Merge pull request #9 from ityuhui/yhkubeconfig

[Configuration]Support X509 client certificate in kube config file

code-check/code-static-check.sh

@@ -0,0 +1,5 @@
+# Usage: 
+# sh ./code-static-check.sh ${source_dir}
+
+cppcheck --enable=all $*
+

examples/create_pod/Makefile

@@ -1,5 +1,5 @@
-INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api
-LIBS:=-L../../kubernetes/build -lkubernetes -lcurl -lpthread -lssl -lz
+INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api -I../../kubernetes/config
+LIBS:=-L../../kubernetes/build -lkubernetes -lcurl -lyaml -lpthread -lssl -lz
 CFLAGS:=-g
 
 all:

examples/create_pod/main.c

@@ -1,22 +1,10 @@
+#include <kube_config.h>
 #include <apiClient.h>
 #include <CoreV1API.h>
 #include <malloc.h>
 #include <stdio.h>
 #include <errno.h>
 
-// kubectl proxy server
-#define K8S_APISERVER_BASEPATH "http://localhost:8001"
-
-// Alternately from within a Kubernetes cluster:
-// #define K8S_APISERVER_BASEPATH https://your.server.here
-
-#define K8S_TOKEN_FILE_IN_CLUSTER "/var/run/secrets/kubernetes.io/serviceaccount/token"
-#define K8S_TOKEN_BUF_SIZE 1024
-#define K8S_AUTH_KEY "Authorization"
-#define K8S_AUTH_VALUE_TEMPLATE "Bearer %s"
-
-apiClient_t *g_k8sAPIConnector;
-
 void create_a_pod(apiClient_t * apiClient)
 {
     char *namespace = "default";
@@ -54,57 +42,34 @@ void create_a_pod(apiClient_t * apiClient)
     v1_pod_free(apod);
 }
 
-int loadK8sConfigInCluster(char *token, int token_buf_size)
-{
-    static char fname[] = "loadK8sConfigInCluster()";
-
-    FILE *fp;
-    fp = fopen(K8S_TOKEN_FILE_IN_CLUSTER, "r");
-
-    if (fp == NULL) {
-        if (errno == ENOENT) {
-            printf("%s: The file %s does not exist.", fname, K8S_TOKEN_FILE_IN_CLUSTER);
-            return (-1);
-        } else {
-            printf("%s: Failed to open file %s.", fname, K8S_TOKEN_FILE_IN_CLUSTER);
-            return (-1);
-        }
-    }
-
-    while (fgets(token, token_buf_size, fp) != NULL) {
-        ;
-    }
-
-    printf("%s\n", token);
-
-    fclose(fp);
-
-    return 0;
-}
-
-int init_k8s_connector(const char *token_out_of_cluster)
-{
-    list_t *apiKeys;
-    apiKeys = list_create();
-
-    char *keyToken = strdup(K8S_AUTH_KEY);
-
-    char valueToken[K8S_TOKEN_BUF_SIZE];
-    memset(valueToken, 0, sizeof(valueToken));
-
-    sprintf(valueToken, K8S_AUTH_VALUE_TEMPLATE, token_out_of_cluster);
-
-    keyValuePair_t *keyPairToken = keyValuePair_create(keyToken, valueToken);
-    list_addElement(apiKeys, keyPairToken);
-
-    g_k8sAPIConnector = apiClient_create_with_base_path(K8S_APISERVER_BASEPATH, NULL, apiKeys);
-}
-
 int main(int argc, char *argv[])
 {
-    init_k8s_connector(argv[1]);
 
-    create_a_pod(g_k8sAPIConnector);
+    int rc = 0;
+
+    char *baseName = NULL;
+    sslConfig_t *sslConfig = NULL;
+    list_t *apiKeys = NULL;
+    apiClient_t *k8sApiClient = NULL;
+
+    rc = load_kube_config(&baseName, &sslConfig, &apiKeys, NULL);
+    if (0 == rc) {
+        k8sApiClient = apiClient_create_with_base_path(baseName, sslConfig, apiKeys);
+    } else {
+        printf("Cannot load kubernetes configuration.\n");
+        return -1;
+    }
+
+    if (k8sApiClient) {
+        create_a_pod(k8sApiClient);
+    }
+
+    free_client_config(baseName, sslConfig, apiKeys);
+    baseName = NULL;
+    sslConfig = NULL;
+    apiKeys = NULL;
+
+    apiClient_free(k8sApiClient);
+    k8sApiClient = NULL;
 
-    apiClient_free(g_k8sAPIConnector);
 }

examples/list_pod/Makefile

@@ -1,5 +1,5 @@
-INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api
-LIBS:=-L../../kubernetes/build -lkubernetes -lcurl -lpthread -lssl -lz
+INCLUDE:=-I../../kubernetes/include -I../../kubernetes/model -I../../kubernetes/api -I../../kubernetes/config
+LIBS:=-L../../kubernetes/build -lkubernetes -lcurl -lyaml -lpthread -lssl -lz
 CFLAGS:=-g
 
 all:

examples/list_pod/main.c

@@ -1,22 +1,10 @@
+#include <kube_config.h>
 #include <apiClient.h>
 #include <CoreV1API.h>
 #include <malloc.h>
 #include <stdio.h>
 #include <errno.h>
 
