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Merge pull request #898 from paulbellamy/weavedns_default_resolver

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Weavedns default resolver

Fixes #383.
This commit is contained in:
Matthias Radestock committed 2015-06-16 14:17:14 +01:00
2 parents a1cb5b16a6 af38f07d26
commit 8b5d0e3fbd
9 files changed
+155 -41
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prog/weaveproxy/main.go
+6 -1
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@@ -36,7 +36,8 @@ func main() {
getopt.BoolVarLong(&c.TLSConfig.Enabled, "tls", 0, "Use TLS; implied by --tlsverify")
getopt.StringVarLong(&c.TLSConfig.Key, "tlskey", 0, "Path to TLS key file")
getopt.BoolVarLong(&c.TLSConfig.Verify, "tlsverify", 0, "Use TLS and verify the remote")
getopt.BoolVarLong(&c.WithDNS, "with-dns", 'w', "instruct created containers to use weaveDNS as their nameserver")
getopt.BoolVarLong(&c.WithDNS, "with-dns", 'w', "instruct created containers to always use weaveDNS as their nameserver")
getopt.BoolVarLong(&c.WithoutDNS, "without-dns", 0, "instruct created containers to never use weaveDNS as their nameserver")
getopt.BoolVarLong(&c.WithIPAM, "with-ipam", 'i', "automatically allocate addresses for containers without a WEAVE_CIDR")
getopt.Parse()
@@ -45,6 +46,10 @@ func main() {
os.Exit(0)
}
if c.WithDNS && c.WithoutDNS {
Error.Fatalf("Cannot use both '--with-dns' and '--without-dns' flags")
}
if debug {
InitDefaultLogging(true)
}
proxy/create_container_interceptor.go
+9 -4
View File
@@ -81,7 +81,12 @@ func (i *createContainerInterceptor) setWeaveWaitEntrypoint(container *docker.Co
}
func (i *createContainerInterceptor) setWeaveDNS(container *createContainerRequestBody, r *http.Request) error {
if !i.proxy.WithDNS {
if i.proxy.WithoutDNS {
return nil
}
dnsDomain, dnsRunning := i.getDNSDomain()
if !(dnsRunning || i.proxy.WithDNS) {
return nil
}
@@ -95,13 +100,13 @@ func (i *createContainerInterceptor) setWeaveDNS(container *createContainerReque
if container.Hostname == "" && name != "" {
container.Hostname = name
// Strip trailing period because it's unusual to see it used on the end of a host name
container.Domainname = strings.TrimSuffix(i.getDNSDomain(), ".")
container.Domainname = strings.TrimSuffix(dnsDomain, ".")
}
return nil
}
func (i *createContainerInterceptor) getDNSDomain() (domain string) {
func (i *createContainerInterceptor) getDNSDomain() (domain string, running bool) {
domain = nameserver.DefaultLocalDomain
dnsContainer, err := i.proxy.client.InspectContainer("weavedns")
if err != nil ||
@@ -122,7 +127,7 @@ func (i *createContainerInterceptor) getDNSDomain() (domain string) {
return
}
return string(b)
return string(b), true
}
func (i *createContainerInterceptor) InterceptResponse(r *http.Response) error {
proxy/proxy.go
+2 -1
View File
@@ -37,6 +37,7 @@ type Config struct {
TLSConfig TLSConfig
Version string
WithDNS bool
WithoutDNS bool
WithIPAM bool
}
@@ -61,7 +62,7 @@ func NewProxy(c Config) (*Proxy, error) {
},
}
if p.WithDNS {
if !p.WithoutDNS {
dockerBridgeIP, err := callWeave("docker-bridge-ip")
if err != nil {
return nil, err
site/proxy.md
+8 -11
View File
@@ -119,17 +119,14 @@ Containers started via the proxy are automatically registered in
[weaveDNS](weavedns.html) if they have a hostname in the weaveDNS
domain (usually `.weave.local`). In order for containers to be able to
look up such names, their DNS resolver needs to be configured to point
at weaveDNS. This can be done [manually](weavedns.html#without-run),
or automatically by the proxy by launching it with the `--with-dns`
option, i.e.
