httpclient: allow to set custom headers

httpclient/httpclient.go

@@ -4,9 +4,11 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"fmt"
+	"io"
 	"net/http"
 	"os"
 	"path/filepath"
+	"strings"
 	"time"
 
 	"github.com/hashicorp/go-retryablehttp"
@@ -21,6 +23,15 @@ type TLSKeyPair struct {
 	Key  string `json:"key" mapstructure:"key"`
 }
 
+// Header defines an HTTP header.
+// If the URL is not empty, the header is added only if the
+// requested URL starts with the one specified
+type Header struct {
+	Key   string `json:"key" mapstructure:"key"`
+	Value string `json:"value" mapstructure:"value"`
+	URL   string `json:"url" mapstructure:"url"`
+}
+
 // Config defines the configuration for HTTP clients.
 // HTTP clients are used for executing hooks such as the ones used for
 // custom actions, external authentication and pre-login user modifications
@@ -44,7 +55,9 @@ type Config struct {
 	// the server and any host name in that certificate.
 	// In this mode, TLS is susceptible to man-in-the-middle attacks.
 	// This should be used only for testing.
-	SkipTLSVerify   bool `json:"skip_tls_verify" mapstructure:"skip_tls_verify"`
+	SkipTLSVerify bool `json:"skip_tls_verify" mapstructure:"skip_tls_verify"`
+	// Headers defines a list of http headers to add to each request
+	Headers         []Header `json:"headers" mapstructure:"headers"`
 	customTransport *http.Transport
 	tlsConfig       *tls.Config
 }
@@ -76,6 +89,13 @@ func (c *Config) Initialize(configDir string) error {
 	if err != nil {
 		return err
 	}
+	var headers []Header
+	for _, h := range c.Headers {
+		if h.Key != "" && h.Value != "" {
+			headers = append(headers, h)
+		}
+	}
+	c.Headers = headers
 	httpConfig = *c
 	return nil
 }
@@ -162,3 +182,63 @@ func GetRetraybleHTTPClient() *retryablehttp.Client {
 
 	return client
 }
+
+// Get issues a GET to the specified URL
+func Get(url string) (*http.Response, error) {
+	req, err := http.NewRequest(http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	addHeaders(req, url)
+	return GetHTTPClient().Do(req)
+}
+
+// Post issues a POST to the specified URL
+func Post(url string, contentType string, body io.Reader) (*http.Response, error) {
+	req, err := http.NewRequest(http.MethodPost, url, body)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", contentType)
+	addHeaders(req, url)
+	return GetHTTPClient().Do(req)
+}
+
+// RetryableGet issues a GET to the specified URL using the retryable client
+func RetryableGet(url string) (*http.Response, error) {
+	req, err := retryablehttp.NewRequest(http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	addHeadersToRetryableReq(req, url)
+	return GetRetraybleHTTPClient().Do(req)
+}
+
+// RetryablePost issues a POST to the specified URL using the retryable client
+func RetryablePost(url string, contentType string, body io.Reader) (*http.Response, error) {
+	req, err := retryablehttp.NewRequest(http.MethodPost, url, body)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", contentType)
+	addHeadersToRetryableReq(req, url)
+	return GetRetraybleHTTPClient().Do(req)
+}
+
+func addHeaders(req *http.Request, url string) {
+	for idx := range httpConfig.Headers {
+		h := &httpConfig.Headers[idx]
+		if h.URL == "" || strings.HasPrefix(url, h.URL) {
+			req.Header.Set(h.Key, h.Value)
+		}
+	}
+}
+
+func addHeadersToRetryableReq(req *retryablehttp.Request, url string) {
+	for idx := range httpConfig.Headers {
+		h := &httpConfig.Headers[idx]
+		if h.URL == "" || strings.HasPrefix(url, h.URL) {
+			req.Header.Set(h.Key, h.Value)
+		}
+	}
+}