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credentials_provider_impl.cc
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credentials_provider_impl.cc
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#include "source/extensions/common/aws/credentials_provider_impl.h"
#include <chrono>
#include <cstddef>
#include <fstream>
#include <memory>
#include "envoy/common/exception.h"
#include "source/common/common/lock_guard.h"
#include "source/common/http/message_impl.h"
#include "source/common/http/utility.h"
#include "source/common/json/json_loader.h"
#include "source/common/runtime/runtime_features.h"
#include "source/common/tracing/http_tracer_impl.h"
#include "source/extensions/common/aws/utility.h"
#include "absl/strings/str_format.h"
#include "absl/strings/str_split.h"
#include "fmt/chrono.h"
#include "metadata_fetcher.h"
namespace Envoy {
namespace Extensions {
namespace Common {
namespace Aws {
using std::chrono::seconds;
namespace {
constexpr char AWS_ACCESS_KEY_ID[] = "AWS_ACCESS_KEY_ID";
constexpr char AWS_SECRET_ACCESS_KEY[] = "AWS_SECRET_ACCESS_KEY";
constexpr char AWS_SESSION_TOKEN[] = "AWS_SESSION_TOKEN";
constexpr char AWS_ROLE_ARN[] = "AWS_ROLE_ARN";
constexpr char AWS_WEB_IDENTITY_TOKEN_FILE[] = "AWS_WEB_IDENTITY_TOKEN_FILE";
constexpr char AWS_ROLE_SESSION_NAME[] = "AWS_ROLE_SESSION_NAME";
constexpr char CREDENTIALS[] = "Credentials";
constexpr char ACCESS_KEY_ID[] = "AccessKeyId";
constexpr char SECRET_ACCESS_KEY[] = "SecretAccessKey";
constexpr char TOKEN[] = "Token";
constexpr char EXPIRATION[] = "Expiration";
constexpr char EXPIRATION_FORMAT[] = "%E4Y-%m-%dT%H:%M:%S%z";
constexpr char TRUE[] = "true";
constexpr char SESSION_TOKEN[] = "SessionToken";
constexpr char WEB_IDENTITY_RESPONSE_ELEMENT[] = "AssumeRoleWithWebIdentityResponse";
constexpr char WEB_IDENTITY_RESULT_ELEMENT[] = "AssumeRoleWithWebIdentityResult";
constexpr char AWS_CONTAINER_CREDENTIALS_RELATIVE_URI[] = "AWS_CONTAINER_CREDENTIALS_RELATIVE_URI";
constexpr char AWS_CONTAINER_CREDENTIALS_FULL_URI[] = "AWS_CONTAINER_CREDENTIALS_FULL_URI";
constexpr char AWS_CONTAINER_AUTHORIZATION_TOKEN[] = "AWS_CONTAINER_AUTHORIZATION_TOKEN";
constexpr char AWS_CONTAINER_AUTHORIZATION_TOKEN_FILE[] = "AWS_CONTAINER_AUTHORIZATION_TOKEN_FILE";
constexpr char AWS_EC2_METADATA_DISABLED[] = "AWS_EC2_METADATA_DISABLED";
constexpr std::chrono::hours REFRESH_INTERVAL{1};
constexpr std::chrono::seconds REFRESH_GRACE_PERIOD{5};
constexpr char EC2_METADATA_HOST[] = "169.254.169.254:80";
constexpr char CONTAINER_METADATA_HOST[] = "169.254.170.2:80";
constexpr char EC2_IMDS_TOKEN_RESOURCE[] = "/latest/api/token";
constexpr char EC2_IMDS_TOKEN_HEADER[] = "X-aws-ec2-metadata-token";
constexpr char EC2_IMDS_TOKEN_TTL_HEADER[] = "X-aws-ec2-metadata-token-ttl-seconds";
constexpr char EC2_IMDS_TOKEN_TTL_DEFAULT_VALUE[] = "21600";
constexpr char SECURITY_CREDENTIALS_PATH[] = "/latest/meta-data/iam/security-credentials";
constexpr char EC2_METADATA_CLUSTER[] = "ec2_instance_metadata_server_internal";
constexpr char CONTAINER_METADATA_CLUSTER[] = "ecs_task_metadata_server_internal";
constexpr char STS_TOKEN_CLUSTER[] = "sts_token_service_internal";
} // namespace
Credentials ConfigCredentialsProvider::getCredentials() {
ENVOY_LOG(debug, "Getting AWS credentials from static configuration");
return credentials_;
}
Credentials EnvironmentCredentialsProvider::getCredentials() {
ENVOY_LOG(debug, "Getting AWS credentials from the environment");
const auto access_key_id = absl::NullSafeStringView(std::getenv(AWS_ACCESS_KEY_ID));
if (access_key_id.empty()) {
return Credentials();
}
const auto secret_access_key = absl::NullSafeStringView(std::getenv(AWS_SECRET_ACCESS_KEY));
const auto session_token = absl::NullSafeStringView(std::getenv(AWS_SESSION_TOKEN));
ENVOY_LOG(debug, "Found following AWS credentials in the environment: {}={}, {}={}, {}={}",
AWS_ACCESS_KEY_ID, access_key_id, AWS_SECRET_ACCESS_KEY,
secret_access_key.empty() ? "" : "*****", AWS_SESSION_TOKEN,
session_token.empty() ? "" : "*****");
return Credentials(access_key_id, secret_access_key, session_token);
}
void CachedCredentialsProviderBase::refreshIfNeeded() {
if (needsRefresh()) {
refresh();
}
}
// Logic for async metadata refresh is as follows:
// Once server has initialized (init target) and per inherited class (instance profile, container
// credentials, web identity)
// 1. Create a single cluster for async handling
// 2. Create tls slot to hold cluster name and a refresh timer pointer. tls slot instantiation of
// ThreadLocalCredentialsCache will register the subclass as a callback handler
// 3. Create refresh timer in the main thread and put it in the slot. Add cluster to
// onClusterAddOrDelete pending cluster list inside tls.