-// kubectl proxy server
-#define K8S_APISERVER_BASEPATH "http://localhost:8001"
-
-// Alternately from within a Kubernetes cluster:
-// #define K8S_APISERVER_BASEPATH https://your.server.here
-
-#define K8S_TOKEN_FILE_IN_CLUSTER "/var/run/secrets/kubernetes.io/serviceaccount/token"
-#define K8S_TOKEN_BUF_SIZE 1024
-#define K8S_AUTH_KEY "Authorization"
-#define K8S_AUTH_VALUE_TEMPLATE "Bearer %s"
-
-apiClient_t *g_k8sAPIConnector;
-
 void list_pod(apiClient_t * apiClient)
 {
     v1_pod_list_t *pod_list = NULL;
@@ -31,71 +19,48 @@ void list_pod(apiClient_t * apiClient)
                                            0,   /* timeoutSeconds */
                                            0    /* watch */
         );
-    printf("return code=%ld\n", apiClient->response_code);
+    printf("The return code of HTTP request=%ld\n", apiClient->response_code);
     if (pod_list) {
-        printf("Get pod list.\n");
+        printf("Get pod list:\n");
         listEntry_t *listEntry = NULL;
         v1_pod_t *pod = NULL;
         list_ForEach(listEntry, pod_list->items) {
             pod = listEntry->data;
-            printf("pod name=%s\n", pod->metadata->name);
+            printf("\tThe pod name: %s\n", pod->metadata->name);
         }
     } else {
-        printf("Cannot list any pod.\n");
+        printf("Cannot get any pod.\n");
     }
 }
 
-int loadK8sConfigInCluster(char *token, int token_buf_size)
-{
-    static char fname[] = "loadK8sConfigInCluster()";
-
-    FILE *fp;
-    fp = fopen(K8S_TOKEN_FILE_IN_CLUSTER, "r");
-
-    if (fp == NULL) {
-        if (errno == ENOENT) {
-            printf("%s: The file %s does not exist.", fname, K8S_TOKEN_FILE_IN_CLUSTER);
-            return (-1);
-        } else {
-            printf("%s: Failed to open file %s.", fname, K8S_TOKEN_FILE_IN_CLUSTER);
-            return (-1);
-        }
-    }
-
-    while (fgets(token, token_buf_size, fp) != NULL) {
-        ;
-    }
-
-    printf("%s\n", token);
-
-    fclose(fp);
-
-    return 0;
-}
-
-int init_k8s_connector(const char *token_out_of_cluster)
-{
-    list_t *apiKeys;
-    apiKeys = list_create();
-
-    char *keyToken = strdup(K8S_AUTH_KEY);
-
-    char valueToken[K8S_TOKEN_BUF_SIZE];
-    memset(valueToken, 0, sizeof(valueToken));
-
-    sprintf(valueToken, K8S_AUTH_VALUE_TEMPLATE, token_out_of_cluster);
-
-    keyValuePair_t *keyPairToken = keyValuePair_create(keyToken, valueToken);
-    list_addElement(apiKeys, keyPairToken);
-
-    g_k8sAPIConnector = apiClient_create_with_base_path(K8S_APISERVER_BASEPATH, NULL, apiKeys);
-}
-
 int main(int argc, char *argv[])
 {
-    init_k8s_connector(argv[1]);
+    int rc = 0;
 
-    list_pod(g_k8sAPIConnector);
+    char *baseName = NULL;
+    sslConfig_t *sslConfig = NULL;
+    list_t *apiKeys = NULL;
+    apiClient_t *k8sApiClient = NULL;
 
-    apiClient_free(g_k8sAPIConnector);
+    rc = load_kube_config(&baseName, &sslConfig, &apiKeys, NULL);
+    if (0 == rc) {
+        k8sApiClient = apiClient_create_with_base_path(baseName, sslConfig, apiKeys);
+    } else {
+        printf("Cannot load kubernetes configuration.\n");
+        return -1;
+    }
+
+    if (k8sApiClient) {
+        list_pod(k8sApiClient);
+    }
+
+    free_client_config(baseName, sslConfig, apiKeys);
+    baseName = NULL;
+    sslConfig = NULL;
+    apiKeys = NULL;
+
+    apiClient_free(k8sApiClient);
+    k8sApiClient = NULL;
+
+    return rc;
 }

kubernetes/CMakeLists.txt

@@ -9,6 +9,7 @@ set(CMAKE_VISIBILITY_INLINES_HIDDEN OFF)
 set(CMAKE_BUILD_TYPE Debug)
 
 set(pkgName "kubernetes")
+ADD_DEFINITIONS(-DOPENSSL)
 
 find_package(CURL 7.58.0 REQUIRED)
 if(CURL_FOUND)
@@ -18,7 +19,11 @@ else(CURL_FOUND)
 	message(FATAL_ERROR "Could not find the CURL library and development files.")
 endif()
 
