Ability to clear The Graph data (ethereum-optimism#121)

* Adding ability to clear The Graph data by setting CLEAR_DATA_KEY environment variable

aws/synthetix/prod/web/ecs-params.yml

@@ -55,8 +55,10 @@ task_definition:
       autoprovision: true
       driver: 'local'
     - name: postgres-data
-      scope: task
+      scope: shared
+      autoprovision: true
       driver: 'local'
     - name: ipfs-data
-      scope: task
+      scope: shared
+      autoprovision: true
       driver: 'local'

aws/synthetix/uat/web/ecs-params.yml

@@ -55,8 +55,10 @@ task_definition:
       autoprovision: true
       driver: 'local'
     - name: postgres-data
-      scope: task
+      scope: shared
+      autoprovision: true
       driver: 'local'
     - name: ipfs-data
-      scope: task
+      scope: shared
+      autoprovision: true
       driver: 'local'

docker/the-graph/wait-for-ovm.sh

@@ -1,5 +1,7 @@
 #!/bin/sh
 # wait-for-ovm.sh <ovm url with port>
+# NOTE: set the CLEAR_DATA_KEY environment variable to clear the /data directory on startup.
+# Directory will only be cleared if CLEAR_DATA_KEY is set AND different from last start.
 
 set -e
 
@@ -29,6 +31,23 @@ wait_for_server_to_be_reachable()
 
 }
 
+clear_data_if_necessary()
+{
+  DATA_DIRECTORY=${DATA_DIRECTORY:-/data}
+  CLEAR_DATA_FILE_PATH="$DATA_DIRECTORY/.clear_data_key_$CLEAR_DATA_KEY"
+
+  if [[ -n "$CLEAR_DATA_KEY" && ! -f "$CLEAR_DATA_FILE_PATH" ]]; then
+    echo "Detected change in CLEAR_DATA_KEY. Purging data."
+    rm -rf ${DATA_DIRECTORY}/*
+    rm -rf ${DATA_DIRECTORY}/.clear_data_key_*
+    echo "Local data cleared from '${DATA_DIRECTORY}/*'"
+    echo "Contents of data dir: $(ls -alh $DATA_DIRECTORY)"
+    touch $CLEAR_DATA_FILE_PATH
+  fi
+}
+
+clear_data_if_necessary
+
 wait_for_server_to_be_reachable $OVM_URL_WITH_PORT
 
 >&2 echo "OVM is up!"