Add remote configuration support as requested by Samantha.

tools/minify/common/buildconfig.go

@@ -2,16 +2,26 @@ package common
 
 import (
 	"fmt"
+	"io"
 	"log"
+	"net/http"
+	"net/url"
 	"os"
 	"regexp"
 	"sort"
+	"time"
 
 	"github.com/influxdata/telegraf/filter"
+	"github.com/influxdata/telegraf/internal"
 	"github.com/influxdata/toml"
 	"github.com/influxdata/toml/ast"
 )
 
+// fetchURLRe is a regex to determine whether the requested file should
+// be fetched from a remote or read from the filesystem.
+var fetchURLRe = regexp.MustCompile(`^\w+://`)
+var httpLoadConfigRetryInterval = 10 * time.Second
+
 type BuildConfig struct {
 	Aggregators map[string]bool
 	Inputs      map[string]bool
@@ -40,16 +50,17 @@ func LoadConfiguration(filename string) (*BuildConfig, error) {
 	return config, nil
 }
 
-func ImportConfigurations(filenames []string) (*BuildConfig, error) {
+func ImportConfigurations(configurations []string) (*BuildConfig, error) {
 	config := NewConfiguration(false)
-	for _, filename := range filenames {
-		buf, err := os.ReadFile(filename)
+
+	for _, cfg := range configurations {
+		buf, err := loadConfig(cfg)
 		if err != nil {
-			return nil, fmt.Errorf("reading %q failed: %v", filename, err)
+			return nil, fmt.Errorf("reading %q failed: %v", cfg, err)
 		}
 
 		if err := config.extractPluginsFromConfig(buf); err != nil {
-			return nil, fmt.Errorf("extracting plugins from %q failed: %v", filename, err)
+			return nil, fmt.Errorf("extracting plugins from %q failed: %v", cfg, err)
 		}
 	}
 
@@ -372,3 +383,56 @@ func globSelection(selection map[string]bool, available []packageInfo) map[strin
 
 	return globbed
 }
+
+func loadConfig(config string) ([]byte, error) {
+	if fetchURLRe.MatchString(config) {
+		u, err := url.Parse(config)
+		if err != nil {
+			return nil, err
+		}
+
+		switch u.Scheme {
+		case "https", "http":
+			return fetchConfig(u)
+		default:
+			return nil, fmt.Errorf("scheme %q not supported", u.Scheme)
+		}
+	}
+
+	// If it isn't a https scheme, try it as a file
+	return os.ReadFile(config)
+}
+
+func fetchConfig(u *url.URL) ([]byte, error) {
+	req, err := http.NewRequest("GET", u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	if v, exists := os.LookupEnv("INFLUX_TOKEN"); exists {
+		req.Header.Add("Authorization", "Token "+v)
+	}
+	req.Header.Add("Accept", "application/toml")
+	req.Header.Set("User-Agent", internal.ProductToken())
+
+	retries := 3
+	for i := 0; i <= retries; i++ {
+		resp, err := http.DefaultClient.Do(req)
+		if err != nil {
+			return nil, fmt.Errorf("retry %d of %d failed connecting to HTTP config server %s", i, retries, err)
+		}
+
+		if resp.StatusCode != http.StatusOK {
+			if i < retries {
+				log.Printf("Error getting HTTP config.  Retry %d of %d in %s.  Status=%d", i, retries, httpLoadConfigRetryInterval, resp.StatusCode)
+				time.Sleep(httpLoadConfigRetryInterval)
+				continue
+			}
+			return nil, fmt.Errorf("retry %d of %d failed to retrieve remote config: %s", i, retries, resp.Status)
+		}
+		defer resp.Body.Close()
+		return io.ReadAll(resp.Body)
+	}
+
+	return nil, nil
+}