GUACAMOLE-623: Stub out implementation of WebSocket client for Kubernetes.

This commit is contained in:
Michael Jumper 2018-09-09 22:55:38 -07:00
parent 519c90a887
commit 7165fa949d
2 changed files with 178 additions and 5 deletions

View File

@ -24,6 +24,7 @@
#include <guacamole/client.h> #include <guacamole/client.h>
#include <guacamole/protocol.h> #include <guacamole/protocol.h>
#include <libwebsockets.h>
#include <errno.h> #include <errno.h>
#include <netdb.h> #include <netdb.h>
@ -36,6 +37,104 @@
#include <sys/time.h> #include <sys/time.h>
#include <unistd.h> #include <unistd.h>
/**
* The name of the WebSocket protocol specific to Kubernetes which should be
* sent to the Kubernetes server when attaching to a pod.
*/
#define GUAC_KUBERNETES_LWS_PROTOCOL "v4.channel.k8s.io"
/**
* Callback invoked by libwebsockets for events related to a WebSocket being
* used for communicating with an attached Kubernetes pod.
*
* @param wsi
* The libwebsockets handle for the WebSocket connection.
*
* @param reason
* The reason (event) that this callback was invoked.
*
* @param user
* Arbitrary data assocated with the WebSocket session. This will always
* be a pointer to the guac_client instance.
*
* @param in
* A pointer to arbitrary, reason-specific data.
*
* @param length
* An arbitrary, reason-specific length value.
*
* @return
* An undocumented integer value related the success of handling the
* event, or -1 if the WebSocket connection should be closed.
*/
static int guac_kubernetes_lws_callback(struct lws* wsi,
enum lws_callback_reasons reason, void* user,
void* in, size_t length) {
guac_client* client = (guac_client*) user;
/*guac_kubernetes_client* kubernetes_client =
(guac_kubernetes_client*) client->data;*/
/* Request connection closure if client is stopped */
if (client->state != GUAC_CLIENT_RUNNING)
return -1;
switch (reason) {
case LWS_CALLBACK_CLIENT_CONNECTION_ERROR:
guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_NOT_FOUND,
"Error connecting to Kubernetes server: %s",
in != NULL ? (char*) in : "(no error description "
"available)");
break;
/* Logged in */
case LWS_CALLBACK_CLIENT_ESTABLISHED:
guac_client_log(client, GUAC_LOG_INFO,
"Kubernetes connection successful.");
break;
case LWS_CALLBACK_CLIENT_RECEIVE:
guac_client_log(client, GUAC_LOG_DEBUG, "Received: %s",
(const char*) in);
break;
/* TODO: Only send data here. Request callback for writing via lws_callback_on_writable(some struct lws*) */
case LWS_CALLBACK_CLIENT_WRITEABLE:
break;
case LWS_CALLBACK_CLOSED:
/* TODO: case LWS_CALLBACK_CLIENT_CLOSED: <-- Needs test and #ifdef */
guac_client_stop(client);
guac_client_log(client, GUAC_LOG_DEBUG, "WebSocket connection to "
"Kubernetes server closed.");
break;
/* No other event types are applicable */
default:
guac_client_log(client, GUAC_LOG_DEBUG, "Unexpected libwebsockets "
"reason: %i", reason);
break;
}
return lws_callback_http_dummy(wsi, reason, user, in, length);
}
/**
* List of all WebSocket protocols which should be declared as supported by
* libwebsockets during the initial WebSocket handshake, along with
* corresponding event-handling callbacks.
*/
struct lws_protocols guac_kubernetes_lws_protocols[] = {
{
.name = GUAC_KUBERNETES_LWS_PROTOCOL,
.callback = guac_kubernetes_lws_callback
},
{ 0 }
};
/** /**
* Input thread, started by the main Kubernetes client thread. This thread * Input thread, started by the main Kubernetes client thread. This thread
* continuously reads from the terminal's STDIN and transfers all read * continuously reads from the terminal's STDIN and transfers all read
@ -111,11 +210,69 @@ void* guac_kubernetes_client_thread(void* data) {
settings->create_typescript_path); settings->create_typescript_path);
} }
