#0 unexpected error error_class=RuntimeError error="No valid AWS credentials found.

my AWS OpenSearch setup only has "Fine-grained access control" so without AWS access key I should be able to access OpenSearch anywhere

Steps to replicate
-----------
```

@type opensearch

host "#{ENV['FLUENT_OPENSEARCH_HOST'] || 'localhost'}"
port "#{ENV['FLUENT_OPENSEARCH_PORT']}"
user "#{ENV['FLUENT_OPENSEARCH_USER']}"
password "#{ENV['FLUENT_OPENSEARCH_PASSWORD']}"

ssl_verify false
logstash_format true
reconnect_on_error true # defaults to false
index_name fluentd-k8s
type_name fluentd

```

```

@type opensearch
user "xx"
password xxxxxx
ssl_verify false
logstash_format true
reconnect_on_error true
index_name "fluentd-k8s"
type_name fluentd

url https://sxxcom:443
region "ap-south-1"


```

#### Using Fluentd and OpenSearch plugin versions

* OS version - ubuntu
* rancher-desktop Kubernetes
* Fluentd version v1.14.3
* OpenSearch plugin version 1.0.1

Fluentd boot logs

2022-02-06 19:57:55 +0000 [info]: parsing config file is succeeded path="/fluentd/etc/fluent.conf"
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-avro' version '1.1.1'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-concat' version '2.5.0'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-detect-exceptions' version '0.0.14'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-elasticsearch' version '5.1.5'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-grok-parser' version '2.6.2'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-json-in-json-2' version '1.0.2'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-kafka' version '0.17.3'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-kubernetes_metadata_filter' version '2.9.2'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-multi-format-parser' version '1.0.0'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-opensearch' version '1.0.1'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-parser-avro' version '0.3.1'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-parser-cri' version '0.1.1'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-prometheus' version '2.0.2'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-record-modifier' version '2.1.0'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-rewrite-tag-filter' version '2.4.0'
2022-02-06 19:57:55 +0000 [info]: gem 'fluent-plugin-systemd' version '1.0.5'
2022-02-06 19:57:55 +0000 [info]: gem 'fluentd' version '1.14.3'
2022-02-06 19:57:55 +0000 [warn]: [filter_kube_metadata] !! The environment variable 'K8S_NODE_NAME' is not set to the node name which can affect the API server and watch efficiency !!
2022-02-06 19:57:56 +0000 [warn]: define to capture fluentd logs in top level is deprecated. Use instead
2022-02-06 19:57:56 +0000 [info]: using configuration file:
```

@type tail
read_from_head true
tag "kubernetes.*"
path "/var/log/containers/*.log"
pos_file "/var/log/fluentd-containers.log.pos"
exclude_path ["/var/log/containers/fluent*"]

@type "json"
time_format "%Y-%m-%dT%H:%M:%S.%NZ"
unmatched_lines
time_type string

@type kubernetes_metadata
@id filter_kube_metadata
kubernetes_url "https://10.43.0.1:443/api"
ca_file ""
skip_labels false
skip_container_metadata false
skip_master_url false
skip_namespace_metadata false

@type opensearch
ssl_verify false
logstash_format true
reconnect_on_error true
index_name "fluentd-k8s"
type_name fluentd

url https:xx.ap-south-1.es.amazonaws.com:443
region "ap-south-1"
user xx
password xx

