diff --git a/.gherkin-lintrc b/.gherkin-lintrc
new file mode 100644
index 0000000..9b12b0b
--- /dev/null
+++ b/.gherkin-lintrc
@@ -0,0 +1,26 @@
+{
+  "no-unnamed-features": "on",
+  "no-unnamed-scenarios": "on",
+  "no-unused-variables": "on",
+  "no-unused-variables": "on",
+  "no-dupe-feature-names": "on",
+  "no-dupe-scenario-names": "on",
+  "no-empty-background": "on",
+  "no-empty-file": "on",
+  "no-examples-in-scenarios": "on",
+  "no-scenario-outlines-without-examples": "on",
+  "no-multiple-empty-lines": "on",
+  "use-and": "on",
+  "indentation": [
+    "on", {}
+  ],
+  "no-trailing-spaces": "on",
+  "new-line-at-eof": ["on", "yes"],
+  "one-space-between-tags": "on",
+
+  "no-files-without-scenarios": "off",
+  "allowed-tags": [
+    "on", {"tags": ["@caho還沒做", "@maherekayto做好了"]}
+  ]
+}
+
diff --git a/.shellcheckrc b/.shellcheckrc
new file mode 100644
index 0000000..0182ace
--- /dev/null
+++ b/.shellcheckrc
@@ -0,0 +1 @@
+disable=SC1091
diff --git a/.travis.yml b/.travis.yml
index 3092055..42672a3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,96 +15,126 @@ branches:
   only:
     - main
 before_install:
-  - curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"
-  - unzip -q awscliv2.zip
-  - sudo ./aws/install
-  - pip install awscli-local
+  - pip install --upgrade pip setuptools
 jobs:
   include:
     - name: Check YAML format
+      install:
+        - pip install tox
+      script:
+        - tox -e yamllint
+    - name: Check Markdown Format
+      install:
+        - pip install tox
+      script:
+        - tox -e pymarkdown
+    - name: Check Gherkin format
+      language: node_js
+      node_js: 22
       before_install: skip
       install:
-        - pip install --upgrade pip setuptools
-        - pip install yamllint
+        - npm install gherkin-lint
       script:
-        - yamllint .
+        - npx gherkin-lint
+    - name: Check Python Format
+      install:
+        - pip install tox
+      script:
+        - tox -e flake8
+    - name: Check Bash format
+      install:
+        - pip install tox
+      script:
+        - tox -e shellcheck
     - name: backup once
+      before_install: &before_install_aws
+        - pip install --upgrade pip setuptools
+        - pip install -r requirements_travisci.txt
+        - DOCKER_CONFIG=${DOCKER_CONFIG:-$HOME/.docker}
+        - mkdir -p $DOCKER_CONFIG/cli-plugins
+        - curl -SL https://github.com/docker/compose/releases/download/v2.38.1/docker-compose-linux-x86_64 -o $DOCKER_CONFIG/cli-plugins/docker-compose
+        - chmod +x $DOCKER_CONFIG/cli-plugins/docker-compose
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       script:
-        - docker-compose --file tests/docker-compose-backup.yml up --detach
+        - docker compose --file tests/docker-compose-backup.yml up --detach --quiet-pull
         - DATE=`date "+%Y-%m-%d"`
         - TIME=`date "+%Y%m%dT%H%M"`
         - sleep 10
-        - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "postgres15_postgres_1/${DATE}/postgres15_postgres_1_${TIME}.sql.gz" postgres15.sql.gz
+        - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "postgres15-postgres-1/${DATE}/postgres15-postgres-1_${TIME}.sql.gz" postgres15.sql.gz
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
     - name: starting message
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       script:
-        - docker-compose --file tests/docker-compose-backup.yml run --rm backup | tee backup.log
+        - docker compose --file tests/docker-compose-backup.yml run --rm backup 2>&1 | tee backup.log
         - cat backup.log | grep 'multiple-databases-backup is starting.'
         - cat backup.log | grep 'multiple-databases-backup is finished, exiting.'