+
 set(SRCS
+    config/kube_config_model.c
+    config/kube_config_yaml.c
+    config/kube_config.c
     src/list.c
     src/apiKey.c
     src/apiClient.c
@@ -770,6 +775,9 @@ set(SRCS
 )
 
 set(HDRS
+    config/kube_config_model.h
+    config/kube_config_yaml.h
+    config/kube_config.h
     include/apiClient.h
     include/list.h
     include/keyValuePair.h

kubernetes/config/kube_config.c

@@ -0,0 +1,264 @@
+#include "kube_config.h"
+#include "kube_config_yaml.h"
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+
+#define ENV_KUBECONFIG "KUBECONFIG"
+#define ENV_HOME "HOME"
+#define KUBE_CONFIG_DEFAULT_LOCATION "%s/.kube/config"
+#define KUBE_CONFIG_TEMPFILE_NAME_TEMPLATE "/tmp/kubeconfig-XXXXXX"
+
+static int setBasePath(char **pBasePath, char *basePath)
+{
+    char *_basePath = strdup(basePath);
+    if (_basePath) {
+        *pBasePath = _basePath;
+        return 0;
+    }
+    return -1;
+}
+
+static char *kubeconfig_mk_cert_key_tempfile(const char *b64data)
+{
+    static char fname[] = "kubeconfig_mk_tempfile()";
+
+    int decoded_bytes = 0;
+    char *b64decode = base64decode(b64data, strlen(b64data), &decoded_bytes);
+    if (!b64decode || 0 == decoded_bytes) {
+        fprintf(stderr, "%s: Base64 decodes failed.\n", fname);
+        return NULL;
+    }
+
+    char tempfile_name_template[] = KUBE_CONFIG_TEMPFILE_NAME_TEMPLATE;
+    int fd = mkstemp(tempfile_name_template);
+    if (-1 == fd) {
+        fprintf(stderr, "%s: Creating temp file for kubeconfig failed with error [%s]\n", fname, strerror(errno));
+        return NULL;
+    }
+
+    int rc = write(fd, b64decode, decoded_bytes);
+    close(fd);
+    if (-1 == rc) {
+        fprintf(stderr, "%s: Writing temp file failed with error [%s]\n", fname, strerror(errno));
+        return NULL;
+    }
+
+    return strdup(tempfile_name_template);
+}
+
+static void kubeconfig_rm_tempfile(const char *filename)
+{
+    if (filename) {
+        unlink(filename);
+    }
+}
+
+static void unsetSslConfig(sslConfig_t * sslConfig)
+{
+    if (!sslConfig) {
+        return;
+    }
+
+    if (sslConfig->clientCertFile) {
+        kubeconfig_rm_tempfile(sslConfig->clientCertFile);
+    }
+    if (sslConfig->clientKeyFile) {
+        kubeconfig_rm_tempfile(sslConfig->clientKeyFile);
+    }
+    if (sslConfig->CACertFile) {
+        kubeconfig_rm_tempfile(sslConfig->CACertFile);
+    }
+}
+
+static int setSslConfig(sslConfig_t ** pSslConfig, const kubeconfig_property_t * cluster, const kubeconfig_property_t * user)
+{
+    int rc = 0;
+    char *client_cert_file = NULL;
+    char *client_key_file = NULL;
+    char *ca_file = NULL;
+    int insecure_skip_tls_verify = 0;
+
+    if (user) {
+        if (user->client_certificate_data) {
+            client_cert_file = kubeconfig_mk_cert_key_tempfile(user->client_certificate_data);
+        }
+        if (user->client_key_data) {
+            client_key_file = kubeconfig_mk_cert_key_tempfile(user->client_key_data);
+        }
+        insecure_skip_tls_verify = user->insecure_skip_tls_verify;
+    }
+
+    if (cluster) {
+        if ((0 == insecure_skip_tls_verify) && (cluster->certificate_authority_data)) {
+            ca_file = kubeconfig_mk_cert_key_tempfile(cluster->certificate_authority_data);
+        }
+    }
+
+    sslConfig_t *sc = sslConfig_create(client_cert_file, client_key_file, ca_file, insecure_skip_tls_verify);
+    if (sc) {
+        *pSslConfig = sc;
+    } else {
+        rc = -1;
+    }
+
+    if (client_cert_file) {
+        free(client_cert_file);
+    }
+    if (client_key_file) {
+        free(client_key_file);
+    }
+    if (ca_file) {
+        free(ca_file);
+    }
+
+    return rc;
+}
+
+static int setApiKeys(list_t ** pApiKeys, const kubeconfig_property_t * user)
+{
+    list_t *apiKeys = list_create();
+    if (apiKeys) {
+
+        /* under development for the token based authentication */
+
+        *pApiKeys = apiKeys;
+        return 0;
+    }
+    return -1;
+}
+
+static char *getWorkingConfigFile(const char *configFileNamePassedIn)
+{
+    char *configFileName = NULL;
+    const char *kubeconfig_env = NULL;
+    const char *homedir_env = NULL;
+
+    if (configFileNamePassedIn) {
+        configFileName = strdup(configFileNamePassedIn);
+    } else {
+        kubeconfig_env = getenv(ENV_KUBECONFIG);
+        if (kubeconfig_env) {
+            configFileName = strdup(kubeconfig_env);
+        } else {
+            homedir_env = getenv(ENV_HOME);
+            if (homedir_env) {
+                configFileName = calloc(strlen(homedir_env) + strlen(KUBE_CONFIG_DEFAULT_LOCATION) + 1, sizeof(char));
+                if (configFileName) {
+                    sprintf(configFileName, KUBE_CONFIG_DEFAULT_LOCATION, homedir_env);
+                }
+            }
+        }
+    }
+
+    return configFileName;
+}
+
+static const kubeconfig_property_t *kubeconfig_get_current_property(kubeconfig_property_t ** properties, int properties_count, const char *property_name)
+{
+    const kubeconfig_property_t *current_property = NULL;
+
+    if (NULL == properties || NULL == property_name) {
+        return NULL;
+    }
+
+    for (int i = 0; i < properties_count; i++) {
+        if (0 == strcmp(properties[i]->name, property_name)) {
+            current_property = properties[i];
+            break;
+        }
+    }
+
+    return current_property;
+}
+
+int load_kube_config(char **pBasePath, sslConfig_t ** pSslConfig, list_t ** pApiKeys, const char *configFileName)
+{
+    static char fname[] = "load_kube_config()";
+
+    int rc = 0;
+
+    const kubeconfig_property_t *current_context = NULL;
+    const kubeconfig_property_t *current_cluster = NULL;
+    const kubeconfig_property_t *current_user = NULL;
+
+    kubeconfig_t *kubeconfig = kubeconfig_create();
+    if (!kubeconfig) {
+        fprintf(stderr, "%s: Cannot create kubeconfig.[%s]\n", fname, strerror(errno));
+        return -1;
+    }
+
+    kubeconfig->fileName = getWorkingConfigFile(configFileName);
+    rc = kubeyaml_load_kubeconfig(kubeconfig);
+    if (0 != rc) {
+        fprintf(stderr, "%s: Cannot load the kubeconfig %s\n", fname, kubeconfig->fileName);
+        rc = -1;
+        goto end;
+    }
+
+    current_context = kubeconfig_get_current_property(kubeconfig->contexts, kubeconfig->contexts_count, kubeconfig->current_context);
+    if (!current_context) {
+        fprintf(stderr, "%s: Cannot get the current context by the kubeconfig.\n", fname);
+        rc = -1;
+        goto end;
+    }
+
+    current_cluster = kubeconfig_get_current_property(kubeconfig->clusters, kubeconfig->clusters_count, current_context->cluster);
+    if (!current_cluster) {
+        fprintf(stderr, "%s: Cannot get the current cluster information by the kubeconfig.\n", fname);
+        rc = -1;
+        goto end;
+    }
+
+    current_user = kubeconfig_get_current_property(kubeconfig->users, kubeconfig->users_count, current_context->user);
+    if (!current_user) {
+        fprintf(stderr, "%s: Cannot get the current user information by the kubeconfig.\n", fname);
+        rc = -1;
+        goto end;
+    }
+
+    if (current_cluster && current_cluster->server) {
+        rc = setBasePath(pBasePath, current_cluster->server);
+        if (0 != rc) {
+            fprintf(stderr, "%s: Cannot set the base path for API server.\n", fname);
+            goto end;
+        }
+    }
+
+    if (current_cluster || current_user) {
+        rc = setSslConfig(pSslConfig, current_cluster, current_user);
+        if (0 != rc) {
+            fprintf(stderr, "%s: Cannot set the SSL Configuration for the client.\n", fname);
+            goto end;
+        }
+    }
+
+    if (current_user) {
+        rc = setApiKeys(pApiKeys, current_user);
+        if (0 != rc) {
+            fprintf(stderr, "%s: Cannot set the tokens for the client.\n", fname);
+            goto end;
+        }
+    }
+
+  end:
+    kubeconfig_free(kubeconfig);
+    kubeconfig = NULL;
+    return rc;
+}
+
+void free_client_config(char *basePath, sslConfig_t * sslConfig, list_t * apiKeys)
+{
+    if (basePath) {
+        free(basePath);
+    }
+
+    if (sslConfig) {
+        unsetSslConfig(sslConfig);
+        sslConfig_free(sslConfig);
+    }
+
+    if (apiKeys) {
+        list_free(apiKeys);
+    }
+}

