DynamoDB

Read an item attribute from an Amazon DynamoDB table, built on aws-sdk-go-v2.


Scheme	`dynamodb://`
Module	`github.com/xavidop/mamori/providers/dynamodb`
Sensitive	no (opt-in with `WithSensitive`)
Watch	poll
Auth	default AWS credential chain (`WithRegion`)

Install

go get github.com/xavidop/mamori/providers/dynamodb

import _ "github.com/xavidop/mamori/providers/dynamodb"

Using the ref

A dynamodb:// ref points at one item in a table, fetched by its primary key with a single GetItem.

dynamodb://<table>/<pk>[#attr][?pk_name=<name>&sk=<value>&sk_name=<name>]

Part	Required	What it means
`<table>`	yes	The DynamoDB table name.
`<pk>`	yes	The partition-key value (a string).
`#attr`	no	Return one top-level attribute instead of the whole item. Without it, the whole item comes back as JSON.
`?pk_name=`	no	The partition-key attribute name. Defaults to `pk`.
`?sk=`	no	The sort-key value, for a table with a composite primary key.
`?sk_name=`	no	The sort-key attribute name. Defaults to `sk`.

Examples

dynamodb://app-config/service reads the item whose pk is service and returns the whole item as JSON.
dynamodb://app-config/service#endpoint returns just the endpoint attribute of that item.
dynamodb://services/payments#url?pk_name=service_id looks the item up by a service_id partition key instead of the default pk.
dynamodb://events/e-1#payload?sk=2024&sk_name=year reads an item with a composite key (partition pk = e-1, sort year = 2024).

type Config struct {
	Endpoint string `source:"dynamodb://app-config/service#endpoint"`
	Whole    string `source:"dynamodb://app-config/service"` // whole item as JSON
}

#attr selects a top-level DynamoDB attribute, not a nested JSON key: a scalar comes back stringified (S/N verbatim, BOOL as true/false, NULL as null), while maps, lists, and sets are JSON. Value.Version is the item’s version attribute when present (bump it to force a refresh), otherwise a content hash. Items are not marked sensitive by default; construct the provider with WithSensitive when a table holds secret material.

Watch

mamori polls (WithPollInterval + jitter). For push, DynamoDB Streams can drive an on-demand reload in your app.

Configuration

import ddbprov "github.com/xavidop/mamori/providers/dynamodb"

mamori.WithProvider(ddbprov.New(ddbprov.WithRegion("eu-west-1")))

Verified with an in-memory fake; live behavior is covered by //go:build integration tests.