         - cat backup.log
     - name: crontab
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-minute.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-minute.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       script:
-        - docker-compose --file tests/docker-compose-backup-minute.yml up --detach
+        - docker compose --file tests/docker-compose-backup-minute.yml up --detach --quiet-pull
         - sleep 1m
         - DATE=`date "+%Y-%m-%d"`
         - TIME=`date "+%Y%m%dT%H%M"`
-        - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "postgres15_postgres_1/${DATE}/postgres15_postgres_1_${TIME}.sql.gz" postgres15.sql.gz
+        - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "postgres15-postgres-1/${DATE}/postgres15-postgres-1_${TIME}.sql.gz" postgres15.sql.gz
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
         - sleep 1m
         - DATE=`date "+%Y-%m-%d"`
         - TIME=`date "+%Y%m%dT%H%M"`
-        - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "postgres15_postgres_1/${DATE}/postgres15_postgres_1_${TIME}.sql.gz" postgres15.sql.gz
+        - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "postgres15-postgres-1/${DATE}/postgres15-postgres-1_${TIME}.sql.gz" postgres15.sql.gz
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
-        - docker-compose --file tests/docker-compose-backup-minute.yml exec backup cat /var/log/cron.log
-        - docker-compose --file tests/docker-compose-backup-minute.yml exec backup cat /var/log/cron.error.log
+        - docker compose --file tests/docker-compose-backup-minute.yml exec backup cat /var/log/cron.log
+        - docker compose --file tests/docker-compose-backup-minute.yml exec backup cat /var/log/cron.error.log
     - name: backup once when erasing the SCHEDULE variable
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-minute.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-minute.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       script:
-        - docker-compose --file tests/docker-compose-backup-minute.yml run -e SCHEDULE= backup | tee backup.log
+        - docker compose --file tests/docker-compose-backup-minute.yml run --rm -e SCHEDULE= backup 2>&1 | tee backup.log
         - cat backup.log | grep 'There is not SCHEDULE variable'
     - name: exit with SCHEDULE wrong format
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-minute.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-minute.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       script:
-        - (docker-compose --file tests/docker-compose-backup-minute.yml run -e SCHEDULE="0 * *" backup > backup.log) || (echo "The exit code is $?." | tee error.log)
+        - (docker compose --file tests/docker-compose-backup-minute.yml run --rm -e SCHEDULE="0 * *" backup > backup.log 2>&1) || (echo "The exit code is $?." | tee error.log)
         - cat backup.log
         - cat backup.log | grep 'The SCHEDULE variable should contain five fields exactly.'
         - cat error.log | grep 'The exit code is 1.'
     - name: GPG encrypt with asymmetric key
+      before_install: *before_install_aws
       env:
         - GPG_PRIVATE_KEY_PATH=tests/gpg-key/ithuan.tw.asc
         - GPG_PRIVATE_KEY_PASSPHRASE_PATH=tests/gpg-key/ithuan.tw.passphrase
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-encrypt.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-encrypt.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       script:
@@ -113,225 +143,235 @@ jobs:
         - echo "GPG_PUBLIC_KEY=${GPG_PUBLIC_KEY}" | tee tests/.env
         - DATE=`date "+%Y-%m-%d"`
         - TIME=`date "+%Y%m%dT%H%M"`
-        - docker-compose --file tests/docker-compose-backup-encrypt.yml run --rm backup
+        - docker compose --file tests/docker-compose-backup-encrypt.yml run --rm backup
         - sleep 10
-        - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "postgres15_postgres_1/${DATE}/postgres15_postgres_1_${TIME}.sql.gz.gpg" postgres15.sql.gz.gpg
+        - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "postgres15-postgres-1/${DATE}/postgres15-postgres-1_${TIME}.sql.gz.gpg" postgres15.sql.gz.gpg
