From 2f9ef4adb7f0281c88600b3b86626757562b3e3d Mon Sep 17 00:00:00 2001
From: Alban Crequy <alban@kinvolk.io>
Date: Tue, 26 Jan 2016 18:54:56 +0100
Subject: [PATCH] *: add "dns" field to the configuration

appc/cni#76 added a "dns" field in the result JSON. But before this
patch, the plugins had no way of knowing which name server to return.

There could be two ways of knowing which name server to return:
1. add it as an extra argument ("CNI_ARGS")
2. add it in the network configuration as a convenience (received via
   stdin)

I chose the second way because it is easier. In the case of rkt, it
means the user could just add the DNS name servers in
/etc/rkt/net.d/mynetwork.conf.
---
 Documentation/ptp.md            |  7 ++++++-
 pkg/types/types.go              |  1 +
 plugins/main/bridge/bridge.go   | 10 ++++++----
 plugins/main/ipvlan/ipvlan.go   |  8 +++++---
 plugins/main/macvlan/macvlan.go |  8 +++++---
 plugins/main/ptp/ptp.go         |  6 ++++--
 6 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/Documentation/ptp.md b/Documentation/ptp.md
index e7f2ffe7..acde8515 100644
--- a/Documentation/ptp.md
+++ b/Documentation/ptp.md
@@ -14,7 +14,11 @@ The traffic of the container interface will be routed through the interface of t
 	"ipam": {
 		"type": "host-local",
 		"subnet": "10.1.1.0/24"
-	}
+	},
+	"dns": [
+		"8.8.8.8",
+		"8.8.4.4"
+	]
 }
 
 ## Network configuration reference
@@ -24,3 +28,4 @@ The traffic of the container interface will be routed through the interface of t
 * `ipMasq` (boolean, optional): set up IP Masquerade on the host for traffic originating from this network and destined outside of it. Defaults to false.
 * `mtu` (integer, optional): explicitly set MTU to the specified value. Defaults to value chosen by the kernel.
 * `ipam` (dictionary, required): IPAM configuration to be used for this network.
+* `dns` (string array, optional): name servers to return as is in the [Result](/SPEC.md#result). Defaults to empty list.
diff --git a/pkg/types/types.go b/pkg/types/types.go
index 7fce5b82..e5558be4 100644
--- a/pkg/types/types.go
+++ b/pkg/types/types.go
@@ -67,6 +67,7 @@ type NetConf struct {
 type Result struct {
 	IP4 *IPConfig `json:"ip4,omitempty"`
 	IP6 *IPConfig `json:"ip6,omitempty"`
+	DNS []string  `json:"dns,omitempty"`
 }
 
 func (r *Result) Print() error {
diff --git a/plugins/main/bridge/bridge.go b/plugins/main/bridge/bridge.go
index 82c3511a..c4d8594d 100644
--- a/plugins/main/bridge/bridge.go
+++ b/plugins/main/bridge/bridge.go
@@ -35,10 +35,11 @@ const defaultBrName = "cni0"
 
 type NetConf struct {
 	types.NetConf
-	BrName string `json:"bridge"`
-	IsGW   bool   `json:"isGateway"`
-	IPMasq bool   `json:"ipMasq"`
-	MTU    int    `json:"mtu"`
+	BrName string   `json:"bridge"`
+	IsGW   bool     `json:"isGateway"`
+	IPMasq bool     `json:"ipMasq"`
+	MTU    int      `json:"mtu"`
+	DNS    []string `json:"dns"`
 }
 
 func init() {
@@ -226,6 +227,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 		}
 	}
 
+	result.DNS = n.DNS
 	return result.Print()
 }
 
diff --git a/plugins/main/ipvlan/ipvlan.go b/plugins/main/ipvlan/ipvlan.go
index 0c16cc04..36977356 100644
--- a/plugins/main/ipvlan/ipvlan.go
+++ b/plugins/main/ipvlan/ipvlan.go
@@ -31,9 +31,10 @@ import (
 
 type NetConf struct {
 	types.NetConf
-	Master string `json:"master"`
-	Mode   string `json:"mode"`
-	MTU    int    `json:"mtu"`
+	Master string   `json:"master"`
+	Mode   string   `json:"mode"`
+	MTU    int      `json:"mtu"`
+	DNS    []string `json:"dns"`
 }
 
 func init() {
@@ -138,6 +139,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 		return err
 	}
 
+	result.DNS = n.DNS
 	return result.Print()
 }
 
diff --git a/plugins/main/macvlan/macvlan.go b/plugins/main/macvlan/macvlan.go
index 77fb65f6..812d91f4 100644
--- a/plugins/main/macvlan/macvlan.go
+++ b/plugins/main/macvlan/macvlan.go
@@ -31,9 +31,10 @@ import (
 
 type NetConf struct {
 	types.NetConf
-	Master string `json:"master"`
-	Mode   string `json:"mode"`
-	MTU    int    `json:"mtu"`
+	Master string   `json:"master"`
+	Mode   string   `json:"mode"`
+	MTU    int      `json:"mtu"`
+	DNS    []string `json:"dns"`
 }
 
 func init() {
@@ -142,6 +143,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 		return err
 	}
 
+	result.DNS = n.DNS
 	return result.Print()
 }
 
diff --git a/plugins/main/ptp/ptp.go b/plugins/main/ptp/ptp.go
index 51aa62e8..a51b42fc 100644
--- a/plugins/main/ptp/ptp.go
+++ b/plugins/main/ptp/ptp.go
@@ -41,8 +41,9 @@ func init() {
 
 type NetConf struct {
 	types.NetConf
-	IPMasq bool `json:"ipMasq"`
-	MTU    int  `json:"mtu"`
+	IPMasq bool     `json:"ipMasq"`
+	MTU    int      `json:"mtu"`
+	DNS    []string `json:"dns"`
 }
 
 func setupContainerVeth(netns, ifName string, mtu int, pr *types.Result) (string, error) {
@@ -185,6 +186,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 		}
 	}
 
+	result.DNS = conf.DNS
 	return result.Print()
 }