Merge remote-tracking branch 'prometheus/main' into add-unit

Signed-off-by: Arianna Vespri <[email protected]>

Author: vesari

.circleci/config.yml

@@ -95,14 +95,14 @@ workflows:
           matrix:
             parameters:
               go_version:
-                - "1.20"
                 - "1.21"
+                - "1.22"
       - test-assets:
           name: assets-go-<< matrix.go_version >>
           matrix:
             parameters:
               go_version:
-                - "1.21"
+                - "1.22"
       - style:
           name: style
-          go_version: "1.21"
+          go_version: "1.22"

.github/workflows/golangci-lint.yml

@@ -28,7 +28,7 @@ jobs:
       - name: install Go
         uses: actions/setup-go@0c52d547c9bc32b1aa3301fd7a9cb496313a4491 # v5.0.0
         with:
-          go-version: 1.21.x
+          go-version: 1.22.x
       - name: Install snmp_exporter/generator dependencies
         run: sudo apt-get update && sudo apt-get -y install libsnmp-dev
         if: github.repository == 'prometheus/snmp_exporter'

Makefile.common

@@ -62,10 +62,10 @@ SKIP_GOLANGCI_LINT :=
 GOLANGCI_LINT :=
 GOLANGCI_LINT_OPTS ?=
 GOLANGCI_LINT_VERSION ?= v1.55.2
-# golangci-lint only supports linux, darwin and windows platforms on i386/amd64.
+# golangci-lint only supports linux, darwin and windows platforms on i386/amd64/arm64.
 # windows isn't included here because of the path separator being different.
 ifeq ($(GOHOSTOS),$(filter $(GOHOSTOS),linux darwin))
-	ifeq ($(GOHOSTARCH),$(filter $(GOHOSTARCH),amd64 i386))
+	ifeq ($(GOHOSTARCH),$(filter $(GOHOSTARCH),amd64 i386 arm64))
 		# If we're in CI and there is an Actions file, that means the linter
 		# is being run in Actions, so we don't need to run it here.
 		ifneq (,$(SKIP_GOLANGCI_LINT))

assets/go.mod

@@ -1,3 +1,3 @@
 module github.com/prometheus/common/assets
 
-go 1.20
+go 1.21

config/http_config.go

@@ -309,6 +309,9 @@ type HTTPClientConfig struct {
 	// The omitempty flag is not set, because it would be hidden from the
 	// marshalled configuration when set to false.
 	EnableHTTP2 bool `yaml:"enable_http2" json:"enable_http2"`
+	// Host optionally overrides the Host header to send.
+	// If empty, the host from the URL will be used.
+	Host string `yaml:"host,omitempty" json:"host,omitempty"`
 	// Proxy configuration.
 	ProxyConfig `yaml:",inline"`
 }
@@ -427,6 +430,7 @@ type httpClientOptions struct {
 	http2Enabled      bool
 	idleConnTimeout   time.Duration
 	userAgent         string
+	host              string
 }
 
 // HTTPClientOption defines an option that can be applied to the HTTP client.
@@ -467,6 +471,13 @@ func WithUserAgent(ua string) HTTPClientOption {
 	}
 }
 
+// WithHost allows setting the host header.
+func WithHost(host string) HTTPClientOption {
+	return func(opts *httpClientOptions) {
+		opts.host = host
+	}
+}
+
 // NewClient returns a http.Client using the specified http.RoundTripper.
 func newClient(rt http.RoundTripper) *http.Client {
 	return &http.Client{Transport: rt}
@@ -568,6 +579,10 @@ func NewRoundTripperFromConfig(cfg HTTPClientConfig, name string, optFuncs ...HT
 			rt = NewUserAgentRoundTripper(opts.userAgent, rt)
 		}
 
+		if opts.host != "" {
+			rt = NewHostRoundTripper(opts.host, rt)
+		}
+
 		// Return a new configured RoundTripper.
 		return rt, nil
 	}
@@ -1164,11 +1179,21 @@ type userAgentRoundTripper struct {
 	rt        http.RoundTripper
 }
 
+type hostRoundTripper struct {
+	host string
+	rt   http.RoundTripper
+}
+
 // NewUserAgentRoundTripper adds the user agent every request header.
 func NewUserAgentRoundTripper(userAgent string, rt http.RoundTripper) http.RoundTripper {
 	return &userAgentRoundTripper{userAgent, rt}
 }
 