kubernetes/config/kube_config.h

@@ -0,0 +1,82 @@
+#ifndef _KUBE_CONFIG_H
+#define _KUBE_CONFIG_H
+
+#include "../include/apiClient.h"
+
+#ifdef  __cplusplus
+extern "C" {
+#endif
+
+/*
+ * load_kube_config
+ *
+ *
+ * Description:
+ *
+ *
+ * Load kubernetes cluster configuration from the file specified 
+ * by parameter or default location: $HOME/.kube/config
+ *
+ *
+ * Return:
+ *
+ *   0     Success
+ *  -1     Failed
+ *
+ *
+ * Parameter:
+ *
+ *
+ * IN:
+
+ * configFileName : kubernetes cluster configuration file name
+ *
+ *
+ * OUT:
+ *
+ * pBasePath: The pointer to API server address
+ * pSslConfig: The pointer to SSL configuration for client
+ * pApiKeys: The pointer to API tokens for client
+ *
+ * The memory will be allocated inside this function. User 
+ * should call free_client_config to free the memory after 
+ * these parameters are not used.
+ *
+ */
+
+int load_kube_config(char **pBasePath, sslConfig_t ** pSslConfig, list_t ** pApiKeys, const char *configFileName);
+
+/*
+ * free_client_config
+ *
+ *
+ * Description:
+ *
+ * Help function to free the memory for the client configuration
+ *
+ *
+ * Return:
+ *
+ * None
+ * 
+ *
+ * Parameter:
+ *
+ * IN:
+ *
+ * basePath: API server address
+ * sslConfig: SSL configuration for client
+ * apiKeys: API tokens for client
+ *
+ * OUT:
+ *
+ * None
+ *
+ */
+
+void free_client_config(char *basePath, sslConfig_t * sslConfig, list_t * apiKeys);
+
+#ifdef  __cplusplus
+}
+#endif
+#endif                          /* _KUBE_CONFIG_H */

