Don't use Docker if resource has a YB_CONTAINER_*_IP environment va…

…riable set (#315)

[Fixes ch4961]

cmd/yb/helpers.go

@@ -11,6 +11,7 @@ import (
 	"os"
 	"os/user"
 	"path/filepath"
+	"runtime"
 	"sort"
 	"strconv"
 	"strings"
@@ -20,6 +21,7 @@ import (
 	"github.com/spf13/pflag"
 	"github.com/yourbase/yb"
 	"github.com/yourbase/yb/internal/biome"
+	"github.com/yourbase/yb/internal/build"
 	"github.com/yourbase/yb/internal/config"
 	"github.com/yourbase/yb/internal/ybdata"
 	"zombiezen.com/go/log"
@@ -249,7 +251,7 @@ func newDockerNetwork(ctx context.Context, client *docker.Client, mode execution
 }
 
 func showDockerWarningsIfNeeded(ctx context.Context, mode executionMode, targets []*yb.Target) {
-	if !willUseDocker(mode, targets) {
+	if !willUseDocker(mode, targets) || runtime.GOOS != biome.Linux {
 		return
 	}
 	dockerGroup, err := user.LookupGroup("docker")
@@ -281,8 +283,10 @@ func showDockerWarningsIfNeeded(ctx context.Context, mode executionMode, targets
 
 func willUseDocker(mode executionMode, targets []*yb.Target) bool {
 	for _, target := range targets {
-		if len(target.Resources) > 0 {
-			return true
+		for name := range target.Resources {
+			if os.Getenv(build.ContainerIPEnvVar(name)) == "" {
+				return true
+			}
 		}
 	}
 	return willUseDockerForCommands(mode, targets)
@@ -291,10 +295,14 @@ func willUseDocker(mode executionMode, targets []*yb.Target) bool {
 func willUseDockerForCommands(mode executionMode, targets []*yb.Target) bool {
 	networkAvailable, _ := hostHasDockerNetwork()
 	for _, target := range targets {
-		if target.UseContainer ||
-			len(target.Resources) > 0 && !networkAvailable {
+		if target.UseContainer {
 			return true
 		}
+		for name := range target.Resources {
+			if os.Getenv(build.ContainerIPEnvVar(name)) == "" && !networkAvailable {
+				return true
+			}
+		}
 	}
 	return mode >= useContainer
 }

cmd/yb/helpers_test.go

@@ -18,13 +18,25 @@ package main
 
 import (
 	"fmt"
+	"os"
 	"strings"
 	"testing"
 
 	"github.com/yourbase/yb"
 )
 
 func TestWillUseDocker(t *testing.T) {
+	const containerEnvVar = "YB_CONTAINER_ENV_IP"
+	oldEnv, oldEnvExists := os.LookupEnv(containerEnvVar)
+	os.Setenv(containerEnvVar, "1.2.3.4")
+	t.Cleanup(func() {
+		if !oldEnvExists {
+			os.Unsetenv(containerEnvVar)
+		} else {
+			os.Setenv(containerEnvVar, oldEnv)
+		}
+	})
+
 	networkAvailable, _ := hostHasDockerNetwork()
 	tests := []struct {
 		mode        executionMode
@@ -104,6 +116,16 @@ func TestWillUseDocker(t *testing.T) {
 			want:        true,
 			forCommands: !networkAvailable,
 		},
+		{
+			mode: preferHost,
+			targets: []*yb.Target{
+				// This is provided as YB_CONTAINER_ENV_IP.
+				{Name: "default", UseContainer: false, Resources: map[string]*yb.ResourceDefinition{"env": {}}},
+				{Name: "foo", UseContainer: false},
+			},
+			want:        false,
+			forCommands: false,
+		},
 		{
 			mode: useContainer,
 			targets: []*yb.Target{

internal/build/setup.go

@@ -121,7 +121,7 @@ func startContainers(ctx context.Context, sys Sys, defs map[string]*yb.ResourceD
 	}
 	containers := make(map[string]*container)
 	for name := range defs {
-		ip := os.Getenv("YB_CONTAINER_" + strings.ToUpper(name) + "_IP")
+		ip := os.Getenv(ContainerIPEnvVar(name))
 		if ip != "" {
 			log.Infof(ctx, "Using %s address from environment: %s", name, ip)
 			exp.ips[name] = ip
@@ -179,6 +179,12 @@ func startContainers(ctx context.Context, sys Sys, defs map[string]*yb.ResourceD
 	return exp, origCloseFunc, nil
 }
 
+// ContainerIPEnvVar returns the name of the environment variable that
+// optionally provides the IP address of a target's resource.
+func ContainerIPEnvVar(resourceName string) string {
+	return "YB_CONTAINER_" + strings.ToUpper(resourceName) + "_IP"
+}
+
 // startContainer starts a single container with the given definition.
 func startContainer(ctx context.Context, sys Sys, resourceName string, cd *yb.ResourceDefinition) (_ *container, err error) {
 	for _, mount := range cd.Mounts {