Files
tromcho.net/src/client/etcd_state_client_http.cpp
T

488 lines
18 KiB
C++

// Copyright (c) Vitaliy Filippov, 2019+
// License: VNPL-1.1 or GNU GPL-2.0+ (see README.md for details)
#include "etcd_state_client_http.h"
#include "addr_util.h"
#include "http_client.h"
#include "str_util.h"
etcd_state_client_http_t::etcd_state_client_http_t(timerfd_manager_t *tfd)
{
this->tfd = tfd;
}
etcd_state_client_http_t::~etcd_state_client_http_t()
{
stop_ws_keepalive();
if (etcd_watch_ws)
{
http_close(etcd_watch_ws);
etcd_watch_ws = NULL;
}
if (keepalive_client)
{
http_close(keepalive_client);
keepalive_client = NULL;
}
if (load_pgs_timer_id >= 0)
{
tfd->clear_timer(load_pgs_timer_id);
load_pgs_timer_id = -1;
}
etcd_watches_initialised = -1;
}
void etcd_state_client_http_t::etcd_add_watch(json11::Json watch)
{
if (etcd_watch_ws)
{
http_post_message(etcd_watch_ws, WS_TEXT, watch.dump());
}
}
void etcd_state_client_http_t::etcd_call_oneshot(std::string etcd_address, std::string api, json11::Json payload,
int timeout, std::function<void(std::string, json11::Json)> callback)
{
std::string etcd_api_path;
int pos = etcd_address.find('/');
if (pos >= 0)
{
etcd_api_path = etcd_address.substr(pos);
etcd_address = etcd_address.substr(0, pos);
}
std::string req = payload.dump();
req = "POST "+etcd_api_path+api+" HTTP/1.1\r\n"
"Host: "+etcd_address+"\r\n"
"Content-Type: application/json\r\n"
"Content-Length: "+std::to_string(req.size())+"\r\n"
"Connection: close\r\n"
"\r\n"+req;
auto http_cli = http_init(tfd);
auto cb = [http_cli, callback](const http_response_t *response)
{
std::string err;
json11::Json data;
response->parse_json_response(err, data);
callback(err, data);
http_close(http_cli);
};
http_request(http_cli, etcd_address, req, { .timeout = timeout }, cb);
}
void etcd_state_client_http_t::etcd_call(std::string api, json11::Json payload, int timeout,
int retries, int interval, std::function<void(std::string, json11::Json)> callback)
{
if (!etcd_addresses.size() && !etcd_local.size())
{
fprintf(stderr, "etcd_address is missing in Vitastor configuration\n");
exit(1);
}
pick_next_etcd();
std::string etcd_address = selected_etcd_address;
std::string etcd_api_path;
int pos = etcd_address.find('/');
if (pos >= 0)
{
etcd_api_path = etcd_address.substr(pos);
etcd_address = etcd_address.substr(0, pos);
}
std::string req = payload.dump();
req = "POST "+etcd_api_path+api+" HTTP/1.1\r\n"
"Host: "+etcd_address+"\r\n"
"Content-Type: application/json\r\n"
"Content-Length: "+std::to_string(req.size())+"\r\n"
"Connection: keep-alive\r\n"
"Keep-Alive: timeout="+std::to_string(etcd_keepalive_timeout)+"\r\n"
"\r\n"+req;
retries--;
auto cb = [this, api, payload, timeout, retries, interval, callback,
cur_addr = selected_etcd_address](const http_response_t *response)
{
std::string err;
json11::Json data;
response->parse_json_response(err, data);
if (err != "")
{
if (cur_addr == selected_etcd_address)
selected_etcd_address = "";
if (retries > 0)
{
if (this->log_level > 0)
{
fprintf(
stderr, "Warning: etcd request failed: %s, retrying %d more times\n",
err.c_str(), retries
);
}
if (interval > 0)
{
// FIXME: Prevent destruction of etcd_state_client if timers or requests are active
tfd->set_timer(interval, false, [this, api, payload, timeout, retries, interval, callback](int)
{
etcd_call(api, payload, timeout, retries, interval, callback);
});