kubernetes/config/kube_config_model.c

@@ -0,0 +1,209 @@
+#include "kube_config_model.h"
+#include <stdlib.h>
+
+kubeconfig_auth_provider_t *kubeconfig_auth_provider_create()
+{
+    kubeconfig_auth_provider_t *provider = calloc(1, sizeof(kubeconfig_auth_provider_t));
+    return provider;
+}
+
+void kubeconfig_auth_provider_free(kubeconfig_auth_provider_t * provider)
+{
+    if (!provider) {
+        return;
+    }
+
+    if (provider->name) {
+        free(provider->name);
+        provider->name = NULL;
+    }
+    if (provider->id_token) {
+        free(provider->id_token);
+        provider->id_token = NULL;
+    }
+    if (provider->cmd_path) {
+        free(provider->cmd_path);
+        provider->cmd_path = NULL;
+    }
+    if (provider->access_token) {
+        free(provider->access_token);
+        provider->access_token = NULL;
+    }
+    if (provider->expires_on) {
+        free(provider->expires_on);
+        provider->expires_on = NULL;
+    }
+    if (provider->expiry) {
+        free(provider->expiry);
+        provider->expiry = NULL;
+    }
+    if (provider->idp_certificate_authority_data) {
+        free(provider->idp_certificate_authority_data);
+        provider->idp_certificate_authority_data = NULL;
+    }
+
+    free(provider);
+}
+
+kubeconfig_exec_t *kubeconfig_exec_create()
+{
+    kubeconfig_exec_t *exec = calloc(1, sizeof(kubeconfig_exec_t));
+    return exec;
+}
+
+void kubeconfig_exec_free(kubeconfig_exec_t * exec)
+{
+    if (!exec) {
+        return;
+    }
+
+    if (exec->command) {
+        free(exec->command);
+        exec->command = NULL;
+    }
+
+    free(exec);
+}
+
+kubeconfig_property_t *kubeconfig_property_create(kubeconfig_property_type_t type)
+{
+    kubeconfig_property_t *property = calloc(1, sizeof(kubeconfig_property_t));
+    property->type = type;
+    return property;
+}
+
+void kubeconfig_property_free(kubeconfig_property_t * property)
+{
+    if (!property) {
+        return;
+    }
+
+    if (property->name) {
+        free(property->name);
+        property->name = NULL;
+    }
+
+    if (KUBECONFIG_PROPERTY_TYPE_CLUSTER == property->type) {
+        if (property->server) {
+            free(property->server);
+            property->server = NULL;
+        }
+        if (property->certificate_authority_data) {
+            free(property->certificate_authority_data);
+            property->certificate_authority_data = NULL;
+        }
+    }
+
+    if (KUBECONFIG_PROPERTY_TYPE_USER == property->type) {
+        if (property->client_certificate_data) {
+            free(property->client_certificate_data);
+            property->client_certificate_data = NULL;
+        }
+        if (property->client_key_data) {
+            free(property->client_key_data);
+            property->client_key_data = NULL;
+        }
+        if (property->username) {
+            free(property->username);
+            property->username = NULL;
+        }
+        if (property->password) {
+            free(property->password);
+            property->password = NULL;
+        }
+        if (property->auth_provider) {
+            kubeconfig_auth_provider_free(property->auth_provider);
+            property->auth_provider = NULL;
+        }
+        if (property->exec) {
+            kubeconfig_exec_free(property->exec);
+            property->exec = NULL;
+        }
+    }
+
+    if (KUBECONFIG_PROPERTY_TYPE_CONTEXT == property->type) {
+        if (property->cluster) {
+            free(property->cluster);
+            property->cluster = NULL;
+        }
+        if (property->user) {
+            free(property->user);
+            property->user = NULL;
+        }
+    }
+
+    free(property);
+}
+
+kubeconfig_property_t **kubeconfig_properties_create(int contexts_count, kubeconfig_property_type_t type)
+{
+    kubeconfig_property_t **properties = (kubeconfig_property_t **) calloc(contexts_count, sizeof(kubeconfig_property_t *));
+    int i = 0;
+    for (i = 0; i < contexts_count; i++) {
+        properties[i] = kubeconfig_property_create(type);
+    }
+    return properties;
+}
+
+void kubeconfig_properties_free(kubeconfig_property_t ** properties, int properties_count)
+{
+    if (!properties) {
+        return;
+    }
+
+    for (int i = 0; i < properties_count; i++) {
+        if (properties[i]) {
+            kubeconfig_property_free(properties[i]);
+            properties[i] = NULL;
+        }
+    }
+    free(properties);
+}
+
+kubeconfig_t *kubeconfig_create()
+{
+    kubeconfig_t *config = calloc(1, sizeof(kubeconfig_t));
+    return config;
+}
+
+void kubeconfig_free(kubeconfig_t * kubeconfig)
+{
+    if (!kubeconfig) {
+        return;
+    }
+
+    if (kubeconfig->fileName) {
+        free(kubeconfig->fileName);
+        kubeconfig->fileName = NULL;
+    }
+    if (kubeconfig->apiVersion) {
+        free(kubeconfig->apiVersion);
+        kubeconfig->apiVersion = NULL;
+    }
+    if (kubeconfig->kind) {
+        free(kubeconfig->kind);
+        kubeconfig->kind = NULL;
+    }
+    if (kubeconfig->preferences) {
+        free(kubeconfig->preferences);
+        kubeconfig->preferences = NULL;
+    }
+    if (kubeconfig->current_context) {
+        free(kubeconfig->current_context);
+        kubeconfig->current_context = NULL;
+    }
+    if (kubeconfig->clusters) {
+        kubeconfig_properties_free(kubeconfig->clusters, kubeconfig->clusters_count);
+        kubeconfig->clusters = NULL;
+    }
+    if (kubeconfig->users) {
+        kubeconfig_properties_free(kubeconfig->users, kubeconfig->users_count);
+        kubeconfig->users = NULL;
+    }
+    if (kubeconfig->contexts) {
+        kubeconfig_properties_free(kubeconfig->contexts, kubeconfig->contexts_count);
+        kubeconfig->contexts = NULL;
+    }
+
+    free(kubeconfig);
+}

