feat: add IoT provider support and related credentials definitions

This update introduces the IoT provider creation function and adds necessary environment variable definitions for IoT credentials in the AWS module. Additionally, the CMake configuration is updated to include the new IoT credentials source file.

Signed-off-by: Eduardo Silva <eduardo@chronosphere.io>

Author: SagiROosto

include/fluent-bit/flb_aws_credentials.h

@@ -225,6 +225,11 @@ struct flb_aws_provider *flb_eks_provider_create(struct flb_config *config,
                                                  flb_aws_client_generator
                                                  *generator);
 
+/*
+ * IoT Provider
+ */
+struct flb_aws_provider *flb_iot_provider_create(struct flb_config *config,
+                                                 struct flb_aws_client_generator *generator);
 
 /*
  * STS Assume Role Provider.

src/aws/CMakeLists.txt

@@ -15,6 +15,7 @@ set(src
   "flb_aws_imds.c"
   "flb_aws_credentials_http.c"
   "flb_aws_credentials_profile.c"
+  "flb_aws_credentials_iot.c"
   )
 
 message(STATUS "=== AWS Credentials ===")

src/aws/flb_aws_credentials.c

@@ -38,6 +38,14 @@
 
 #define EKS_POD_EXECUTION_ROLE         "EKS_POD_EXECUTION_ROLE"
 
+/* IoT Credentials Environment Variables */
+#define AWS_IOT_KEY_FILE               "AWS_IOT_KEY_FILE"
+#define AWS_IOT_CERT_FILE              "AWS_IOT_CERT_FILE"
+#define AWS_IOT_CA_CERT_FILE           "AWS_IOT_CA_CERT_FILE"
+#define AWS_IOT_CREDENTIALS_ENDPOINT   "AWS_IOT_CREDENTIALS_ENDPOINT"
+#define AWS_IOT_THING_NAME             "AWS_IOT_THING_NAME"
+#define AWS_IOT_ROLE_ALIAS             "AWS_IOT_ROLE_ALIAS"
+
 /* declarations */
 static struct flb_aws_provider *standard_chain_create(struct flb_config
                                                       *config,
@@ -51,6 +59,10 @@ static struct flb_aws_provider *standard_chain_create(struct flb_config
                                                       int eks_irsa,
                                                       char *profile);
 
+/* IoT Provider declaration */
+struct flb_aws_provider *flb_iot_provider_create(struct flb_config *config,
+                                                 struct flb_aws_client_generator *generator);
+
 
 /*
  * The standard credential provider chain:
@@ -59,6 +71,7 @@ static struct flb_aws_provider *standard_chain_create(struct flb_config
  * 3. EKS OIDC
  * 4. EC2 IMDS
  * 5. ECS HTTP credentials endpoint
+ * 6. IoT credentials endpoint
  *
  * This provider will evaluate each provider in order, returning the result
  * from the first provider that returns valid credentials.
@@ -566,6 +579,14 @@ static struct flb_aws_provider *standard_chain_create(struct flb_config
 
     mk_list_add(&sub_provider->_head, &implementation->sub_providers);
 
+    /* IoT Provider - check early since it requires specific environment variables */
+    sub_provider = flb_iot_provider_create(config, generator);
+    if (sub_provider) {
+        /* IoT provider can fail if we are not running in IoT */
+        mk_list_add(&sub_provider->_head, &implementation->sub_providers);
+        flb_debug("[aws_credentials] Initialized IoT Provider in standard chain");
+    }
+
     flb_debug("[aws_credentials] creating profile %s provider", profile);
     sub_provider = flb_profile_provider_create(profile);
     if (sub_provider) {