Add support for IPC subscriptions

.cspell.json

@@ -9,5 +9,10 @@
     }
   ],
   "dictionaries": ["project"],
-  "ignorePaths": ["**/CMakeLists.txt", "**/*.nix", "**/iwyu_mappings.yml"]
+  "ignorePaths": [
+    "**/CMakeLists.txt",
+    "**/*.yml",
+    "**/*.nix",
+    "**/iwyu_mappings.yml"
+  ]
 }

.github/workflows/ci.yml

@@ -21,6 +21,8 @@ jobs:
         include:
           - name: build with GCC
             check: packages-default
+          - name: static build
+            check: packages-ggl-sdk-static
           - name: build with Clang
             check: build-clang
           - name: cross-build for arm32 Musl

CMakeLists.txt

@@ -11,6 +11,8 @@ if(PROJECT_IS_TOP_LEVEL)
 
   option(ENABLE_WERROR "Compile warnings as errors")
 
+  option(BUILD_SAMPLES "Build sample components" ON)
+
   set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
   include(GNUInstallDirs)
@@ -173,11 +175,21 @@ target_compile_definitions(ggl-sdk PRIVATE _GNU_SOURCE)
 target_include_directories(ggl-sdk PRIVATE include priv_include)
 target_include_directories(ggl-sdk SYSTEM INTERFACE include)
 
-target_compile_definitions(ggl-sdk PRIVATE "GGL_MODULE=(\"${ggl-sdk}\")")
+target_compile_definitions(ggl-sdk PRIVATE "GGL_MODULE=(\"ggl-sdk\")")
 string(TOUPPER "${GGL_LOG_LEVEL}" log_level)
 set(choose_level "$<IF:$<BOOL:${log_level}>,${log_level},DEBUG>")
 target_compile_definitions(ggl-sdk PUBLIC GGL_LOG_LEVEL=GGL_LOG_${choose_level})
 
 if(PROJECT_IS_TOP_LEVEL)
   install(TARGETS ggl-sdk)
+
+  if(BUILD_SAMPLES)
+    file(GLOB SAMPLE_DIRS CONFIGURE_DEPENDS "samples/*")
+    foreach(sample_dir ${SAMPLE_DIRS})
+      get_filename_component(sample_name ${sample_dir} NAME_WLE)
+      add_executable(sample_${sample_name} ${sample_dir}/main.c)
+      target_link_libraries(sample_${sample_name} PRIVATE ggl-sdk)
+      install(TARGETS sample_${sample_name})
+    endforeach()
+  endif()
 endif()

flake.nix

@@ -16,6 +16,7 @@
             ./priv_include
             ./src
             ./.clang-tidy
+            ./samples
           ];
         };
 
@@ -65,6 +66,8 @@
             meta = defaultMeta;
           };
 
+        packages.ggl-sdk-static = { pkgsStatic }: pkgsStatic.ggl-sdk;
+
         checks =
           let
             clangBuildDir = { pkgs, pkg-config, clang-tools, cmake, ... }:
@@ -95,7 +98,7 @@
               PATH=${lib.makeBinPath
                 (with pkgs; [clangd-tidy clang-tools fd])}:$PATH
               clangd-tidy -j$(nproc) -p ${clangBuildDir pkgs} --color=always \
-                $(fd . ${filteredSrc} -e c -e h) |\
+                $(fd . ${filteredSrc}/src -e c -e h) |\
                 sed 's|\.\.${filteredSrc}/||'
             '';
 

include/ggl/ipc/client.h

@@ -6,66 +6,73 @@
 #define GGL_IPC_CLIENT_H
 
 #include <ggl/arena.h>
+#include <ggl/attr.h>
 #include <ggl/buffer.h>
 #include <ggl/error.h>
-#include <ggl/ipc/error.h>
 #include <ggl/object.h>
 #include <time.h> // IWYU pragma: keep
 #include <stdint.h>
 
 struct timespec;
 
-#define GGL_IPC_SVCUID_STR_LEN (16)
+// Connection APIs
 
-GglError ggipc_call(
-    int conn,
-    GglBuffer operation,
-    GglBuffer service_model_type,
-    GglMap params,
-    GglArena *alloc,
-    GglObject *result,
-    GglIpcError *remote_err
-);
+/// Connect to the Greengrass Nucleus from a component.
+/// Not thread-safe due to use of getenv.
+GglError ggipc_connect(void);
 