// 4. When cluster is alive, onClusterAddOrDelete is called which enables the refresh timer. Cluster
// is then deleted from the pending cluster list to prevent repeated refresh when other threads come
// alive.
// 5. Initial credential refresh occurs in main thread and continues in main thread periodically
// refreshing based on expiration time
//
// TODO(suniltheta): The field context is of type ServerFactoryContextOptRef so
// that an optional empty value can be set. Especially in aws iam plugin the cluster manager
// obtained from server factory context object is not fully initialized due to the
// reasons explained in https://github.com/envoyproxy/envoy/issues/27586 which cannot
// utilize http async client here to fetch AWS credentials. For time being if context
// is empty then will use libcurl to fetch the credentials.
MetadataCredentialsProviderBase::MetadataCredentialsProviderBase(
Api::Api& api, ServerFactoryContextOptRef context,
const CurlMetadataFetcher& fetch_metadata_using_curl,
CreateMetadataFetcherCb create_metadata_fetcher_cb, absl::string_view cluster_name,
const envoy::config::cluster::v3::Cluster::DiscoveryType cluster_type, absl::string_view uri,
MetadataFetcher::MetadataReceiver::RefreshState refresh_state,
std::chrono::seconds initialization_timer)
: api_(api), context_(context), fetch_metadata_using_curl_(fetch_metadata_using_curl),
create_metadata_fetcher_cb_(create_metadata_fetcher_cb),
cluster_name_(std::string(cluster_name)), cluster_type_(cluster_type), uri_(std::string(uri)),
cache_duration_(getCacheDuration()), refresh_state_(refresh_state),
initialization_timer_(initialization_timer), debug_name_(cluster_name) {
// Async provider cluster setup
if (useHttpAsyncClient() && context_) {
// Set up metadata credentials statistics
scope_ = api.rootScope().createScope(
fmt::format("aws.metadata_credentials_provider.{}.", cluster_name_));
stats_ = std::make_shared<MetadataCredentialsProviderStats>(MetadataCredentialsProviderStats{
ALL_METADATACREDENTIALSPROVIDER_STATS(POOL_COUNTER(*scope_), POOL_GAUGE(*scope_))});
stats_->metadata_refresh_state_.set(uint64_t(refresh_state_));
init_target_ = std::make_unique<Init::TargetImpl>(debug_name_, [this]() -> void {
tls_slot_ =
ThreadLocal::TypedSlot<ThreadLocalCredentialsCache>::makeUnique(context_->threadLocal());
tls_slot_->set(
[&](Event::Dispatcher&) { return std::make_shared<ThreadLocalCredentialsCache>(*this); });
createCluster(true);
init_target_->ready();
init_target_.reset();
});
context_->initManager().add(*init_target_);
}
};
MetadataCredentialsProviderBase::ThreadLocalCredentialsCache::~ThreadLocalCredentialsCache() {
for (const auto& it : pending_clusters_) {
for (auto cluster : it.second) {
cluster->cancel();
}
}
}
void MetadataCredentialsProviderBase::createCluster(bool new_timer) {
auto cluster = Utility::createInternalClusterStatic(cluster_name_, cluster_type_, uri_);
// Async credential refresh timer. Only create this if it is the first time we're creating a
// cluster
if (new_timer) {
cache_duration_timer_ = context_->mainThreadDispatcher().createTimer([this]() -> void {
stats_->credential_refreshes_performed_.inc();
refresh();
});
// Store the timer in pending cluster list for use in onClusterAddOrUpdate
cluster_load_handle_ = std::make_unique<LoadClusterEntryHandleImpl>(
(*tls_slot_)->pending_clusters_, cluster_name_, cache_duration_timer_);
const auto cluster_type_str = envoy::config::cluster::v3::Cluster::DiscoveryType_descriptor()
->FindValueByNumber(cluster.type())
->name();
absl::string_view host_port;
absl::string_view path;
Http::Utility::extractHostPathFromUri(uri_, host_port, path);
ENVOY_LOG_MISC(info,
"Added a {} internal cluster [name: {}, address:{}] to fetch aws "
"credentials",
cluster_type_str, cluster_name_, host_port);
}
context_->clusterManager().addOrUpdateCluster(cluster, "");
}
// A thread local callback that occurs on every worker thread during cluster initialization.
// Credential refresh is only allowed on the main thread as its execution logic is not thread safe.
// So the first thread local cluster that comes online will post a job to the main thread to perform
// credential refresh logic. Further thread local clusters that come online will not trigger the
// timer.
void MetadataCredentialsProviderBase::ThreadLocalCredentialsCache::onClusterAddOrUpdate(
absl::string_view cluster_name, Upstream::ThreadLocalClusterCommand&) {
Thread::LockGuard lock(lock_);
if (cluster_name == parent_.cluster_name_) {
// Cluster has been created
auto already_creating_ = parent_.is_creating_.exchange(false);
if (already_creating_) {
parent_.stats_->clusters_readded_after_cds_.inc();
}
}
auto it = pending_clusters_.find(cluster_name);
if (it != pending_clusters_.end()) {
for (auto* cluster : it->second) {
auto& timer = cluster->timer_;
cluster->cancel();
ENVOY_LOG_MISC(debug, "Async cluster {} ready, performing initial credential refresh",
parent_.cluster_name_);
parent_.context_->mainThreadDispatcher().post([&timer]() {
if (!timer->enabled()) {
timer->enableTimer(std::chrono::milliseconds(1));
}
});
}
pending_clusters_.erase(it);
}
}
// If we have a cluster removal event, such as during cds update, recreate the cluster but leave the
// refresh timer as-is
void MetadataCredentialsProviderBase::ThreadLocalCredentialsCache::onClusterRemoval(
const std::string& name) {
if (name == parent_.cluster_name_) {
// Atomic check to prevent excessive cluster re-adds
auto already_creating_ = parent_.is_creating_.exchange(true);
if (!already_creating_) {
parent_.stats_->clusters_removed_by_cds_.inc();
// Recreate our cluster if it has been deleted via CDS
parent_.context_->mainThreadDispatcher().post([this]() { parent_.createCluster(false); });
ENVOY_LOG_MISC(debug, "Re-adding async credential cluster {}", parent_.cluster_name_);
}
}
};
// Async provider uses its own refresh mechanism. Calling refreshIfNeeded() here is not thread safe.
