support config dns via network stanza

containerd/driver.go

@@ -31,6 +31,7 @@ import (
 	"github.com/hashicorp/nomad/client/stats"
 	"github.com/hashicorp/nomad/client/taskenv"
 	"github.com/hashicorp/nomad/drivers/shared/eventer"
+	"github.com/hashicorp/nomad/drivers/shared/resolvconf"
 	"github.com/hashicorp/nomad/plugins/base"
 	"github.com/hashicorp/nomad/plugins/drivers"
 	"github.com/hashicorp/nomad/plugins/shared/hclspec"
@@ -229,7 +230,7 @@ func NewPlugin(logger log.Logger) drivers.DriverPlugin {
 	}
 }
 
-func (tc *TaskConfig) setVolumeMounts(cfg *drivers.TaskConfig) {
+func (tc *TaskConfig) setVolumeMounts(cfg *drivers.TaskConfig) error {
 	for _, m := range cfg.Mounts {
 		hm := Mount{
 			Type:    "bind",
@@ -243,6 +244,21 @@ func (tc *TaskConfig) setVolumeMounts(cfg *drivers.TaskConfig) {
 
 		tc.Mounts = append(tc.Mounts, hm)
 	}
+
+	if cfg.DNS != nil {
+		dnsMount, err := resolvconf.GenerateDNSMount(cfg.TaskDir().Dir, cfg.DNS)
+		if err != nil {
+			return fmt.Errorf("failed to build mount for resolv.conf: %v", err)
+		}
+		tc.HostDNS = false
+		tc.Mounts = append(tc.Mounts, Mount{
+			Type:    "bind",
+			Target:  dnsMount.TaskPath,
+			Source:  dnsMount.HostPath,
+			Options: []string{"bind", "ro"},
+		})
+	}
+	return nil
 }
 
 // PluginInfo returns information describing the plugin.
@@ -361,7 +377,9 @@ func (d *Driver) StartTask(cfg *drivers.TaskConfig) (*drivers.TaskHandle, *drive
 		return nil, nil, fmt.Errorf("host_network and bridge network mode are mutually exclusive, and only one of them should be set")
 	}
 
-	driverConfig.setVolumeMounts(cfg)
+	if err := driverConfig.setVolumeMounts(cfg); err != nil {
+		return nil, nil, err
+	}
 
 	d.logger.Info("starting task", "driver_cfg", hclog.Fmt("%+v", driverConfig))
 	handle := drivers.NewTaskHandle(taskHandleVersion)

example/dns.nomad

@@ -0,0 +1,27 @@
+
+job "dns" {
+  datacenters = ["dc1"]
+
+  group "dns-group" {
+
+    network {
+        dns {
+            servers = ["127.0.0.1", "127.0.0.2"]
+        }
+    }
+
+    task "dns-task" {
+      driver = "containerd-driver"
+      config {
+        image           = "docker.io/library/ubuntu:16.04"
+        command         = "sleep"
+        args            = ["600s"]
+      }
+
+      resources {
+        cpu    = 500
+        memory = 256
+      }
+    }
+  }
+}

go.mod

@@ -18,40 +18,29 @@ require (
 	github.com/coreos/go-iptables v0.4.3 // indirect
 	github.com/coreos/go-semver v0.3.0 // indirect
 	github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f // indirect
-	github.com/cyphar/filepath-securejoin v0.2.2 // indirect
-	github.com/docker/cli v0.0.0-20191202230238-13fb276442f5 // indirect
-	github.com/docker/docker v1.13.1 // indirect
 	github.com/docker/docker-credential-helpers v0.6.3 // indirect
 	github.com/docker/go-events v0.0.0-20190806004212-e31b211e4f1c // indirect
 	github.com/docker/go-metrics v0.0.1 // indirect
 	github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7 // indirect
-	github.com/fsouza/go-dockerclient v1.6.0 // indirect
 	github.com/gogo/googleapis v1.4.0 // indirect
 	github.com/google/uuid v1.1.2 // indirect
-	github.com/hashicorp/consul v1.6.2 // indirect
-	github.com/hashicorp/consul-template v0.23.0
+	github.com/gorhill/cronexpr v0.0.0-20180427100037-88b0669f7d75 // indirect
+	github.com/hashicorp/consul-template v0.25.1
 	github.com/hashicorp/go-envparse v0.0.0-20190703193109-150b3a2a4611 // indirect
-	github.com/hashicorp/go-getter v1.4.0 // indirect
-	github.com/hashicorp/go-hclog v0.10.0
-	github.com/hashicorp/go-plugin v1.0.1
+	github.com/hashicorp/go-hclog v0.12.0
+	github.com/hashicorp/go-plugin v1.0.2-0.20191004171845-809113480b55
 	github.com/hashicorp/go-uuid v1.0.1
 	github.com/hashicorp/hcl2 v0.0.0-20191002203319-fb75b3253c80 // indirect
-	github.com/hashicorp/nomad v0.10.1
-	github.com/hashicorp/nomad/api v0.0.0-20191203164002-b31573ae7206 // indirect
+	github.com/hashicorp/nomad v1.0.2
 	github.com/mitchellh/go-ps v0.0.0-20190716172923-621e5597135b // indirect
-	github.com/mrunalp/fileutils v0.0.0-20171103030105-7d4729fb3618 // indirect
-	github.com/opencontainers/runc v1.0.0-rc8.0.20190611121236-6cc515888830 // indirect
-	github.com/opencontainers/runtime-spec v1.0.2
-	github.com/opencontainers/selinux v1.3.1 // indirect
-	github.com/seccomp/libseccomp-golang v0.9.1 // indirect
-	github.com/shirou/gopsutil v2.19.11+incompatible // indirect
+	github.com/opencontainers/runtime-spec v1.0.3-0.20200728170252-4d89ac9fbff6
 	github.com/spf13/cobra v1.1.1
 	github.com/syndtr/gocapability v0.0.0-20180916011248-d98352740cb2 // indirect
 	github.com/ugorji/go v1.1.7 // indirect
 	github.com/vbatts/tar-split v0.11.1 // indirect
-	github.com/zclconf/go-cty v1.1.1 // indirect
 	go4.org v0.0.0-20191010144846-132d2879e1e9 // indirect
 	google.golang.org/grpc v1.32.0 // indirect
+	istio.io/gogo-genproto v0.0.0-20190124151557-6d926a6e6feb // indirect
 )
 
 // use lower-case sirupsen