[26.0 backport] Enable external DNS for ipvlan-l3, and disable it for macvlan/ipvlan with no parent interface #47705
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Signed-off-by: Rob Murray <rob.murray@docker.com>
The internal DNS resolver should only forward requests to external resolvers if the libnetwork.Sandbox served by the resolver has external network access (so, no forwarding for '--internal' networks). The test for external network access was whether the Sandbox had an Endpoint with a gateway configured. However, an ipvlan-l3 networks with external network access does not have a gateway, it has a default route bound to an interface. Also, we document that an ipvlan network with no parent interface is equivalent to a '--internal' network. But, in this case, an ipvlan-l2 network was configured with a gateway. So, DNS proxying would be enabled in the internal resolver (and, if the host's resolver was on a localhost address, requests to external resolvers from the host's network namespace would succeed). So, this change adjusts the test for enabling DNS proxying to include a check for '--internal' (as a shortcut) and, for non-internal networks, checks for a default route as well as a gateway. It also disables configuration of a gateway or a default route for an ipvlan Endpoint if no parent interface is specified. (Note if a parent interface with no external network is supplied as '-o parent=<dummy>', the gateway/default route will still be set up and external DNS proxying will be enabled. The network must be configured as '--internal' to prevent that from happening.) Signed-off-by: Rob Murray <rob.murray@docker.com>
We document that an macvlan network with no parent interface is equivalent to a '--internal' network. But, in this case, an macvlan network was still configured with a gateway. So, DNS proxying would be enabled in the internal resolver (and, if the host's resolver was on a localhost address, requests to external resolvers from the host's network namespace would succeed). This change disables configuration of a gateway for a macvlan Endpoint if no parent interface is specified. (Note if a parent interface with no external network is supplied as '-o parent=<dummy>', the gateway will still be set up. Documentation will need to be updated to note that '--internal' should be used to prevent DNS request forwarding in this case.) Signed-off-by: Rob Murray <rob.murray@docker.com>
This reverts commit a77e147. The ipvlan integration tests have been skipped in CI because of a check intended to ensure the kernel has ipvlan support - which failed, but seems to be unnecessary (probably because kernels have moved on). Signed-off-by: Rob Murray <rob.murray@docker.com>
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[](https://renovatebot.com) This PR contains the following updates: | Package | Update | Change | |---|---|---| | [docker/docker](https://togithub.com/docker/docker) | patch | `26.0.0` -> `26.0.1` | --- ### Release Notes <details> <summary>docker/docker (docker/docker)</summary> ### [`v26.0.1`](https://togithub.com/moby/moby/releases/tag/v26.0.1) [Compare Source](https://togithub.com/docker/docker/compare/v26.0.0-rc2...v26.0.1) #### 26.0.1 For a full list of pull requests and changes in this release, refer to the relevant GitHub milestones: - [docker/cli, 26.0.1 milestone](https://togithub.com/docker/cli/issues?q=is%3Aclosed+milestone%3A26.0.1) - [moby/moby, 26.0.1 milestone](https://togithub.com/moby/moby/issues?q=is%3Aclosed+milestone%3A26.0.1) - Deprecated and removed features, see [Deprecated Features](https://togithub.com/docker/cli/blob/v26.0.1/docs/deprecated.md). - Changes to the Engine API, see [API version history](https://togithub.com/moby/moby/blob/v26.0.1/docs/api/version-history.md). ##### Bug fixes and enhancements - Fix a regression that meant network interface specific `--sysctl` options prevented container startup. [moby/moby#47646](https://togithub.com/moby/moby/pull/47646) - Remove erroneous `platform` from image `config` OCI descriptor in `docker save` output. [moby/moby#47694](https://togithub.com/moby/moby/pull/47694) - containerd image store: OCI archives produced by `docker save` will now have a non-empty `mediaType` field in `index.json` [moby/moby#47701](https://togithub.com/moby/moby/pull/47701) - Fix a regression that prevented the internal resolver from forwarding requests from IPvlan L3 networks to external resolvers. [moby/moby#47705](https://togithub.com/moby/moby/pull/47705) - Prevent the use of external resolvers in IPvlan and Macvlan networks created with no parent interface specified. [moby/moby#47705](https://togithub.com/moby/moby/pull/47705) ##### Packaging updates - Update Go runtime to 1.21.9 [moby/moby#47671](https://togithub.com/moby/moby/pull/47671), [docker/cli#4987](https://togithub.com/docker/cli/pull/4987) - Update Compose to [v1.26.1 ](https://togithub.com/docker/compose/releases/tag/v2.26.1), [docker/docker-ce-packaging#1009](https://togithub.com/docker/docker-ce-packaging/pull/1009) - Update containerd to [v1.7.15](https://togithub.com/containerd/containerd/releases/tag/v1.7.15) (static binaries only) [moby/moby#47692](https://togithub.com/moby/moby/pull/47692) </details> --- ### Configuration 📅 **Schedule**: Branch creation - "after 6am on monday" (UTC), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Enabled. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box --- This PR has been generated by [Mend Renovate](https://www.mend.io/free-developer-tools/renovate/). View repository job log [here](https://developer.mend.io/github/earthly/dind). <!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzNy4yOTMuMCIsInVwZGF0ZWRJblZlciI6IjM3LjI5My4wIiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6WyJyZW5vdmF0ZSJdfQ==--> Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
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- What I did
The internal DNS resolver should only forward requests to external resolvers if the libnetwork.Sandbox served by the resolver has external network access (so, no forwarding for '--internal' networks).
The test for external network access was whether the Sandbox had an Endpoint with a gateway configured.
However, an ipvlan-l3 networks with external network access does not have a gateway, it has a default route bound to an interface.
Also, we document that an ipvlan/macvlan network with no parent interface is equivalent to a '--internal' network. But, in these cases, endpoints were still configured with a gateway (or a default route). So, DNS proxying would be enabled in the internal resolver (and, if the host's resolver was on a localhost address, requests to external resolvers from the host's network namespace would succeed).
Also also, CI hasn't been running most of the ipvlan tests becuase a check that the kernel supports ipvlan has been failing. However, without that check, tests pass (locally, and on the CI test runners). I want the new ipvlan/dns tests to run in CI, and it'd be weird to run only those and not the existing tests. So, removed the kernel-check.
- How I did it
Adjusted the test for enabling DNS proxying to include a check for '--internal' (as a shortcut) and, for non-internal networks, check for a default route as well as a gateway.
Disable configuration of a gateway or a default route for an ipvlan/macvlan Endpoint when no parent interface is specified. (Note that if a parent interface with no external network is supplied as '-o parent=', the gateway/default route will still be set up and external DNS proxying will be enabled. The network must be configured as '--internal' to prevent that from happening.)
Revert the changes from #39358 ... run ipvlan tests without a kernel-check (but not in rootless mode).
- How to verify it
New macvlan/ipvlan integration tests.
- Description for the changelog