If the resolver's DNSBackend returns a name that cannot be marshaled
into a well-formed DNS message, the resolver will only discover this
when it attempts to write the reply message and it fails with an error.
No reply message is sent, leaving the client to wait out its timeout and
the user in the dark about what went wrong.
When writing the intended reply message fails, retry once with a
ServFail response to inform the client and user that the DNS query was
not resolved due to a problem with to the resolver, not the network.
Signed-off-by: Cory Snider <csnider@mirantis.com>
The well-formedness of a DNS message is only checked when it is
serialized, through the (*dns.Msg).Pack() method. Add a call to Pack()
to our tstwriter mock to mirror the behaviour of the real
dns.ResponseWriter implementation. And fix tests which generated
ill-formed DNS query messages.
Signed-off-by: Cory Snider <csnider@mirantis.com>
The github.com/containerd/containerd/log package was moved to a separate
module, which will also be used by upcoming (patch) releases of containerd.
This patch moves our own uses of the package to use the new module.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This change creates a few OTEL spans and plumb context through the DNS
resolver and DNS backends (ie. Sandbox and Network). This should help
better understand how much lock contention impacts performance, and
help debug issues related to DNS queries (we basically have no
visibility into what's happening here right now).
Signed-off-by: Albin Kerouanton <albinker@gmail.com>
TestProxyNXDOMAIN has proven to be susceptible to failing as a
consequence of unlocked threads being set to the wrong network
namespace. As the failure mode looks a lot like a bug in the test
itself, it seems prudent to add a check for mismatched namespaces to the
test so we will know for next time that the root cause lies elsewhere.
Signed-off-by: Cory Snider <csnider@mirantis.com>
Swapping out the global logger on the fly is causing tests to flake out
by logging to a test's log output after the test function has returned.
Refactor Resolver to use a dependency-injected logger and the resolver
unit tests to inject a private logger instance into the Resolver under
test.
Signed-off-by: Cory Snider <csnider@mirantis.com>
tstwriter mocks the server-side connection between the resolver and the
container, not the resolver and the external DNS server, so returning
the external DNS server's address as w.LocalAddr() is technically
incorrect and misleading. Only the protocols need to match as the
resolver uses the client's choice of protocol to determine which
protocol to use when forwarding the query to the external DNS server.
While this change has no material impact on the tests, it makes the
tests slightly more comprehensible for the next person.
Signed-off-by: Cory Snider <csnider@mirantis.com>
Our resolver is just a forwarder for external DNS so it should act like
it. Unless it's a server failure or refusal, take the response at face
value and forward it along to the client. RFC 8020 is only applicable to
caching recursive name servers and our resolver is neither caching nor
recursive.
Signed-off-by: Cory Snider <csnider@mirantis.com>
Basically every exported method which takes a libnetwork.Sandbox
argument asserts that the value's concrete type is *sandbox. Passing any
other implementation of the interface is a runtime error! This interface
is a footgun, and clearly not necessary. Export and use the concrete
type instead.
Signed-off-by: Cory Snider <csnider@mirantis.com>
Reusing the same "OS context" (read: network namespace) and
NetworkController across multiple tests risks tests interfering with
each other, or worse: _depending on_ other tests to set up
preconditions. Construct a new controller for every test which needs
one, and run every test which mutates or inspects the host environment
in a fresh OS context.
The only outlier is runParallelTests. It is the only remaining test
implementation which references the "global" package-scoped controller,
so the global controller instance is effectively private to that one
test.
Signed-off-by: Cory Snider <csnider@mirantis.com>
There are a handful of libnetwork tests which need to have multiple
concurrent goroutines inside the same test OS context (network
namespace), including some platform-agnostic tests. Provide test
utilities for spawning goroutines inside an OS context and
setting/restoring an existing goroutine's OS context to abstract away
platform differences and so that each test does not need to reinvent the
wheel.
