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README.md

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//#if kafka

Propulsion EventStore $all/CosmosDb ChangeFeedProcessor/DynamoStoreSource -> Kafka Projector

//#else

Propulsion EventStore $all/CosmosDb ChangeFeedProcessor/DynamoStoreSource Projector (without Kafka emission)

//#endif

This project was generated using: //#if kafka

dotnet new -i Equinox.Templates # just once, to install/update in the local templates store
dotnet new proReactor -k # -k => include Kafka projection logic

//#else

dotnet new -i Equinox.Templates # just once, to install/update in the local templates store
# add -k to add Kafka Projection logic
dotnet new proReactor # use --help to see options

//#endif

Usage instructions

  1. establish connection strings etc. per https://github.com/jet/equinox README

     $env:EQUINOX_COSMOS_CONNECTION="AccountEndpoint=https://....;AccountKey=....=;" # or use -s
 $env:EQUINOX_COSMOS_DATABASE="equinox-test" # or use -d
 $env:EQUINOX_COSMOS_CONTAINER="equinox-test" # or use -c

  2. Use the eqx tool to initialize a CosmosDb container

     dotnet tool install -g Equinox.Tool # only needed once

 # (either add environment variables as per step 0 or use -s/-d/-c to specify them)
 # generate a cosmos container to store events in
 eqx init -ru 400 cosmos

  3. We'll be operating a ChangeFeedProcessor, so use propulsion init to make a -aux container (unless there already is one)

     # (either add environment variables as per step 0 or use -s/-d/-c to specify them)
 # default name is "($EQUINOX_COSMOS_CONTAINER)-aux"
 propulsion init -ru 400 cosmos

    NOTE when projecting from EventStore, the current implementation stores the checkpoints within a CosmosStore or DynamoStore in order to remove feedback effects.

    (Yes, someone should do a PR to store the checkpoints in EventStore itself; this is extracted from working code, which can assume there's always a CosmosDB around)

  4. To run an instance of the Projector from a CosmosDb ChangeFeed

//#if kafka $env:PROPULSION_KAFKA_BROKER="instance.kafka.example.com:9092" # or use -b

    # `-g default` defines the Projector Group identity - each id has separated state in the checkpoints store (`Sync-default` in the cited `cosmos` store)
    # `-t topic0` identifies the Kafka topic to which the Projector should write
    # `-c $env:EQUINOX_COSMOS_CONTAINER ` specifies the source (if you have specified 2x EQUINOX_COSMOS_* environment vars, no connection/database arguments are needed, but the monitored (source) container must be specified explicitly)
    # the second `cosmos` specifies the target store for the reactions (if you have specified 3x EQUINOX_COSMOS_* environment vars, no arguments are needed)
    dotnet run -- -g default kafka -t topic0 cosmos -c $env:EQUINOX_COSMOS_CONTAINER cosmos

//#else # -g default defines the Projector Group identity - each id has separated state in the checkpoints store (Sync-default in the cited cosmos store) # -c $env:EQUINOX_COSMOS_CONTAINER specifies the source (if you have specified EQUINOX_COSMOS_* environment vars, no connection/database arguments are needed, but the monitored (source) container must be specified explicitly) # cosmos specifies the target store for the reactions (if you have specified 3x EQUINOX_COSMOS_* environment vars, no arguments are needed) dotnet run -- -g default cosmos -c $env:EQUINOX_COSMOS_CONTAINER cosmos //#endif

  1. To run an instance of the Projector from EventStore

     # (either add environment variables like this, or use -h/-u/-p to specify them after the `es` argument token)

 $env:EQUINOX_ES_HOST="localhost" # or use -h
 $env:EQUINOX_ES_USERNAME="admin" # or use -u
 $env:EQUINOX_ES_PASSWORD="changeit" # or use -p

//#if kafka $env:PROPULSION_KAFKA_BROKER="instance.kafka.example.com:9092" # or use -b

    # `-g default` defines the Projector Group identity - each id has separated state in the checkpoints store (`Sync-default` in the cited `cosmos` store)
    # `-t topic0` identifies the Kafka topic to which the Projector should write
    # `es` specifies the source (if you have specified 3x EQUINOX_ES_* environment vars, no arguments are needed)
    # `cosmos` specifies the checkpoint store (if you have specified 3x EQUINOX_COSMOS_* environment vars, no arguments are needed)
    dotnet run -- -g default kafka -t topic0 es cosmos

//#else # -g default defines the Projector Group identity - each id has separated state in the checkpoints store (Sync-default in the cited cosmos store) # es specifies the source (if you have specified 3x EQUINOX_ES_* environment vars, no arguments are needed) # cosmos specifies the checkpoint store (if you have specified 3x EQUINOX_COSMOS_* environment vars, no arguments are needed) dotnet run -- -g default es cosmos //#endif

    # NB running more than one projector will cause them to duel, and is hence not advised
  1. To create a Consumer, use dotnet new proConsumer (see README therein for details)