-GglError ggipc_get_config_str(
-    int conn, GglBufList key_path, GglBuffer *component_name, GglBuffer *value
-);
+/// Connect to a GG-IPC socket with a given SVCUID token.
+GglError ggipc_connect_with_token(GglBuffer socket_path, GglBuffer auth_token);
 
-GglError ggipc_get_config_obj(
-    int conn,
-    GglBufList key_path,
-    GglBuffer *component_name,
-    GglArena *alloc,
-    GglObject *value
-);
+// IPC calls
 
-GglError ggipc_update_config(
-    int conn,
-    GglBufList key_path,
-    const struct timespec *timestamp,
-    GglObject value_to_merge
-);
+/// Publish a message to a local topic in JSON format
+GglError ggipc_publish_to_topic_json(GglBuffer topic, GglObject payload);
 
+/// Publish a message to a local topic in binary format
 /// Uses an allocator to base64-encode a binary message.
 /// base64 encoding will allocate 4 bytes for every 3 payload bytes.
 /// Additionally, up to 128 bytes may be allocated for an error message.
 GglError ggipc_publish_to_topic_binary(
-    int conn, GglBuffer topic, GglBuffer payload, GglArena alloc
-);
-
-GglError ggipc_publish_to_topic_obj(
-    int conn, GglBuffer topic, GglObject payload
+    GglBuffer topic, GglBuffer payload, GglArena alloc
 );
 
+/// Publish an MQTT message to AWS IoT Core on a topic
 /// Uses an allocator to base64-encode a binary message.
 /// base64 encoding will allocate 4 bytes for every 3 payload bytes.
 /// Additionally, up to 128 bytes may be allocated for an error message.
 GglError ggipc_publish_to_iot_core(
-    int conn,
-    GglBuffer topic_name,
-    GglBuffer payload,
-    uint8_t qos,
-    GglArena *alloc
+    GglBuffer topic_name, GglBuffer payload, uint8_t qos, GglArena alloc
+);
+
+typedef void (*GgIpcSubscribeToIotCoreCallback)(
+    GglBuffer topic, GglBuffer payload
+);
+
+/// Subscribe to MQTT messages from AWS IoT Core on a topic or topic filter
+GglError ggipc_subscribe_to_iot_core(
+    GglBuffer topic_filter, uint8_t qos, GgIpcSubscribeToIotCoreCallback handler
+) NONNULL(3);
+
+/// Get a configuration value for a component on the core device
+GglError ggipc_get_config(
+    GglBufList key_path,
+    const GglBuffer *component_name,
+    GglArena *alloc,
+    GglObject *value
+);
+
+/// Get a string-typed configuration value for a component on the core device
+/// Alternative API to ggipc_get_config for string type values.
+GglError ggipc_get_config_str(
+    GglBufList key_path, const GglBuffer *component_name, GglBuffer *value
+);
+
+/// Update a configuration value for this component on the core device
+GglError ggipc_update_config(
+    GglBufList key_path,
+    const struct timespec *timestamp,
+    GglObject value_to_merge
 );
 
 #endif

include/ggl/ipc/client_raw.h

@@ -0,0 +1,48 @@
+// aws-greengrass-sdk-lite - Lightweight AWS IoT Greengrass SDK
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+#ifndef GGL_IPC_CLIENT_RAW_H
+#define GGL_IPC_CLIENT_RAW_H
+
+#include <ggl/arena.h>
+#include <ggl/attr.h>
+#include <ggl/buffer.h>
+#include <ggl/error.h>
+#include <ggl/ipc/error.h>
+#include <ggl/object.h>
+
+#define GGL_IPC_SVCUID_STR_LEN (16)
+
+/// Maximum number of eventstream streams. Limits subscriptions.
+/// Max subscriptions is this minus 2.
+/// Can be configured with `-D GGL_IPC_MAX_MSG_LEN=<N>`.
+#ifndef GGL_IPC_MAX_STREAMS
+#define GGL_IPC_MAX_STREAMS 16
+#endif
+
+GglError ggipc_call(
+    GglBuffer operation,
+    GglBuffer service_model_type,
+    GglMap params,
+    GglArena *alloc,
+    GglObject *result,
+    GglIpcError *remote_err
+);
+
+typedef GglError (*GgIpcSubscribeCallback)(
+    void *ctx, GglBuffer service_model_type, GglMap data
+);
+
+GglError ggipc_subscribe(
+    GglBuffer operation,
+    GglBuffer service_model_type,
+    GglMap params,
+    GgIpcSubscribeCallback on_response,
+    void *ctx,
+    GglArena *alloc,
+    GglObject *result,
+    GglIpcError *remote_err
+) NONNULL(4);
+
+#endif

