[Example] Multi-threaded programming example

ityuhui · ityuhui · commit 91b5f8aff8c5 · 2020-11-29T10:55:11.000+08:00
diff --git a/README.md b/README.md
@@ -125,6 +125,15 @@ list all pods in cluster:
     apiClient_unsetupGlobalEnv();
 ```
 
+## Multi-threaded Usage
+
+If the C client library is used in multi-threaded program, the following 2 actions must be taken:
+
+1. After the program starts up, main thread must call the function ```apiClient_setupGlobalEnv()``` before any worker thread is created.
+
+2. If the C client is no longer used, main thread must call the function ```apiClient_unsetupGlobalEnv()``` after all worker threads end.
+
+Refer to the [example](https://github.com/kubernetes-client/c/tree/master/examples/multi_thread/) for detail. 
 
 ## Community, discussion, contribution, and support
 
diff --git a/examples/Makefile b/examples/Makefile
@@ -7,6 +7,7 @@ all:
 	cd generic; make
 	cd auth_provider; make
 	cd watch_list_pod; make
+	cd multi_thread; make
 
 clean:
 	cd create_pod; make clean
@@ -17,3 +18,4 @@ clean:
 	cd generic; make clean
 	cd auth_provider; make clean
 	cd watch_list_pod; make clean
+	cd multi_thread; make clean
diff --git a/examples/auth_provider/Makefile b/examples/auth_provider/Makefile
@@ -1,5 +1,5 @@
 INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api -I../../kubernetes/config
-LIBS:=-L../../kubernetes/build -lkubernetes -lcurl -lyaml -lpthread -lssl -lz
+LIBS:=-L../../kubernetes/build -lkubernetes -lyaml
 CFLAGS:=-g
 
 all:
diff --git a/examples/create_pod/Makefile b/examples/create_pod/Makefile
@@ -1,5 +1,5 @@
 INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api -I../../kubernetes/config
-LIBS:=-L../../kubernetes/build -lkubernetes -lcurl -lyaml -lpthread -lssl -lz
+LIBS:=-L../../kubernetes/build -lkubernetes -lyaml
 CFLAGS:=-g
 
 all:
diff --git a/examples/delete_pod/Makefile b/examples/delete_pod/Makefile
@@ -1,5 +1,5 @@
 INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api -I../../kubernetes/config
-LIBS:=-L../../kubernetes/build -lkubernetes -lcurl -lyaml -lpthread -lssl -lz
+LIBS:=-L../../kubernetes/build -lkubernetes -lyaml
 CFLAGS:=-g
 BIN:=delete_pod_bin
 
diff --git a/examples/exec_provider/Makefile b/examples/exec_provider/Makefile
@@ -1,5 +1,5 @@
 INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api -I../../kubernetes/config
-LIBS:=-L../../kubernetes/build -lkubernetes -lcurl -lyaml -lpthread -lssl -lz
+LIBS:=-L../../kubernetes/build -lkubernetes -lyaml
 CFLAGS:=-g
 
 all: my_exec_provider_bin list_pod_by_exec_provider_bin
diff --git a/examples/generic/Makefile b/examples/generic/Makefile
@@ -1,5 +1,5 @@
 INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api -I../../kubernetes/config
-LIBS:=-L../../kubernetes/build -lkubernetes -lcurl -lyaml -lpthread -lssl -lz
+LIBS:=-L../../kubernetes/build -lkubernetes -lyaml
 CFLAGS:=-g
 
 all:
diff --git a/examples/list_pod/Makefile b/examples/list_pod/Makefile
@@ -1,5 +1,5 @@
 INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api -I../../kubernetes/config
-LIBS:=-L../../kubernetes/build -lkubernetes -lcurl -lyaml -lpthread -lssl -lz
+LIBS:=-L../../kubernetes/build -lkubernetes -lyaml
 CFLAGS:=-g
 
 all:
diff --git a/examples/list_pod_incluster/Makefile b/examples/list_pod_incluster/Makefile
@@ -1,5 +1,5 @@
 INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api -I../../kubernetes/config