kubernetes/config/kube_config_model.h

@@ -0,0 +1,84 @@
+#ifndef _KUBE_CONFIG_MODEL_H
+#define _KUBE_CONFIG_MODEL_H
+
+#ifdef  __cplusplus
+extern "C" {
+#endif
+
+typedef struct kubeconfig_auth_provider_t {
+    char *name;
+    char *id_token;
+    char *cmd_path;
+    char *access_token;
+    char *expires_on;
+    char *expiry;
+    char *idp_certificate_authority_data;
+} kubeconfig_auth_provider_t;
+
+typedef struct kubeconfig_exec_t {
+    char *command;
+} kubeconfig_exec_t;
+
+typedef enum kubeconfig_property_type_t {
+    KUBECONFIG_PROPERTY_TYPE_CONTEXT = 1,
+    KUBECONFIG_PROPERTY_TYPE_CLUSTER,
+    KUBECONFIG_PROPERTY_TYPE_USER
+} kubeconfig_property_type_t;
+
+typedef struct kubeconfig_property_t {
+    kubeconfig_property_type_t type;
+    char *name;
+    union {
+        struct {            /* context */
+            char *cluster;
+            char *user;
+        };
+        struct {            /* cluster */
+            char *server;
+            char *certificate_authority_data;
+        };
+        struct {            /* user */
+            char *client_certificate_data;
+            char *client_key_data;
+            kubeconfig_auth_provider_t *auth_provider;
+            kubeconfig_exec_t *exec;
+            int insecure_skip_tls_verify;
+            char *username;
+            char *password;
+        };
+    };
+} kubeconfig_property_t;
+
+typedef struct kubeconfig_t {
+    char *fileName;
+    char *apiVersion;
+    char *preferences;
+    char *kind;
+    char *current_context;
+    kubeconfig_property_t **contexts;
+    int contexts_count;
+    kubeconfig_property_t **clusters;
+    int clusters_count;
+    kubeconfig_property_t **users;
+    int users_count;
+} kubeconfig_t;
+
+kubeconfig_auth_provider_t *kubeconfig_auth_provider_create();
+void kubeconfig_auth_provider_free(kubeconfig_auth_provider_t * provider);
+
+kubeconfig_exec_t *kubeconfig_exec_create();
+void kubeconfig_exec_free(kubeconfig_exec_t * exec);
+
+kubeconfig_property_t *kubeconfig_property_create(kubeconfig_property_type_t type);
+void kubeconfig_property_free(kubeconfig_property_t * property);
+
+kubeconfig_property_t **kubeconfig_properties_create(int contexts_count, kubeconfig_property_type_t type);
+void kubeconfig_properties_free(kubeconfig_property_t ** properties, int properties_count);
+
+kubeconfig_t *kubeconfig_create();
+void kubeconfig_free(kubeconfig_t * kubeconfig);
+
+#ifdef  __cplusplus
+}
+#endif
+#endif                          /* _KUBE_CONFIG_MODEL_H */

