swh-scrubber: Refactor the entrypoint to not only support database scrubbers

Related to swh/infra/sysadm-environment#5108

apps/swh-scrubber/entrypoint.sh

 #!/bin/bash
 
-if [ -e "${SWH_CONFIG_FILENAME}" ]; then
-  echo "The config file ${SWH_CONFIG_FILENAME} does not exist."
-  exit 1
-fi
-
-ENV_VARS="LOGLEVEL STATSD_TAGS OBJECT_TYPE PARTITION_COUNT FIRST_PARTITION LAST_PARTITION"
-ERROR=0
-
-for VAR in ${ENV_VARS}; do
-    if [ -z "${!VAR}" ]; then
-        echo "The ${VAR} environment variable must be set"
-        ERROR=1
-    fi
-done
-
-if [ $ERROR -ne 0 ]; then
-    exit 1
-fi
-
-echo "Starting scrubber for OBJECT_TYPE=${OBJECT_TYPE} from FIRST_PARTITION=${FIRST_PARTITION} to LAST_PARTITION=${LAST_PARTITION}"
-exec swh \
-  --log-level $LOGLEVEL \
-  scrubber check storage \
-  --object-type ${OBJECT_TYPE} \
-  --nb-partitions ${NB_PARTITIONS} \
-  --start-partition-id ${START_OBJECT} \
-  --end-partition-id ${END_OBJECT}
+case "$1" in
+    "shell")
+        shift
+        if (( $# == 0)); then
+            exec bash -i
+        else
+            "$@"
+        fi
+        ;;
+    "swh")
+        shift
+        echo "Running swh command $@"
+        exec swh $@
+        ;;
+    *)
+        echo Unknown command $@
+        exit 1
+esac