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
         - gpg --decrypt --batch --pinentry-mode loopback --passphrase-file ${GPG_PRIVATE_KEY_PASSPHRASE_PATH} postgres15.sql.gz.gpg | zcat
     - name: backup strategy for keeping backup in 72 hours(3 days)
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-strategy.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-strategy.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       before_script:
         - TARGET_TIME=`date "+%Y-%m-%d %H:%M" --date '3 days ago'`
         - DATE=`date "+%Y-%m-%d" --date "${TARGET_TIME}"`
         - TIME=`date "+%Y%m%dT%H%M" --date "${TARGET_TIME}"`
-        - OLD_BACKUP="postgres15_postgres_1/${DATE}/postgres15_postgres_1_${TIME}.sql.gz"
+        - OLD_BACKUP="postgres15-postgres-1/${DATE}/postgres15-postgres-1_${TIME}.sql.gz"
       script:
         - echo '# SQL' | gzip > test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${OLD_BACKUP}" --body test.sql.gz
-        - docker-compose --file tests/docker-compose-backup-strategy.yml run --rm backup
+        - docker compose --file tests/docker-compose-backup-strategy.yml run --rm backup
         - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "${OLD_BACKUP}" postgres15.sql.gz
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
     - name: backup strategy for deleting backup exceeding 72 hours(3 days)
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-strategy.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-strategy.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       before_script:
         - TARGET_TIME=`date "+%Y-%m-%d %H:%M" --date '3 days ago 1 hour ago'`
         - DATE=`date "+%Y-%m-%d" --date "${TARGET_TIME}"`
         - TIME=`date "+%Y%m%dT%H%M" --date "${TARGET_TIME}"`
-        - OLD_BACKUP="postgres15_postgres_1/${DATE}/postgres15_postgres_1_${TIME}.sql.gz"
+        - OLD_BACKUP="postgres15-postgres-1/${DATE}/postgres15-postgres-1_${TIME}.sql.gz"
         - DAY_TARGET_TIME=`date "+%Y-%m-%d" --date "${TARGET_TIME}"`
         - DAY_DATE=`date "+%Y-%m-%d" --date "${DAY_TARGET_TIME}"`
         - DAY_TIME=`date "+%Y%m%dT%H%M" --date "${DAY_TARGET_TIME}"`
-        - DAY_BACKUP="postgres15_postgres_1/${DAY_DATE}/postgres15_postgres_1_${DAY_TIME}.sql.gz"
+        - DAY_BACKUP="postgres15-postgres-1/${DAY_DATE}/postgres15-postgres-1_${DAY_TIME}.sql.gz"
       script:
         - echo '# SQL' | gzip > test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${DAY_BACKUP}" --body test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${OLD_BACKUP}" --body test.sql.gz
-        - docker-compose --file tests/docker-compose-backup-strategy.yml run --rm backup
+        - docker compose --file tests/docker-compose-backup-strategy.yml run --rm backup
         - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "${OLD_BACKUP}" postgres15.sql.gz || (echo 'Not found.' | tee error.log)
         - cat error.log | grep 'Not found.'
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
     - name: backup strategy for keeping day backup in 90 days(3 months)
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-strategy.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-strategy.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       before_script:
         - TARGET_TIME=`date "+%Y-%m-01" --date '3 months ago'`
         - DATE=`date "+%Y-%m-%d" --date "${TARGET_TIME}"`
         - TIME=`date "+%Y%m%dT%H%M" --date "${TARGET_TIME}"`
-        - OLD_BACKUP="postgres15_postgres_1/${DATE}/postgres15_postgres_1_${TIME}.sql.gz"
+        - OLD_BACKUP="postgres15-postgres-1/${DATE}/postgres15-postgres-1_${TIME}.sql.gz"
       script:
         - echo '# SQL' | gzip > test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${OLD_BACKUP}" --body test.sql.gz
-        - docker-compose --file tests/docker-compose-backup-strategy.yml run --rm backup
+        - docker compose --file tests/docker-compose-backup-strategy.yml run --rm backup
         - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "${OLD_BACKUP}" postgres15.sql.gz
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
     - name: backup strategy for keeping day backups if they are backuped in different day.