kubernetes/config/kube_config_yaml.c

@@ -0,0 +1,263 @@
+#include <yaml.h>
+#include <errno.h>
+#include "kube_config_yaml.h"
+
+/*
+A valid sequence of events should obey the grammar :
+
+stream :: = STREAM - START document * STREAM - END
+document :: = DOCUMENT - START node DOCUMENT - END
+node :: = ALIAS | SCALAR | sequence | mapping
+sequence :: = SEQUENCE - START node * SEQUENCE - END
+mapping :: = MAPPING - START(node node) * MAPPING - END
+*/
+
+#define KEY_APIVERSION "apiVersion"
+#define KEY_KIND "kind"
+#define KEY_CURRENT_CONTEXT "current-context"
+#define KEY_CLUSTERS "clusters"
+#define KEY_CLUSTER "cluster"
+#define KEY_CONTEXTS "contexts"
+#define KEY_USERS "users"
+#define KEY_USER "user"
+#define KEY_NAME "name"
+#define KEY_CERTIFICATE_AUTHORITY_DATA "certificate-authority-data"
+#define KEY_SERVER "server"
+#define KEY_CLIENT_CERTIFICATE_DATA "client-certificate-data"
+#define KEY_CLIENT_KEY_DATA "client-key-data"
+
+static int parse_kubeconfig_yaml_property_info_mapping(kubeconfig_property_t * property, yaml_document_t * document, yaml_node_t * node)
+{
+    static char fname[] = "parse_kubeconfig_yaml_property_info_mapping()";
+
+    yaml_node_pair_t *pair = NULL;
+    yaml_node_t *key = NULL;
+    yaml_node_t *value = NULL;
+
+    for (pair = node->data.mapping.pairs.start; pair < node->data.mapping.pairs.top; pair++) {
+        key = yaml_document_get_node(document, pair->key);
+        value = yaml_document_get_node(document, pair->value);
+
+        if (key->type != YAML_SCALAR_NODE) {
+            fprintf(stderr, "%s: The key node is not YAML_SCALAR_NODE.\n", fname);
+            return -1;
+        }
+
+        if (value->type == YAML_SCALAR_NODE) {
+            if (KUBECONFIG_PROPERTY_TYPE_CLUSTER == property->type) {
+                if (0 == strcmp(key->data.scalar.value, KEY_CERTIFICATE_AUTHORITY_DATA)) {
+                    property->certificate_authority_data = strdup(value->data.scalar.value);
+                } else if (0 == strcmp(key->data.scalar.value, KEY_SERVER)) {
+                    property->server = strdup(value->data.scalar.value);
+                }
+            } else if (KUBECONFIG_PROPERTY_TYPE_USER == property->type) {
+                if (0 == strcmp(key->data.scalar.value, KEY_CLIENT_CERTIFICATE_DATA)) {
+                    property->client_certificate_data = strdup(value->data.scalar.value);
+                } else if (0 == strcmp(key->data.scalar.value, KEY_CLIENT_KEY_DATA)) {
+                    property->client_key_data = strdup(value->data.scalar.value);
+                }
+            } else if (KUBECONFIG_PROPERTY_TYPE_CONTEXT == property->type) {
+                if (0 == strcmp(key->data.scalar.value, KEY_CLUSTER)) {
+                    property->cluster = strdup(value->data.scalar.value);
+                } else if (0 == strcmp(key->data.scalar.value, KEY_USER)) {
+                    property->user = strdup(value->data.scalar.value);
+                }
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int parse_kubeconfig_yaml_property_mapping(kubeconfig_property_t * property, yaml_document_t * document, yaml_node_t * node)
+{
+    static char fname[] = "parse_kubeconfig_yaml_property_mapping()";
+    int rc = 0;
+
+    yaml_node_pair_t *pair = NULL;
+    yaml_node_t *key = NULL;
+    yaml_node_t *value = NULL;
+
+    for (pair = node->data.mapping.pairs.start; pair < node->data.mapping.pairs.top; pair++) {
+        key = yaml_document_get_node(document, pair->key);
+        value = yaml_document_get_node(document, pair->value);
+
+        if (key->type != YAML_SCALAR_NODE) {
+            fprintf(stderr, "%s: The key node is not YAML_SCALAR_NODE.\n", fname);
+            return -1;
+        }
+
+        if (value->type == YAML_SCALAR_NODE) {
+            if (0 == strcmp(key->data.scalar.value, KEY_NAME)) {
+                property->name = strdup(value->data.scalar.value);
+            }
+        } else if (value->type == YAML_MAPPING_NODE) {
+            rc = parse_kubeconfig_yaml_property_info_mapping(property, document, value);
+        }
+    }
+
+    return rc;
+}
+
+static int parse_kubeconfig_yaml_sequence(kubeconfig_property_t *** p_properties, int *p_properties_count, kubeconfig_property_type_t type, yaml_document_t * document, yaml_node_t * node)
+{
+    yaml_node_item_t *item = NULL;
+    yaml_node_t *value = NULL;
+    int item_count = 0;
+    int i = 0;
+    int rc = 0;
+
+    // Get the count of data (e.g. cluster, context, user)
+    for (item = node->data.sequence.items.start, item_count = 0; item < node->data.sequence.items.top; item++, item_count++) {
+        ;
+    }
+
+    int properties_count = item_count;
+    kubeconfig_property_t **properties = kubeconfig_properties_create(properties_count, type);
+    if (!properties) {
+        fprintf(stderr, "Cannot allocate memory for kubeconfig properties.\n");
+        return -1;
+    }
+
+    for (item = node->data.sequence.items.start, i = 0; item < node->data.sequence.items.top; item++, i++) {
+        value = yaml_document_get_node(document, *item);
+        rc = parse_kubeconfig_yaml_property_mapping(properties[i], document, value);
+        if (0 != rc) {
+            fprintf(stderr, "Cannot parse kubeconfi properties.\n");
