app/vmctl: add flag where use can define path to the source remote read protocol (#4744)

https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4655

app/vmctl/flags.go

@@ -477,6 +477,7 @@ const (
 	remoteReadHTTPTimeout        = "remote-read-http-timeout"
 	remoteReadHeaders            = "remote-read-headers"
 	remoteReadInsecureSkipVerify = "remote-read-insecure-skip-verify"
+	remoteReadDisablePathAppend  = "remote-read-disable-path-append"
 )
 
 var (
@@ -553,6 +554,11 @@ var (
 			Usage: "Whether to skip TLS certificate verification when connecting to the remote read address",
 			Value: false,
 		},
+		&cli.BoolFlag{
+			Name:  remoteReadDisablePathAppend,
+			Usage: "Whether to disable automatic appending of the path to the remote storage.",
+			Value: true,
+		},
 	}
 )
 

app/vmctl/main.go

@@ -133,6 +133,7 @@ func main() {
 						LabelName:          c.String(remoteReadFilterLabel),
 						LabelValue:         c.String(remoteReadFilterLabelValue),
 						InsecureSkipVerify: c.Bool(remoteReadInsecureSkipVerify),
+						DisablePathAppend:  c.Bool(remoteReadDisablePathAppend),
 					})
 					if err != nil {
 						return fmt.Errorf("error create remote read client: %s", err)

app/vmctl/remoteread/remoteread.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/url"
 	"strings"
 	"time"
 
@@ -32,6 +33,7 @@ type StreamCallback func(series *vm.TimeSeries) error
 // time series via remote read protocol.
 type Client struct {
 	addr              string
+	disablePathAppend bool
 	c                 *http.Client
 	user              string
 	password          string
@@ -44,6 +46,8 @@ type Client struct {
 type Config struct {
 	// Addr of remote storage
 	Addr string
+	// DisablePathAppend disable automatic appending of the remote read path
+	DisablePathAppend bool
 	// Timeout defines timeout for HTTP requests
 	// made by remote read client
 	Timeout time.Duration
@@ -105,12 +109,14 @@ func NewClient(cfg Config) (*Client, error) {
 			Transport: utils.Transport(cfg.Addr, cfg.InsecureSkipVerify),
 		},
 		addr:              strings.TrimSuffix(cfg.Addr, "/"),
+		disablePathAppend: cfg.DisablePathAppend,
 		user:              cfg.Username,
 		password:          cfg.Password,
 		useStream:         cfg.UseStream,
 		headers:           headers,
 		matchers:          []*prompb.LabelMatcher{m},
 	}
+
 	return c, nil
 }
 
@@ -155,8 +161,16 @@ func (c *Client) do(req *http.Request) (*http.Response, error) {
 
 func (c *Client) fetch(ctx context.Context, data []byte, streamCb StreamCallback) error {
 	r := bytes.NewReader(data)
-	url := c.addr + remoteReadPath
+	// by default, we are using a common remote read path
-	req, err := http.NewRequest(http.MethodPost, url, r)
+	u, err := url.JoinPath(c.addr, remoteReadPath)
+	if err != nil {
+		return fmt.Errorf("error create url from addr %s and default remote read path %s", c.addr, remoteReadPath)
+	}
+	// we should use full address from the remote-read-src-addr flag
+	if c.disablePathAppend {
+		u = c.addr
+	}
+	req, err := http.NewRequest(http.MethodPost, u, r)
 	if err != nil {
 		return fmt.Errorf("failed to create new HTTP request: %w", err)
 	}

docs/CHANGELOG.md

@@ -29,9 +29,10 @@ The following `tip` changes can be tested by building VictoriaMetrics components
 * FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert.html): remove support of deprecated web links of `/api/v1/<groupID>/<alertID>/status` form in favour of `/api/v1/alerts?group_id=<>&alert_id=<>` links. Links of `/api/v1/<groupID>/<alertID>/status` form were deprecated in v1.79.0. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2825) for details.
 * FEATURE: [vmctl](https://docs.victoriametrics.com/vmctl.html): allow disabling binary export API protocol via `-vm-native-disable-binary-protocol` cmd-line flag when [migrating data from VictoriaMetrics](https://docs.victoriametrics.com/vmctl.html#migrating-data-from-victoriametrics). Disabling binary protocol can be useful for deduplication of the exported data before ingestion. For this, deduplication need [to be configured](https://docs.victoriametrics.com/#deduplication) at `-vm-native-src-addr` side and `-vm-native-disable-binary-protocol` should be set on vmctl side.
 * FEATURE: [vmctl](https://docs.victoriametrics.com/vmctl.html): add support of `week` step for [time-based chunking migration](https://docs.victoriametrics.com/vmctl.html#using-time-based-chunking-of-migration). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4738).
+* FEATURE: [vmctl](https://docs.victoriametrics.com/vmctl.html): do not add `/api/v1/read` suffix to remote read storage address defined by `--remote-read-src-addr` if a `--remote-read-disable-path-append` command-line flag is set. It allows an overriding path for remote-read API via `--remote-read-src-addr`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4655).
 
-* BUGFIX: [vmbackupmanager](https://docs.victoriametrics.com/vmbackupmanager.html): fix panic when creating a backup to a local filesystem on Windows. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4704).
 * BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent.html): use local scrape timestamps for the scraped metrics unless `honor_timestamps: true` option is explicitly set at [scrape_config](https://docs.victoriametrics.com/sd_configs.html#scrape_configs). This fixes gaps for metrics collected from [cadvisor](https://github.com/google/cadvisor) or similar exporters, which export metrics with invalid timestamps. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4697) and [this comment](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4697#issuecomment-1654614799) for details. The issue has been introduced in [v1.68.0](#v1680).
+* BUGFIX: [vmbackupmanager](https://docs.victoriametrics.com/vmbackupmanager.html): fix panic when creating a backup to a local filesystem on Windows. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4704).
 
 
 ## [v1.92.1](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v1.92.1)