log stderr on failed CGIs

4 files changed, 29 insertions, 3 deletions

diff --git a/contrib/cgi/cgi.go b/contrib/cgi/cgi.go
index 749a284..de0d35f 100644
--- a/contrib/cgi/cgi.go
+++ b/contrib/cgi/cgi.go
@@ -88,6 +88,7 @@ func RunCGI(
 	request *sr.Request,
 	executable string,
 	pathInfo string,
+	stderr io.Writer,
 ) (*bytes.Buffer, int, error) {
 	pathSegments := strings.Split(executable, "/")
 
@@ -114,6 +115,7 @@ func RunCGI(
 	}
 	responseBuffer := &bytes.Buffer{}
 	cmd.Stdout = responseBuffer
+	cmd.Stderr = stderr
 
 	err := cmd.Run()
 	if err != nil {
diff --git a/contrib/cgi/gemini.go b/contrib/cgi/gemini.go
index d245c8e..1e97939 100644
--- a/contrib/cgi/gemini.go
+++ b/contrib/cgi/gemini.go
@@ -1,12 +1,14 @@
 package cgi
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"strings"
 
 	sr "tildegit.org/tjp/sliderule"
 	"tildegit.org/tjp/sliderule/gemini"
+	"tildegit.org/tjp/sliderule/logging"
 )
 
 // GeminiCGIDirectory runs any executable files relative to a root directory on the file system.
@@ -30,11 +32,17 @@ func GeminiCGIDirectory(pathRoot, fsRoot string) sr.Handler {
 			return nil
 		}
 
-		stdout, exitCode, err := RunCGI(ctx, request, filepath, pathinfo)
+		stderr := &bytes.Buffer{}
+		stdout, exitCode, err := RunCGI(ctx, request, filepath, pathinfo, stderr)
 		if err != nil {
 			return gemini.Failure(err)
 		}
 		if exitCode != 0 {
+			ctx.Value("warnlog").(logging.Logger).Log(
+				"msg", "cgi exited with non-zero exit code",
+				"code", exitCode,
+				"stderr", stderr.String(),
+			)
 			return gemini.CGIError(fmt.Sprintf("CGI process exited with status %d", exitCode))
 		}
 
diff --git a/contrib/cgi/gopher.go b/contrib/cgi/gopher.go
index 67ea688..2f90f22 100644
--- a/contrib/cgi/gopher.go
+++ b/contrib/cgi/gopher.go
@@ -1,6 +1,7 @@
 package cgi
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"os"
@@ -11,6 +12,7 @@ import (
 	sr "tildegit.org/tjp/sliderule"
 	"tildegit.org/tjp/sliderule/gopher"
 	"tildegit.org/tjp/sliderule/gopher/gophermap"
+	"tildegit.org/tjp/sliderule/logging"
 )
 
 // GopherCGIDirectory runs any executable files relative to a root directory on the file system.
@@ -113,11 +115,17 @@ func runGopherCGI(
 	pathinfo string,
 	settings gophermap.FileSystemSettings,
 ) *sr.Response {
-	stdout, exitCode, err := RunCGI(ctx, request, fullpath, pathinfo)
+	stderr := &bytes.Buffer{}
+	stdout, exitCode, err := RunCGI(ctx, request, fullpath, pathinfo, stderr)
 	if err != nil {
 		return gopher.Error(err).Response()
 	}
 	if exitCode != 0 {
+		ctx.Value("warnlog").(logging.Logger).Log(
+			"msg", "cgi exited with non-zero exit code",
+			"code", exitCode,
+			"stderr", stderr.String(),
+		)
 		return gopher.Error(
 			fmt.Errorf("CGI process exited with status %d", exitCode),
 		).Response()
diff --git a/contrib/cgi/spartan.go b/contrib/cgi/spartan.go
index 6994466..272bd92 100644
--- a/contrib/cgi/spartan.go
+++ b/contrib/cgi/spartan.go
@@ -1,11 +1,13 @@
 package cgi
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"strings"
 
 	sr "tildegit.org/tjp/sliderule"
+	"tildegit.org/tjp/sliderule/logging"
 	"tildegit.org/tjp/sliderule/spartan"
 )
 
@@ -29,11 +31,17 @@ func SpartanCGIDirectory(pathRoot, fsRoot string) sr.Handler {
 			return nil
 		}
 
-		stdout, exitCode, err := RunCGI(ctx, request, filepath, pathinfo)
+		stderr := &bytes.Buffer{}
+		stdout, exitCode, err := RunCGI(ctx, request, filepath, pathinfo, stderr)
 		if err != nil {
 			return spartan.ServerError(err)
 		}
 		if exitCode != 0 {
+			ctx.Value("warnlog").(logging.Logger).Log(
+				"msg", "cgi exited with non-zero exit code",
+				"code", exitCode,
+				"stderr", stderr.String(),
+			)
 			return spartan.ServerError(fmt.Errorf("CGI process exited with status %d", exitCode))
 		}