}
else
etcd_call(api, payload, timeout, retries, interval, callback);
}
else
callback(err, data);
}
else
callback(err, data);
};
if (!keepalive_client)
{
keepalive_client = http_init(tfd);
}
http_request(keepalive_client, etcd_address, req, { .timeout = timeout, .keepalive = true }, cb);
}
void etcd_state_client_http_t::parse_config(const json11::Json & config)
{
auto old_etcd_ws_keepalive_interval = this->etcd_ws_keepalive_interval;
etcd_state_client_t::parse_config(config);
if (this->etcd_ws_keepalive_interval != old_etcd_ws_keepalive_interval && ws_keepalive_timer >= 0)
{
stop_ws_keepalive();
start_ws_keepalive();
}
}
void etcd_state_client_http_t::pick_next_etcd()
{
if (selected_etcd_address != "")
return;
if (addresses_to_try.size() == 0)
{
// Prefer local etcd, if any
for (int i = 0; i < etcd_local.size(); i++)
addresses_to_try.push_back(etcd_local[i]);
std::vector<int> ns;
for (int i = 0; i < etcd_addresses.size(); i++)
ns.push_back(i);
if (!rand_initialized)
{
timespec tv;
clock_gettime(CLOCK_REALTIME, &tv);
srand48(tv.tv_sec*1000000000 + tv.tv_nsec);
rand_initialized = true;
}
while (ns.size())
{
int i = lrand48() % ns.size();
addresses_to_try.push_back(etcd_addresses[ns[i]]);
ns.erase(ns.begin()+i, ns.begin()+i+1);
}
}
selected_etcd_address = addresses_to_try[0];
addresses_to_try.erase(addresses_to_try.begin(), addresses_to_try.begin()+1);
}
void etcd_state_client_http_t::start_etcd_watcher()
{
if (!etcd_addresses.size() && !etcd_local.size())
{
fprintf(stderr, "etcd_address is missing in Vitastor configuration\n");
exit(1);
}
pick_next_etcd();
std::string etcd_address = selected_etcd_address;
std::string etcd_api_path;
int pos = etcd_address.find('/');
if (pos >= 0)
{
etcd_api_path = etcd_address.substr(pos);
etcd_address = etcd_address.substr(0, pos);
}
etcd_watches_initialised = 0;
ws_alive = 1;
if (etcd_watch_ws)
{
http_close(etcd_watch_ws);
etcd_watch_ws = NULL;
}
if (this->log_level > 1)
{
fprintf(stderr, "Trying to connect to etcd websocket at %s, watch from revision %ju/%ju/%ju\n", etcd_address.c_str(),
etcd_watch_revision_config, etcd_watch_revision_osd, etcd_watch_revision_pg);
}
etcd_watch_ws = open_websocket(tfd, etcd_address, etcd_api_path+"/watch", etcd_slow_timeout,
[this, cur_addr = selected_etcd_address](const http_response_t *msg)
{
if (msg->body.length())
{
ws_alive = 1;
std::string json_err;
json11::Json data = json11::Json::parse(msg->body, json_err);
if (json_err != "")
{
fprintf(stderr, "Bad JSON in etcd event: %s, ignoring event\n", json_err.c_str());
}
else
{
uint64_t watch_id = data["result"]["watch_id"].uint64_value();
if (data["result"]["created"].bool_value())
{
if (watch_id == ETCD_CONFIG_WATCH_ID ||
watch_id == ETCD_PG_STATE_WATCH_ID ||
watch_id == ETCD_OSD_STATE_WATCH_ID)
{
etcd_watches_initialised++;
}
if (etcd_watches_initialised == ETCD_TOTAL_WATCHES && this->log_level > 0)
{
fprintf(stderr, "Successfully subscribed to etcd at %s, revision %ju/%ju/%ju\n", cur_addr.c_str(),
etcd_watch_revision_config, etcd_watch_revision_osd, etcd_watch_revision_pg);
}
}
if (data["result"]["canceled"].bool_value())
{
// etcd watch canceled, maybe because the revision was compacted
if (data["result"]["compact_revision"].uint64_value())
{
// we may miss events if we proceed
// so we should restart from the beginning if we can
if (on_reload_hook != NULL)
{