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-strategy.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-strategy.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       before_script:
         - TARGET1_TIME=`date "+%Y-%m-01" --date '2 months ago'`
         - DATE1=`date "+%Y-%m-%d" --date "${TARGET1_TIME}"`
         - TIME1=`date "+%Y%m%dT%H%M" --date "${TARGET1_TIME}"`
-        - DAY1_BACKUP="postgres15_postgres_1/${DATE1}/postgres15_postgres_1_${TIME1}.sql.gz"
+        - DAY1_BACKUP="postgres15-postgres-1/${DATE1}/postgres15-postgres-1_${TIME1}.sql.gz"
         - TARGET2_TIME=`date "+%Y-%m-02" --date '2 months ago'`
         - DATE2=`date "+%Y-%m-%d" --date "${TARGET2_TIME}"`
         - TIME2=`date "+%Y%m%dT%H%M" --date "${TARGET2_TIME}"`
-        - DAY2_BACKUP="postgres15_postgres_1/${DATE2}/postgres15_postgres_1_${TIME2}.sql.gz"
+        - DAY2_BACKUP="postgres15-postgres-1/${DATE2}/postgres15-postgres-1_${TIME2}.sql.gz"
       script:
         - echo '# SQL' | gzip > test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${DAY1_BACKUP}" --body test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${DAY2_BACKUP}" --body test.sql.gz
-        - docker-compose --file tests/docker-compose-backup-strategy.yml run --rm backup
+        - docker compose --file tests/docker-compose-backup-strategy.yml run --rm backup
         - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "${DAY1_BACKUP}" postgres15-1.sql.gz
         - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "${DAY2_BACKUP}" postgres15-2.sql.gz
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
     - name: backup strategy for deleting backup because of keeping day backup only
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-strategy.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-strategy.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       before_script:
         - TARGET1_TIME="`date "+%Y-%m-01 09:00" --date '3 months ago'`"
         - DATE1=`date "+%Y-%m-%d" --date "${TARGET1_TIME}"`
         - TIME1=`date "+%Y%m%dT%H%M" --date "${TARGET1_TIME}"`
-        - DAY_BACKUP="postgres15_postgres_1/${DATE1}/postgres15_postgres_1_${TIME1}.sql.gz"
+        - DAY_BACKUP="postgres15-postgres-1/${DATE1}/postgres15-postgres-1_${TIME1}.sql.gz"
         - TARGET2_TIME="`date "+%Y-%m-01 10:00" --date '3 months ago'`"
         - DATE2=`date "+%Y-%m-%d" --date "${TARGET2_TIME}"`
         - TIME2=`date "+%Y%m%dT%H%M" --date "${TARGET2_TIME}"`
-        - NOT_DAY_BACKUP="postgres15_postgres_1/${DATE2}/postgres15_postgres_1_${TIME2}.sql.gz"
+        - NOT_DAY_BACKUP="postgres15-postgres-1/${DATE2}/postgres15-postgres-1_${TIME2}.sql.gz"
       script:
         - echo '# SQL' | gzip > test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${DAY_BACKUP}" --body test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${NOT_DAY_BACKUP}" --body test.sql.gz
-        - docker-compose --file tests/docker-compose-backup-strategy.yml run --rm backup
+        - docker compose --file tests/docker-compose-backup-strategy.yml run --rm backup
         - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "${NOT_DAY_BACKUP}" postgres15.sql.gz || (echo 'Not found.' | tee error.log)
         - cat error.log | grep 'Not found.'
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
     - name: backup strategy for deleting day backup exceeding 90 days(3 months)
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-strategy.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-strategy.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       before_script:
         - TARGET_TIME=`date "+%Y-%m-10" --date '5 months ago'`
         - DATE=`date "+%Y-%m-%d" --date "${TARGET_TIME}"`
         - TIME=`date "+%Y%m%dT%H%M" --date "${TARGET_TIME}"`
-        - OLD_BACKUP="postgres15_postgres_1/${DATE}/postgres15_postgres_1_${TIME}.sql.gz"
+        - OLD_BACKUP="postgres15-postgres-1/${DATE}/postgres15-postgres-1_${TIME}.sql.gz"
         - MONTH_TARGET_TIME=`date "+%Y-%m-01" --date "${TARGET_TIME}"`
         - MONTH_DATE=`date "+%Y-%m-%d" --date "${MONTH_TARGET_TIME}"`
         - MONTH_TIME=`date "+%Y%m%dT%H%M" --date "${MONTH_TARGET_TIME}"`
-        - MONTH_BACKUP="postgres15_postgres_1/${MONTH_DATE}/postgres15_postgres_1_${MONTH_TIME}.sql.gz"
+        - MONTH_BACKUP="postgres15-postgres-1/${MONTH_DATE}/postgres15-postgres-1_${MONTH_TIME}.sql.gz"
       script:
         - echo '# SQL' | gzip > test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${MONTH_BACKUP}" --body test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${OLD_BACKUP}" --body test.sql.gz
-        - docker-compose --file tests/docker-compose-backup-strategy.yml run --rm backup
+        - docker compose --file tests/docker-compose-backup-strategy.yml run --rm backup
         - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "${OLD_BACKUP}" postgres15.sql.gz || (echo 'Not found.' | tee error.log)
         - cat error.log | grep 'Not found.'
