Add support for Ubuntu 16.04 (#114)

Signed-off-by: Lauri Nevala <[email protected]>

Jenkinsfile

@@ -15,6 +15,16 @@ pipeline {
     }
     stage("Smoke test") {
       parallel {
+        stage("Ubuntu 16.04: apply") {
+          agent {
+            node {
+              label 'amd64 && ubuntu-1804 && overlay2'
+            }
+          }
+          steps {
+            sh "make smoke-test LINUX_IMAGE=quay.io/footloose/ubuntu16.04"
+          }
+        }
         stage("Ubuntu 18.04: apply") {
           agent {
             node {
@@ -65,6 +75,16 @@ pipeline {
             sh "make smoke-reset-test LINUX_IMAGE=quay.io/footloose/ubuntu18.04"
           }
         }
+        stage("Ubuntu 16.04: reset") {
+          agent {
+            node {
+              label 'amd64 && ubuntu-1804 && overlay2'
+            }
+          }
+          steps {
+            sh "make smoke-reset-test LINUX_IMAGE=quay.io/footloose/ubuntu16.04"
+          }
+        }
         stage("CentOS 8: reset") {
           agent {
             node {

pkg/configurer/linux.go

@@ -26,7 +26,12 @@ func (c *LinuxConfigurer) InstallEngine(engineConfig *api.EngineConfig) error {
 		return err
 	}
 
-	err = c.Host.Exec("sudo systemctl enable --now docker")
+	err = c.Host.Exec("sudo systemctl enable docker")
+	if err != nil {
+		return err
+	}
+
+	err = c.Host.Exec("sudo systemctl start docker")
 	if err != nil {
 		return err
 	}

pkg/configurer/ubuntu/ubuntu.go

@@ -51,6 +51,15 @@ func resolveUbuntuConfigurer(h *api.Host) api.HostConfigurer {
 			},
 		}
 		return configurer
+	case "16.04":
+		configurer := &XenialConfigurer{
+			Configurer: Configurer{
+				LinuxConfigurer: configurer.LinuxConfigurer{
+					Host: h,
+				},
+			},
+		}
+		return configurer
 	}
 
 	return nil

pkg/configurer/ubuntu/xenial.go

@@ -0,0 +1,6 @@
+package ubuntu
+
+// XenialConfigurer is the Ubuntu Xenial specific host configurer implementation
+type XenialConfigurer struct {
+	Configurer
+}