host1$ weave launch-proxy --with-dns
Now any containers started via the proxy, and with a `WEAVE_CIDR=...`
environment variable (or even without it, if IPAM is
[configured](#ipam)), will use weaveDNS for name resolution. If not
provided, the hostname will default to the container name and will be
registered in weaveDNS.
at weaveDNS. This will be done automatically by the proxy while
weaveDNS is running. To override this behaviour launch the proxy with
either `--with-dns` or `--without-dns`, which will force the proxy to
always/never set the resolver to weaveDNS. If there is no hostname
provided, the container will be registered in weaveDNS using its
container name. Otherwise, if there is no container name, and no
hostname (or a hostname outside the weaveDNS domain), the container
will not be registered in weaveDNS.
## <a name="multi-host"></a>Multi-host example
site/weavedns.md
+24 -8
View File
@@ -27,16 +27,27 @@ hosts.
WeaveDNS is deployed as a set of containers that communicate with each
other over the weave network. One such container needs to be started
on every weave host, by invoking the weave script command
`launch-dns`. Application containers are then instructed to use
weaveDNS as their nameserver by supplying the `--with-dns` option when
starting them; containers so started also automatically register their
container name in the weaveDNS domain. For example:
`launch-dns`.
```bash
$ weave launch
$ weave launch-dns 10.2.254.1/24
$ weave run --with-dns 10.2.1.25/24 -ti --name=pingme ubuntu
$ shell1=$(weave run --with-dns 10.2.1.26/24 -ti --name=ubuntu ubuntu)
```
Containers started while weaveDNS is running are automatically
registered in [weaveDNS](weavedns.html) if they have a hostname in the
weaveDNS domain (usually `.weave.local`). In order for containers to
be able to look up such names, their DNS resolver needs to be
configured to point at weaveDNS. This will be done automatically while
weaveDNS is running. If there is no hostname provided, the container
will be registered in weaveDNS using its container name. Otherwise, if
there is no container name, and no hostname (or a hostname outside the
weaveDNS domain), the container will not be registered in weaveDNS.
For example, to use the container name as the hostname:
```bash
$ weave run 10.2.1.25/24 -ti --name=pingme ubuntu
$ shell1=$(weave run 10.2.1.26/24 -ti --name=ubuntu ubuntu)
$ docker attach $shell1
root@ubuntu:/# ping pingme
@@ -51,6 +62,11 @@ it in weaveDNS simply by giving the container a hostname in the
$ weave run 10.2.1.25/24 -ti -h pingme.weave.local ubuntu
```
It is also possible to force or forbid an application container's use
of weaveDNS with the `--with-dns` and `--without-dns` options to
`weave run`; these override the runtime detection of the weaveDNS
container.
Each weaveDNS container started with `launch-dns` needs to be given
its own, unique, IP address, in a subnet that is common to all
weaveDNS containers and not in use on any of the hosts.
@@ -62,7 +78,7 @@ use weaveDNS on a second host we would run:
```bash
host2$ weave launch $HOST1
host2$ weave launch-dns 10.2.254.2/24
host2$ shell2=$(weave run --with-dns 10.2.1.36/24 -ti --name=ubuntu2 ubuntu)
host2$ shell2=$(weave run 10.2.1.36/24 -ti --name=ubuntu2 ubuntu)
host2$ docker attach $shell2
root@ubuntu2:/# ping pingme
@@ -117,7 +133,7 @@ Returning to our earlier example, let us start an additional `pingme`
container, this time on the 2nd host, and then run some ping tests...