Credentials MetadataCredentialsProviderBase::getCredentials() {
if (useHttpAsyncClient()) {
if (tls_slot_) {
return *(*tls_slot_)->credentials_.get();
} else {
return Credentials();
}
} else {
// Refresh for non async case
refreshIfNeeded();
return cached_credentials_;
}
}
std::chrono::seconds MetadataCredentialsProviderBase::getCacheDuration() {
return std::chrono::seconds(
REFRESH_INTERVAL -
REFRESH_GRACE_PERIOD /*TODO: Add jitter from context.api().randomGenerator()*/);
}
void MetadataCredentialsProviderBase::handleFetchDone() {
if (useHttpAsyncClient() && context_) {
if (cache_duration_timer_ && !cache_duration_timer_->enabled()) {
// Receiver state handles the initial credential refresh scenario. If for some reason we are
// unable to perform credential refresh after cluster initialization has completed, we use a
// short timer to keep retrying. Once successful, we fall back to the normal cache duration
// or whatever expiration is provided in the credential payload
if (refresh_state_ == MetadataFetcher::MetadataReceiver::RefreshState::FirstRefresh) {
cache_duration_timer_->enableTimer(initialization_timer_);
ENVOY_LOG_MISC(debug, "Metadata fetcher initialization failed, retrying in {}",
std::chrono::seconds(initialization_timer_.count()));
// Timer begins at 2 seconds and doubles each time, to a maximum of 32 seconds. This avoids
// excessive retries against STS or instance metadata service
if (initialization_timer_ < std::chrono::seconds(32)) {
initialization_timer_ = initialization_timer_ * 2;
}
} else {
// If our returned token had an expiration time, use that to set the cache duration
if (expiration_time_.has_value()) {
const auto now = api_.timeSource().systemTime();
cache_duration_ =
std::chrono::duration_cast<std::chrono::seconds>(expiration_time_.value() - now);
ENVOY_LOG_MISC(debug,
"Metadata fetcher setting credential refresh to {}, based on "
"credential expiration",
std::chrono::seconds(cache_duration_.count()));
} else {
cache_duration_ = getCacheDuration();
ENVOY_LOG_MISC(
debug,
"Metadata fetcher setting credential refresh to {}, based on default expiration",
std::chrono::seconds(cache_duration_.count()));
}
cache_duration_timer_->enableTimer(cache_duration_);
}
}
}
}
void MetadataCredentialsProviderBase::setCredentialsToAllThreads(
CredentialsConstUniquePtr&& creds) {
CredentialsConstSharedPtr shared_credentials = std::move(creds);
if (tls_slot_) {
tls_slot_->runOnAllThreads([shared_credentials](OptRef<ThreadLocalCredentialsCache> obj) {
obj->credentials_ = shared_credentials;
});
}
}
bool MetadataCredentialsProviderBase::useHttpAsyncClient() {
return Runtime::runtimeFeatureEnabled(
"envoy.reloadable_features.use_http_client_to_fetch_aws_credentials");
}
bool CredentialsFileCredentialsProvider::needsRefresh() {
return api_.timeSource().systemTime() - last_updated_ > REFRESH_INTERVAL;
}
void CredentialsFileCredentialsProvider::refresh() {
ENVOY_LOG(debug, "Getting AWS credentials from the credentials file");
auto credentials_file = Utility::getCredentialFilePath();
auto profile = profile_.empty() ? Utility::getCredentialProfileName() : profile_;
ENVOY_LOG(debug, "Credentials file path = {}, profile name = {}", credentials_file, profile);
extractCredentials(credentials_file, profile);
}
void CredentialsFileCredentialsProvider::extractCredentials(const std::string& credentials_file,
const std::string& profile) {
// Update last_updated_ now so that even if this function returns before successfully
// extracting credentials, this function won't be called again until after the REFRESH_INTERVAL.
// This prevents envoy from attempting and failing to read the credentials file on every request
// if there are errors extracting credentials from it (e.g. if the credentials file doesn't
// exist).
