Add OCI Object Storage Bucket support

Address comment from GiedriusS

Signed-off-by: aaron.tam <aaron.tam@oracle.com>

docs/storage.md

@@ -46,6 +46,7 @@ Current object storage client implementations:
 | [Tencent COS](#tencent-cos)                                                            | Beta               | Production Usage      | no                | @jojohappy,@hanjm       |
 | [AliYun OSS](#aliyun-oss)                                                              | Beta               | Production Usage      | no                | @shaulboozhiao,@wujinhu |
 | [Local Filesystem](#filesystem)                                                        | Stable             | Testing and Demo only | yes               | @bwplotka               |
+| [OCI Object Storage](#oci)                                                             | Beta               | Production Usage      | yes               | @aarontams,@ericrrath    |
 
 **Missing support to some object storage?** Check out [how to add your client section](#how-to-add-a-new-client-to-thanos)
 
@@ -449,6 +450,80 @@ config:
   directory: ""
 ```
 
+### OCI
+
+[Oracle Cloud Infrastructure](https://www.oracle.com/cloud). To configure OCI Object Storage as Thanos Object Store, you need access to OCI Object Storage.
+You can get a free OCI Cloud Services by following the [Oracle Cloud Free Tier](https://www.oracle.com/cloud/free) page.
+More information about [Overview of Object Storage](https://docs.cloud.oracle.com/en-us/iaas/Content/Object/Concepts/objectstorageoverview.htm).
+
+OCI Object Storage supports three different providers, default, instance principle, and raw. 
+The default HTTP Client comes with this Thanos OCI Object Storage should be able to handle most of the use cases.
+
+By default, like other clients, Thanos OCI Object Storage client will store the data from a single prometheus instance to the top directory of the bucket. 
+This means each bucket can only store one prometheus instance data.
+
+To support multiple prometheus instances with a single bucket, a new `object_base_path` option is introduced in OCI Object Storage client. 
+If defined, the value will be used as the prefix of the prometheus data in OCI bucket.
+
+For example, if you want to use the same bucket for 2 prometheus instances, you can define `object_base_path` as `/path/for/prometheus1` 
+for the first prometheus instance, and `/path/for/prometheus2` for the second prometheus instance.
+
+#### Default Provider
+The default config provider will look for configurations in 3 places: file in `$HOME/.oci/config`, `$HOME/.obmcs/config`, and
+variables names starting with the string TF_VAR. If the same configuration is found in multiple places the provider will
+prefer the first one.
+
+For Example:
+```yaml
+type: OCI
+config:
+  provider: "default"
+  bucket: ""
+  compartment_ocid: ""
+  object_base_path: ""            // Optional object base path (prefix) in OCI bucket.
+  part_size: ""                   // Optional part size to override the OCI default of 128 MiB, value is in bytes.
+  max_request_retries: ""         // Optional maximum number of retries for a request.
+  http_config:
+    idle_conn_timeout: 1m30s      // Optional maximum amount of time an idle (keep-alive) connection will remain idle before closing itself. Zero means no limit.
+    response_header_timeout: 2m   // Optional amount of time to wait for a server's response headers after fully writing the request.
+    tls_handshake_timeout: 10s    // Optional maximum amount of time waiting to wait for a TLS handshake. Zero means no timeout.
+    expect_continue_timeout: 1s   // Optional amount of time to wait for a server's first response headers. Zero means no timeout and causes the body to be sent immediately.
+    insecure_skip_verify: false   // Optional. If true, crypto/tls accepts any certificate presented by the server and any host name in that certificate.
+    max_idle_conns: 100           // Optional maximum number of idle (keep-alive) connections across all hosts. Zero means no limit.
+    max_idle_conns_per_host: 100  // Optional maximum idle (keep-alive) connections to keep per-host. If zero, DefaultMaxIdleConnsPerHost=2 is used.
+    max_conns_per_host: 0         // Optional maximum total number of connections per host.
