stellar#4493: doc the image builds, and other pr feedback

exp/lighthorizon/build/README.md

@@ -0,0 +1,24 @@
+# Light Horizon services deployment
+
+Light Horizon is composed of a few micro services:
+* index-batch    - contains map and reduce binaries to parallize tx-meta reads and index writes.
+* index-single   - contains single binary that reads tx-meta and writes indexes.
+* ledgerexporter - contains single binary that reads from captive core and writes tx-meta
+* web            - contains single binary that runs web api which reads from tx-meta and index.
+
+See [godoc](https://godoc.org/github.com/stellar/go/exp/lighthorizon) for details on each service.
+
+## Buiding docker images of each service
+Each service is packaged into a Docker image, use the helper script included here to build:
+`./build.sh <service_name> <dockerhub_registry_name> <tag_name> <push_to_repo[true|false]>`
+
+example to build just the mydockerhubname/lighthorizon-index-single:latest image to docker local images, no push to registry:
+`./build.sh index-single mydockerhubname latest false`
+
+example to build images for all the services and push them to mydockerhubname/lighthorizon-<servicename>:testversion:
+`./build.sh all mydockerhubname testversion true`
+
+## Deploy service images on kubernetes(k8s) 
+* `k8s/ledgerexporter.yml` - creates a deployment with ledgerexporter image and supporting resources, such as configmap, secret, pvc for captive core on-disk storage. Review the settings to confirm they work in your environment before deployment.
+* `k8s/lighthorizon_index.yml` - creates a deployment with index-single image and supporting resources, such as configmap, secret. Review the settings to confirm they work in your environment before deployment.
+* `k8s/lighthorizon_web.yml` - creates a deployment with the web image and supporting resources, such as configmap, ingress rule. Review the settings to confirm they work in your environment before deployment. 

exp/lighthorizon/build/build.sh

@@ -6,46 +6,50 @@ cd "$DIR/../../.."
 # module name is the sub-folder name under ./build
 MODULE=$1
 DOCKER_REPO_PREFIX=$2
-DOCKER_PUSH=$3
+DOCKER_TAG=$3
+DOCKER_PUSH=$4
 
-if [ ! -z "$DOCKER_REPO_PREFIX" ]; then
-   DOCKER_REPO_PREFIX="$DOCKER_REPO_PREFIX/" 
+if [ -z "$MODULE" ] ||\
+   [ -z "$DOCKER_REPO_PREFIX" ] ||\
+   [ -z "$DOCKER_TAG" ] ||\
+   [ -z "$DOCKER_PUSH" ]; then
+   echo "invalid parameters, requires './build.sh <service_name> <tag_name> <dockerhub_registry_name> <push_to_repo[true|false]>'"
+   exit 1
 fi
 
 build_target () { 
-    DOCKER_TAG="$DOCKER_REPO_PREFIX"lighthorizon-"$MODULE_NAME"
-    docker build --tag $DOCKER_TAG --platform linux/amd64 -f "exp/lighthorizon/build/$MODULE_NAME/Dockerfile" . 
+    DOCKER_LABEL="$DOCKER_REPO_PREFIX"/lighthorizon-"$MODULE":"$DOCKER_TAG"
+    docker build --tag $DOCKER_LABEL --platform linux/amd64 -f "exp/lighthorizon/build/$MODULE/Dockerfile" . 
     if [ "$DOCKER_PUSH" == "true" ]; then
-        docker push $DOCKER_TAG
+        docker push $DOCKER_LABEL
     fi
 }
 
-MODULE_NAME=$MODULE
 case $MODULE in
-index_batch)
+index-batch)
     build_target
     ;;
 ledgerexporter)
     build_target
     ;;
-index_single)
+index-single)
     build_target
     ;;
 web)
     build_target
     ;;
 all)
-    MODULE_NAME=index-batch
+    MODULE=index-batch
     build_target
-    MODULE_NAME=web
+    MODULE=web
     build_target
-    MODULE_NAME=index-single
+    MODULE=index-single
     build_target
-    MODULE_NAME=ledgerexporter
+    MODULE=ledgerexporter
     build_target
     ;;  
 *)
-    echo -n "unknown MODULE build parameter, must be one of all|index_batch|web|index_single|ledgerexporter"
+    echo "unknown MODULE build parameter ('$MODULE'), must be one of all|index-batch|web|index-single|ledgerexporter"
     exit 1
     ;;
 esac

exp/lighthorizon/build/index-batch/start

@@ -13,6 +13,6 @@ elif [ "$RUN_MODE" == "map" ]; then
     echo "Running Map, TARGET INDEX: $INDEX_TARGET FIRST CHECKPOINT: $FIRST_CHECKPOINT"
     /map 
 else
-    echo "error: undefined RUN_MODE env variable, must be map or reduce"
+    echo "error: undefined RUN_MODE env variable ('$RUN_MODE'), must be 'map' or 'reduce'"
     exit 1
 fi

exp/lighthorizon/build/k8s/lighthorizon_index.yml

@@ -13,7 +13,7 @@ data:
   START: "41809728"
   END: "0"
   WATCH: "true"
-  MODULES: "transactions,accounts"
+  MODULES: "accounts"
   WORKERS: "3"
 ---  
 apiVersion: v1

exp/lighthorizon/main.go

@@ -34,6 +34,7 @@ if left empty, uses a temporary directory`)
 	L := log.WithField("service", "horizon-lite")
 	logLevel, err := logrus.ParseLevel(*logLevelParam)
 	if err != nil {
+		log.Warnf("Failed to parse -log-level '%s', defaulting to 'info'.", *logLevelParam)
 		logLevel = log.InfoLevel
 	}