last_updated_ = api_.timeSource().systemTime();
std::string access_key_id, secret_access_key, session_token;
absl::flat_hash_map<std::string, std::string> elements = {
{AWS_ACCESS_KEY_ID, ""}, {AWS_SECRET_ACCESS_KEY, ""}, {AWS_SESSION_TOKEN, ""}};
absl::flat_hash_map<std::string, std::string>::iterator it;
Utility::resolveProfileElements(credentials_file, profile, elements);
// if profile file fails to load, or these elements are not found in the profile, their values
// will remain blank when retrieving them from the hash map
access_key_id = elements.find(AWS_ACCESS_KEY_ID)->second;
secret_access_key = elements.find(AWS_SECRET_ACCESS_KEY)->second;
session_token = elements.find(AWS_SESSION_TOKEN)->second;
if (access_key_id.empty() || secret_access_key.empty()) {
// Return empty credentials if we're unable to retrieve from profile
cached_credentials_ = Credentials();
} else {
ENVOY_LOG(debug, "Found following AWS credentials for profile '{}' in {}: {}={}, {}={}, {}={}",
profile, credentials_file, AWS_ACCESS_KEY_ID, access_key_id, AWS_SECRET_ACCESS_KEY,
secret_access_key.empty() ? "" : "*****", AWS_SESSION_TOKEN,
session_token.empty() ? "" : "*****");
cached_credentials_ = Credentials(access_key_id, secret_access_key, session_token);
}
last_updated_ = api_.timeSource().systemTime();
}
InstanceProfileCredentialsProvider::InstanceProfileCredentialsProvider(
Api::Api& api, ServerFactoryContextOptRef context,
const CurlMetadataFetcher& fetch_metadata_using_curl,
CreateMetadataFetcherCb create_metadata_fetcher_cb,
MetadataFetcher::MetadataReceiver::RefreshState refresh_state,
std::chrono::seconds initialization_timer,
absl::string_view cluster_name)
: MetadataCredentialsProviderBase(api, context, fetch_metadata_using_curl,
create_metadata_fetcher_cb, cluster_name,
envoy::config::cluster::v3::Cluster::STATIC /*cluster_type*/,
EC2_METADATA_HOST, refresh_state, initialization_timer) {}
bool InstanceProfileCredentialsProvider::needsRefresh() {
return api_.timeSource().systemTime() - last_updated_ > REFRESH_INTERVAL;
}
void InstanceProfileCredentialsProvider::refresh() {
ENVOY_LOG(debug, "Getting AWS credentials from the EC2MetadataService");
// First request for a session TOKEN so that we can call EC2MetadataService securely.
// https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/configuring-instance-metadata-service.html
Http::RequestMessageImpl token_req_message;
token_req_message.headers().setScheme(Http::Headers::get().SchemeValues.Http);
token_req_message.headers().setMethod(Http::Headers::get().MethodValues.Put);
token_req_message.headers().setHost(EC2_METADATA_HOST);
token_req_message.headers().setPath(EC2_IMDS_TOKEN_RESOURCE);
token_req_message.headers().setCopy(Http::LowerCaseString(EC2_IMDS_TOKEN_TTL_HEADER),
EC2_IMDS_TOKEN_TTL_DEFAULT_VALUE);
if (!useHttpAsyncClient() || !context_) {
// Using curl to fetch the AWS credentials where we first get the token.
const auto token_string = fetch_metadata_using_curl_(token_req_message);
if (token_string) {
ENVOY_LOG(debug, "Obtained IMDSv2 token to make secure call to EC2MetadataService");
fetchInstanceRole(std::move(token_string.value()));
} else {
ENVOY_LOG(warn, "Failed to get IMDSv2 token from EC2MetadataService, falling back to IMDSv1");
fetchInstanceRole(std::move(""));
}
} else {
// Stop any existing timer.
if (cache_duration_timer_ && cache_duration_timer_->enabled()) {
cache_duration_timer_->disableTimer();
}
// Using Http async client to fetch the AWS credentials where we first get the token.
if (!metadata_fetcher_) {
metadata_fetcher_ = create_metadata_fetcher_cb_(context_->clusterManager(), clusterName());
} else {
metadata_fetcher_->cancel(); // Cancel if there is any inflight request.
}
on_async_fetch_cb_ = [this](const std::string&& arg) {
return this->fetchInstanceRoleAsync(std::move(arg));
};
continue_on_async_fetch_failure_ = true;
continue_on_async_fetch_failure_reason_ = "Token fetch failed, falling back to IMDSv1";
metadata_fetcher_->fetch(token_req_message, Tracing::NullSpan::instance(), *this);
}
}
void InstanceProfileCredentialsProvider::fetchInstanceRole(const std::string&& token_string,
bool async /*default = false*/) {
// Discover the Role of this instance.
Http::RequestMessageImpl message;
message.headers().setScheme(Http::Headers::get().SchemeValues.Http);
message.headers().setMethod(Http::Headers::get().MethodValues.Get);
message.headers().setHost(EC2_METADATA_HOST);
message.headers().setPath(SECURITY_CREDENTIALS_PATH);
if (!token_string.empty()) {
message.headers().setCopy(Http::LowerCaseString(EC2_IMDS_TOKEN_HEADER),
StringUtil::trim(token_string));
}
if (!async) {
// Using curl to fetch the Instance Role.
const auto instance_role_string = fetch_metadata_using_curl_(message);
if (!instance_role_string) {
ENVOY_LOG(error, "Could not retrieve credentials listing from the EC2MetadataService");
return;
}
fetchCredentialFromInstanceRole(std::move(instance_role_string.value()),
std::move(token_string));
} else {
// Using Http async client to fetch the Instance Role.
metadata_fetcher_->cancel(); // Cancel if there is any inflight request.
