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>

2 files changed, 5 insertions, 6 deletions

diff --git a/libpod/define/container_inspect.go b/libpod/define/container_inspect.go
index 38b3a6686..775965477 100644
--- a/libpod/define/container_inspect.go
+++ b/libpod/define/container_inspect.go
@@ -575,6 +575,8 @@ type InspectAdditionalNetwork struct {
 	// Links is presently unused and maintained exclusively for
 	// compatibility.
 	Links []string `json:"Links"`
+	// Aliases are any network aliases the container has in this network.
+	Aliases []string `json:"Aliases,omitempty"`
 }
 
 // InspectNetworkSettings holds information about the network settings of the
diff --git a/libpod/define/errors.go b/libpod/define/errors.go
index 27c5febf4..471827b7c 100644
--- a/libpod/define/errors.go
+++ b/libpod/define/errors.go
@@ -33,9 +33,6 @@ var (
 	// ErrNoAliases indicates that the container does not have any network
 	// aliases.
 	ErrNoAliases = errors.New("no aliases for container")
-	// ErrNoAliasesForNetwork indicates that the container has no aliases
-	// for a specific network.
-	ErrNoAliasesForNetwork = errors.New("no aliases for network")
 
 	// ErrCtrExists indicates a container with the same name or ID already
 	// exists
@@ -49,9 +46,9 @@ var (
 	// ErrExecSessionExists indicates an exec session with the same ID
 	// already exists.
 	ErrExecSessionExists = errors.New("exec session already exists")
-	// ErrAliasExists indicates that a network alias with the same name
-	// already exists in the network.
-	ErrAliasExists = errors.New("alias already exists")
+	// ErrNetworkExists indicates that a network with the given name already
+	// exists.
+	ErrNetworkExists = errors.New("network already exists")
 
 	// ErrCtrStateInvalid indicates a container is in an improper state for
 	// the requested operation