Add support for network connect / disconnect to DB

Convert the existing network aliases set/remove code to network
connect and disconnect. We can no longer modify aliases for an
existing network, but we can add and remove entire networks. As
part of this, we need to add a new function to retrieve current
aliases the container is connected to (we had a table for this
as of the first aliases PR, but it was not externally exposed).

At the same time, remove all deconflicting logic for aliases.
Docker does absolutely no checks of this nature, and allows two
containers to have the same aliases, aliases that conflict with
container names, etc - it's just left to DNS to return all the
IP addresses, and presumably we round-robin from there? Most
tests for the existing code had to be removed because of this.

Convert all uses of the old container config.Networks field,
which previously included all networks in the container, to use
the new DB table. This ensures we actually get an up-to-date list
of in-use networks. Also, add network aliases to the output of
`podman inspect`.

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

1 files changed, 28 insertions, 0 deletions

diff --git a/libpod/container.go b/libpod/container.go
index ea5a6e09c..580fa7b3d 100644
--- a/libpod/container.go
+++ b/libpod/container.go
@@ -1085,3 +1085,31 @@ func (c *Container) Timezone() string {
 func (c *Container) Umask() string {
 	return c.config.Umask
 }
+
+// Networks gets all the networks this container is connected to.
+// Please do NOT use ctr.config.Networks, as this can be changed from those
+// values at runtime via network connect and disconnect.
+// If the container is configured to use CNI and this function returns an empty
+// array, the container will still be connected to the default network.
+func (c *Container) Networks() ([]string, error) {
+	if !c.batched {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return nil, err
+		}
+	}
+
+	return c.networks()
+}
+
+// Unlocked accessor for networks
+func (c *Container) networks() ([]string, error) {
+	networks, err := c.runtime.state.GetNetworks(c)
+	if err != nil && errors.Cause(err) == define.ErrNoSuchNetwork {
+		return c.config.Networks, nil
+	}
+
+	return networks, err
+}