on_async_fetch_cb_ = [this, token_string = std::move(token_string)](const std::string&& arg) {
return this->fetchCredentialFromInstanceRoleAsync(std::move(arg), std::move(token_string));
};
metadata_fetcher_->fetch(message, Tracing::NullSpan::instance(), *this);
}
}
void InstanceProfileCredentialsProvider::fetchCredentialFromInstanceRole(
const std::string&& instance_role, const std::string&& token_string,
bool async /*default = false*/) {
if (instance_role.empty()) {
ENVOY_LOG(error, "No roles found to fetch AWS credentials from the EC2MetadataService");
if (async) {
handleFetchDone();
}
return;
}
const auto instance_role_list = StringUtil::splitToken(StringUtil::trim(instance_role), "\n");
if (instance_role_list.empty()) {
ENVOY_LOG(error, "No roles found to fetch AWS credentials from the EC2MetadataService");
if (async) {
handleFetchDone();
}
return;
}
ENVOY_LOG(debug, "AWS credentials list:\n{}", instance_role);
// Only one Role can be associated with an instance:
// https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html
const auto credential_path =
std::string(SECURITY_CREDENTIALS_PATH) + "/" +
std::string(instance_role_list[0].data(), instance_role_list[0].size());
ENVOY_LOG(debug, "AWS credentials path: {}", credential_path);
Http::RequestMessageImpl message;
message.headers().setScheme(Http::Headers::get().SchemeValues.Http);
message.headers().setMethod(Http::Headers::get().MethodValues.Get);
message.headers().setHost(EC2_METADATA_HOST);
message.headers().setPath(credential_path);
if (!token_string.empty()) {
message.headers().setCopy(Http::LowerCaseString(EC2_IMDS_TOKEN_HEADER),
StringUtil::trim(token_string));
}
if (!async) {
// Fetch and parse the credentials.
const auto credential_document = fetch_metadata_using_curl_(message);
if (!credential_document) {
ENVOY_LOG(error, "Could not load AWS credentials document from the EC2MetadataService");
return;
}
extractCredentials(std::move(credential_document.value()));
} else {
// Using Http async client to fetch and parse the AWS credentials.
metadata_fetcher_->cancel(); // Cancel if there is any inflight request.
on_async_fetch_cb_ = [this](const std::string&& arg) {
return this->extractCredentialsAsync(std::move(arg));
};
metadata_fetcher_->fetch(message, Tracing::NullSpan::instance(), *this);
}
}
void InstanceProfileCredentialsProvider::extractCredentials(
const std::string&& credential_document_value, bool async /*default = false*/) {
if (credential_document_value.empty()) {
if (async) {
handleFetchDone();
}
return;
}
absl::StatusOr<Json::ObjectSharedPtr> document_json_or_error;
document_json_or_error = Json::Factory::loadFromStringNoThrow(credential_document_value);
if (!document_json_or_error.ok()) {
ENVOY_LOG(error, "Could not parse AWS credentials document: {}",
document_json_or_error.status().message());
if (async) {
handleFetchDone();
}
return;
}
const auto access_key_id =
Utility::getStringFromJsonOrDefault(document_json_or_error.value(), ACCESS_KEY_ID, "");
const auto secret_access_key =
Utility::getStringFromJsonOrDefault(document_json_or_error.value(), SECRET_ACCESS_KEY, "");
const auto session_token =
Utility::getStringFromJsonOrDefault(document_json_or_error.value(), TOKEN, "");
ENVOY_LOG(debug,
"Obtained following AWS credentials from the EC2MetadataService: {}={}, {}={}, {}={}",
AWS_ACCESS_KEY_ID, access_key_id, AWS_SECRET_ACCESS_KEY,
secret_access_key.empty() ? "" : "*****", AWS_SESSION_TOKEN,
session_token.empty() ? "" : "*****");
last_updated_ = api_.timeSource().systemTime();
if (useHttpAsyncClient() && context_) {
setCredentialsToAllThreads(
std::make_unique<Credentials>(access_key_id, secret_access_key, session_token));
stats_->credential_refreshes_succeeded_.inc();
ENVOY_LOG(debug, "Metadata receiver moving to Ready state");
refresh_state_ = MetadataFetcher::MetadataReceiver::RefreshState::Ready;
// Set receiver state in statistics
stats_->metadata_refresh_state_.set(uint64_t(refresh_state_));
} else {
cached_credentials_ = Credentials(access_key_id, secret_access_key, session_token);
}
handleFetchDone();
}
void InstanceProfileCredentialsProvider::onMetadataSuccess(const std::string&& body) {
ENVOY_LOG(debug, "AWS Instance metadata fetch success, calling callback func");
on_async_fetch_cb_(std::move(body));
}
void InstanceProfileCredentialsProvider::onMetadataError(Failure reason) {
stats_->credential_refreshes_failed_.inc();
if (continue_on_async_fetch_failure_) {
ENVOY_LOG(warn, "{}. Reason: {}", continue_on_async_fetch_failure_reason_,
metadata_fetcher_->failureToString(reason));
continue_on_async_fetch_failure_ = false;
continue_on_async_fetch_failure_reason_ = "";
on_async_fetch_cb_(std::move(""));
} else {
ENVOY_LOG(error, "AWS Instance metadata fetch failure: {}",
metadata_fetcher_->failureToString(reason));
handleFetchDone();
}
}
ContainerCredentialsProvider::ContainerCredentialsProvider(
Api::Api& api, ServerFactoryContextOptRef context,
const CurlMetadataFetcher& fetch_metadata_using_curl,
CreateMetadataFetcherCb create_metadata_fetcher_cb, absl::string_view credential_uri,
MetadataFetcher::MetadataReceiver::RefreshState refresh_state,
std::chrono::seconds initialization_timer, absl::string_view authorization_token = {},
absl::string_view cluster_name = {})
: MetadataCredentialsProviderBase(api, context, fetch_metadata_using_curl,
create_metadata_fetcher_cb, cluster_name,
envoy::config::cluster::v3::Cluster::STATIC /*cluster_type*/,
credential_uri, refresh_state, initialization_timer),
credential_uri_(credential_uri), authorization_token_(authorization_token) {}
bool ContainerCredentialsProvider::needsRefresh() {
const auto now = api_.timeSource().systemTime();
auto expired = (now - last_updated_ > REFRESH_INTERVAL);
if (expiration_time_.has_value()) {
return expired || (expiration_time_.value() - now < REFRESH_GRACE_PERIOD);
} else {
return expired;
}
}
void ContainerCredentialsProvider::refresh() {
ENVOY_LOG(debug, "Getting AWS credentials from the container role at URI: {}", credential_uri_);
// ECS Task role: use const authorization_token set during initialization
absl::string_view authorization_header = authorization_token_;
absl::StatusOr<std::string> token_or_error;
if (authorization_token_.empty()) {
// EKS Pod Identity token is sourced from AWS_CONTAINER_AUTHORIZATION_TOKEN_FILE
if (const auto token_file = std::getenv(AWS_CONTAINER_AUTHORIZATION_TOKEN_FILE)) {
token_or_error = api_.fileSystem().fileReadToEnd(std::string(token_file));
if (token_or_error.ok()) {
ENVOY_LOG_MISC(debug, "Container authorization token file contents loaded");
authorization_header = token_or_error.value();
}
}
}
absl::string_view host;
absl::string_view path;
Http::Utility::extractHostPathFromUri(credential_uri_, host, path);
Http::RequestMessageImpl message;
message.headers().setScheme(Http::Headers::get().SchemeValues.Http);
message.headers().setMethod(Http::Headers::get().MethodValues.Get);
message.headers().setHost(host);
message.headers().setPath(path);
message.headers().setCopy(Http::CustomHeaders::get().Authorization, authorization_header);
if (!useHttpAsyncClient() || !context_) {
// Using curl to fetch the AWS credentials.
