feat(ssh): Add BODY placeholder support for SSH endpoints

- Modify ExecuteSSHCommand to capture stdout output
- Update SSH endpoint handling to use needsToReadBody() mechanism
- Add comprehensive test cases for SSH BODY functionality
- Support basic body content, pattern matching, JSONPath, and functions
- Maintain backward compatibility with existing SSH endpoints

client/client.go

@@ -1,6 +1,7 @@
 package client
 
 import (
+	"bytes"
 	"context"
 	"crypto/tls"
 	"crypto/x509"
@@ -301,7 +302,7 @@ func CheckSSHBanner(address string, cfg *Config) (bool, int, error) {
 }
 
 // ExecuteSSHCommand executes a command to an address using the SSH protocol.
-func ExecuteSSHCommand(sshClient *ssh.Client, body string, config *Config) (bool, int, error) {
+func ExecuteSSHCommand(sshClient *ssh.Client, body string, config *Config) (bool, int, []byte, error) {
 	type Body struct {
 		Command string `json:"command"`
 	}
@@ -309,26 +310,35 @@ func ExecuteSSHCommand(sshClient *ssh.Client, body string, config *Config) (bool
 	var b Body
 	body = parseLocalAddressPlaceholder(body, sshClient.Conn.LocalAddr())
 	if err := json.Unmarshal([]byte(body), &b); err != nil {
-		return false, 0, err
+		return false, 0, nil, err
 	}
 	sess, err := sshClient.NewSession()
 	if err != nil {
-		return false, 0, err
+		return false, 0, nil, err
 	}
+
+	// Capture stdout
+	var stdout bytes.Buffer
+	sess.Stdout = &stdout
+
 	err = sess.Start(b.Command)
 	if err != nil {
-		return false, 0, err
+		return false, 0, nil, err
 	}
 	defer sess.Close()
 	err = sess.Wait()
+
+	// Get the output
+	output := stdout.Bytes()
+
 	if err == nil {
-		return true, 0, nil
+		return true, 0, output, nil
 	}
 	var exitErr *ssh.ExitError
 	if ok := errors.As(err, &exitErr); !ok {
-		return false, 0, err
+		return false, 0, nil, err
 	}
-	return true, exitErr.ExitStatus(), nil
+	return true, exitErr.ExitStatus(), output, nil
 }
 
 // Ping checks if an address can be pinged and returns the round-trip time if the address can be pinged

config/endpoint/endpoint.go

@@ -514,11 +514,16 @@ func (e *Endpoint) call(result *Result) {
 			result.AddError(err.Error())
 			return
 		}
-		result.Success, result.HTTPStatus, err = client.ExecuteSSHCommand(cli, e.getParsedBody(), e.ClientConfig)
+		var output []byte
+		result.Success, result.HTTPStatus, output, err = client.ExecuteSSHCommand(cli, e.getParsedBody(), e.ClientConfig)
 		if err != nil {
 			result.AddError(err.Error())
 			return
 		}
+		// Only store the output in result.Body if there's a condition that uses the BodyPlaceholder
+		if e.needsToReadBody() {
+			result.Body = output
+		}
 		result.Duration = time.Since(startTime)
 	} else {
 		response, err = client.GetHTTPClient(e.ClientConfig).Do(request)

config/endpoint/endpoint_test.go

@@ -834,6 +834,93 @@ func TestIntegrationEvaluateHealthForSSH(t *testing.T) {
 			conditions: []Condition{Condition("[STATUS] == 1")},
 			success:    false,
 		},
+		{
+			name: "ssh-body-basic",
+			endpoint: Endpoint{
+				Name: "ssh-body-basic",
+				URL:  "ssh://localhost",
+				SSHConfig: &ssh.Config{
+					Username: "scenario",
+					Password: "scenario",
+				},
+				Body: "{ \"command\": \"echo 'test-output'\" }",
+			},
+			conditions: []Condition{
+				Condition("[STATUS] == 0"),
+				Condition("[BODY] == test-output"),
+			},
+			success: true,
+		},
+		{
+			name: "ssh-body-pattern",
+			endpoint: Endpoint{
+				Name: "ssh-body-pattern",
+				URL:  "ssh://localhost",
+				SSHConfig: &ssh.Config{
+					Username: "scenario",
+					Password: "scenario",
+				},
+				Body: "{ \"command\": \"echo 'test-pattern-match'\" }",
+			},
+			conditions: []Condition{
+				Condition("[STATUS] == 0"),
+				Condition("[BODY] == pat(*pattern*)"),
+			},
+			success: true,
+		},
+		{
+			name: "ssh-body-json-path",
+			endpoint: Endpoint{
+				Name: "ssh-body-json",
+				URL:  "ssh://localhost",
+				SSHConfig: &ssh.Config{
+					Username: "scenario",
+					Password: "scenario",
+				},
+				Body: "{ \"command\": \"echo '{\\\"status\\\": \\\"healthy\\\", \\\"memory\\\": {\\\"used\\\": 512}}'\" }",
+			},
+			conditions: []Condition{
+				Condition("[STATUS] == 0"),
+				Condition("[BODY].status == healthy"),
+				Condition("[BODY].memory.used > 500"),
+			},
+			success: true,
+		},
+		{
+			name: "ssh-body-functions",
+			endpoint: Endpoint{
+				Name: "ssh-body-functions",
+				URL:  "ssh://localhost",
+				SSHConfig: &ssh.Config{
+					Username: "scenario",
+					Password: "scenario",
+				},
+				Body: "{ \"command\": \"echo -n '12345'\" }",
+			},
+			conditions: []Condition{
+				Condition("[STATUS] == 0"),
+				Condition("len([BODY]) == 5"),
+				Condition("has([BODY]) == true"),
+			},
+			success: true,
+		},
+		{
+			name: "ssh-command-fail-with-body",
+			endpoint: Endpoint{
+				Name: "ssh-command-fail-body",
+				URL:  "ssh://localhost",
+				SSHConfig: &ssh.Config{
+					Username: "scenario",
+					Password: "scenario",
+				},
+				Body: "{ \"command\": \"echo 'error message'; exit 1\" }",
+			},
+			conditions: []Condition{
+				Condition("[STATUS] == 1"),
+				Condition("[BODY] == pat(*error*)"),
+			},
+			success: true,
+		},
 	}
 
 	for _, scenario := range scenarios {