Linting: require braces around variables

.github/workflows/ci.yml

@@ -13,4 +13,4 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Lint
-        run: shellcheck *.sh
+        run: make lint

Makefile

@@ -0,0 +1,4 @@
+SHELL_FILES := $(wildcard *.sh)
+
+lint:
+	@shellcheck --enable=require-variable-braces $(SHELL_FILES) && echo "ShellCheck passed"

backup.sh

@@ -6,73 +6,73 @@
 set -e
 set -o pipefail
 
-if [ "$S3_ACCESS_KEY_ID" = "**None**" ]; then
+if [ "${S3_ACCESS_KEY_ID}" = "**None**" ]; then
   echo "You need to set the S3_ACCESS_KEY_ID environment variable."
   exit 1
 fi
 
-if [ "$S3_SECRET_ACCESS_KEY" = "**None**" ]; then
+if [ "${S3_SECRET_ACCESS_KEY}" = "**None**" ]; then
   echo "You need to set the S3_SECRET_ACCESS_KEY environment variable."
   exit 1
 fi
 
-if [ "$S3_BUCKET" = "**None**" ]; then
+if [ "${S3_BUCKET}" = "**None**" ]; then
   echo "You need to set the S3_BUCKET environment variable."
   exit 1
 fi
 
-if [ "$POSTGRES_DATABASE" = "**None**" ]; then
+if [ "${POSTGRES_DATABASE}" = "**None**" ]; then
   echo "You need to set the POSTGRES_DATABASE environment variable."
   exit 1
 fi
 
-if [ "$POSTGRES_HOST" = "**None**" ]; then
+if [ "${POSTGRES_HOST}" = "**None**" ]; then
   if [ -n "${POSTGRES_PORT_5432_TCP_ADDR}" ]; then
-    POSTGRES_HOST="$POSTGRES_PORT_5432_TCP_ADDR"
-    POSTGRES_PORT="$POSTGRES_PORT_5432_TCP_PORT"
+    POSTGRES_HOST="${POSTGRES_PORT_5432_TCP_ADDR}"
+    POSTGRES_PORT="${POSTGRES_PORT_5432_TCP_PORT}"
   else
     echo "You need to set the POSTGRES_HOST environment variable."
     exit 1
   fi
 fi
 
-if [ "$POSTGRES_USER" = "**None**" ]; then
+if [ "${POSTGRES_USER}" = "**None**" ]; then
   echo "You need to set the POSTGRES_USER environment variable."
   exit 1
 fi
 
-if [ "$POSTGRES_PASSWORD" = "**None**" ]; then
+if [ "${POSTGRES_PASSWORD}" = "**None**" ]; then
   echo "You need to set the POSTGRES_PASSWORD environment variable or link to a container named POSTGRES."
   exit 1
 fi
 
-if [ "$S3_ENDPOINT" = "**None**" ]; then
+if [ "${S3_ENDPOINT}" = "**None**" ]; then
   AWS_ARGS=""
 else
-  AWS_ARGS="--endpoint-url $S3_ENDPOINT"
+  AWS_ARGS="--endpoint-url ${S3_ENDPOINT}"
 fi
 
 # env vars needed for aws tools
-export AWS_ACCESS_KEY_ID="$S3_ACCESS_KEY_ID"
-export AWS_SECRET_ACCESS_KEY="$S3_SECRET_ACCESS_KEY"
-export AWS_DEFAULT_REGION="$S3_REGION"
+export AWS_ACCESS_KEY_ID="${S3_ACCESS_KEY_ID}"
+export AWS_SECRET_ACCESS_KEY="${S3_SECRET_ACCESS_KEY}"
+export AWS_DEFAULT_REGION="${S3_REGION}"
 
-export PGPASSWORD="$POSTGRES_PASSWORD"
-POSTGRES_HOST_OPTS="-h $POSTGRES_HOST -p $POSTGRES_PORT -U $POSTGRES_USER $POSTGRES_EXTRA_OPTS"
+export PGPASSWORD="${POSTGRES_PASSWORD}"
+POSTGRES_HOST_OPTS="-h ${POSTGRES_HOST} -p ${POSTGRES_PORT} -U ${POSTGRES_USER} ${POSTGRES_EXTRA_OPTS}"
 
-echo "Creating dump of $POSTGRES_DATABASE database from $POSTGRES_HOST..."
+echo "Creating dump of ${POSTGRES_DATABASE} database from ${POSTGRES_HOST}..."
 
-pg_dump -Fc $POSTGRES_HOST_OPTS "$POSTGRES_DATABASE" > db.dump
+pg_dump -Fc ${POSTGRES_HOST_OPTS} "${POSTGRES_DATABASE}" > db.dump
 
-echo "Uploading dump to $S3_BUCKET"
+echo "Uploading dump to ${S3_BUCKET}"
 
-aws $AWS_ARGS s3 cp db.dump "s3://$S3_BUCKET/$S3_PREFIX/${POSTGRES_DATABASE}_$(date +"%Y-%m-%dT%H:%M:%SZ").dump" || exit 2
+aws ${AWS_ARGS} s3 cp db.dump "s3://${S3_BUCKET}/${S3_PREFIX}/${POSTGRES_DATABASE}_$(date +"%Y-%m-%dT%H:%M:%SZ").dump" || exit 2
 
 echo "DB backup uploaded successfully"
 
 rm db.dump
 
-if [ ! "$SUCCESS_WEBHOOK" = "**None**" ]; then
-    echo "Notifying $SUCCESS_WEBHOOK"
-    curl -m 10 --retry 5 "$SUCCESS_WEBHOOK"
+if [ ! "${SUCCESS_WEBHOOK}" = "**None**" ]; then
+    echo "Notifying ${SUCCESS_WEBHOOK}"
+    curl -m 10 --retry 5 "${SUCCESS_WEBHOOK}"
 fi

entrypoint.sh

@@ -2,14 +2,14 @@
 
 set -e
 
-if [ "$S3_S3V4" = "yes" ]; then
+if [ "${S3_S3V4}" = "yes" ]; then
     aws configure set default.s3.signature_version s3v4
 fi
 
-if [ "$SCHEDULE" = "**None**" ]; then
+if [ "${SCHEDULE}" = "**None**" ]; then
   echo You need to set up SCHEDULE env var
   exit 127
 else
-  echo "$SCHEDULE /bin/sh /backup.sh" > /etc/crontab.backup
+  echo "${SCHEDULE} /bin/sh /backup.sh" > /etc/crontab.backup
   exec supercronic -debug -prometheus-listen-address 0.0.0.0 /etc/crontab.backup
 fi