const auto credential_document = fetch_metadata_using_curl_(message);
if (!credential_document) {
ENVOY_LOG(error, "Could not load AWS credentials document from the container role");
return;
}
extractCredentials(std::move(credential_document.value()));
} else {
// Stop any existing timer.
if (cache_duration_timer_ && cache_duration_timer_->enabled()) {
cache_duration_timer_->disableTimer();
}
// Using Http async client to fetch the AWS credentials.
if (!metadata_fetcher_) {
metadata_fetcher_ = create_metadata_fetcher_cb_(context_->clusterManager(), clusterName());
} else {
metadata_fetcher_->cancel(); // Cancel if there is any inflight request.
}
on_async_fetch_cb_ = [this](const std::string&& arg) {
return this->extractCredentials(std::move(arg));
};
metadata_fetcher_->fetch(message, Tracing::NullSpan::instance(), *this);
}
}
void ContainerCredentialsProvider::extractCredentials(
const std::string&& credential_document_value) {
if (credential_document_value.empty()) {
handleFetchDone();
return;
}
absl::StatusOr<Json::ObjectSharedPtr> document_json_or_error;
document_json_or_error = Json::Factory::loadFromStringNoThrow(credential_document_value);
if (!document_json_or_error.ok()) {
ENVOY_LOG(error, "Could not parse AWS credentials document from the container role: {}",
document_json_or_error.status().message());
handleFetchDone();
return;
}
const auto access_key_id =
Utility::getStringFromJsonOrDefault(document_json_or_error.value(), ACCESS_KEY_ID, "");
const auto secret_access_key =
Utility::getStringFromJsonOrDefault(document_json_or_error.value(), SECRET_ACCESS_KEY, "");
const auto session_token =
Utility::getStringFromJsonOrDefault(document_json_or_error.value(), TOKEN, "");
ENVOY_LOG(debug, "Found following AWS credentials in the container role: {}={}, {}={}, {}={}",
AWS_ACCESS_KEY_ID, access_key_id, AWS_SECRET_ACCESS_KEY,
secret_access_key.empty() ? "" : "*****", AWS_SESSION_TOKEN,
session_token.empty() ? "" : "*****");
const auto expiration_str =
Utility::getStringFromJsonOrDefault(document_json_or_error.value(), EXPIRATION, "");
if (!expiration_str.empty()) {
absl::Time expiration_time;
if (absl::ParseTime(EXPIRATION_FORMAT, expiration_str, &expiration_time, nullptr)) {
ENVOY_LOG(debug, "Container role AWS credentials expiration time: {}", expiration_str);
expiration_time_ = absl::ToChronoTime(expiration_time);
}
}
last_updated_ = api_.timeSource().systemTime();
if (useHttpAsyncClient() && context_) {
setCredentialsToAllThreads(
std::make_unique<Credentials>(access_key_id, secret_access_key, session_token));
ENVOY_LOG(debug, "Metadata receiver {} moving to Ready state", cluster_name_);
refresh_state_ = MetadataFetcher::MetadataReceiver::RefreshState::Ready;
// Set receiver state in statistics
stats_->metadata_refresh_state_.set(uint64_t(refresh_state_));
} else {
cached_credentials_ = Credentials(access_key_id, secret_access_key, session_token);
}
handleFetchDone();
}
void ContainerCredentialsProvider::onMetadataSuccess(const std::string&& body) {
stats_->credential_refreshes_succeeded_.inc();
ENVOY_LOG(debug, "AWS Task metadata fetch success, calling callback func");
on_async_fetch_cb_(std::move(body));
}
void ContainerCredentialsProvider::onMetadataError(Failure reason) {
stats_->credential_refreshes_failed_.inc();
ENVOY_LOG(error, "AWS metadata fetch failure: {}", metadata_fetcher_->failureToString(reason));
handleFetchDone();
}
WebIdentityCredentialsProvider::WebIdentityCredentialsProvider(
Api::Api& api, ServerFactoryContextOptRef context,
const CurlMetadataFetcher& fetch_metadata_using_curl,
CreateMetadataFetcherCb create_metadata_fetcher_cb, absl::string_view token_file_path,
absl::string_view token, absl::string_view sts_endpoint, absl::string_view role_arn,
absl::string_view role_session_name,
MetadataFetcher::MetadataReceiver::RefreshState refresh_state,
std::chrono::seconds initialization_timer, absl::string_view cluster_name = {})
: MetadataCredentialsProviderBase(
api, context, fetch_metadata_using_curl, create_metadata_fetcher_cb, cluster_name,
envoy::config::cluster::v3::Cluster::LOGICAL_DNS /*cluster_type*/, sts_endpoint,
refresh_state, initialization_timer),
token_file_path_(token_file_path), token_(token), sts_endpoint_(sts_endpoint),
role_arn_(role_arn), role_session_name_(role_session_name) {}
bool WebIdentityCredentialsProvider::needsRefresh() {
const auto now = api_.timeSource().systemTime();
auto expired = (now - last_updated_ > REFRESH_INTERVAL);
if (expiration_time_.has_value()) {
return expired || (expiration_time_.value() - now < REFRESH_GRACE_PERIOD);
} else {
return expired;
}
}
void WebIdentityCredentialsProvider::refresh() {
// If http async client is not enabled then just set empty credentials and return.
