@4devso/serverless-dynamodb-local
v1.0.1
Published
Serverless dynamodb local plugin
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serverless-dynamodb-local
This Plugin Requires
- serverless@^1
- Java Runtime Engine (JRE) version 6.x or newer OR docker CLI client
Features
- Install DynamoDB Local Java program
- Run DynamoDB Local as Java program on the local host or in docker container
- Start DynamoDB Local with all the parameters supported (e.g port, inMemory, sharedDb)
- Table Creation for DynamoDB Local
Install Plugin
npm install --save serverless-dynamodb-local
Then in serverless.yml
add following entry to the plugins array: serverless-dynamodb-local
plugins:
- serverless-dynamodb-local
Using the Plugin
Install DynamoDB Local (unless using docker setup, see below)
sls dynamodb install
Add DynamoDB Resource definitions to your Serverless configuration, as defined here: https://serverless.com/framework/docs/providers/aws/guide/resources/#configuration
Start DynamoDB Local and migrate (DynamoDB will process incoming requests until you stop it. To stop DynamoDB, type Ctrl+C in the command prompt window). Make sure above command is executed before this.
sls dynamodb start --migrate
Note: Read the detailed section for more information on advanced options and configurations. Open a browser and go to the url http://localhost:8000/shell to access the web shell for dynamodb local.
Install: sls dynamodb install
This installs the Java program locally. If using docker, this step is not required.
To remove the installed dynamodb local, run:
sls dynamodb remove
Note: This is useful if the sls dynamodb install failed in between to completely remove and install a new copy of DynamoDB local.
Start: sls dynamodb start
This starts the DynamoDB Local instance, either as a local Java program or, if the --docker
flag is set,
by running it within a docker container. The default is to run it as a local Java program.
All CLI options are optional:
--port -p Port to listen on. Default: 8000
--cors -c Enable CORS support (cross-origin resource sharing) for JavaScript. You must provide a comma-separated "allow" list of specific domains. The default setting for -cors is an asterisk (*), which allows public access.
--inMemory -i DynamoDB; will run in memory, instead of using a database file. When you stop DynamoDB;, none of the data will be saved. Note that you cannot specify both -dbPath and -inMemory at once.
--dbPath -d The directory where DynamoDB will write its database file. If you do not specify this option, the file will be written to the current directory. Note that you cannot specify both -dbPath and -inMemory at once. For the path, current working directory is <projectroot>/node_modules/serverless-dynamodb-local/dynamob. For example to create <projectroot>/node_modules/serverless-dynamodb-local/dynamob/<mypath> you should specify -d <mypath>/ or --dbPath <mypath>/ with a forwardslash at the end.
--sharedDb -h DynamoDB will use a single database file, instead of using separate files for each credential and region. If you specify -sharedDb, all DynamoDB clients will interact with the same set of tables regardless of their region and credential configuration.
--delayTransientStatuses -t Causes DynamoDB to introduce delays for certain operations. DynamoDB can perform some tasks almost instantaneously, such as create/update/delete operations on tables and indexes; however, the actual DynamoDB service requires more time for these tasks. Setting this parameter helps DynamoDB simulate the behavior of the Amazon DynamoDB web service more closely. (Currently, this parameter introduces delays only for global secondary indexes that are in either CREATING or DELETING status.)
--optimizeDbBeforeStartup -o Optimizes the underlying database tables before starting up DynamoDB on your computer. You must also specify -dbPath when you use this parameter.
--migration -m After starting dynamodb local, run dynamodb migrations.
--heapInitial The initial heap size
--heapMax The maximum heap size
--migrate -m After starting DynamoDB local, create DynamoDB tables from the Serverless configuration.
--seed -s After starting and migrating dynamodb local, injects seed data into your tables. The --seed option determines which data categories to onload.
--convertEmptyValues -e Set to true if you would like the document client to convert empty values (0-length strings, binary buffers, and sets) to be converted to NULL types when persisting to DynamoDB.
