Implement curl KeepAlive for watch connections

examples/watch_list_pod/main.c

@@ -75,6 +75,7 @@ void watch_list_pod(apiClient_t * apiClient)
     int watch = 1;
     int timeoutSeconds = 30;    /* Watch for 30 seconds */
     // int timeoutSeconds = 0;  /* Set timeoutSeconds to 0 to keep watching and not exit */
+    // apiClient->curlConfig->keepalive = 1; /* Enable keepalive */
     CoreV1API_listNamespacedPod(apiClient, "default",   /*namespace */
                                 NULL,   /* pretty */
                                 NULL,   /* allowWatchBookmarks */

kubernetes/include/apiClient.h

@@ -19,9 +19,19 @@ typedef struct sslConfig_t {
                                   /* 1 -- skip ssl verify for server certificate */
 } sslConfig_t;
 
+typedef struct curl_config_t {
+    int keepalive;  /* 0 -- disable keepalive */
+                    /* 1 -- enable keepalive */
+    long keepidle;  /* keep-alive idle time: default to 120 seconds */
+    long keepintvl; /* interval time between keep-alive probes: default to 60 seconds */
+} curl_config_t;
+
+bool isWatchCall(list_t *queryParameters);
+
 typedef struct apiClient_t {
     char *basePath;
     sslConfig_t *sslConfig;
+    curl_config_t *curlConfig;
     void *dataReceived;
     long dataReceivedLen;
     void (*data_callback_func)(void **, long *);

kubernetes/src/apiClient.c

@@ -6,10 +6,25 @@
 
 size_t writeDataCallback(void *buffer, size_t size, size_t nmemb, void *userp);
 
+bool isWatchCall(list_t * queryParameters)
+{
+    bool found = false;
+    listEntry_t *listEntry = NULL;
+    list_ForEach(listEntry, queryParameters) {
+        keyValuePair_t *pair = listEntry->data;
+        if (strcmp(pair->key, "watch") == 0) {
+            found = (strcmp(pair->key, "1") == 0);   
+            break;
+        }
+    }
+    return found;
+}
+
 apiClient_t *apiClient_create() {
     apiClient_t *apiClient = malloc(sizeof(apiClient_t));
     apiClient->basePath = strdup("http://localhost");
     apiClient->sslConfig = NULL;
+    apiClient->curlConfig = NULL;
     apiClient->dataReceived = NULL;
     apiClient->dataReceivedLen = 0;
     apiClient->data_callback_func = NULL;
@@ -38,6 +53,11 @@ apiClient_t *apiClient_create_with_base_path(const char *basePath
         apiClient->sslConfig = NULL;
     }
 
+    apiClient->curlConfig = malloc(sizeof(curl_config_t));
+    apiClient->curlConfig->keepalive = 0; // default value, it can be set to 1 to enable keepalive by user
+    apiClient->curlConfig->keepidle = 120; // default value
+    apiClient->curlConfig->keepintvl = 60; // default value
+
     apiClient->dataReceived = NULL;
     apiClient->dataReceivedLen = 0;
     apiClient->data_callback_func = NULL;
@@ -80,6 +100,10 @@ void apiClient_free(apiClient_t *apiClient) {
         }
         list_freeList(apiClient->apiKeys_BearerToken);
     }
+    if(apiClient->curlConfig) {
+        free(apiClient->curlConfig);
+        apiClient->curlConfig = NULL;
+    }
     free(apiClient);
 }
 
@@ -407,6 +431,14 @@ void apiClient_invoke(apiClient_t    *apiClient,
             assembleTargetUrl(apiClient->basePath,
                               operationParameter,
                               queryParameters);
+
+        if(apiClient->curlConfig->keepalive == 1 && isWatchCall(queryParameters)) {
+            curl_easy_setopt(handle, CURLOPT_TCP_KEEPALIVE, 1L);
+            curl_easy_setopt(handle, CURLOPT_TCP_KEEPIDLE, apiClient->curlConfig->keepidle);
+            curl_easy_setopt(handle, CURLOPT_TCP_KEEPINTVL, apiClient->curlConfig->keepintvl);
+            // curl_easy_setopt(handle, CURLOPT_TCP_KEEPCNT, apiClient->curlConfig->keepcnt);
+        }
+
 
         curl_easy_setopt(handle, CURLOPT_URL, targetUrl);
         curl_easy_setopt(handle,