+            return -1;
+        }
+    }
+
+    *p_properties = properties;
+    *p_properties_count = properties_count;
+
+    return 0;
+
+}
+
+static int parse_kubeconfig_yaml_top_mapping(kubeconfig_t * kubeconfig, yaml_document_t * document, yaml_node_t * node)
+{
+    static char fname[] = "parse_kubeconfig_yaml_top_mapping()";
+    int rc = 0;
+
+    yaml_node_pair_t *pair = NULL;
+    yaml_node_t *key = NULL;
+    yaml_node_t *value = NULL;
+
+    for (pair = node->data.mapping.pairs.start; pair < node->data.mapping.pairs.top; pair++) {
+        key = yaml_document_get_node(document, pair->key);
+        value = yaml_document_get_node(document, pair->value);
+
+        if (key->type != YAML_SCALAR_NODE) {
+            fprintf(stderr, "%s: The key node is not YAML_SCALAR_NODE.\n", fname);
+            return -1;
+        }
+
+        if (value->type == YAML_SCALAR_NODE) {
+            if (0 == strcmp(key->data.scalar.value, KEY_APIVERSION)) {
+                kubeconfig->apiVersion = strdup(value->data.scalar.value);
+            } else if (0 == strcmp(key->data.scalar.value, KEY_KIND)) {
+                kubeconfig->kind = strdup(value->data.scalar.value);
+            } else if (0 == strcmp(key->data.scalar.value, KEY_CURRENT_CONTEXT)) {
+                kubeconfig->current_context = strdup(value->data.scalar.value);
+            }
+        } else {
+            if (0 == strcmp(key->data.scalar.value, KEY_CLUSTERS)) {
+                rc = parse_kubeconfig_yaml_sequence(&(kubeconfig->clusters), &(kubeconfig->clusters_count), KUBECONFIG_PROPERTY_TYPE_CLUSTER, document, value);
+            } else if (0 == strcmp(key->data.scalar.value, KEY_CONTEXTS)) {
+                rc = parse_kubeconfig_yaml_sequence(&(kubeconfig->contexts), &(kubeconfig->contexts_count), KUBECONFIG_PROPERTY_TYPE_CONTEXT, document, value);
+            } else if (0 == strcmp(key->data.scalar.value, KEY_USERS)) {
+                rc = parse_kubeconfig_yaml_sequence(&(kubeconfig->users), &(kubeconfig->users_count), KUBECONFIG_PROPERTY_TYPE_USER, document, value);
+            }
+        }
+    }
+
+    return rc;
+
+}
+
+static int parse_kubeconfig_yaml_node(kubeconfig_t * kubeconfig, yaml_document_t * document, yaml_node_t * node)
+{
+    static char fname[] = "parse_kubeconfig_yaml_node()";
+    int rc = 0;
+
+    if (YAML_MAPPING_NODE == node->type) {
+        rc = parse_kubeconfig_yaml_top_mapping(kubeconfig, document, node);
+    } else {
+        fprintf(stderr, "%s: %s is not a valid kubeconfig file.\n", fname, kubeconfig->fileName);
+        rc = -1;
+    }
+
+    return rc;
+}
+
+static int parse_kubeconfig_yaml_document(kubeconfig_t * kubeconfig, yaml_document_t * document)
+{
+    static char fname[] = "parse_kubeconfig_yaml_document()";
+    int rc = 0;
+
+    yaml_node_t *root;
+    root = yaml_document_get_root_node(document);
+    if (NULL == root) {
+        fprintf(stderr, "%s: The document is null\n", fname);
+        return -1;
+    }
+
+    rc = parse_kubeconfig_yaml_node(kubeconfig, document, root);
+
+    return rc;
+}
+
+int kubeyaml_load_kubeconfig(kubeconfig_t * kubeconfig)
+{
+    static char fname[] = "kubeyaml_load_kubeconfig()";
+
+    yaml_parser_t parser;
+    yaml_document_t document;
+
+    int done = 0;
+
+    /* Create the Parser object. */
+    yaml_parser_initialize(&parser);
+
+    /* Set a file input. */
+    FILE *input = NULL;
+    if (kubeconfig->fileName) {
+        input = fopen(kubeconfig->fileName, "rb");
+        if (!input) {
+            fprintf(stderr, "%s: Cannot open the file %s.[%s]\n", fname, kubeconfig->fileName, strerror(errno));
+            return -1;
+        }
+    } else {
+        fprintf(stderr, "%s: The kubeconf file name needs be set by kubeconfig->fileName .\n", fname);
+        return -1;
+    }
+
+    yaml_parser_set_input_file(&parser, input);
+
+    while (!done) {
+
+        if (!yaml_parser_load(&parser, &document)) {
+            goto error;
+        }
+
+        done = (!yaml_document_get_root_node(&document));
+
+        if (!done) {
+            parse_kubeconfig_yaml_document(kubeconfig, &document);
+        }
+
+        yaml_document_delete(&document);
+
+    }
+
+    /* Cleanup */
+    yaml_parser_delete(&parser);
+    fclose(input);
+    return 0;
+
+  error:
+    yaml_parser_delete(&parser);
+    fclose(input);
+    return -1;
+}

kubernetes/config/kube_config_yaml.h

@@ -0,0 +1,37 @@
+#ifndef _KUBE_CONFIG_YAML_H
+#define _KUBE_CONFIG_YAML_H
+
+#include "kube_config_model.h"
+
+#ifdef  __cplusplus
+extern "C" {
+
+#endif                          /* __cplusplus */
+
+/*
+ * kubeyaml_load_kubeconfig
+ *
+ * Description:
+ *
+ * Load the kubeconfig file specified by kubeconfig->fileName
+ * and get the kuberntes configuration for other fields of kubeconfig.
+ *
+ * Return:
+ *
+ *   0     Success
+ *  -1     Failed
+ *
+ * Parameter:
+ *
+ * IN:
+ * kubeconfig->fileName: kubernetes cluster configuration file name
+ *
+ * OUT:
+ * kubeconfig: kubernetes cluster configuration
+ */
+int kubeyaml_load_kubeconfig(kubeconfig_t * kubeconfig);
+
+#ifdef  __cplusplus
+}
+#endif                          /* __cplusplus  */
+#endif                          /* _KUBE_CONFIG_YAML_H */