+// NewHostRoundTripper sets the [http.Request.Host] of every request.
+func NewHostRoundTripper(host string, rt http.RoundTripper) http.RoundTripper {
+	return &hostRoundTripper{host, rt}
+}
+
 func (rt *userAgentRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
 	req = cloneRequest(req)
 	req.Header.Set("User-Agent", rt.userAgent)
@@ -1181,6 +1206,19 @@ func (rt *userAgentRoundTripper) CloseIdleConnections() {
 	}
 }
 
+func (rt *hostRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	req = cloneRequest(req)
+	req.Host = rt.host
+	req.Header.Set("Host", rt.host)
+	return rt.rt.RoundTrip(req)
+}
+
+func (rt *hostRoundTripper) CloseIdleConnections() {
+	if ci, ok := rt.rt.(closeIdler); ok {
+		ci.CloseIdleConnections()
+	}
+}
+
 func (c HTTPClientConfig) String() string {
 	b, err := yaml.Marshal(c)
 	if err != nil {

config/http_config_test.go

@@ -35,7 +35,7 @@ import (
 	"testing"
 	"time"
 
-	yaml "gopkg.in/yaml.v2"
+	"gopkg.in/yaml.v2"
 )
 
 const (
@@ -1671,6 +1671,32 @@ func TestOAuth2UserAgent(t *testing.T) {
 	}
 }
 
+func TestHost(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Host != "localhost.localdomain" {
+			t.Fatalf("Expected Host header in request to be 'localhost.localdomain', got '%s'", r.Host)
+		}
+
+		w.Header().Add("Content-Type", "application/json")
+	}))
+	defer ts.Close()
+
+	config := DefaultHTTPClientConfig
+
+	rt, err := NewRoundTripperFromConfig(config, "test_host", WithHost("localhost.localdomain"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	client := http.Client{
+		Transport: rt,
+	}
+	_, err = client.Get(ts.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestOAuth2WithFile(t *testing.T) {
 	var expectedAuth string
 	ts := newTestOAuthServer(t, &expectedAuth)

expfmt/decode.go

@@ -45,29 +45,29 @@ func ResponseFormat(h http.Header) Format {
 
 	mediatype, params, err := mime.ParseMediaType(ct)
 	if err != nil {
-		return FmtUnknown
+		return fmtUnknown
 	}
 
 	const textType = "text/plain"
 
 	switch mediatype {
 	case ProtoType:
 		if p, ok := params["proto"]; ok && p != ProtoProtocol {
-			return FmtUnknown
+			return fmtUnknown
 		}
 		if e, ok := params["encoding"]; ok && e != "delimited" {
-			return FmtUnknown
+			return fmtUnknown
 		}
-		return FmtProtoDelim
+		return fmtProtoDelim
 
 	case textType:
 		if v, ok := params["version"]; ok && v != TextVersion {
-			return FmtUnknown
+			return fmtUnknown
 		}
-		return FmtText
+		return fmtText
 	}
 
-	return FmtUnknown
+	return fmtUnknown
 }
 
 // NewDecoder returns a new decoder based on the given input format.

expfmt/decode_test.go

@@ -421,27 +421,27 @@ func testDiscriminatorHTTPHeader(t testing.TB) {
 	}{
 		{
 			input:  map[string]string{"Content-Type": `application/vnd.google.protobuf; proto="io.prometheus.client.MetricFamily"; encoding="delimited"`},
-			output: FmtProtoDelim,
+			output: fmtProtoDelim,
 		},
 		{
 			input:  map[string]string{"Content-Type": `application/vnd.google.protobuf; proto="illegal"; encoding="delimited"`},
-			output: FmtUnknown,
+			output: fmtUnknown,
 		},
 		{
 			input:  map[string]string{"Content-Type": `application/vnd.google.protobuf; proto="io.prometheus.client.MetricFamily"; encoding="illegal"`},
-			output: FmtUnknown,
+			output: fmtUnknown,
 		},
 		{
 			input:  map[string]string{"Content-Type": `text/plain; version=0.0.4`},
-			output: FmtText,
+			output: fmtText,
 		},
 		{
 			input:  map[string]string{"Content-Type": `text/plain`},
-			output: FmtText,
+			output: fmtText,
 		},
 		{
 			input:  map[string]string{"Content-Type": `text/plain; version=0.0.3`},
-			output: FmtUnknown,
+			output: fmtUnknown,
 		},
 	}
 