if (!useHttpAsyncClient()) {
cached_credentials_ = Credentials();
return;
}
ENVOY_LOG(debug, "Getting AWS web identity credentials from STS: {}", sts_endpoint_);
std::string identity_token = token_;
if (identity_token.empty()) {
const auto web_token_file_or_error = api_.fileSystem().fileReadToEnd(token_file_path_);
if (!web_token_file_or_error.ok()) {
ENVOY_LOG(debug, "Unable to read AWS web identity credentials from {}", token_file_path_);
cached_credentials_ = Credentials();
return;
}
identity_token = web_token_file_or_error.value();
}
Http::RequestMessageImpl message;
message.headers().setScheme(Http::Headers::get().SchemeValues.Https);
message.headers().setMethod(Http::Headers::get().MethodValues.Get);
message.headers().setHost(Http::Utility::parseAuthority(sts_endpoint_).host_);
message.headers().setPath(
fmt::format("/?Action=AssumeRoleWithWebIdentity"
"&Version=2011-06-15"
"&RoleSessionName={}"
"&RoleArn={}"
"&WebIdentityToken={}",
Envoy::Http::Utility::PercentEncoding::encode(role_session_name_),
Envoy::Http::Utility::PercentEncoding::encode(role_arn_),
Envoy::Http::Utility::PercentEncoding::encode(identity_token)));
// Use the Accept header to ensure that AssumeRoleWithWebIdentityResponse is returned as JSON.
message.headers().setReference(Http::CustomHeaders::get().Accept,
Http::Headers::get().ContentTypeValues.Json);
// Stop any existing timer.
if (cache_duration_timer_ && cache_duration_timer_->enabled()) {
cache_duration_timer_->disableTimer();
}
// Using Http async client to fetch the AWS credentials.
if (!metadata_fetcher_) {
metadata_fetcher_ = create_metadata_fetcher_cb_(context_->clusterManager(), clusterName());
} else {
metadata_fetcher_->cancel(); // Cancel if there is any inflight request.
}
on_async_fetch_cb_ = [this](const std::string&& arg) {
return this->extractCredentials(std::move(arg));
};
metadata_fetcher_->fetch(message, Tracing::NullSpan::instance(), *this);
}
void WebIdentityCredentialsProvider::extractCredentials(
const std::string&& credential_document_value) {
if (credential_document_value.empty()) {
handleFetchDone();
ENVOY_LOG(error, "Could not load AWS credentials document from STS");
return;
}
absl::StatusOr<Json::ObjectSharedPtr> document_json_or_error;
document_json_or_error = Json::Factory::loadFromStringNoThrow(credential_document_value);
if (!document_json_or_error.ok()) {
ENVOY_LOG(error, "Could not parse AWS credentials document from STS: {}",
document_json_or_error.status().message());
handleFetchDone();
return;
}
absl::StatusOr<Json::ObjectSharedPtr> root_node =
document_json_or_error.value()->getObjectNoThrow(WEB_IDENTITY_RESPONSE_ELEMENT);
if (!root_node.ok()) {
ENVOY_LOG(error, "AWS STS credentials document is empty");
handleFetchDone();
return;
}
absl::StatusOr<Json::ObjectSharedPtr> result_node =
root_node.value()->getObjectNoThrow(WEB_IDENTITY_RESULT_ELEMENT);
if (!result_node.ok()) {
ENVOY_LOG(error, "AWS STS returned an unexpected result");
handleFetchDone();
return;
}
absl::StatusOr<Json::ObjectSharedPtr> credentials =
result_node.value()->getObjectNoThrow(CREDENTIALS);
if (!credentials.ok()) {
ENVOY_LOG(error, "AWS STS credentials document does not contain any credentials");
handleFetchDone();
return;
}
const auto access_key_id =
Utility::getStringFromJsonOrDefault(credentials.value(), ACCESS_KEY_ID, "");
const auto secret_access_key =
Utility::getStringFromJsonOrDefault(credentials.value(), SECRET_ACCESS_KEY, "");
const auto session_token =
Utility::getStringFromJsonOrDefault(credentials.value(), SESSION_TOKEN, "");
// Mandatory response fields
if (access_key_id.empty() || secret_access_key.empty() || session_token.empty()) {
ENVOY_LOG(error, "Bad format, could not parse AWS credentials document from STS");
handleFetchDone();
return;
}
ENVOY_LOG(debug, "Received the following AWS credentials from STS: {}={}, {}={}, {}={}",
AWS_ACCESS_KEY_ID, access_key_id, AWS_SECRET_ACCESS_KEY,
secret_access_key.empty() ? "" : "*****", AWS_SESSION_TOKEN,
session_token.empty() ? "" : "*****");
setCredentialsToAllThreads(
std::make_unique<Credentials>(access_key_id, secret_access_key, session_token));
ENVOY_LOG(debug, "Metadata receiver {} moving to Ready state", cluster_name_);
refresh_state_ = MetadataFetcher::MetadataReceiver::RefreshState::Ready;
// Set receiver state in statistics
stats_->metadata_refresh_state_.set(uint64_t(refresh_state_));
const auto expiration = Utility::getIntegerFromJsonOrDefault(credentials.value(), EXPIRATION, 0);
if (expiration != 0) {
expiration_time_ =
std::chrono::time_point<std::chrono::system_clock>(std::chrono::seconds(expiration));
ENVOY_LOG(debug, "AWS STS credentials expiration time (unix timestamp): {}", expiration);
} else {
// We don't have a valid expiration time from the json response
expiration_time_.reset();
