Test and develop against Dynamodb Local

CONTRIBUTING.md

@@ -30,3 +30,39 @@ It will also auto-generate user votes over time for the questions there.
 
 If you're curious about the technologies used in the server and client,
 see their respective `README.md` files.
+
+To run tests against a DynamoDB instance running [locally](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/DynamoDBLocal.html), make sure
+you got [`docker`](https://docs.docker.com/engine/install/) and
+[`AWS CLI`](https://docs.aws.amazon.com/cli/latest/userguide/getting-started-install.html#getting-started-install-instructions) installed, then hit:
+
+```console
+$ cd server
+$ ./run-dynamodb-local.sh
+```
+
+This will also spin a [Web UI](https://github.com/aaronshaf/dynamodb-admin?tab=readme-ov-file)
+for your local DynamoDB instance.
+
+You can now run tests with:
+
+```sh
+AWS_DEFAULT_REGION=us-east-1 \
+   AWS_ACCESS_KEY_ID=lorem \
+   AWS_SECRET_ACCESS_KEY=ipsum \
+   AWS_ENDPOINT_URL=http://localhost:8000 \
+   cargo t -- --ignored
+```
+
+Assuming you are staying in the `server` directory, to run the back-end application against
+your local DynamoDB instance, hit:
+
+```sh
+AWS_DEFAULT_REGION=us-east-1 \
+   AWS_ACCESS_KEY_ID=lorem \
+   AWS_SECRET_ACCESS_KEY=ipsum \
+   USE_DYNAMODB=1 \
+   AWS_ENDPOINT_URL=http://localhost:8000 \
+   cargo run
+```
+
+Note that you can omit setting those dummy values for `AWS_DEFAULT_REGION`, `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY` in case you've got AWS profile(s) [configured](https://docs.aws.amazon.com/cli/latest/reference/configure/) on your workstation.

