ACLK agent 1 (#7894)

* - Add initial mqtt support

* [WIP] Agent cloud link

- Setup main mqtt thread to connect to a broker using V5 of the MQTT protocol (TBD)

- Send alarms to "netdata/alarm"

- Add error checks to handle connection failures

- Add params for
  Broker, port
  Maximum concurrent sent  / recev messages

- Dummy function to check claiming status

- Generic mqtt_send command to publish message to a base topic , sub topic
  It will end up in the form base_topic/sub_topic

- Add host/port in the connection failure error message

* Test libmosquitto libs

* connect to broker locally (assume localhost:1883)
* subscribe to channel netdata/command
* Test try a reload command to trigger health reload
* publish alerts to netdata/alarm

* - Fix compile issues

* - Use sleep_usec instead of usleep

* - Delay reconnection on failure due to misconfiguration (high cpu usage)

* - Remove the TLS connection config

* - Fix NETDATA_MQTT_INITIALIZATION_SLEEP_WAIT to use seconds

* - Gather ACLK related code under aclk folder
- Add aclk_ functions for abstract layer
- Moved low level libs intergration in mqtt.c

* - Add README.md file with initial comment

* - Clean MQTT v5

* - Code cleanup

* - Remove alarm log for now
- Remove the heart beat

* - Remove message properties for V5

* - Remove message properties for V5 (header)

* Fixed the netdata target to use a local static version of libmosquitto.

The installer does not yet have steps to pull and build the local library.
cd project_root
git clone ssh://git@github.com/netdata/mosquitto mosquitto/
(cd mosquitto/lib && make)      # Ignore the cpp error

This will leave mosquitto/lib/libmosquitto.a for the build process to use.

* - Fix compile issues with older < 1.6 libmosquitto lib

* - Enable alarm events to check it works

- Re arrange includes

- Rework topic to be agent/guid/. Actual id will be
  returned by the is_agent_claimed

* - Add initial metadata info

- Added helper function in web_api

- Added a debug command (info)

* Update the claiming state to retrieve the claimed id.

* - Use define for constants like command and metadata topics

- Function to wait for initialization of the ACLK link

- New aclk_subscribe command with QOS parameter for the mqtt subscription

- Use the is_agent_claimed function to get the real claim id and use it to build the topics
  that will be used for the cloud communication

- Change in netdata-claim.sh.in to write the claim id without a trailing \n

* - Use define for constants like command and metadata topics

- Function to wait for initialization of the ACLK link

- New aclk_subscribe command with QOS parameter for the mqtt subscription

- Use the is_agent_claimed function to get the real claim id and use it to build the topics
  that will be used for the cloud communication

- Change in netdata-claim.sh.in to write the claim id without a trailing \n

* - Remove the alarm log for now

- Add code (but disabled) to send charts

* - Use dummy anon, anon as username and password for testing purposes

* - Use client id anon as well

* Testing without TLS

* Switching TLS back on to fix docker environment.

* - Added query processing
  An incoming URL now calls web_client_api_request_v1_data to handle a request and push the results
  back to the "data" topic

- Move the above processing from the message callback to the query handle loop

- Added helper "pause" , "resume" commands to stop and resume query processing to stress test loading the queue
  with queries before executing them

- Changed the endpoint topics to "meta", and "cmd"  (previously metadata and command)

* make info message follow protocol

* move metadata msg generation into new func

* move metadata msg generation into new func

* - Add metadata to the responses

- Add hook to queue chart changes on creation and dimensions

- Changed the queue mechanism to include delay for X seconds

- Add delayed submittion of charts to the cloud so that all DIMs are defined to avoid resubmission

* - Add additional data info for aclk_queue command

* - Use web_clinet_api_request_v1 to handle the incoming request
  This will handle all requests coming from the cloud

* - Cleanup and aclk_query structure
- Add msg_id parameter
- Enable the incoming JSON request
- Enable the outgoing JSON response

* - Added new thread to handle query processing
- Add lock and cond wait to wakeup thread when queries are submitted
- Cleanup on the main init function

* - Add wait time on agent init, to allow for chart, alarms and other definitions to be completed.
- During the wait time, no queries will be queued

* - Send metadata on query thread init
- New generic create header function for the JSON response
- Pack info and charts into one message
- Modified chart to remove entries (test)
- Modified charts mod to remove entries  e.g alarms and volatile info
- Change input to aclk_update_chart (RRDHOST / instead of hostname)

* - When a request fails, add to the payload
  - We may need to handle in a different key
- Error check in json parsing

* - Add dummy aclk_update_alarm command

* - Move incoming request JSON parsing code away from mqtt.c
- Added #ifdef ACLK_ENABLE so that we can have code merged but disabled by default
- Added version in incoming and outgoing JSON dict

* - Disable code if ACLK_ENABLE is not defined
- Remove references to the mqtt (mosquitto) lib
- Add dummy stubs in mqtt.c for completeness if ACLK_ENABLE is not defined

* - Disable challenge sample code for now

* - Remove libmosquitto from makefile

* - Fix spaces in Makefile.am
- Remove ifdef to avoid warning from LGTM

* - Remove for now the code that builds an along log test message to send to the cloud

* - Add check for ACLK_ENABLE definition and avoid calling the chart update functions

* - Remove commented code

* - Move source files to the correct place (ACLK_PLUGIN_FILES)

* - Remove include file thats not needed

* - Remove include file thats not needed
- Add improved checks for load_claiming_state()

