skip pulling if nothing to pull

Fixes #87

CHANGELOG.md

@@ -1,5 +1,8 @@
 ## Unreleased
 
+- Fix [issue](https://github.com/cisco/elsy/issues/87) where a docker-compose
+containing only services using local images would break bootstrapping.
+
 ## v3.1.0
 
 - Add support for a `local_images` config in `lc.yml`. Images listed in this

blackbox-test/features/bootstrap.feature

@@ -123,6 +123,21 @@ Feature: bootstrap task
     When I run `lc bootstrap`
     Then it should succeed
 
+  ## https://github.com/cisco/elsy/issues/87
+  Scenario: with services only using local images
+    Given a file named "docker-compose.yml" with:
+    """yaml
+    prodserver:
+      image: bazzer
+    """
+    And a file named "lc.yml" with:
+    """yaml
+    name: testbootstrap
+    docker_image_name: bazzer
+    """
+    When I run `lc bootstrap`
+    Then it should succeed
+
   Scenario: running in offline mode
     If we run with --offline, we should not try to pull any images.
     Given a file named "docker-compose.yml" with:

command/bootstrap.go

@@ -38,20 +38,30 @@ func CmdBootstrap(c *cli.Context) error {
 			args = append(args, "pull", "--parallel")
 		}
 
+		var skipPull bool
 		if c.String("docker-image-name") != "" || len(c.StringSlice("local-images")) > 0 {
 			excludes := c.StringSlice("local-images")
 			if c.String("docker-image-name") != "" {
 				excludes = append(excludes, c.String("docker-image-name"))
 			}
 			logrus.WithField("docker-image-name", excludes).Debug("not pulling services using repo's docker artifact")
-			args = append(args, helpers.DockerComposeServicesExcluding(excludes)...)
+
+			services := helpers.DockerComposeServicesExcluding(excludes)
+			if len(services) == 0 {
+				skipPull = true
+				logrus.Debug("no services to pull")
+			} else {
+				args = append(args, services...)
+			}
 		}
 
-		pullCmd := helpers.DockerComposeCommand(args...)
-		if err := helpers.RunCommand(pullCmd); err != nil {
-			return err
+		if !skipPull {
+			pullCmd := helpers.DockerComposeCommand(args...)
+			if err := helpers.RunCommand(pullCmd); err != nil {
+				return err
+			}
 		}
-	}
 
+	}
 	return CmdInstallDependencies(c)
 }