-LIBS:=-L../../kubernetes/build -lkubernetes -lcurl -lyaml -lpthread -lssl -lz
+LIBS:=-L../../kubernetes/build -lkubernetes -lyaml
 CFLAGS:=-g
 
 all:
diff --git a/examples/multi_thread/.gitignore b/examples/multi_thread/.gitignore
@@ -0,0 +1 @@
+multi_thread_bin
diff --git a/examples/multi_thread/Makefile b/examples/multi_thread/Makefile
@@ -0,0 +1,16 @@
+INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api -I../../kubernetes/config -I../../kubernetes/watch
+LIBS:=-L../../kubernetes/build -lkubernetes -lyaml -lpthread
+CFLAGS:=-g
+
+BIN:= multi_thread_bin
+OBJECTS:=main.o watch_pod.o create_pod.o
+
+all: $(OBJECTS)
+	$(CC) -o $(BIN) $(OBJECTS) $(LIBS)
+
+$(OBJECTS): %.o: %.c
+	$(CC) $(CFLAGS) $(INCLUDE) -c $< -o $@
+
+.PHONY : clean
+clean:
+	rm $(BIN) $(OBJECTS)
diff --git a/examples/multi_thread/create_pod.c b/examples/multi_thread/create_pod.c
@@ -0,0 +1,83 @@
+#include "mt.h"
+
+static void create_a_pod(apiClient_t * apiClient)
+{
+    char *namespace = "default";
+
+    v1_pod_t *podinfo = calloc(1, sizeof(v1_pod_t));
+    podinfo->api_version = strdup("v1");
+    podinfo->kind = strdup("Pod");
+    podinfo->spec = calloc(1, sizeof(v1_pod_spec_t));
+
+    podinfo->metadata = calloc(1, sizeof(v1_object_meta_t));
+    /* set pod name */
+    podinfo->metadata->name = strdup("test-pod-8");
+
+    /* set containers for pod */
+    list_t *containerlist = list_create();
+    v1_container_t *con = calloc(1, sizeof(v1_container_t));
+    con->name = strdup("my-container");
+    con->image = strdup("ubuntu:latest");
+    con->image_pull_policy = strdup("IfNotPresent");
+
+    /* set command for container */
+    list_t *commandlist = list_create();
+    char *cmd = strdup("sleep");
+    list_addElement(commandlist, cmd);
+    con->command = commandlist;
+
+    list_t *arglist = list_create();
+    char *arg1 = strdup("3600");
+    list_addElement(arglist, arg1);
+    con->args = arglist;
+
+    /* set volume mounts for container  */
+    list_t *volumemounts = list_create();
+    v1_volume_mount_t *volmou = calloc(1, sizeof(v1_volume_mount_t));
+    volmou->mount_path = strdup("/test");
+    volmou->name = strdup("test");
+    list_addElement(volumemounts, volmou);
+    con->volume_mounts = volumemounts;
+
+    list_addElement(containerlist, con);
+    podinfo->spec->containers = containerlist;
+
+    /* set volumes for pod */
+    list_t *volumelist = list_create();
+    v1_volume_t *volume = calloc(1, sizeof(v1_volume_t));
+    volume->name = strdup("test");
+
+    v1_host_path_volume_source_t *hostPath = calloc(1, sizeof(v1_host_path_volume_source_t));
+    hostPath->path = strdup("/test");
+    volume->host_path = hostPath;
+
+    list_addElement(volumelist, volume);
+    podinfo->spec->volumes = volumelist;
+
+    /* call API in libkubernetes to create pod */
+    v1_pod_t *apod = CoreV1API_createNamespacedPod(apiClient, namespace, podinfo, NULL, NULL, NULL);
+    printf("code=%ld\n", apiClient->response_code);
+
+    v1_pod_free(apod);
+    v1_pod_free(podinfo);
+}
+
+void *create_pod_thread_func(void *arg)
+{
+    kube_params_t *params = (kube_params_t *) arg;
+
+    sleep(10);                  // wait watch_pod_thread to start for 10 seconds 
+
+    apiClient_t *apiClient = apiClient_create_with_base_path(params->basePath, params->sslConfig, params->apiKeys);
+    if (!apiClient) {
+        fprintf(stderr, "Cannot create a kubernetes client.\n");