+    disable_compression: false    // Optional. If true, prevents the Transport from requesting compression.
+```
+
+
+#### Instance Principle Provider
+For Example:
+```yaml
+type: OCI
+config:
+  provider: "instance-principal"
+  bucket: ""
+  compartment_ocid: ""
+```
+You can also include any of the optional configuration just like the example in `Default Provider`. 
+
+#### Raw Provider
+For Example:
+```yaml
+type: OCI
+config:
+  provider: "raw"
+  bucket: ""
+  compartment_ocid: ""
+  tenancy_ocid: ""
+  user_ocid: ""
+  region: ""
+  fingerprint: ""
+  privatekey: ""
+  passphrase: ""         // Optional passphrase to encrypt the private API Signing key
+```
+You can also include any of the optional configuration just like the example in `Default Provider`.
+
 ### How to add a new client to Thanos?
 
 Following checklist allows adding new Go code client to supported providers:

go.mod

@@ -52,6 +52,7 @@ require (
 	github.com/olekukonko/tablewriter v0.0.2
 	github.com/opentracing/basictracer-go v1.0.0
 	github.com/opentracing/opentracing-go v1.2.0
+	github.com/oracle/oci-go-sdk/v46 v46.2.0
 	github.com/pkg/errors v0.9.1
 	github.com/pmezard/go-difflib v1.0.0
 	github.com/prometheus/alertmanager v0.23.1-0.20210914172521-e35efbddb66a

go.sum

@@ -1386,6 +1386,8 @@ github.com/openzipkin/zipkin-go v0.1.6/go.mod h1:QgAqvLzwWbR/WpD4A3cGpPtJrZXNIiJ
 github.com/openzipkin/zipkin-go v0.2.1/go.mod h1:NaW6tEwdmWMaCDZzg8sh+IBNOxHMPnhQw8ySjnjRyN4=
 github.com/openzipkin/zipkin-go v0.2.2/go.mod h1:NaW6tEwdmWMaCDZzg8sh+IBNOxHMPnhQw8ySjnjRyN4=
 github.com/openzipkin/zipkin-go v0.2.5/go.mod h1:KpXfKdgRDnnhsxw4pNIH9Md5lyFqKUa4YDFlwRYAMyE=
+github.com/oracle/oci-go-sdk/v46 v46.2.0 h1:yCb/AKio4q7jHgq7ktbGqwkOloOopW3Oy/P2UG2B6Is=
+github.com/oracle/oci-go-sdk/v46 v46.2.0/go.mod h1:DwFVvDNhpY+iZ2bD2ITEqENhO6/iBRttbJky49HRH6A=
 github.com/pact-foundation/pact-go v1.0.4/go.mod h1:uExwJY4kCzNPcHRj+hCR/HBbOOIwwtUjcrb0b5/5kLM=
 github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
 github.com/pascaldekloe/goe v0.1.0 h1:cBOtyMzM9HTpWjXfbbunk26uA6nG3a8n06Wieeh0MwY=

pkg/objstore/client/factory.go

@@ -20,6 +20,7 @@ import (
 	"github.com/thanos-io/thanos/pkg/objstore/cos"
 	"github.com/thanos-io/thanos/pkg/objstore/filesystem"
 	"github.com/thanos-io/thanos/pkg/objstore/gcs"
+	"github.com/thanos-io/thanos/pkg/objstore/oci"
 	"github.com/thanos-io/thanos/pkg/objstore/oss"
 	"github.com/thanos-io/thanos/pkg/objstore/s3"
 	"github.com/thanos-io/thanos/pkg/objstore/swift"
@@ -36,6 +37,7 @@ const (
 	COS        ObjProvider = "COS"
 	ALIYUNOSS  ObjProvider = "ALIYUNOSS"
 	BOS        ObjProvider = "BOS"
+	OCI        ObjProvider = "OCI"
 )
 
 type BucketConfig struct {
@@ -75,6 +77,8 @@ func NewBucket(logger log.Logger, confContentYaml []byte, reg prometheus.Registe
 		bucket, err = filesystem.NewBucketFromConfig(config)
 	case string(BOS):
 		bucket, err = bos.NewBucket(logger, config, component)
+	case string(OCI):
+		bucket, err = oci.NewBucket(logger, config)
 	default:
 		return nil, errors.Errorf("bucket with type %s is not supported", bucketConf.Type)
 	}

pkg/objstore/objtesting/foreach.go

@@ -17,14 +17,15 @@ import (
 	"github.com/thanos-io/thanos/pkg/objstore/azure"
 	"github.com/thanos-io/thanos/pkg/objstore/cos"
 	"github.com/thanos-io/thanos/pkg/objstore/gcs"
+	"github.com/thanos-io/thanos/pkg/objstore/oci"
 	"github.com/thanos-io/thanos/pkg/objstore/oss"
 	"github.com/thanos-io/thanos/pkg/objstore/s3"
 	"github.com/thanos-io/thanos/pkg/objstore/swift"
 	"github.com/thanos-io/thanos/pkg/testutil"
 )
 
 // IsObjStoreSkipped returns true if given provider ID is found in THANOS_TEST_OBJSTORE_SKIP array delimited by comma e.g:
-// THANOS_TEST_OBJSTORE_SKIP=GCS,S3,AZURE,SWIFT,COS,ALIYUNOSS,BOS.
+// THANOS_TEST_OBJSTORE_SKIP=GCS,S3,AZURE,SWIFT,COS,ALIYUNOSS,BOS.OCI.
 func IsObjStoreSkipped(t *testing.T, provider client.ObjProvider) bool {
 	if e, ok := os.LookupEnv("THANOS_TEST_OBJSTORE_SKIP"); ok {
 		obstores := strings.Split(e, ",")
@@ -162,4 +163,18 @@ func ForeachStore(t *testing.T, testFn func(t *testing.T, bkt objstore.Bucket))
 			testFn(t, bkt)
 		})
 	}
+
+	// Optional OCI.
+	if !IsObjStoreSkipped(t, client.OCI) {
+		t.Run("oci", func(t *testing.T) {
+			bkt, closeFn, err := oci.NewTestBucket(t)
+			testutil.Ok(t, err)
+
+			t.Parallel()
+			defer closeFn()
+
+			testFn(t, bkt)
+		})
+	}
+
 }