/* TODO: Open WebSocket connection to Kubernetes */ /* Init libwebsockets context creation parameters */
struct lws_context_creation_info context_info = {
.port = CONTEXT_PORT_NO_LISTEN, /* We are not a WebSocket server */
.protocols = guac_kubernetes_lws_protocols
};
/* Logged in */ /* Init WebSocket connection parameters which do not vary by Guacmaole
guac_client_log(client, GUAC_LOG_INFO, * connection parameters or creation of future libwebsockets objects */
"Kubernetes connection successful."); struct lws_client_connect_info connection_info = {
.host = settings->hostname,
.address = settings->hostname,
.origin = settings->hostname,
.port = settings->port,
.protocol = GUAC_KUBERNETES_LWS_PROTOCOL,
.pwsi = &kubernetes_client->wsi,
.userdata = client
};
/* If requested, use an SSL/TLS connection for communication with
* Kubernetes */
if (settings->use_ssl) {
/* Enable use of SSL/TLS */
context_info.options = LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT;
connection_info.ssl_connection = LCCSCF_USE_SSL;
/* Bypass certificate checks if requested */
if (settings->ignore_cert) {
connection_info.ssl_connection |=
LCCSCF_ALLOW_SELFSIGNED
| LCCSCF_SKIP_SERVER_CERT_HOSTNAME_CHECK
| LCCSCF_ALLOW_EXPIRED;
}
/* Otherwise use the given CA certificate to validate (if any) */
else
context_info.client_ssl_ca_filepath = settings->ca_cert_file;
/* Certificate and key file for SSL/TLS client auth */
context_info.client_ssl_cert_filepath = settings->client_cert_file;
context_info.client_ssl_private_key_filepath = settings->client_key_file;
}
/* Create libwebsockets context */
struct lws_context* context = lws_create_context(&context_info);
if (!context) {
guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR,
"Initialization of libwebsockets failed");
return NULL;
}
/* FIXME: Generate path dynamically */
connection_info.context = context;
connection_info.path = "/api/v1/namespaces/default/pods/my-shell-68974bb7f7-rpjgr/attach?container=my-shell&stdin=true&stdout=true&tty=true";
/* Open WebSocket connection to Kubernetes */
kubernetes_client->wsi = lws_client_connect_via_info(&connection_info);
if (kubernetes_client->wsi == NULL) {
guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR,
"Connection via libwebsockets failed");
return NULL;
}
/* Start input thread */ /* Start input thread */
if (pthread_create(&(input_thread), NULL, guac_kubernetes_input_thread, (void*) client)) { if (pthread_create(&(input_thread), NULL, guac_kubernetes_input_thread, (void*) client)) {
@ -123,12 +280,22 @@ void* guac_kubernetes_client_thread(void* data) {
return NULL; return NULL;
} }
/* TODO: While data available, write to terminal */ /* As long as client is connected, continue polling libwebsockets */
while (client->state == GUAC_CLIENT_RUNNING) {
/* Cease polling libwebsockets if an error condition is signalled */
if (lws_service(context, 1000) < 0)
break;
}
/* Kill client and Wait for input thread to die */ /* Kill client and Wait for input thread to die */
guac_client_stop(client); guac_client_stop(client);
pthread_join(input_thread, NULL); pthread_join(input_thread, NULL);
/* All done with libwebsockets */
lws_context_destroy(context);
guac_client_log(client, GUAC_LOG_INFO, "Kubernetes connection ended."); guac_client_log(client, GUAC_LOG_INFO, "Kubernetes connection ended.");
return NULL; return NULL;

View File

@ -26,6 +26,7 @@
#include "settings.h" #include "settings.h"
#include "terminal/terminal.h" #include "terminal/terminal.h"
#include <libwebsockets.h>
#include <stdint.h> #include <stdint.h>
/** /**
@ -38,6 +39,11 @@ typedef struct guac_kubernetes_client {
*/ */
guac_kubernetes_settings* settings; guac_kubernetes_settings* settings;
/**
* The connected WebSocket.
*/
struct lws* wsi;
/** /**
* The Kubernetes client thread. * The Kubernetes client thread.
*/ */