// check to not trigger on_reload_hook multiple times
if (etcd_watch_ws != NULL)
{
fprintf(stderr, "Revisions before %ju were compacted by etcd, reloading state\n",
data["result"]["compact_revision"].uint64_value());
http_close(etcd_watch_ws);
etcd_watch_ws = NULL;
etcd_watch_revision_config = etcd_watch_revision_osd = etcd_watch_revision_pg = 0;
on_reload_hook();
}
return;
}
else
{
fprintf(stderr, "Revisions before %ju were compacted by etcd, exiting\n",
data["result"]["compact_revision"].uint64_value());
exit(1);
}
}
else
{
fprintf(stderr, "Watch canceled by etcd, reason: %s, exiting\n", data["result"]["cancel_reason"].string_value().c_str());
exit(1);
}
}
// Save revision only if it's present in the message - because sometimes etcd sends something without a header, like:
// {"error": {"grpc_code": 14, "http_code": 503, "http_status": "Service Unavailable", "message": "error reading from server: EOF"}}
// Also don't save revision from the initial created: true messages because they always contain the latest revision
if (etcd_watches_initialised == ETCD_TOTAL_WATCHES &&
!data["result"]["header"]["revision"].is_null() &&
!data["result"]["created"].bool_value())
{
// Restart watchers from the same revision number as in the last received message,
// not from the next one to protect against revision being split into multiple messages,
// even though etcd guarantees not to do that **within a single watcher** without fragment=true:
// https://etcd.io/docs/v3.5/learning/api_guarantees/#watch-apis
// Revision contents are ALWAYS split into separate messages for different watchers though!
// So generally we have to resume each watcher from its own revision...
// Progress messages may have watch_id=-1 if sent on behalf of multiple watchers though.
// And antietcd has an advanced semantic which merges the same revision for all watchers
// into one message and just omits watch_id.
// So we also have to handle the case where watch_id is -1 or not present (0).
auto watch_rev = data["result"]["header"]["revision"].uint64_value();
if (!watch_id || watch_id == UINT64_MAX)
etcd_watch_revision_config = etcd_watch_revision_osd = etcd_watch_revision_pg = watch_rev;
else if (watch_id == ETCD_CONFIG_WATCH_ID)
etcd_watch_revision_config = watch_rev;
else if (watch_id == ETCD_PG_STATE_WATCH_ID)
etcd_watch_revision_pg = watch_rev;
else if (watch_id == ETCD_OSD_STATE_WATCH_ID)
etcd_watch_revision_osd = watch_rev;
addresses_to_try.clear();
}
// First gather all changes into a hash to remove multiple overwrites
std::map<std::string, etcd_kv_t> changes;
for (auto & ev: data["result"]["events"].array_items())
{
auto kv = parse_etcd_kv(ev["kv"]);
if (kv.key != "")
{
changes[kv.key] = kv;
}
}
for (auto & kv: changes)
{
if (this->log_level > 3)
{
fprintf(stderr, "Incoming event: %s -> %s\n", kv.first.c_str(), kv.second.value.dump().c_str());
}
parse_state(kv.second);
}
// React to changes
if (on_change_hook != NULL)
{
on_change_hook(changes);
}
}
}
if (msg->eof)
{
fprintf(stderr, "Disconnected from etcd %s\n", cur_addr.c_str());
if (cur_addr == selected_etcd_address)
selected_etcd_address = "";
if (etcd_watch_ws)
{
http_close(etcd_watch_ws);
etcd_watch_ws = NULL;
}
if (etcd_watches_initialised == 0)
{
// Connection not established, retry in <etcd_quick_timeout>
tfd->set_timer(etcd_quick_timeout, false, [this](int)
{
start_etcd_watcher();
});
}
