fix(http-hooks): apply url encoding for ERROR_* env vars (#538)

* fix(http-hooks): apply url encoding for ERROR_* env vars

* docs(http-hooks): clarify url encoding conditions

* test(http-hooks): improve test coverage

Author: zumm

docs/content/configuration/http_hooks.md

@@ -300,6 +300,8 @@ Additionally, for the `send-after-fail` hooks, these environment variables will
 - `ERROR_EXIT_CODE` containing the exit code of the command line that failed
 - `ERROR_STDERR` containing any message that the failed command sent to the standard error (stderr)
 
+URL encoding is applayed for variables `ERROR`, `ERROR_COMMANDLINE` and `ERROR_STDERR` if they are used in URL.
+
 The `send-finally` hooks are also getting the environment of `send-after-fail` when any previous operation has failed (except any `send` operation).
 
 Failures in any `send-*` are logged but do not influence environment or return code.

monitor/hook/sender.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	urlpkg "net/url"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -74,8 +75,8 @@ func (s *Sender) Send(cfg config.SendMonitoringSection, ctx Context) error {
 	if cfg.URL.Value() == "" {
 		return errors.New("URL field is empty")
 	}
-	url := resolve(cfg.URL.Value(), ctx)
-	publicUrl := resolve(cfg.URL.String(), ctx)
+	url := resolveURL(cfg.URL.Value(), ctx)
+	publicUrl := resolveURL(cfg.URL.String(), ctx)
 	method := cfg.Method
 	if method == "" {
 		method = http.MethodGet
@@ -93,7 +94,7 @@ func (s *Sender) Send(cfg config.SendMonitoringSection, ctx Context) error {
 		bodyReader = bytes.NewBufferString(body)
 	}
 	if cfg.Body != "" {
-		body = resolve(cfg.Body, ctx)
+		body = resolveBody(cfg.Body, ctx)
 		bodyReader = bytes.NewBufferString(body)
 	}
 
@@ -202,8 +203,8 @@ func getRootCAs(certificates []string) *x509.CertPool {
 	return caCertPool
 }
 
-func resolve(body string, ctx Context) string {
-	body = os.Expand(body, func(s string) string {
+func resolveBody(body string, ctx Context) string {
+	return os.Expand(body, func(s string) string {
 		switch s {
 		case constants.EnvProfileName:
 			return ctx.ProfileName
@@ -230,7 +231,36 @@ func resolve(body string, ctx Context) string {
 			return os.Getenv(s)
 		}
 	})
-	return body
+}
+
+func resolveURL(url string, ctx Context) string {
+	return os.Expand(url, func(s string) string {
+		switch s {
+		case constants.EnvProfileName:
+			return ctx.ProfileName
+
+		case constants.EnvProfileCommand:
+			return ctx.ProfileCommand
+
+		case constants.EnvError:
+			return urlpkg.QueryEscape(ctx.Error.Message)
+
+		case constants.EnvErrorCommandLine:
+			return urlpkg.QueryEscape(ctx.Error.CommandLine)
+
+		case constants.EnvErrorExitCode:
+			return ctx.Error.ExitCode
+
+		case constants.EnvErrorStderr:
+			return urlpkg.QueryEscape(ctx.Error.Stderr)
+
+		case "$":
+			return "$" // allow to escape "$" as "$$"
+
+		default:
+			return os.Getenv(s)
+		}
+	})
 }
 
 func loadBodyTemplate(filename string, ctx Context) (string, error) {

monitor/hook/sender_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/creativeprojects/resticprofile/config"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"github.com/creativeprojects/resticprofile/constants"
 )
 
 func TestSend(t *testing.T) {
@@ -273,6 +274,57 @@ func TestConfidentialURL(t *testing.T) {
 	assert.Equal(t, 1, calls)
 }
 
+func TestURLEncoding(t *testing.T) {
+	ctx := Context{
+		ProfileName:    "unencoded/name",
+		ProfileCommand: "unencoded/command",
+		Error: ErrorContext{
+			Message:     "some/error/message",
+			CommandLine: "some < tricky || command & line",
+			ExitCode:    "1",
+			Stderr:      "some\nmultiline\nerror\nwith strange &/~!^., characters",
+		},
+		Stdout: "unused",
+	}
+
+	calls := 0
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		query := r.URL.Query()
+
+		assert.Equal(t, fmt.Sprintf("/%s-%s", ctx.ProfileName, ctx.ProfileCommand), r.URL.Path)
+
+		assert.Equal(t, ctx.Error.Message, query.Get("message"))
+		assert.Equal(t, ctx.Error.CommandLine, query.Get("command_line"))
+		assert.Equal(t, ctx.Error.ExitCode, query.Get("exit_code"))
+		assert.Equal(t, ctx.Error.Stderr, query.Get("stderr"))
+
+		assert.Equal(t, "$TEST_MONITOR_URL", query.Get("escaped"))
+
+		calls++
+	}))
+	defer server.Close()
+
+	// test if env vars are untouched
+	t.Setenv("TEST_MONITOR_URL", server.URL)
+
+	serverURL := fmt.Sprintf(
+		"$TEST_MONITOR_URL/$%s-$%s?message=$%s&command_line=$%s&exit_code=$%s&stderr=$%s&escaped=$$TEST_MONITOR_URL",
+		constants.EnvProfileName,
+		constants.EnvProfileCommand,
+		constants.EnvError,
+		constants.EnvErrorCommandLine,
+		constants.EnvErrorExitCode,
+		constants.EnvErrorStderr,
+	)
+
+	sender := NewSender(nil, "", 300*time.Millisecond, false)
+	err := sender.Send(config.SendMonitoringSection{
+		URL: config.NewConfidentialValue(serverURL),
+	}, ctx)
+	assert.NoError(t, err)
+	assert.Equal(t, 1, calls)
+}
+
 func TestConfidentialHeader(t *testing.T) {
 	clog.SetTestLog(t)
 	defer clog.CloseTestLog()