ensure consistent timeout behaviour for health checks

healthchecks/types.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"github.com/dbcdk/morph/ssh"
+	"github.com/dbcdk/morph/utils"
 	"net/http"
 	"time"
 )
@@ -55,7 +56,7 @@ func (healthCheck CmdHealthCheck) GetPeriod() int {
 }
 
 func (healthCheck CmdHealthCheck) Run(host Host) error {
-	ctx, cancel := context.WithTimeout(context.TODO(), time.Duration(healthCheck.Timeout)*time.Second)
+	ctx, cancel := utils.ContextWithConditionalTimeout(context.TODO(), healthCheck.Timeout)
 	defer cancel()
 
 	cmd, err := healthCheck.SshContext.CmdContext(ctx, host, healthCheck.Cmd...)
@@ -92,6 +93,12 @@ func (healthCheck HttpHealthCheck) Run(host Host) error {
 		healthCheck.Host = &replacementHostname
 	}
 
+	// http.Client interprets a timeout of 0 as "no timeout", but we still have to avoid passing
+	// a negative timeout to it
+	if healthCheck.Timeout < 0 {
+		healthCheck.Timeout = 0
+	}
+
 	transport := &http.Transport{}
 
 	transport.TLSClientConfig = &tls.Config{InsecureSkipVerify: healthCheck.InsecureSSL}

ssh/ssh.go

@@ -5,14 +5,14 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"github.com/dbcdk/morph/utils"
 	"golang.org/x/crypto/ssh/terminal"
 	"io"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"strings"
 	"syscall"
-	"time"
 )
 
 type Context interface {
@@ -154,7 +154,7 @@ func valCommand(parts []string) ([]string, error) {
 }
 
 func (sshCtx *SSHContext) CmdInteractive(host Host, timeout int, parts ...string) {
-	ctx, cancel := context.WithTimeout(context.TODO(), time.Duration(timeout)*time.Second)
+	ctx, cancel := utils.ContextWithConditionalTimeout(context.TODO(), timeout)
 	defer cancel()
 
 	cmd, err := sshCtx.CmdContext(ctx, host, parts...)

utils/context.go

@@ -0,0 +1,22 @@
+package utils
+
+import (
+	"context"
+	"time"
+)
+
+// Create a context with a timeout, but only if the timeout is longer than 0
+func ContextWithConditionalTimeout(parent context.Context, timeout int) (context.Context, context.CancelFunc) {
+	var (
+		ctx context.Context
+		cancel context.CancelFunc
+	)
+
+	if timeout <= 0 {
+		ctx, cancel = context.WithCancel(context.TODO())
+	} else {
+		ctx, cancel = context.WithTimeout(context.TODO(), time.Duration(timeout)*time.Second)
+	}
+
+	return ctx, cancel
+}