+        return ((void *) 1);
+    }
+
+    create_a_pod(apiClient);
+
+    apiClient_free(apiClient);
+    apiClient = NULL;
+
+    pthread_exit(NULL);
+}
diff --git a/examples/multi_thread/main.c b/examples/multi_thread/main.c
@@ -0,0 +1,55 @@
+#include <kube_config.h>
+#include "mt.h"
+
+bool g_exit_watch = false;
+pthread_mutex_t exit_watch_mutex;
+
+int main(int argc, char *argv[])
+{
+    char *basePath = NULL;
+    sslConfig_t *sslConfig = NULL;
+    list_t *apiKeys = NULL;
+    int rc = load_kube_config(&basePath, &sslConfig, &apiKeys, NULL);   /* NULL means loading configuration from $HOME/.kube/config */
+    if (rc != 0) {
+        printf("Cannot load kubernetes configuration.\n");
+        return -1;
+    }
+    kube_params_t *params = calloc(1, sizeof(kube_params_t));
+    params->basePath = basePath;
+    params->sslConfig = sslConfig;
+    params->apiKeys = apiKeys;
+    apiClient_setupGlobalEnv();
+
+    pthread_t watch_pod_thread;
+    int err = pthread_create(&watch_pod_thread, NULL, watch_pod_thread_func, (void *) params);
+    if (0 != err) {
+        perror("creating thread error");
+        exit(-1);
+    }
+
+    pthread_t create_pod_thread;
+    err = pthread_create(&create_pod_thread, NULL, create_pod_thread_func, (void *) params);
+    if (0 != err) {
+        perror("creating thread error");
+        exit(-1);
+    }
+
+    sleep(30);
+
+    pthread_mutex_lock(&exit_watch_mutex);
+    g_exit_watch = true;        // notify watch thread to exit
+    pthread_mutex_unlock(&exit_watch_mutex);
+
+    pthread_join(watch_pod_thread, NULL);
+    pthread_join(create_pod_thread, NULL);
+
+    free_client_config(basePath, sslConfig, apiKeys);
+    basePath = NULL;
+    sslConfig = NULL;
+    apiKeys = NULL;
+    free(params);
+    params = NULL;
+    apiClient_unsetupGlobalEnv();
+
+    return 0;
+}
diff --git a/examples/multi_thread/mt.h b/examples/multi_thread/mt.h
@@ -0,0 +1,33 @@
+#ifndef __MT_H__
+#define __MT_H__
+
+#include "../include/apiClient.h"
+
+#ifdef  __cplusplus
+extern "C" {
+#endif
+
+#include <malloc.h>
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <apiClient.h>
+#include <CoreV1API.h>
+
+typedef struct kube_params_t {
+    char *basePath;
+    sslConfig_t *sslConfig;
+    list_t *apiKeys;
+} kube_params_t;
+
+extern void *watch_pod_thread_func(void *);
+extern void *create_pod_thread_func(void *);
+
+extern bool g_exit_watch;
+extern pthread_mutex_t exit_watch_mutex;
+
+#ifdef  __cplusplus
+}
+#endif
+#endif                          // __MT_H__
diff --git a/examples/multi_thread/watch_pod.c b/examples/multi_thread/watch_pod.c
@@ -0,0 +1,109 @@
+#include "mt.h"
+#include <watch_util.h>
+
+#define WATCH_EVENT_KEY_TYPE "type"
+#define WATCH_EVENT_KEY_OBJECT "object"
+
+static void on_pod_event_comes(const char *event_string)
+{
+    static char fname[] = "process_one_watch_event()";
+
+    if (!event_string) {
+        return;
+    }
+
+    cJSON *event_json_obj = cJSON_Parse(event_string);
+    if (!event_json_obj) {
+        fprintf(stderr, "%s: Cannot create JSON from string.[%s].\n", fname, cJSON_GetErrorPtr());
+        goto end;
+    }
+
+    cJSON *json_value_type = cJSON_GetObjectItem(event_json_obj, WATCH_EVENT_KEY_TYPE);
+    if (!json_value_type || json_value_type->type != cJSON_String) {
+        fprintf(stderr, "%s: Cannot get type in watch event.\n", fname);
+        goto end;