--docker Run DynamoDB inside docker container instead of as a local Java program
--dockerImage Specify custom docker image. Default: amazon/dynamodb-local
All the above options can be added to serverless.yml to set default configuration: e.g.
custom:
dynamodb:
# If you only want to use DynamoDB Local in some stages, declare them here
stages:
- dev
start:
port: 8000
inMemory: true
heapInitial: 200m
heapMax: 1g
migrate: true
seed: true
convertEmptyValues: true
# Uncomment only if you already have a DynamoDB running locally
# noStart: true
Docker setup:
custom:
dynamodb:
# If you only want to use DynamoDB Local in some stages, declare them here
stages:
- dev
start:
docker: true
port: 8000
inMemory: true
migrate: true
seed: true
convertEmptyValues: true
# Uncomment only if you already have a DynamoDB running locally
# noStart: true
Migrations: sls dynamodb migrate
Configuration
In serverless.yml
add following to execute all the migration upon DynamoDB Local Start
custom:
dynamodb:
start:
migrate: true
AWS::DynamoDB::Table Resource Template for serverless.yml
resources:
Resources:
usersTable:
Type: AWS::DynamoDB::Table
Properties:
TableName: usersTable
AttributeDefinitions:
- AttributeName: email
AttributeType: S
KeySchema:
- AttributeName: email
KeyType: HASH
ProvisionedThroughput:
ReadCapacityUnits: 1
WriteCapacityUnits: 1
Note: DynamoDB local doesn't support TTL specification, therefore plugin will simply ignore ttl configuration from Cloudformation template.
Seeding: sls dynamodb seed
Configuration
In serverless.yml
seeding categories are defined under dynamodb.seed
.
If dynamodb.start.seed
is true, then seeding is performed after table migrations.
If you wish to use raw AWS AttributeValues to specify your seed data instead of Javascript types then simply change the variable of any such json files from sources:
to rawsources:
.
custom:
dynamodb:
start:
seed: true
seed:
domain:
sources:
- table: domain-widgets
sources: [./domainWidgets.json]
- table: domain-fidgets
sources: [./domainFidgets.json]
test:
sources:
- table: users
rawsources: [./fake-test-users.json]
- table: subscriptions
sources: [./fake-test-subscriptions.json]
> sls dynamodb seed --seed=domain,test
> sls dynamodb start --seed=domain,test
If seed config is set to true, your configuration will be seeded automatically on startup. You can also put the seed to false to prevent initial seeding to use manual seeding via cli.
[
{
"id": "John",
"name": "Doe",
},
]
Using DynamoDB Local in your code
You need to add the following parameters to the AWS NODE SDK dynamodb constructor
e.g. for dynamodb document client sdk
var AWS = require('aws-sdk');
new AWS.DynamoDB.DocumentClient({
region: 'localhost',
endpoint: 'http://localhost:8000',
accessKeyId: 'DEFAULT_ACCESS_KEY', // needed if you don't have aws credentials at all in env
secretAccessKey: 'DEFAULT_SECRET' // needed if you don't have aws credentials at all in env
})
e.g. for dynamodb document client sdk
new AWS.DynamoDB({
region: 'localhost',
endpoint: 'http://localhost:8000',
accessKeyId: 'DEFAULT_ACCESS_KEY', // needed if you don't have aws credentials at all in env
secretAccessKey: 'DEFAULT_SECRET' // needed if you don't have aws credentials at all in env
})
Using with serverless-offline plugin
When using this plugin with serverless-offline, it is difficult to use above syntax since the code should use DynamoDB Local for development, and use DynamoDB Online after provisioning in AWS. Therefore we suggest you to use serverless-dynamodb-client plugin in your code.
The serverless dynamodb start
command can be triggered automatically when using serverless-offline
plugin.
Please note that you still need to install DynamoDB Local first.
Add both plugins to your serverless.yml
file:
plugins:
- serverless-dynamodb-local
- serverless-offline
Make sure that serverless-dynamodb-local
is above serverless-offline
so it will be loaded earlier.
Now your local DynamoDB database will be automatically started before running serverless offline
.
Using with serverless-offline and serverless-webpack plugin
Run serverless offline start
. In comparison with serverless offline
, the start
command will fire an init
and a end
lifecycle hook which is needed for serverless-offline and serverless-dynamodb-local to switch off both ressources.
Add plugins to your serverless.yml
file:
plugins:
- serverless-webpack
- serverless-dynamodb-local
- serverless-offline #serverless-offline needs to be last in the list