server/.gitignore

@@ -1 +1,3 @@
-/target
+/target
+/dynamodb-data
+Makefile

server/run-dynamodb-local.sh

@@ -0,0 +1,85 @@
+#!/usr/bin/env bash
+
+if ! [ -x "$(command -v docker)" ]; then
+    echo '❌ Error: please make sure docker is installed and is in the PATH' >&2
+    exit 1
+fi
+
+if ! [ -x "$(command -v aws)" ]; then
+    echo '❌ Error: please make sure AWS CLI is installed and is in the PATH' >&2
+    exit 1
+fi
+
+# AWS CLI wants us to either run `aws configure` or provide the three essential variables
+# from the environment. Most of us will have aws profile(s) configured on the workstation,
+# but this should not be a requirement to be able to spin up and query a DynamoDB Local
+# instance. This is why we are setting those variables in the current shell. Note that
+# the  credential values themselves do not matter, it is rather the fact that they _are_ set.
+#
+# see: https://docs.aws.amazon.com/cli/v1/userguide/cli-configure-envvars.html#envvars-set
+export AWS_ACCESS_KEY_ID=lorem
+export AWS_SECRET_ACCESS_KEY=ipsum
+export AWS_DEFAULT_REGION=us-east-1
+
+DYNAMODB_CONTAINER_NAME=dynamodb-local
+DYNAMODB_ADMIN_CONTAINER_NAME=dynamodb-admin
+ENDPOINT_URL=http://localhost:8000
+
+docker ps | grep ${DYNAMODB_CONTAINER_NAME} >/dev/null &&
+    echo "🚫 Container \"${DYNAMODB_CONTAINER_NAME}\" with DynamoDB Local service is already running." && exit 0
+
+echo "🖴 Preparing volumes for DynamoDB..."
+rm -rf dynamodb-data
+mkdir dynamodb-data
+
+echo "🚀 Spinning up a container with DynamoDB..."
+(
+    docker run --rm -d -v ./dynamodb-data:/home/dynamodblocal/data -p 127.0.0.1:8000:8000 \
+        -w /home/dynamodblocal --name ${DYNAMODB_CONTAINER_NAME} amazon/dynamodb-local:latest \
+        -jar DynamoDBLocal.jar -sharedDb -dbPath ./data
+) >/dev/null
+
+while ! (AWS_ACCESS_KEY_ID=lorem AWS_SECRET_ACCESS_KEY=ipsum aws dynamodb list-tables --endpoint-url ${ENDPOINT_URL} --region us-east-1 >/dev/null); do
+    echo "⏳ Waiting for the database to start accepting connections..."
+done
+
+echo "🗒️ Creating 'events' table..."
+aws dynamodb create-table \
+    --table-name events \
+    --attribute-definitions AttributeName=id,AttributeType=S \
+    --key-schema AttributeName=id,KeyType=HASH \
+    --billing-mode PAY_PER_REQUEST \
+    --endpoint-url ${ENDPOINT_URL} >/dev/null
+
+aws dynamodb update-time-to-live \
+    --table-name events \
+    --time-to-live-specification Enabled=true,AttributeName=expire \
+    --endpoint-url ${ENDPOINT_URL} >/dev/null
+
+echo "🗒️ Creating 'questions' table and 🚄 GSI..."
+aws dynamodb create-table \
+    --table-name questions \
+    --attribute-definitions AttributeName=id,AttributeType=S \
+    AttributeName=eid,AttributeType=S \
+    AttributeName=votes,AttributeType=N \
+    --key-schema AttributeName=id,KeyType=HASH \
+    --global-secondary-indexes 'IndexName=top,KeySchema=[{AttributeName=eid,KeyType=HASH},{AttributeName=votes,KeyType=RANGE}],Projection={ProjectionType=INCLUDE,NonKeyAttributes=[answered,hidden]}' \
+    --billing-mode PAY_PER_REQUEST \
+    --endpoint-url ${ENDPOINT_URL} >/dev/null
+
+aws dynamodb update-time-to-live \
+    --table-name questions \
+    --time-to-live-specification Enabled=true,AttributeName=expire \
+    --endpoint-url ${ENDPOINT_URL} >/dev/null
+
+echo "✅ Container \"${DYNAMODB_CONTAINER_NAME}\" with DynamoDB Local is ready!"
+
+docker ps | grep ${DYNAMODB_ADMIN_CONTAINER_NAME} >/dev/null &&
+    echo "🚫 Container "${DYNAMODB_ADMIN_CONTAINER_NAME}" with DynamoDB Admin service is already running." &&
+    exit 0
+
+echo "🚀 Spinning up a container with DynamoDB Admin..."
+(docker run -d --rm --net host --name ${DYNAMODB_ADMIN_CONTAINER_NAME} aaronshaf/dynamodb-admin) >/dev/null
+echo "🔎 DynamoDB Admin is available at http://localhost:8001"
+
+echo "✅ Done!"

server/src/main.rs

@@ -134,8 +134,10 @@ async fn main() -> Result<(), Error> {
         .with_env_filter(EnvFilter::from_default_env())
         .without_time(/* cloudwatch does that */).init();
 
-    #[cfg(debug_assertions)]
-    let backend = {
+    let backend = if !cfg!(debug_assertions) || std::env::var_os("USE_DYNAMODB").is_some() {
+        let config = aws_config::load_from_env().await;
+        Backend::Dynamo(aws_sdk_dynamodb::Client::new(&config))
+    } else {
         use rand::prelude::SliceRandom;
         use serde::Deserialize;
         use std::time::Duration;
@@ -202,11 +204,6 @@ async fn main() -> Result<(), Error> {
         });
         state
     };
-    #[cfg(not(debug_assertions))]
-    let backend = {
-        let config = aws_config::load_from_env().await;
-        Backend::Dynamo(aws_sdk_dynamodb::Client::new(&config))
-    };
 
     let app = Router::new()
         .route("/api/event", post(new::new))