else if (etcd_watches_initialised > 0)
{
// Connection was live, retry immediately
etcd_watches_initialised = 0;
start_etcd_watcher();
}
}
});
http_post_message(etcd_watch_ws, WS_TEXT, json11::Json(json11::Json::object {
{ "create_request", json11::Json::object {
{ "key", base64_encode(etcd_prefix+"/config/") },
{ "range_end", base64_encode(etcd_prefix+"/config0") },
{ "start_revision", etcd_watch_revision_config },
{ "watch_id", ETCD_CONFIG_WATCH_ID },
{ "progress_notify", true },
} }
}).dump());
http_post_message(etcd_watch_ws, WS_TEXT, json11::Json(json11::Json::object {
{ "create_request", json11::Json::object {
{ "key", base64_encode(etcd_prefix+"/osd/state/") },
{ "range_end", base64_encode(etcd_prefix+"/osd/state0") },
{ "start_revision", etcd_watch_revision_osd },
{ "watch_id", ETCD_OSD_STATE_WATCH_ID },
{ "progress_notify", true },
} }
}).dump());
http_post_message(etcd_watch_ws, WS_TEXT, json11::Json(json11::Json::object {
{ "create_request", json11::Json::object {
{ "key", base64_encode(etcd_prefix+"/pg/") },
{ "range_end", base64_encode(etcd_prefix+"/pg0") },
{ "start_revision", etcd_watch_revision_pg },
{ "watch_id", ETCD_PG_STATE_WATCH_ID },
{ "progress_notify", true },
} }
}).dump());
// FIXME: Do not watch /pg/history/ at all in client code (not in OSD)
if (on_start_watcher_hook)
{
on_start_watcher_hook(etcd_watch_ws);
}
start_ws_keepalive();
}
void etcd_state_client_http_t::stop_ws_keepalive()
{
if (ws_keepalive_timer >= 0)
{
tfd->clear_timer(ws_keepalive_timer);
ws_keepalive_timer = -1;
}
}
void etcd_state_client_http_t::start_ws_keepalive()
{
if (ws_keepalive_timer < 0)
{
ws_keepalive_timer = tfd->set_timer(etcd_ws_keepalive_interval*1000, true, [this](int)
{
if (!etcd_watch_ws || etcd_watches_initialised < ETCD_TOTAL_WATCHES)
{
// Do nothing
}
else if (!ws_alive)
{
if (this->log_level > 0)
{
fprintf(stderr, "Websocket ping failed, disconnecting from etcd %s\n", selected_etcd_address.c_str());
}
if (etcd_watch_ws)
{
http_close(etcd_watch_ws);
etcd_watch_ws = NULL;
}
start_etcd_watcher();
}
else
{
ws_alive = 0;
http_post_message(etcd_watch_ws, WS_TEXT, json11::Json(json11::Json::object {
{ "progress_request", json11::Json::object { } }
}).dump());
}
});
}
}
void etcd_state_client_http_t::load_global_config()
{
etcd_state_client_t::load_global_config([this](const std::string & err)
{
if (err != "")
{
fprintf(stderr, "Error reading configuration from etcd: %s\n", err.c_str());
if (infinite_start)
{
tfd->set_timer(etcd_slow_timeout, false, [this](int timer_id)
{
load_global_config();
});
}
else
{
exit(1);
}
}
});
}
void etcd_state_client_http_t::load_pgs()
{
timespec tv;
clock_gettime(CLOCK_REALTIME, &tv);
uint64_t ms_passed = (tv.tv_sec-etcd_last_reload.tv_sec)*1000 + (tv.tv_nsec-etcd_last_reload.tv_nsec)/1000000;
if (ms_passed < etcd_min_reload_interval)
{
if (load_pgs_timer_id < 0)
{
load_pgs_timer_id = tfd->set_timer(etcd_min_reload_interval+50-ms_passed, false, [this](int) { load_pgs(); });
}
return;
}
etcd_last_reload = tv;
if (load_pgs_timer_id >= 0)
{
tfd->clear_timer(load_pgs_timer_id);
load_pgs_timer_id = -1;
}
etcd_state_client_t::load_pgs([this](const std::string & err)
{
if (err != "")
{
// Retry indefinitely
fprintf(stderr, "Error loading PGs from etcd: %s\n", err.c_str());
tfd->set_timer(etcd_slow_timeout, false, [this](int timer_id)
{
load_pgs();
});
}
else
{
start_etcd_watcher();
}
});
}