Databases

Redshift

The aws_db_redshift_create function creates a cluster for you (a Redshift instance is called a “cluster”).

There’s an important distinction between Redshift and RDS. Redshift uses IAM username/password, whereas with RDS you can use username/password setup for each instance of a RDS database, or do authentication through IAM. However, with RDS you can’t simply pass your IAM username/password (see notes below).

First, let’s create a security group with an ingress rule so you can access your Redshift cluster.

my_security_group <- aws_vpc_sg_with_ingresss("redshift")

Notes on the parameters used in the example below:

• id: this is an ID you come up with, it must be unique for all clusters within your AWS account
• user/pwd: your IAM username and password
• security_group_ids: it’s best to first create a security group to handle permissions to your Redshift cluster. See example above for how to do that. Pass in it’s identifier here
• wait: Since we’re using wait=TRUE the call to aws_db_redshift_create will likely take about 3 minutes to run. You can set wait=FALSE and not wait, but then you’ll want to check yourself when the instance is available.

aws_db_redshift_create(
  id = "some-id",
  user = "your-username",
  pwd = "your-pwd",
  security_group_ids = list(my_security_group),
  wait = TRUE
)

Connect to the cluster

con <- aws_db_redshift_con(
  user = "your-username",
  pwd = "your-pwd",
  id = "some-id"
)

List tables, create a table, etc

library(DBI)
dbListTables(con)
dbWriteTable(con, "mtcars", mtcars)
dbListTables(con)
dbReadTable(con, "mtcars")

Use dplyr/et al.

library(dplyr)
tbl(con, "mtcars") %>%
  filter(mpg == 4)

Important: Remember to delete your cluster when your done!

RDS

The process for MariaDB, MySQL, and Postgres are more or less the same, so we’ll only demonstrate MariaDB.

In a future version of this package you’ll be able to use IAM to authenticate with RDS, but for now sixtyfour does not support IAM for RDS. The current “happy path” (read: easy) process of starting an RDS instance with aws_db_rds_create is as follows:

• Supply an ID (identifier) for your instance that you create
• A random username is created and used for database authentication
• A random password is created (via AWS Secretamanager) and used for database authentication
• A security groups is created
  • An ingress rule is added to the security group with your IP address
• On RDS instance creation, we use the above username, password, and security group
• The username, password, and security group information are stored in AWS Secretamanager for subsequent use

To connect to your RDS instance, you use aws_db_rds_con. The “happy path” for connecting is:

• Pass in only the ID used above
• We fetch secrets from the AWS Secretamanager and ask you which you’d like to use
• We gather all the necessary details to connect to your instance
• Return a DBI connection object, e.g., MariaDBConnection for MariaDB

Let’s walk through the steps with some code.

First, create an RDS instance - in this case for MariaDB.

Notes on the parameters used in the example below:

• id: this is an ID you come up with. see ?aws_db_rds_create for constraints
• class: The compute and memory capacity of the instance; see the AWS docs for instance class options. The default for this parameter (db.t3.micro) gives you an instance with relatively small capacity in terms of memory and compute - but is set that way to minimize costs in case you forget to turn it off if you’re not using it!
• engine: the default is mariadb; other options are mysql or postgres
• wait: Since we’re using wait=TRUE (the default for this function) the call to aws_db_rds_create will likely take about 5 minutes to run. You can set wait=FALSE and not wait, but then you’ll want to check yourself when the instance is available.

aws_db_rds_create(
  id = "myinstance",
  class = "db.t3.micro",
  engine = "mariadb",
  wait = TRUE
)

Connect to the instance

con <- aws_db_rds_con(id = "myinstance")

List tables, create a table, etc

library(DBI)
dbListTables(con)
dbWriteTable(con, "mtcars", mtcars)
dbListTables(con)
dbReadTable(con, "mtcars")

Use dplyr/et al.

library(dplyr)
tbl(con, "mtcars") %>%
  filter(mpg == 4)