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>

4 files changed, 115 insertions, 24 deletions

diff --git a/pkg/adapter/client.go b/pkg/adapter/client.go
index 01914834f..69aa3220a 100644
--- a/pkg/adapter/client.go
+++ b/pkg/adapter/client.go
@@ -6,42 +6,52 @@ import (
 	"fmt"
 	"os"
 
+	"github.com/containers/libpod/cmd/podman/remoteclientconfig"
 	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 	"github.com/varlink/go/varlink"
 )
 
 var remoteEndpoint *Endpoint
 
 func (r RemoteRuntime) RemoteEndpoint() (remoteEndpoint *Endpoint, err error) {
-	if remoteEndpoint == nil {
-		remoteEndpoint = &Endpoint{Unknown, ""}
-	} else {
-		return remoteEndpoint, nil
-	}
+	remoteConfigConnections, _ := remoteclientconfig.ReadRemoteConfig(r.config)
 
-	// I'm leaving this here for now as a document of the birdge format.  It can be removed later once the bridge
-	// function is more flushed out.
-	// bridge := `ssh -T root@192.168.122.1 "/usr/bin/varlink -A '/usr/bin/podman varlink \$VARLINK_ADDRESS' bridge"`
-	if len(r.cmd.RemoteHost) > 0 {
-		// The user has provided a remote host endpoint
+	// If the user defines an env variable for podman_varlink_bridge
+	// we use that as passed.
+	if bridge := os.Getenv("PODMAN_VARLINK_BRIDGE"); bridge != "" {
+		logrus.Debug("creating a varlink bridge based on env variable")
+		remoteEndpoint, err = newBridgeConnection(bridge, nil, r.cmd.LogLevel)
+		// if an environment variable for podman_varlink_address is defined,
+		// we used that as passed
+	} else if address := os.Getenv("PODMAN_VARLINK_ADDRESS"); address != "" {
+		logrus.Debug("creating a varlink address based on env variable: %s", address)
+		remoteEndpoint, err = newSocketConnection(address)
+		//	if the user provides a remote host, we use it to configure a bridge connection
+	} else if len(r.cmd.RemoteHost) > 0 {
+		logrus.Debug("creating a varlink bridge based on user input")
 		if len(r.cmd.RemoteUserName) < 1 {
 			return nil, errors.New("you must provide a username when providing a remote host name")
 		}
-		remoteEndpoint.Type = BridgeConnection
-		remoteEndpoint.Connection = fmt.Sprintf(
-			`ssh -T %s@%s /usr/bin/varlink -A \'/usr/bin/podman --log-level=%s varlink \\\$VARLINK_ADDRESS\' bridge`,
-			r.cmd.RemoteUserName, r.cmd.RemoteHost, r.cmd.LogLevel)
-
-	} else if bridge := os.Getenv("PODMAN_VARLINK_BRIDGE"); bridge != "" {
-		remoteEndpoint.Type = BridgeConnection
-		remoteEndpoint.Connection = bridge
-	} else {
-		address := os.Getenv("PODMAN_VARLINK_ADDRESS")
-		if address == "" {
-			address = DefaultAddress
+		rc := remoteclientconfig.RemoteConnection{r.cmd.RemoteHost, r.cmd.RemoteUserName, false}
+		remoteEndpoint, err = newBridgeConnection("", &rc, r.cmd.LogLevel)
+		//  if the user has a config file with connections in it
+	} else if len(remoteConfigConnections.Connections) > 0 {
+		logrus.Debug("creating a varlink bridge based configuration file")
+		var rc *remoteclientconfig.RemoteConnection
+		if len(r.cmd.ConnectionName) > 0 {
+			rc, err = remoteConfigConnections.GetRemoteConnection(r.cmd.ConnectionName)
+		} else {
+			rc, err = remoteConfigConnections.GetDefault()
+		}
+		if err != nil {
+			return nil, err
 		}
-		remoteEndpoint.Type = DirectConnection
-		remoteEndpoint.Connection = address
+		remoteEndpoint, err = newBridgeConnection("", rc, r.cmd.LogLevel)
+		//	last resort is to make a socket connection with the default varlink address for root user
+	} else {
+		logrus.Debug("creating a varlink address based default root address")
+		remoteEndpoint, err = newSocketConnection(DefaultAddress)
 	}
 	return
 }
@@ -72,3 +82,12 @@ func (r RemoteRuntime) RefreshConnection() error {
 	r.Conn = newConn
 	return nil
 }
+
+// newSocketConnection returns an endpoint for a uds based connection
+func newSocketConnection(address string) (*Endpoint, error) {
+	endpoint := Endpoint{
+		Type:       DirectConnection,
+		Connection: address,
+	}
+	return &endpoint, nil
+}
diff --git a/pkg/adapter/client_unix.go b/pkg/adapter/client_unix.go
new file mode 100644
index 000000000..e0406567c
--- /dev/null
+++ b/pkg/adapter/client_unix.go
@@ -0,0 +1,30 @@
+// +build linux darwin
+// +build remoteclient
+
+package adapter
+
+import (
+	"fmt"
+
+	"github.com/containers/libpod/cmd/podman/remoteclientconfig"
+	"github.com/pkg/errors"
+)
+
+// newBridgeConnection creates a bridge type endpoint with username, destination, and log-level
+func newBridgeConnection(formattedBridge string, remoteConn *remoteclientconfig.RemoteConnection, logLevel string) (*Endpoint, error) {
+	endpoint := Endpoint{
+		Type: BridgeConnection,
+	}
+
+	if len(formattedBridge) < 1 && remoteConn == nil {
+		return nil, errors.New("bridge connections must either be created by string or remoteconnection")
+	}
+	if len(formattedBridge) > 0 {
+		endpoint.Connection = formattedBridge
+		return &endpoint, nil
+	}
+	endpoint.Connection = fmt.Sprintf(
+		`ssh -T %s@%s -- /usr/bin/varlink -A \'/usr/bin/podman --log-level=%s varlink \\\$VARLINK_ADDRESS\' bridge`,
+		remoteConn.Username, remoteConn.Destination, logLevel)
+	return &endpoint, nil
+}
diff --git a/pkg/adapter/client_windows.go b/pkg/adapter/client_windows.go
new file mode 100644
index 000000000..088550667
--- /dev/null
+++ b/pkg/adapter/client_windows.go
@@ -0,0 +1,15 @@
+// +build remoteclient
+
+package adapter
+
+import (
+	"github.com/containers/libpod/cmd/podman/remoteclientconfig"
+	"github.com/containers/libpod/libpod"
+)
+
+func newBridgeConnection(formattedBridge string, remoteConn *remoteclientconfig.RemoteConnection, logLevel string) (*Endpoint, error) {
+	// TODO
+	// Unix and Windows appear to quote their ssh implementations differently therefore once we figure out what
+	// windows ssh is doing here, we can then get the format correct.
+	return nil, libpod.ErrNotImplemented
+}
diff --git a/pkg/adapter/runtime_remote.go b/pkg/adapter/runtime_remote.go
index e0c0898bd..a1d358f68 100644
--- a/pkg/adapter/runtime_remote.go
+++ b/pkg/adapter/runtime_remote.go
@@ -20,6 +20,7 @@ import (
 	"github.com/containers/image/docker/reference"
 	"github.com/containers/image/types"
 	"github.com/containers/libpod/cmd/podman/cliconfig"
+	"github.com/containers/libpod/cmd/podman/remoteclientconfig"
 	"github.com/containers/libpod/cmd/podman/varlink"
 	"github.com/containers/libpod/libpod"
 	"github.com/containers/libpod/libpod/events"
@@ -40,6 +41,7 @@ type RemoteRuntime struct {
 	Conn   *varlink.Connection
 	Remote bool
 	cmd    cliconfig.MainFlags
+	config io.Reader
 }
 