```
2022-02-06 19:57:56 +0000 [info]: starting fluentd-1.14.3 pid=7 ruby="2.6.9"
2022-02-06 19:57:56 +0000 [info]: spawn command to main: cmdline=["/usr/local/bin/ruby", "-Eascii-8bit:ascii-8bit", "/fluentd/vendor/bundle/ruby/2.6.0/bin/fluentd", "-c", "/fluentd/etc/fluent.conf", "-p", "/fluentd/plugins", "--gemfile", "/fluentd/Gemfile", "--under-supervisor"]
2022-02-06 19:57:56 +0000 [info]: adding filter pattern="kubernetes.**" type="kubernetes_metadata"
2022-02-06 19:57:57 +0000 [warn]: #0 [filter_kube_metadata] !! The environment variable 'K8S_NODE_NAME' is not set to the node name which can affect the API server and watch efficiency !!
2022-02-06 19:57:57 +0000 [info]: adding match pattern="**" type="opensearch"
2022-02-06 19:58:09 +0000 [error]: #0 unexpected error error_class=RuntimeError error="No valid AWS credentials found."
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluent-plugin-opensearch-1.0.1/lib/fluent/plugin/out_opensearch.rb:246:in `aws_credentials'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluent-plugin-opensearch-1.0.1/lib/fluent/plugin/out_opensearch.rb:601:in `block in client'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/faraday-1.9.3/lib/faraday/connection.rb:91:in `initialize'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/faraday-1.9.3/lib/faraday.rb:118:in `new'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/faraday-1.9.3/lib/faraday.rb:118:in `new'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/opensearch-transport-1.0.0/lib/opensearch/transport/transport/http/faraday.rb:72:in `__build_connection'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/opensearch-transport-1.0.0/lib/opensearch/transport/transport/base.rb:166:in `block in __build_connections'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/opensearch-transport-1.0.0/lib/opensearch/transport/transport/base.rb:158:in `map'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/opensearch-transport-1.0.0/lib/opensearch/transport/transport/base.rb:158:in `__build_connections'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/opensearch-transport-1.0.0/lib/opensearch/transport/transport/base.rb:69:in `initialize'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluent-plugin-opensearch-1.0.1/lib/fluent/plugin/out_opensearch.rb:624:in `new'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluent-plugin-opensearch-1.0.1/lib/fluent/plugin/out_opensearch.rb:624:in `client'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/opensearch-transport-1.0.0/lib/opensearch/transport/transport/base.rb:158:in `__build_connections'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/opensearch-transport-1.0.0/lib/opensearch/transport/transport/base.rb:69:in `initialize'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluent-plugin-opensearch-1.0.1/lib/fluent/plugin/out_opensearch.rb:624:in `new'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluent-plugin-opensearch-1.0.1/lib/fluent/plugin/out_opensearch.rb:624:in `client'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluent-plugin-opensearch-1.0.1/lib/fluent/plugin/opensearch_index_template.rb:62:in `host_unreachable_exceptions'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluent-plugin-opensearch-1.0.1/lib/fluent/plugin/opensearch_index_template.rb:71:in `rescue in retry_operate'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluent-plugin-opensearch-1.0.1/lib/fluent/plugin/opensearch_index_template.rb:69:in `retry_operate'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluent-plugin-opensearch-1.0.1/lib/fluent/plugin/out_opensearch.rb:497:in `handle_last_seen_os_major_version'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluent-plugin-opensearch-1.0.1/lib/fluent/plugin/out_opensearch.rb:380:in `configure'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/lib/fluent/plugin.rb:187:in `configure'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/lib/fluent/agent.rb:132:in `add_match'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/lib/fluent/agent.rb:74:in `block in configure'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/lib/fluent/agent.rb:64:in `each'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/lib/fluent/agent.rb:64:in `configure'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/lib/fluent/root_agent.rb:149:in `configure'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/lib/fluent/engine.rb:105:in `configure'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/lib/fluent/engine.rb:80:in `run_configure'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/lib/fluent/supervisor.rb:716:in `block in run_worker'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/lib/fluent/supervisor.rb:968:in `main_process'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/lib/fluent/supervisor.rb:708:in `run_worker'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/lib/fluent/command/fluentd.rb:372:in `'
2022-02-06 19:58:09 +0000 [error]: #0 /usr/local/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
2022-02-06 19:58:09 +0000 [error]: #0 /usr/local/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/gems/fluentd-1.14.3/bin/fluentd:15:in `'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/bin/fluentd:23:in `load'
2022-02-06 19:58:09 +0000 [error]: #0 /fluentd/vendor/bundle/ruby/2.6.0/bin/fluentd:23:in `'
2022-02-06 19:58:09 +0000 [info]: Worker 0 finished unexpectedly with status 1