Support environmental properties to set protocol properties #374

Review properties that can be exposed as managed properties and disallow writing to properties that don't support it #386

README.adoc

@@ -34,14 +34,60 @@ This library implements a JGroups discovery protocol which replaces protocols li
 The `aws.S3_PING` automatically registers itself to JGroups with the magic number `789`.
 You can overwrite this by setting the system property `s3ping.magic_number` to different number, e.g. `-Ds3ping.magic_number=123`.
 
-=== Possible Configurations
-
-// TODO change this to table format
-* *region_name*: like "eu-west-1", "us-east-1", etc.
-* *bucket_name*: the S3 bucket to store the files in
-* *bucket_prefix* (optional): if you don't want the plugin to pollute your S3 bucket, you can configure a prefix like "jgroups/"
-* *endpoint* (optional): you can override the S3 endpoint if you know what you are doing
-* *kms_key_id* (optional): you can set this to a kms key id to enable KMS-SSE encryption when writing data to S3 (see https://docs.aws.amazon.com/AmazonS3/latest/userguide/UsingKMSEncryption.html)
+=== Configurations Properties
+
+[align="left",cols="3,1,10",options="header"]
+|===
+| Attribute Name +
+System Property
+| Default
+| Description
+
+| `region_name` +
+System property: `jgroups.aws.s3.region_name`
+| *required*
+| The S3 region to use.
+
+| `bucket_name` +
+System property: `jgroups.aws.s3.bucket_name`
+| *required*
+| The S3 bucket to use.
+
+| `bucket_prefix` +
+System property: `jgroups.aws.s3.bucket_prefix`
+|
+| The S3 bucket prefix to use (optional e.g. 'jgroups/').
+
+
+| `check_if_bucket_exists` +
+System property: `jgroups.aws.s3.check_if_bucket_exists`
+| `true`
+| Checks if the bucket exists in S3 and creates a new one if missing
+
+| `endpoint` +
+System property: `jgroups.aws.s3.endpoint`
+|
+| The S3 endpoint to use (optional).
+
+| `path_style_access_enabled` +
+System property: `jgroups.aws.s3.path_style_access_enabled`
+| `false`
+| The S3 path-style enable (optional).
+
+| `kms_key_id` +
+System property: `jgroups.aws.s3.kms_key_id`
+|
+| Use kms encryption with s3 with the given kms key (optionally - enables KMS Server side encryption (SSE-KMS) using the given kms key)
+
+| `acl_grant_bucket_owner_full_control` +
+System property: `jgroups.aws.s3.acl_grant_bucket_owner_full_control`
+| `false`
+| Flag indicating whether or not to grant the bucket owner full control over the bucket on each update. This is useful in multi-region deployments where each region exists in its own AWS account.
+
+|===
+
+NOTE: System properties are supported since JGroups AWS release version 3.0.1.Final.
+      To use properties in the previous version, the property must be explicitly defined in the configuration.
 
 === Example Stack
 

src/main/java/org/jgroups/protocols/aws/S3_PING.java

@@ -46,30 +46,45 @@ public class S3_PING extends FILE_PING {
     protected static final String SERIALIZED_CONTENT_TYPE="text/plain";
     protected static final String MAGIC_NUMBER_SYSTEM_PROPERTY="s3ping.magic_number";
 
-    @Property(description="The S3 path-style enable (optional).", exposeAsManagedAttribute=false)
-    protected boolean  path_style_access_enabled=false;
-
-    @Property(description="The S3 endpoint to use (optional).", exposeAsManagedAttribute=false)
-    protected String   endpoint;
-
-    @Property(description="The S3 region to use.", exposeAsManagedAttribute=false)
-    protected String   region_name;
-
-    @Property(description="The S3 bucket to use.", exposeAsManagedAttribute=false)
-    protected String   bucket_name;
-
-    @Property(description="The S3 bucket prefix to use (optional e.g. 'jgroups/').", exposeAsManagedAttribute=false)
-    protected String   bucket_prefix;
-
-    @Property(description="Checks if the bucket exists in S3 and creates a new one if missing")
-    protected boolean  check_if_bucket_exists=true;
-
-    @Property(description = "Flag indicating whether or not to grant the bucket owner full control over the bucket  " +
-        "on each update. This is useful in multi-region deployments where each region exists in its own AWS account.")
-    protected boolean acl_grant_bucket_owner_full_control = false;
-
-    @Property(description="KMS key to use for enabling KMS server-side encryption (SSE-KMS) for S3 (optional).", exposeAsManagedAttribute=false)
-    protected String  kms_key_id;
+    @Property(description = "The S3 path-style enable (optional).",
+            systemProperty = "jgroups.aws.s3.path_style_access_enabled",
+            writable = false)
+    protected boolean path_style_access_enabled;
+
+    @Property(description = "The S3 endpoint to use (optional).",
+            systemProperty = "jgroups.aws.s3.endpoint",
+            writable = false)
+    protected String endpoint;
+
+    @Property(description = "The S3 region to use.",
+            systemProperty = "jgroups.aws.s3.region_name",
+            writable = false)
+    protected String region_name;
+
+    @Property(description = "The S3 bucket to use.",
+            systemProperty = "jgroups.aws.s3.bucket_name",
+            writable = false)
+    protected String bucket_name;
+
+    @Property(description = "The S3 bucket prefix to use (optional e.g. 'jgroups/').",
+            systemProperty = "jgroups.aws.s3.bucket_prefix",
+            writable = false)
+    protected String bucket_prefix;
+
+    @Property(description = "Checks if the bucket exists in S3 and creates a new one if missing",
+            systemProperty = "jgroups.aws.s3.check_if_bucket_exists",
+            writable = false)
+    protected boolean check_if_bucket_exists = true;
+
+    @Property(description = "Flag indicating whether or not to grant the bucket owner full control over the bucket on each update. This is useful in multi-region deployments where each region exists in its own AWS account.",
+            systemProperty = "jgroups.aws.s3.acl_grant_bucket_owner_full_control",
+            writable = false)
+    protected boolean acl_grant_bucket_owner_full_control;
+
+    @Property(description = "KMS key to use for enabling KMS server-side encryption (SSE-KMS) for S3 (optional).",
+            systemProperty = "jgroups.aws.s3.kms_key_id",
+            exposeAsManagedAttribute = false)
+    protected String kms_key_id;
 
     protected S3Client s3Client;