From 118c1740da309545fa6db7caa165eb6da50a701f Mon Sep 17 00:00:00 2001
From: Yu Yang <yuyang0@users.noreply.github.com>
Date: Mon, 21 Aug 2023 14:14:58 +0800
Subject: [PATCH] fetch ip address fort NIC when IPAddress is null (#106)

---
 .golangci.yml            |  2 +-
 go.mod                   |  1 +
 go.sum                   |  2 ++
 runtime/docker/docker.go | 49 +++++++++++++++++++++++++++++++++++++++-
 4 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/.golangci.yml b/.golangci.yml
index b29f6a7..6fd02de 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -19,7 +19,7 @@ linters:
   enable:
     - bodyclose
     - deadcode
-      # - depguard
+    # - depguard
     - dogsled
     - gochecknoinits
     - goconst
diff --git a/go.mod b/go.mod
index 1f3ecd8..9a598ec 100644
--- a/go.mod
+++ b/go.mod
@@ -20,6 +20,7 @@ require (
 	github.com/shirou/gopsutil v3.21.11+incompatible
 	github.com/stretchr/testify v1.8.2
 	github.com/urfave/cli/v2 v2.25.1
+	github.com/vishvananda/netns v0.0.4
 	go.uber.org/automaxprocs v1.5.2
 	golang.org/x/sys v0.8.0
 	gopkg.in/yaml.v2 v2.4.0
diff --git a/go.sum b/go.sum
index 881706f..b35ca93 100644
--- a/go.sum
+++ b/go.sum
@@ -292,6 +292,8 @@ github.com/valyala/fasthttp v1.6.0/go.mod h1:FstJa9V+Pj9vQ7OJie2qMHdwemEDaDiSdBn
 github.com/valyala/fasttemplate v1.0.1/go.mod h1:UQGH1tvbgY+Nz5t2n7tXsz52dQxojPUpymEIMZ47gx8=
 github.com/valyala/fasttemplate v1.2.1/go.mod h1:KHLXt3tVN2HBp8eijSv/kGJopbvo7S+qRAEEKiv+SiQ=
 github.com/valyala/tcplisten v0.0.0-20161114210144-ceec8f93295a/go.mod h1:v3UYOV9WzVtRmSR+PDvWpU/qWl4Wa5LApYYX4ZtKbio=
+github.com/vishvananda/netns v0.0.4 h1:Oeaw1EM2JMxD51g9uhtC0D7erkIjgmj8+JZc26m1YX8=
+github.com/vishvananda/netns v0.0.4/go.mod h1:SpkAiCQRtJ6TvvxPnOSyH3BMl6unz3xZlaprSwhNNJM=
 github.com/xeipuuv/gojsonpointer v0.0.0-20180127040702-4e3ac2762d5f/go.mod h1:N2zxlSyiKSe5eX1tZViRH5QA0qijqEDrYZiPEAiq3wU=
 github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415/go.mod h1:GwrjFmJcFw6At/Gs6z4yjiIwzuJ1/+UwLxMQDVQXShQ=
 github.com/xeipuuv/gojsonschema v1.2.0/go.mod h1:anYRn/JVcOK2ZgGU+IjEV4nwlhoK5sQluxsYJ78Id3Y=
diff --git a/runtime/docker/docker.go b/runtime/docker/docker.go
index 6615044..45361f5 100644
--- a/runtime/docker/docker.go
+++ b/runtime/docker/docker.go
@@ -6,8 +6,10 @@ import (
 	"fmt"
 	"io"
 	"math"
+	"net"
 	"net/http/httputil"
 	"os"
+	"runtime"
 	"strings"
 	"time"
 
@@ -16,6 +18,7 @@ import (
 	"github.com/projecteru2/agent/utils"
 	"github.com/projecteru2/core/cluster"
 	coreutils "github.com/projecteru2/core/utils"
+	"github.com/vishvananda/netns"
 
 	enginetypes "github.com/docker/docker/api/types"
 	enginecontainer "github.com/docker/docker/api/types/container"
@@ -169,6 +172,36 @@ func (d *Docker) checkHostname(env []string) bool {
 	return false
 }
 
+func getAddrsFromNS(cid string, ifname string) ([]net.Addr, error) {
+	// Lock the OS Thread so we don't accidentally switch namespaces
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	// Save the current network namespace
+	origns, _ := netns.Get()
+	defer origns.Close()
+	defer netns.Set(origns) //nolint:errcheck
+
+	containerNS, err := netns.GetFromDocker(cid)
+	if err != nil {
+		return nil, err
+	}
+	defer containerNS.Close()
+
+	if err := netns.Set(containerNS); err != nil {
+		return nil, err
+	}
+	eth0, err := net.InterfaceByName(ifname)
+	if err != nil {
+		return nil, err
+	}
+	addrs, err := eth0.Addrs()
+	if err != nil {
+		return nil, err
+	}
+	return addrs, nil
+}
+
 // detectWorkload detect a container by ID
 func (d *Docker) detectWorkload(ctx context.Context, ID string) (*Container, error) {
 	// 标准化为 inspect 的数据
@@ -205,7 +238,7 @@ func (d *Docker) detectWorkload(ctx context.Context, ID string) (*Container, err
 		container.Memory = d.memory
 	}
 	// 活着才有发布必要
-	if c.NetworkSettings != nil && container.Running {
+	if c.NetworkSettings != nil && container.Running { //nolint:nestif
 		networks := map[string]string{}
 		for name, endpoint := range c.NetworkSettings.Networks {
 			networkmode := enginecontainer.NetworkMode(name)
@@ -216,6 +249,20 @@ func (d *Docker) detectWorkload(ctx context.Context, ID string) (*Container, err
 				container.LocalIP = endpoint.IPAddress
 				networks[name] = endpoint.IPAddress
 			}
+			if networks[name] == "" {
+				addrs, err := getAddrsFromNS(c.ID, "eth0")
+				if err != nil {
+					log.Error(ctx, err, "failed to get eth0 addrs")
+				}
+				if len(addrs) > 0 {
+					ip, _, err := net.ParseCIDR(addrs[0].String())
+					if err == nil {
+						networks[name] = ip.String()
+					} else {
+						log.Error(ctx, err, "failed to parse cidr %s", addrs[0].String())
+					}
+				}
+			}
 			break
 		}
 		container.Networks = networks