misc/dictionary.txt

@@ -8,4 +8,5 @@ LOGE
 LOGI
 LOGT
 LOGW
+MQTT
 NOLINTNEXTLINE

priv_include/ggl/ipc/client_priv.h

@@ -5,7 +5,6 @@
 #ifndef GGL_IPC_CLIENT_PRIV_H
 #define GGL_IPC_CLIENT_PRIV_H
 
-#include <ggl/attr.h>
 #include <ggl/buffer.h>
 #include <ggl/error.h>
 
@@ -23,12 +22,10 @@
 /// Connect to GG-IPC server using component name.
 /// If svcuid is non-null, it will be filled with the component's identity
 /// token. Buffer must be able to hold at least GGL_IPC_SVCUID_STR_LEN.
-GglError ggipc_connect_by_name(
-    GglBuffer socket_path, GglBuffer component_name, int *fd, GglBuffer *svcuid
-) NONNULL(3);
-
-GglError ggipc_private_get_system_config(
-    int conn, GglBuffer key, GglBuffer *value
+GglError ggipc_connect_with_name(
+    GglBuffer socket_path, GglBuffer component_name, GglBuffer *svcuid
 );
 
+GglError ggipc_private_get_system_config(GglBuffer key, GglBuffer *value);
+
 #endif

samples/iot_core_mqtt/main.c

@@ -0,0 +1,58 @@
+//! Sample component demonstrating pubsub with AWS IoT Core
+
+#include <ggl/arena.h>
+#include <ggl/buffer.h>
+#include <ggl/error.h>
+#include <ggl/ipc/client.h>
+#include <ggl/sdk.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static void response_handler(GglBuffer topic, GglBuffer payload) {
+    printf(
+        "Received [%.*s] on [%.*s].\n",
+        (int) payload.len,
+        payload.data,
+        (int) topic.len,
+        topic.data
+    );
+}
+
+int main(void) {
+    setvbuf(stdout, NULL, _IONBF, 0);
+
+    ggl_sdk_init();
+
+    GglError ret = ggipc_connect();
+    if (ret != GGL_ERR_OK) {
+        fprintf(stderr, "Failed to connect to GG nucleus.\n");
+        exit(1);
+    }
+    printf("Connected to GG nucleus.\n");
+
+    ret = ggipc_subscribe_to_iot_core(GGL_STR("hello"), 0, &response_handler);
+    if (ret != GGL_ERR_OK) {
+        fprintf(stderr, "Failed to call subscribe_to_iot_core.\n");
+        exit(1);
+    }
+    printf("Subscribed to topic.\n");
+
+    while (true) {
+        static uint8_t publish_mem[5000];
+        GglArena publish_arena = ggl_arena_init(GGL_BUF(publish_mem));
+
+        ret = ggipc_publish_to_iot_core(
+            GGL_STR("hello"), GGL_STR("world"), 0, publish_arena
+        );
+        if (ret != GGL_ERR_OK) {
+            fprintf(stderr, "Failed to call publish_to_iot_core.\n");
+            exit(1);
+        }
+        printf("Published to topic.\n");
+
+        sleep(15);
+    }
+}

samples/iot_core_mqtt/recipe.yml

@@ -0,0 +1,29 @@
+---
+RecipeFormatVersion: "2020-01-25"
+ComponentName: "aws-greengrass-sdk-lite.samples.iot_core_mqtt"
+ComponentVersion: "1.0.0"
+ComponentType: "aws.greengrass.generic"
+ComponentDescription:
+  Example component using aws-greengrass-sdk-lite to publish/subscribe to AWS
+  IoT Core
+ComponentPublisher: AWS
+ComponentConfiguration:
+  DefaultConfiguration:
+    accessControl:
+      aws.greengrass.ipc.mqttproxy:
+        access_policy:
+          policyDescription: "Allows pub/sub to IoT Core topic hello"
+          operations:
+            - aws.greengrass#PublishToIoTCore"
+            - aws.greengrass#SubscribeToIoTCore"
+          resources:
+            - "hello"
+Manifests:
+  - Platform:
+      os: linux
+      runtime: "*"
+    Lifecycle:
+      run:
+        Script: "{artifacts:path}/sample_iot_core_mqtt"
+    Artifacts:
+      - URI: s3://EXAMPLE_BUCKET/sample_iot_core_mqtt