* - Fix error message. Used error() that also logs errno and message

* - Fix some codacy issues

* - Fix more codacy issues, code cleanup

* - Revert code to address codacy warnings

* - Revert spaces added in a previous commit by mistake

* clean up if/else nest

* print error if fopen fails

* minor - error already logs errno

* - Fix version formatting

* - Cleanup all ACLK related compiler warnings
- Re-arrange include files
- Removed unused defines

* - More compilation warnings fixed
- Bug with thread creation fixed

* - Add condition to skip compilation of the ACLK code entirely. Add env variable ACLK="yes" to enable

* - Add condition to skip the libmosquitto

* - Change feature flag from ACLK_ENABLE to ENABLE_ACLK in accordance with the rest of ENABLE_xx flags
- Typo in info message fix

Co-authored-by: Andrew Moss <1043609+amoss@users.noreply.github.com>
Co-authored-by: Timo <6674623+underhood@users.noreply.github.com>

3 files changed, 34 insertions, 18 deletions

diff --git a/claim/claim.c b/claim/claim.c
index 75f0a437d6..72b6b42914 100644
--- a/claim/claim.c
+++ b/claim/claim.c
@@ -21,13 +21,12 @@ static char *claiming_errors[] = {
         "internal server error"                         // 12
 };
 
-#define AGENT_UNCLAIMED 0
-#define AGENT_CLAIMED 1
-static uint8_t claiming_status = AGENT_UNCLAIMED;
 
-uint8_t is_agent_claimed(void)
+static char *claimed_id = NULL;
+
+char *is_agent_claimed(void)
 {
-    return (AGENT_CLAIMED == claiming_status);
+    return claimed_id;
 }
 
 #define CLAIMING_COMMAND_LENGTH 16384
@@ -64,8 +63,7 @@ void claim_agent(char *claiming_arguments)
     exit_code = mypclose(fp, command_pid);
     info("Agent claiming command returned with code %d", exit_code);
     if (0 == exit_code) {
-        claiming_status = AGENT_CLAIMED;
-        info("Agent successfully claimed.");
+        load_claiming_state();
         return;
     }
     if (exit_code < 0) {
@@ -85,19 +83,37 @@ void claim_agent(char *claiming_arguments)
 
 void load_claiming_state(void)
 {
-    info("The claiming feature is under development and still subject to change before the next release");
-    return;
+    if (claimed_id != NULL) {
+        freez(claimed_id);
+        claimed_id = NULL;
+    }
 
     char filename[FILENAME_MAX + 1];
     struct stat statbuf;
 
-    snprintfz(filename, FILENAME_MAX, "%s/claim.d/is_claimed", netdata_configured_user_config_dir);
+    snprintfz(filename, FILENAME_MAX, "%s/claim.d/claimed_id", netdata_configured_user_config_dir);
+
     // check if the file exists
     if (lstat(filename, &statbuf) != 0) {
-        info("File '%s' was not found. Setting state to AGENT_UNCLAIMED.", filename);
-        claiming_status = AGENT_UNCLAIMED;
-   } else {
-        info("File '%s' was found. Setting state to AGENT_CLAIMED.", filename);
-        claiming_status = AGENT_CLAIMED;
+        info("lstat on File '%s' failed reason=\"%s\". Setting state to AGENT_UNCLAIMED.", filename, strerror(errno));
+        return;
     }
+    if (unlikely(statbuf.st_size == 0)) {
+        info("File '%s' has no contents. Setting state to AGENT_UNCLAIMED.", filename);
+        return;
+    }
+
+    FILE *f = fopen(filename, "rt");
+    if (unlikely(f == NULL)) {
+        error("File '%s' cannot be opened. Setting state to AGENT_UNCLAIMED.", filename);
+        return;
+    }
+
+    claimed_id = callocz(1, statbuf.st_size + 1);
+    size_t bytes_read = fread(claimed_id, 1, statbuf.st_size, f);
+    claimed_id[bytes_read] = 0;
+    info("File '%s' was found. Setting state to AGENT_CLAIMED.", filename);
+    fclose(f);
+
+    snprintfz(filename, FILENAME_MAX, "%s/claim.d/private.pem", netdata_configured_user_config_dir);
 }
diff --git a/claim/claim.h b/claim/claim.h
index 3b2b867434..8eda3560b6 100644
--- a/claim/claim.h
+++ b/claim/claim.h
@@ -8,7 +8,7 @@
 extern char *claiming_pending_arguments;
 
 void claim_agent(char *claiming_arguments);
-uint8_t is_agent_claimed(void);
+char *is_agent_claimed(void);
 void load_claiming_state(void);
 
 #endif //NETDATA_CLAIM_H
diff --git a/claim/netdata-claim.sh.in b/claim/netdata-claim.sh.in
index e565e3de28..42eb99d718 100755
--- a/claim/netdata-claim.sh.in
+++ b/claim/netdata-claim.sh.in
@@ -211,6 +211,6 @@ if [ "${HTTP_STATUS_CODE}" -ne 200 ] ; then
 fi
 
 rm -f "${CLAIMING_DIR}/tmpout.txt"
-touch "${CLAIMING_DIR}/is_claimed"
+echo -n "${ID}" >"${CLAIMING_DIR}/claimed_id"
 rm -f "${CLAIMING_DIR}/token"
-echo >&2 "Agent was successfully claimed."
\ No newline at end of file
+echo >&2 "Agent was successfully claimed."