podman-remote.conf enablement

add the ability for the podman remote client to use a configuration file
which describes its connections. users can now define a connection the
configuration and then call it by name like:

podman-remote -c connection1

and the destination and user will be derived from the configuration
file.  if no -c is provided, we look for a connection in the
configuration file designated as 'default'.  If the configuration file
has only one connection, it will be deemed the 'default'.

Signed-off-by: baude <bbaude@redhat.com>

1 files changed, 62 insertions, 0 deletions

diff --git a/cmd/podman/remoteclientconfig/configfile.go b/cmd/podman/remoteclientconfig/configfile.go
new file mode 100644
index 000000000..aa3e82a31
--- /dev/null
+++ b/cmd/podman/remoteclientconfig/configfile.go
@@ -0,0 +1,62 @@
+package remoteclientconfig
+
+import (
+	"io"
+
+	"github.com/BurntSushi/toml"
+	"github.com/pkg/errors"
+)
+
+// ReadRemoteConfig takes an io.Reader representing the remote configuration
+// file and returns a remoteconfig
+func ReadRemoteConfig(reader io.Reader) (*RemoteConfig, error) {
+	var remoteConfig RemoteConfig
+	// the configuration file does not exist
+	if reader == nil {
+		return &remoteConfig, ErrNoConfigationFile
+	}
+	_, err := toml.DecodeReader(reader, &remoteConfig)
+	if err != nil {
+		return nil, err
+	}
+	// We need to validate each remote connection has fields filled out
+	for name, conn := range remoteConfig.Connections {
+		if len(conn.Destination) < 1 {
+			return nil, errors.Errorf("connection %s has no destination defined", name)
+		}
+	}
+	return &remoteConfig, err
+}
+
+// GetDefault returns the default RemoteConnection. If there is only one
+// connection, we assume it is the default as well
+func (r *RemoteConfig) GetDefault() (*RemoteConnection, error) {
+	if len(r.Connections) == 0 {
+		return nil, ErrNoDefinedConnections
+	}
+	for _, v := range r.Connections {
+		if len(r.Connections) == 1 {
+			// if there is only one defined connection, we assume it is
+			// the default whether tagged as such or not
+			return &v, nil
+		}
+		if v.IsDefault {
+			return &v, nil
+		}
+	}
+	return nil, ErrNoDefaultConnection
+}
+
+// GetRemoteConnection "looks up" a remote connection by name and returns it in the
+// form of a RemoteConnection
+func (r *RemoteConfig) GetRemoteConnection(name string) (*RemoteConnection, error) {
+	if len(r.Connections) == 0 {
+		return nil, ErrNoDefinedConnections
+	}
+	for k, v := range r.Connections {
+		if k == name {
+			return &v, nil
+		}
+	}
+	return nil, errors.Wrap(ErrConnectionNotFound, name)
+}