@@ -547,7 +547,7 @@ func TestTextDecoderWithBufioReader(t *testing.T) {
 
 	var decoded bool
 	r := bufio.NewReader(strings.NewReader(example))
-	dec := NewDecoder(r, FmtText)
+	dec := NewDecoder(r, fmtText)
 	for {
 		var mf dto.MetricFamily
 		if err := dec.Decode(&mf); err != nil {

expfmt/encode.go

@@ -76,18 +76,18 @@ func Negotiate(h http.Header) Format {
 		if ac.Type+"/"+ac.SubType == ProtoType && ac.Params["proto"] == ProtoProtocol {
 			switch ac.Params["encoding"] {
 			case "delimited":
-				return FmtProtoDelim + escapingScheme
+				return fmtProtoDelim + escapingScheme
 			case "text":
-				return FmtProtoText + escapingScheme
+				return fmtProtoText + escapingScheme
 			case "compact-text":
-				return FmtProtoCompact + escapingScheme
+				return fmtProtoCompact + escapingScheme
 			}
 		}
 		if ac.Type == "text" && ac.SubType == "plain" && (ver == TextVersion || ver == "") {
-			return FmtText + escapingScheme
+			return fmtText + escapingScheme
 		}
 	}
-	return FmtText + escapingScheme
+	return fmtText + escapingScheme
 }
 
 // NegotiateIncludingOpenMetrics works like Negotiate but includes
@@ -109,26 +109,26 @@ func NegotiateIncludingOpenMetrics(h http.Header) Format {
 		if ac.Type+"/"+ac.SubType == ProtoType && ac.Params["proto"] == ProtoProtocol {
 			switch ac.Params["encoding"] {
 			case "delimited":
-				return FmtProtoDelim + escapingScheme
+				return fmtProtoDelim + escapingScheme
 			case "text":
-				return FmtProtoText + escapingScheme
+				return fmtProtoText + escapingScheme
 			case "compact-text":
-				return FmtProtoCompact + escapingScheme
+				return fmtProtoCompact + escapingScheme
 			}
 		}
 		if ac.Type == "text" && ac.SubType == "plain" && (ver == TextVersion || ver == "") {
-			return FmtText + escapingScheme
+			return fmtText + escapingScheme
 		}
 		if ac.Type+"/"+ac.SubType == OpenMetricsType && (ver == OpenMetricsVersion_0_0_1 || ver == OpenMetricsVersion_1_0_0 || ver == "") {
 			switch ver {
 			case OpenMetricsVersion_1_0_0:
-				return FmtOpenMetrics_1_0_0 + escapingScheme
+				return fmtOpenMetrics_1_0_0 + escapingScheme
 			default:
-				return FmtOpenMetrics_0_0_1 + escapingScheme
+				return fmtOpenMetrics_0_0_1 + escapingScheme
 			}
 		}
 	}
-	return FmtText + escapingScheme
+	return fmtText + escapingScheme
 }
 
 // NewEncoder returns a new encoder based on content type negotiation. All
@@ -139,7 +139,13 @@ func NegotiateIncludingOpenMetrics(h http.Header) Format {
 // interface is kept for backwards compatibility.
 // In cases where the Format does not allow for UTF-8 names, the global
 // NameEscapingScheme will be applied.
-func NewEncoder(w io.Writer, format Format, options ...ToOpenMetricsOption) Encoder {
+//
+// NewEncoder can be called with additional options to customize the OpenMetrics text output.
+// For example:
+// NewEncoder(w, FmtOpenMetrics_1_0_0, WithCreatedLines())
+//
+// Extra options are ignored for all other formats.
+func NewEncoder(w io.Writer, format Format, options ...EncoderOption) Encoder {
 	escapingScheme := format.ToEscapingScheme()
 
 	switch format.FormatType() {
@@ -178,7 +184,7 @@ func NewEncoder(w io.Writer, format Format, options ...ToOpenMetricsOption) Enco
 	case TypeOpenMetrics:
 		return encoderCloser{
 			encode: func(v *dto.MetricFamily) error {
-				_, err := MetricFamilyToOpenMetrics(w, model.EscapeMetricFamily(v, escapingScheme), options...)
+				_, err := MetricFamilyToOpenMetrics(w, model.EscapeMetricFamily(v, escapingScheme)) // , options...?
 				return err
 			},
 			close: func() error {