fix(docker): get container id by /proc/self/mountinfo

internal/docker/container_id.go

@@ -0,0 +1,42 @@
+package docker
+
+import (
+	"bufio"
+	"os"
+	"regexp"
+	"strings"
+)
+
+// GetContainerID retrieves the Docker container ID by parsing /proc/self/mountinfo
+func GetContainerID() (string, error) {
+	// Open the mountinfo file
+	file, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return "", err
+	}
+	defer file.Close()
+
+	// Regular expression to extract container ID from paths like:
+	// /var/lib/docker/containers/bd4bd482f7e28566389fe7e4ce6b168e93b372c3fc18091c37923588664ca950/resolv.conf
+	containerIDPattern := regexp.MustCompile(`/var/lib/docker/containers/([a-f0-9]{64})/`)
+
+	// Scan the file line by line
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		// Look for container ID in the line
+		if strings.Contains(line, "/var/lib/docker/containers/") {
+			matches := containerIDPattern.FindStringSubmatch(line)
+			if len(matches) >= 2 {
+				return matches[1], nil
+			}
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return "", err
+	}
+
+	return "", os.ErrNotExist
+}

internal/docker/errors.go

@@ -12,7 +12,7 @@ var (
 	ErrContainerStatusUnknown            = e.New(500006, "container status unknown")
 	ErrInspectContainer                  = e.New(500007, "failed to inspect container: {0}")
 	ErrNginxNotRunningInAnotherContainer = e.New(500008, "nginx is not running in another container")
-	ErrFailedToGetHostname               = e.New(500009, "failed to get hostname: {0}")
+	ErrFailedToGetContainerID            = e.New(500009, "failed to get container id: {0}")
 	ErrFailedToPullImage                 = e.New(500010, "failed to pull image: {0}")
 	ErrFailedToInspectCurrentContainer   = e.New(500011, "failed to inspect current container: {0}")
 	ErrFailedToCreateTempContainer       = e.New(500012, "failed to create temp container: {0}")

internal/docker/ota.go

@@ -143,11 +143,11 @@ func UpgradeStepOne(channel string, progressChan chan<- float64) (err error) {
 	tempContainerName := getTimestampedTempName()
 
 	// Get current container name
-	hostname, err := os.Hostname()
+	containerID, err := GetContainerID()
 	if err != nil {
-		return cosy.WrapErrorWithParams(ErrFailedToGetHostname, err.Error())
+		return cosy.WrapErrorWithParams(ErrFailedToGetContainerID, err.Error())
 	}
-	containerInfo, err := cli.ContainerInspect(ctx, hostname)
+	containerInfo, err := cli.ContainerInspect(ctx, containerID)
 	if err != nil {
 		return cosy.WrapErrorWithParams(ErrFailedToInspectCurrentContainer, err.Error())
 	}