```bash
host2$ weave run --with-dns 10.2.1.35/24 -ti --name=pingme ubuntu
host2$ weave run 10.2.1.35/24 -ti --name=pingme ubuntu
host2$ docker attach $shell2
root@ubuntu2:/# ping -nq -c 1 pingme
test/240_dns_add_name_test.sh
+2 -2
View File
@@ -12,8 +12,8 @@ start_suite "Add and remove names on a single host"
weave_on $HOST1 launch-dns 10.2.254.1/24 $WEAVEDNS_ARGS
start_container $HOST1 $C2/24 --name=c2
start_container_with_dns $HOST1 $C1/24 --name=c1
start_container $HOST1 --without-dns $C2/24 --name=c2
start_container_with_dns $HOST1 $C1/24 --name=c1
weave_on $HOST1 dns-add $C2 c2 -h $NAME2
test/280_with_or_without_dns_test.sh
Executable
+40
View File
@@ -0,0 +1,40 @@
#! /bin/bash
. ./config.sh
IP=10.2.0.34
TARGET=seetwo.weave.local
TARGET_IP=10.2.0.78
assert_no_resolution() {
container=$(weave_on $HOST1 run "$@" $IP/24 -t $DNS_IMAGE /bin/sh)
assert_no_dns_record $HOST1 $container $TARGET
rm_containers $HOST1 $container
}
assert_resolution() {
container=$(weave_on $HOST1 run "$@" $IP/24 -t $DNS_IMAGE /bin/sh)
assert_dns_record $HOST1 $container $TARGET $TARGET_IP
rm_containers $HOST1 $container
}
start_suite "With or without DNS test"
weave_on $HOST1 launch
DNS_IP=$(weave_on $HOST1 docker-bridge-ip)
# Assert behaviour without weaveDNS running
assert_no_resolution --without-dns
assert_no_resolution
assert_no_resolution --with-dns
weave_on $HOST1 launch-dns 10.2.254.1/24 $WEAVEDNS_ARGS
start_container $HOST1 $TARGET_IP/24 --name c2 -h $TARGET
# Assert behaviour with weaveDNS running
assert_no_resolution --without-dns
assert_resolution
assert_resolution --with-dns
end_suite
test/630_proxy_dns_test.sh
+35 -4
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@@ -7,14 +7,45 @@ C2=10.2.0.34
C1_NAME=c1.weave.local
C2_NAME=seetwo.weave.local
boot_containers() {
proxy docker_on $HOST1 run -e WEAVE_CIDR=$C2/24 -dt --name=c2 -h $C2_NAME $DNS_IMAGE /bin/sh
proxy docker_on $HOST1 run -e WEAVE_CIDR=$C1/24 -dt --name=c1 $DNS_IMAGE /bin/sh
}
kill_containers() {
rm_containers $HOST1 c1 c2
}
assert_no_resolution() {
boot_containers
assert_no_dns_record $HOST1 c1 $C2_NAME $C2
assert_no_dns_record $HOST1 c2 $C1_NAME $C1
kill_containers
}
start_suite "Proxy registers containers with dns"
weave_on $HOST1 launch-dns 10.2.254.1/24 $WEAVEDNS_ARGS
weave_on $HOST1 launch-proxy --with-dns
proxy docker_on $HOST1 run -e WEAVE_CIDR=$C2/24 -dt --name=c2 -h $C2_NAME $DNS_IMAGE /bin/sh
proxy docker_on $HOST1 run -e WEAVE_CIDR=$C1/24 -dt --name=c1 $DNS_IMAGE /bin/sh
bridge_ip=$(weave_on $HOST1 docker-bridge-ip)
# Assert behaviour without weaveDNS running, but dns forced
weave_on $HOST1 launch-proxy --with-dns
assert_no_resolution
weave_on $HOST1 stop-proxy
# Assert behaviour without weaveDNS
weave_on $HOST1 launch-proxy
assert_no_resolution
# Assert behaviour with weaveDNS running
weave_on $HOST1 launch-dns 10.2.254.1/24 $WEAVEDNS_ARGS
boot_containers
assert_dns_record $HOST1 c1 $C2_NAME $C2
assert_dns_record $HOST1 c2 $C1_NAME $C1
kill_containers
weave_on $HOST1 stop-proxy
# Assert behaviour with weaveDNS running, but dns forced off
weave_on $HOST1 launch-proxy --without-dns
assert_no_resolution
end_suite
weave
+29 -10
View File
@@ -29,10 +29,11 @@ usage() {
echo "weave launch [-password <password>] [-nickname <nickname>] [-nodiscovery]"
echo " [-iprange <cidr> [-ipsubnet <cidr>]] <peer> ..."
