From 97d108f415e362081da3a3c4adb459d7799d5bcd Mon Sep 17 00:00:00 2001
From: ubergesundheit <ubergesundheit@googlemail.com>
Date: Tue, 7 Feb 2017 15:48:38 +0100
Subject: [PATCH] do not fail when container could't killed

---
 actions/notify_slack.go | 92 +++++++++++++++++++++++++++++++++++++++++
 container/client.go     |  2 +-
 2 files changed, 93 insertions(+), 1 deletion(-)
 create mode 100644 actions/notify_slack.go

diff --git a/actions/notify_slack.go b/actions/notify_slack.go
new file mode 100644
index 0000000..2f4b219
--- /dev/null
+++ b/actions/notify_slack.go
@@ -0,0 +1,92 @@
+package actions
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/mozillazg/request"
+)
+
+// SlackNotifier is used to make the https requests to a specified slack
+// webhook URL
+type SlackNotifier struct {
+	slackURL string
+	identity string
+}
+
+const (
+	slackMessageStartup = "Watchtower startup"
+	slackMessageError   = "Some errors while checking and redeployment (Please check logs):"
+	slackMessageSuccess = "Successfully redeployed images:"
+)
+
+// NewSlackNotifier instantiates a new SlackNotifier with an URL and an identifier which will
+// be prepended to each message it sends
+func NewSlackNotifier(slackURL, identity string) *SlackNotifier {
+	identity = strings.Trim(identity, " ")
+
+	if len(identity) != 0 {
+		identity = fmt.Sprintf("[%s]: ", identity)
+	}
+
+	return &SlackNotifier{
+		slackURL: slackURL,
+		identity: identity,
+	}
+}
+
+func (s SlackNotifier) sendNotification(json map[string]interface{}) {
+	c := new(http.Client)
+	req := request.NewRequest(c)
+	req.Json = json
+	_, err := req.Post(s.slackURL)
+
+	if err != nil {
+		fmt.Println(err)
+	}
+}
+
+// NotifyStartup sends a startup message to slack
+func (s SlackNotifier) NotifyStartup() {
+	s.sendNotification(map[string]interface{}{
+		"text": fmt.Sprintf("%s%s", s.identity, slackMessageStartup),
+	})
+}
+
+func buildAttachment(items []string, title, color string) map[string]interface{} {
+
+	var fields []map[string]string
+
+	for _, item := range items {
+		fields = append(fields, map[string]string{"value": item, "short": "false"})
+	}
+
+	return map[string]interface{}{
+		"fallback": title + strings.Join(items, ", "),
+		"color":    color,
+		"title":    title,
+		"fields":   fields,
+	}
+}
+
+// NotifyContainerUpdate sends a Message after updating containers which yielded either success or errors or both
+func (s SlackNotifier) NotifyContainerUpdate(successfulContainers, errorMessages []string) {
+
+	var attachments []map[string]interface{}
+
+	if len(successfulContainers) != 0 {
+		attachments = append(attachments, buildAttachment(successfulContainers, slackMessageSuccess, "good"))
+	}
+
+	if len(errorMessages) != 0 {
+		attachments = append(attachments, buildAttachment(errorMessages, slackMessageError, "danger"))
+	}
+
+	// add a pretext to the first attachment
+	attachments[0]["pretext"] = s.identity
+
+	s.sendNotification(map[string]interface{}{
+		"attachments": attachments,
+	})
+}
diff --git a/container/client.go b/container/client.go
index 7fe12b4..c3a083f 100644
--- a/container/client.go
+++ b/container/client.go
@@ -114,7 +114,7 @@ func (client dockerClient) StopContainer(c Container, timeout time.Duration) err
 	log.Infof("Stopping %s (%s) with %s", c.Name(), c.ID(), signal)
 
 	if err := client.api.ContainerKill(bg, c.ID(), signal); err != nil {
-		return err
+		fmt.Errorf("Container %s (%s) could not be killed", c.Name(), c.ID())
 	}
 
 	// Wait for container to exit, but proceed anyway after the timeout elapses