 // LocalRuntime describes a typical libpod runtime
@@ -49,10 +51,35 @@ type LocalRuntime struct {
 
 // GetRuntime returns a LocalRuntime struct with the actual runtime embedded in it
 func GetRuntime(ctx context.Context, c *cliconfig.PodmanCommand) (*LocalRuntime, error) {
+	var (
+		customConfig bool
+		err          error
+		f            *os.File
+	)
 	runtime := RemoteRuntime{
 		Remote: true,
 		cmd:    c.GlobalFlags,
 	}
+	configPath := remoteclientconfig.GetConfigFilePath()
+	if len(c.GlobalFlags.RemoteConfigFilePath) > 0 {
+		configPath = c.GlobalFlags.RemoteConfigFilePath
+		customConfig = true
+	}
+
+	f, err = os.Open(configPath)
+	if err != nil {
+		// If user does not explicitly provide a configuration file path and we cannot
+		// find a default, no error should occur.
+		if os.IsNotExist(err) && !customConfig {
+			logrus.Debugf("unable to load configuration file at %s", configPath)
+			runtime.config = nil
+		} else {
+			return nil, errors.Wrapf(err, "unable to load configuration file at %s", configPath)
+		}
+	} else {
+		// create the io reader for the remote client
+		runtime.config = bufio.NewReader(f)
+	}
 	conn, err := runtime.Connect()
 	if err != nil {
 		return nil, err