, dockerUA string) string { 73 charsToEscape := `();\` 74 upstreamUAEscaped := escapeStr(upstreamUA, charsToEscape) 75 return fmt.Sprintf("%s UpstreamClient(%s)", dockerUA, upstreamUAEscaped) 76 }