Signed-off-by: Cory Snider <csnider@mirantis.com>
libnetwork/etchosts/etchosts_test.go:167:54: empty-lines: extra empty line at the end of a block (revive)
libnetwork/osl/route_linux.go:185:74: empty-lines: extra empty line at the start of a block (revive)
libnetwork/osl/sandbox_linux_test.go:323:36: empty-lines: extra empty line at the start of a block (revive)
libnetwork/bitseq/sequence.go:412:48: empty-lines: extra empty line at the start of a block (revive)
libnetwork/datastore/datastore_test.go:67:46: empty-lines: extra empty line at the end of a block (revive)
libnetwork/datastore/mock_store.go:34:60: empty-lines: extra empty line at the end of a block (revive)
libnetwork/iptables/firewalld.go:202:44: empty-lines: extra empty line at the end of a block (revive)
libnetwork/iptables/firewalld_test.go:76:36: empty-lines: extra empty line at the end of a block (revive)
libnetwork/iptables/iptables.go:256:67: empty-lines: extra empty line at the end of a block (revive)
libnetwork/iptables/iptables.go:303:128: empty-lines: extra empty line at the start of a block (revive)
libnetwork/networkdb/cluster.go:183:72: empty-lines: extra empty line at the end of a block (revive)
libnetwork/ipams/null/null_test.go:44:38: empty-lines: extra empty line at the end of a block (revive)
libnetwork/drivers/macvlan/macvlan_store.go:45:52: empty-lines: extra empty line at the end of a block (revive)
libnetwork/ipam/allocator_test.go:1058:39: empty-lines: extra empty line at the start of a block (revive)
libnetwork/drivers/bridge/port_mapping.go:88:111: empty-lines: extra empty line at the end of a block (revive)
libnetwork/drivers/bridge/link.go:26:90: empty-lines: extra empty line at the end of a block (revive)
libnetwork/drivers/bridge/setup_ipv6_test.go:17:34: empty-lines: extra empty line at the end of a block (revive)
libnetwork/drivers/bridge/setup_ip_tables.go:392:4: empty-lines: extra empty line at the start of a block (revive)
libnetwork/drivers/bridge/bridge.go:804:50: empty-lines: extra empty line at the start of a block (revive)
libnetwork/drivers/overlay/ov_serf.go:183:29: empty-lines: extra empty line at the start of a block (revive)
libnetwork/drivers/overlay/ov_utils.go:81:64: empty-lines: extra empty line at the end of a block (revive)
libnetwork/drivers/overlay/peerdb.go:172:67: empty-lines: extra empty line at the start of a block (revive)
libnetwork/drivers/overlay/peerdb.go:209:67: empty-lines: extra empty line at the start of a block (revive)
libnetwork/drivers/overlay/peerdb.go:344:89: empty-lines: extra empty line at the start of a block (revive)
libnetwork/drivers/overlay/peerdb.go:436:63: empty-lines: extra empty line at the start of a block (revive)
libnetwork/drivers/overlay/overlay.go:183:36: empty-lines: extra empty line at the start of a block (revive)
libnetwork/drivers/overlay/encryption.go:69:28: empty-lines: extra empty line at the end of a block (revive)
libnetwork/drivers/overlay/ov_network.go:563:81: empty-lines: extra empty line at the start of a block (revive)
libnetwork/default_gateway.go:32:43: empty-lines: extra empty line at the start of a block (revive)
libnetwork/errors_test.go:9:40: empty-lines: extra empty line at the start of a block (revive)
libnetwork/service_common.go:184:64: empty-lines: extra empty line at the end of a block (revive)
libnetwork/endpoint.go:161:55: empty-lines: extra empty line at the end of a block (revive)
libnetwork/store.go:320:33: empty-lines: extra empty line at the end of a block (revive)
libnetwork/store_linux_test.go:11:38: empty-lines: extra empty line at the end of a block (revive)
libnetwork/sandbox.go:571:36: empty-lines: extra empty line at the start of a block (revive)
libnetwork/service_common.go:317:246: empty-lines: extra empty line at the start of a block (revive)
libnetwork/endpoint.go:550:17: empty-lines: extra empty line at the end of a block (revive)
libnetwork/sandbox_dns_unix.go:213:106: empty-lines: extra empty line at the start of a block (revive)
libnetwork/controller.go:676:85: empty-lines: extra empty line at the end of a block (revive)
libnetwork/agent.go:876:60: empty-lines: extra empty line at the end of a block (revive)
libnetwork/resolver.go:324:69: empty-lines: extra empty line at the end of a block (revive)
libnetwork/network.go:1153:92: empty-lines: extra empty line at the end of a block (revive)
libnetwork/network.go:1955:67: empty-lines: extra empty line at the start of a block (revive)
libnetwork/network.go:2235:9: empty-lines: extra empty line at the start of a block (revive)
libnetwork/libnetwork_internal_test.go:336:26: empty-lines: extra empty line at the start of a block (revive)
libnetwork/resolver_test.go:76:35: empty-lines: extra empty line at the end of a block (revive)
libnetwork/libnetwork_test.go:303:38: empty-lines: extra empty line at the end of a block (revive)
libnetwork/libnetwork_test.go:985:46: empty-lines: extra empty line at the end of a block (revive)
libnetwork/ipam/allocator_test.go:1263:37: empty-lines: extra empty line at the start of a block (revive)
libnetwork/errors_test.go:9:40: empty-lines: extra empty line at the end of a block (revive)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The correct formatting for machine-readable comments is;
//<some alphanumeric identifier>:<options>[,<option>...][ // comment]
Which basically means:
- MUST NOT have a space before `<identifier>` (e.g. `nolint`)
- Identified MUST be alphanumeric
- MUST be followed by a colon
- MUST be followed by at least one `<option>`
- Optionally additional `<options>` (comma-separated)
- Optionally followed by a comment
Any other format will not be considered a machine-readable comment by `gofmt`,
and thus formatted as a regular comment. Note that this also means that a
`//nolint` (without anything after it) is considered invalid, same for `//#nosec`
(starts with a `#`).
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
RFC434 states that DNS Servers should be case insensitive
This commit makes sure that all DNS queries will be translated
to lower ASCII characters and all svcRecords will be saved in
lower case to abide by the RFC
Relates to https://github.com/moby/moby/issues/21169
Signed-off-by: Arko Dasgupta <arko.dasgupta@docker.com>
