containerd: add cni-networking configuration

When running a containerd-only stack, we need a CNI configuration
to be available.

When running containerd as part of something like K3S, we expect
the orchestration package will provide that configuration.

This commit makes a containerd-cni package available that contains
a starting point configuration.

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

recipes-containers/containerd/containerd/cni-containerd-net.conf

@@ -0,0 +1,24 @@
+{
+  "cniVersion": "0.4.0",
+  "name": "containerd-net",
+  "plugins": [
+    {
+      "type": "bridge",
+      "bridge": "cni0",
+      "isGateway": true,
+      "ipMasq": true,
+      "promiscMode": true,
+      "ipam": {
+        "type": "host-local",
+        "subnet": "10.88.0.0/16",
+        "routes": [
+          { "dst": "0.0.0.0/0" }
+        ]
+      }
+    },
+    {
+      "type": "portmap",
+      "capabilities": {"portMappings": true}
+    }
+  ]
+}

recipes-containers/containerd/containerd_git.bb

@@ -9,6 +9,7 @@ SRCREV = "19430264c19b8bd9f940101ec71d52ab2d2e54d5"
 SRC_URI = "git://github.com/containerd/containerd;branch=main;protocol=https;destsuffix=git/src/github.com/containerd/containerd/v2 \
            file://0001-Makefile-allow-GO_BUILD_FLAGS-to-be-externally-speci.patch \
            file://0001-build-don-t-use-gcflags-to-define-trimpath.patch \
+           file://cni-containerd-net.conf \
           "
 
 # Apache-2.0 for containerd
@@ -98,3 +99,7 @@ COMPATIBLE_HOST = "^(?!(qemu)?mips).*"
 
 RDEPENDS:${PN} += " ${VIRTUAL-RUNTIME_container_runtime}"
 
+## This may need to be made conditional on K3S or similar being
+## configured in the distro, since we may have collisions.
+CNI_NETWORKING_FILES ?= "${UNPACKDIR}/cni-containerd-net.conf"
+inherit cni_networking