+    }
+    char *type = strdup(json_value_type->valuestring);
+    printf("type: %s\n", type);
+
+    cJSON *json_value_object = cJSON_GetObjectItem(event_json_obj, WATCH_EVENT_KEY_OBJECT);
+    if (!json_value_object || json_value_object->type != cJSON_Object) {
+        fprintf(stderr, "%s: Cannot get object in watch event.\n", fname);
+        goto end;
+    }
+    v1_pod_t *pod = v1_pod_parseFromJSON(json_value_object);
+    if (!pod) {
+        fprintf(stderr, "%s: Cannot get pod from watch event object.\n", fname);
+        goto end;
+    }
+    printf("pod:\n\tname: %s\n", pod->metadata->name);
+
+  end:
+    if (pod) {
+        v1_pod_free(pod);
+        pod = NULL;
+    }
+    if (type) {
+        free(type);
+        type = NULL;
+    }
+    if (event_json_obj) {
+        cJSON_Delete(event_json_obj);
+        event_json_obj = NULL;
+    }
+}
+
+static void my_pod_watch_handler(void **pData, long *pDataLen)
+{
+    kubernets_watch_handler(pData, pDataLen, on_pod_event_comes);
+}
+
+static int my_watch_progress_func(void *clientp, curl_off_t dltotal, curl_off_t dlnow, curl_off_t ultotal, curl_off_t ulnow)
+{
+    bool exit_watch = false;
+
+    pthread_mutex_lock(&exit_watch_mutex);
+    exit_watch = g_exit_watch;
+    pthread_mutex_unlock(&exit_watch_mutex);
+
+    if (true == exit_watch) {
+        /* Returning any other non-zero value from this callback will cause libcurl to 
+         * abort the transfer and return CURLE_ABORTED_BY_CALLBACK.
+         */
+        return 1;
+    }
+
+    return 0;
+}
+
+void *watch_pod_thread_func(void *arg)
+{
+    kube_params_t *params = (kube_params_t *) arg;
+    apiClient_t *apiClient = apiClient_create_with_base_path(params->basePath, params->sslConfig, params->apiKeys);
+    if (!apiClient) {
+        fprintf(stderr, "Cannot create a kubernetes client.\n");
+        return ((void *) 1);
+    }
+
+    apiClient->data_callback_func = my_pod_watch_handler;
+    apiClient->progress_func = my_watch_progress_func;
+
+    CoreV1API_listNamespacedPod(apiClient, "default",   /*namespace */
+                                NULL,   /* pretty */
+                                0,  /* allowWatchBookmarks */
+                                NULL,   /* continue */
+                                NULL,   /* fieldSelector */
+                                NULL,   /* labelSelector */
+                                0,  /* limit */
+                                NULL,   /* resourceVersion */
+                                0,  /* timeoutSeconds
+                                       Setting the value to 0 means the watch never stops.
+                                     */
+                                1   /* watch */
+        );
+
+    apiClient_free(apiClient);
+    apiClient = NULL;
+
+    pthread_exit(NULL);
+}
diff --git a/examples/watch_list_pod/Makefile b/examples/watch_list_pod/Makefile
@@ -1,5 +1,5 @@
 INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api -I../../kubernetes/config -I../../kubernetes/watch
-LIBS:=-L../../kubernetes/build -lkubernetes -lcurl -lyaml -lpthread -lssl -lz
+LIBS:=-L../../kubernetes/build -lkubernetes -lyaml
 CFLAGS:=-g
 
 all:
diff --git a/kubernetes/include/apiClient.h b/kubernetes/include/apiClient.h
diff --git a/kubernetes/src/apiClient.c b/kubernetes/src/apiClient.c
diff --git a/kubernetes/watch/watch_util.c b/kubernetes/watch/watch_util.c