echo "weave launch-dns [<addr>]"
echo "weave launch-proxy [-D <endpoint>] [-H <endpoint>] [--with-dns] [--with-ipam]"
echo "weave launch-proxy [-D <endpoint>] [-H <endpoint>]"
echo " [--with-dns | --without-dns] [--with-ipam]"
echo "weave connect [--replace] [<peer> ...]"
echo "weave forget <peer> ..."
echo "weave run [--with-dns] [<addr> ...] <docker run args> ..."
echo "weave run [--with-dns | --without-dns] [<addr> ...] <docker run args> ..."
echo "weave start [<addr> ...] <container_id>"
echo "weave attach [<addr> ...] <container_id>"
echo "weave detach [<addr> ...] <container_id>"
@@ -119,6 +120,14 @@ collect_ip_args() {
done
}
dns_arg_count() {
if [ "$1" = "--with-dns" -o "$1" = "--without-dns" ]; then
echo 1
else
echo 0
fi
}
# "run" is a special case because we want to use docker directly,
# rather than the docker in $EXEC_IMAGE remotely. That's because we
# are passing arbitrary arguments on to docker run, and we can't rely
@@ -126,10 +135,10 @@ collect_ip_args() {
if [ "$1" = "run" ] ; then
shift 1
check_docker_version
if [ "$1" = "--with-dns" ] ; then
shift 1
DNS_ARGS=$(exec_remote dns-args "$@")
if [ "$1" != "--without-dns" ] ; then
DNS_ARGS=$(exec_remote dns-args "$@" || true)
fi
shift $(dns_arg_count "$@")
collect_cidr_args "$@"
shift $CIDR_ARG_COUNT
CONTAINER=$(docker $DOCKER_CLIENT_ARGS run $DNS_ARGS -d "$@")
@@ -631,7 +640,7 @@ dns_args() {
# versions prior to 1.3.0 fail to include the domain when
# setting the hostname, so lookups for non-fully-qualified
# names fail.
echo "ERROR: The '--with-dns' option requires Docker 1.3.0 or later; you are running $DOCKER_VERSION" >&2
echo "ERROR: Need Docker 1.3.0 or later to configure container DNS; you are running $DOCKER_VERSION" >&2
exit 1
fi
docker_bridge_ip
@@ -639,6 +648,8 @@ dns_args() {
DNS_SEARCH_ARG="--dns-search=."
NAME_ARG=""
HOSTNAME_SPECIFIED=
WITH_DNS=
WITHOUT_DNS=
while [ $# -gt 0 ] ; do
case "$1" in
--dns-search=*)
@@ -654,9 +665,19 @@ dns_args() {
-h|--hostname|--hostname=*)
HOSTNAME_SPECIFIED=1
;;
--with-dns)
WITH_DNS=1
;;
--without-dns)
WITHOUT_DNS=1
;;
esac
shift
done
[ -n "$WITHOUT_DNS" ] && return 0
if [ -z "$WITH_DNS" ] ; then
check_running $DNS_CONTAINER_NAME 2>/dev/null || return 0
fi
DNS_ARGS="$DNS_ARG $DNS_SEARCH_ARG"
if [ -n "$NAME_ARG" -a -z "$HOSTNAME_SPECIFIED" ] ; then
DOMAIN=$(call_dns GET /domain 2>/dev/null) || DOMAIN=weave.local.
@@ -1071,10 +1092,8 @@ case "$COMMAND" in
fi
;;
run)
if [ "$1" = "--with-dns" ] ; then
shift 1
dns_args "$@"
fi
dns_args "$@"
shift $(dns_arg_count "$@")
collect_cidr_args "$@"
shift $CIDR_ARG_COUNT
CONTAINER=$(docker run $DNS_ARGS -d "$@")