}
last_updated_ = api_.timeSource().systemTime();
handleFetchDone();
}
void WebIdentityCredentialsProvider::onMetadataSuccess(const std::string&& body) {
stats_->credential_refreshes_succeeded_.inc();
ENVOY_LOG(debug, "AWS metadata fetch from STS success, calling callback func");
on_async_fetch_cb_(std::move(body));
}
void WebIdentityCredentialsProvider::onMetadataError(Failure reason) {
stats_->credential_refreshes_failed_.inc();
ENVOY_LOG(error, "AWS metadata fetch failure: {}", metadata_fetcher_->failureToString(reason));
handleFetchDone();
}
Credentials CredentialsProviderChain::getCredentials() {
for (auto& provider : providers_) {
const auto credentials = provider->getCredentials();
if (credentials.accessKeyId() && credentials.secretAccessKey()) {
return credentials;
}
}
ENVOY_LOG(debug, "No AWS credentials found, using anonymous credentials");
return Credentials();
}
std::string sessionName(Api::Api& api) {
const auto role_session_name = absl::NullSafeStringView(std::getenv(AWS_ROLE_SESSION_NAME));
std::string actual_session_name;
if (!role_session_name.empty()) {
actual_session_name = std::string(role_session_name);
} else {
// In practice, this value will be provided by the environment, so the placeholder value is
// not important. Some AWS SDKs use time in nanoseconds, so we'll just use that.
const auto now_nanos = std::chrono::duration_cast<std::chrono::nanoseconds>(
api.timeSource().systemTime().time_since_epoch())
.count();
actual_session_name = fmt::format("{}", now_nanos);
}
return actual_session_name;
}
// Edge case handling for cluster naming.
//
// Region is appended to the cluster name, to differentiate between multiple web identity
// credential providers configured with different regions.
//
// UUID is also appended, to differentiate two identically configured web identity credential
// providers, as we cannot make these singletons
//
// TODO: @nbaws: Modify cluster creation logic for web identity credential providers
// to allow these also to be created as singletons
std::string stsClusterName(absl::string_view region) {
return absl::StrCat(STS_TOKEN_CLUSTER, "-", region);
}
DefaultCredentialsProviderChain::DefaultCredentialsProviderChain(
Api::Api& api, ServerFactoryContextOptRef context, Singleton::Manager& singleton_manager,
absl::string_view region,
const MetadataCredentialsProviderBase::CurlMetadataFetcher& fetch_metadata_using_curl,
const CredentialsProviderChainFactories& factories) {
ENVOY_LOG(debug, "Using environment credentials provider");
add(factories.createEnvironmentCredentialsProvider());
ENVOY_LOG(debug, "Using credentials file credentials provider");
add(factories.createCredentialsFileCredentialsProvider(api));
// Initial state for an async credential receiver
auto refresh_state = MetadataFetcher::MetadataReceiver::RefreshState::FirstRefresh;
// Initial amount of time for async credential receivers to wait for an initial refresh to succeed
auto initialization_timer = std::chrono::seconds(2);
// WebIdentityCredentialsProvider can be used only if `context` is supplied which is required to
// use http async http client to make http calls to fetch the credentials.
if (context) {
const auto web_token_path = absl::NullSafeStringView(std::getenv(AWS_WEB_IDENTITY_TOKEN_FILE));
const auto role_arn = absl::NullSafeStringView(std::getenv(AWS_ROLE_ARN));
if (!web_token_path.empty() && !role_arn.empty()) {
const auto session_name = sessionName(api);
const auto sts_endpoint = Utility::getSTSEndpoint(region) + ":443";
const auto region_uuid = absl::StrCat(region, "_", context->api().randomGenerator().uuid());
const auto cluster_name = stsClusterName(region_uuid);
ENVOY_LOG(
debug,
"Using web identity credentials provider with STS endpoint: {} and session name: {}",
sts_endpoint, session_name);
add(factories.createWebIdentityCredentialsProvider(
api, context, fetch_metadata_using_curl, MetadataFetcher::create, cluster_name,
web_token_path, "", sts_endpoint, role_arn, session_name, refresh_state,
initialization_timer));
}
}
// Even if WebIdentity is supported keep the fallback option open so that
// Envoy can use other credentials provider if available.
const auto relative_uri =
absl::NullSafeStringView(std::getenv(AWS_CONTAINER_CREDENTIALS_RELATIVE_URI));
const auto full_uri = absl::NullSafeStringView(std::getenv(AWS_CONTAINER_CREDENTIALS_FULL_URI));
const auto metadata_disabled = absl::NullSafeStringView(std::getenv(AWS_EC2_METADATA_DISABLED));
if (!relative_uri.empty()) {
const auto uri = absl::StrCat(CONTAINER_METADATA_HOST, relative_uri);
ENVOY_LOG(debug, "Using container role credentials provider with URI: {}", uri);
add(factories.createContainerCredentialsProvider(
api, context, singleton_manager, fetch_metadata_using_curl, MetadataFetcher::create,