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
     - name: backup strategy for keeping month backup in 36 months(3 years)
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-strategy.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-strategy.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       before_script:
         - TARGET_TIME=`date "+%Y-%m-01" --date '3 years ago'`
         - DATE=`date "+%Y-%m-%d" --date "${TARGET_TIME}"`
         - TIME=`date "+%Y%m%dT%H%M" --date "${TARGET_TIME}"`
-        - OLD_BACKUP="postgres15_postgres_1/${DATE}/postgres15_postgres_1_${TIME}.sql.gz"
+        - OLD_BACKUP="postgres15-postgres-1/${DATE}/postgres15-postgres-1_${TIME}.sql.gz"
       script:
         - echo '# SQL' | gzip > test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${OLD_BACKUP}" --body test.sql.gz
-        - docker-compose --file tests/docker-compose-backup-strategy.yml run --rm backup
+        - docker compose --file tests/docker-compose-backup-strategy.yml run --rm backup
         - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "${OLD_BACKUP}" postgres15.sql.gz
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
     - name: backup strategy for keeping month backups if they are backuped in different month.
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-strategy.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-strategy.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       before_script:
         - TARGET1_TIME=`date "+%Y-01-01" --date '1 years ago'`
         - DATE1=`date "+%Y-%m-%d" --date "${TARGET1_TIME}"`
         - TIME1=`date "+%Y%m%dT%H%M" --date "${TARGET1_TIME}"`
-        - MONTH1_BACKUP="postgres15_postgres_1/${DATE1}/postgres15_postgres_1_${TIME1}.sql.gz"
+        - MONTH1_BACKUP="postgres15-postgres-1/${DATE1}/postgres15-postgres-1_${TIME1}.sql.gz"
         - TARGET2_TIME=`date "+%Y-02-02" --date '1 years ago'`
         - DATE2=`date "+%Y-%m-%d" --date "${TARGET2_TIME}"`
         - TIME2=`date "+%Y%m%dT%H%M" --date "${TARGET2_TIME}"`
-        - MONTH2_BACKUP="postgres15_postgres_1/${DATE2}/postgres15_postgres_1_${TIME2}.sql.gz"
+        - MONTH2_BACKUP="postgres15-postgres-1/${DATE2}/postgres15-postgres-1_${TIME2}.sql.gz"
       script:
         - echo '# SQL' | gzip > test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${MONTH1_BACKUP}" --body test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${MONTH2_BACKUP}" --body test.sql.gz
-        - docker-compose --file tests/docker-compose-backup-strategy.yml run --rm backup
+        - docker compose --file tests/docker-compose-backup-strategy.yml run --rm backup
         - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "${MONTH1_BACKUP}" postgres15-1.sql.gz
         - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "${MONTH2_BACKUP}" postgres15-2.sql.gz
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
     - name: backup strategy for deleting backup because of keeping month backup only
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-strategy.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-strategy.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       before_script:
         - TARGET1_TIME="`date "+%Y-%m-01 09:00" --date '10 months ago'`"
         - DATE1=`date "+%Y-%m-%d" --date "${TARGET1_TIME}"`
         - TIME1=`date "+%Y%m%dT%H%M" --date "${TARGET1_TIME}"`
-        - MONTH_BACKUP="postgres15_postgres_1/${DATE1}/postgres15_postgres_1_${TIME1}.sql.gz"
+        - MONTH_BACKUP="postgres15-postgres-1/${DATE1}/postgres15-postgres-1_${TIME1}.sql.gz"
         - TARGET2_TIME="`date "+%Y-%m-20 09:00" --date '10 months ago'`"
         - DATE2=`date "+%Y-%m-%d" --date "${TARGET2_TIME}"`
         - TIME2=`date "+%Y%m%dT%H%M" --date "${TARGET2_TIME}"`
-        - NOT_MONTH_BACKUP="postgres15_postgres_1/${DATE2}/postgres15_postgres_1_${TIME2}.sql.gz"
+        - NOT_MONTH_BACKUP="postgres15-postgres-1/${DATE2}/postgres15-postgres-1_${TIME2}.sql.gz"
       script:
         - echo '# SQL' | gzip > test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${MONTH_BACKUP}" --body test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${NOT_MONTH_BACKUP}" --body test.sql.gz
-        - docker-compose --file tests/docker-compose-backup-strategy.yml run --rm backup
+        - docker compose --file tests/docker-compose-backup-strategy.yml run --rm backup
         - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "${NOT_MONTH_BACKUP}" postgres15.sql.gz || (echo 'Not found.' | tee error.log)
         - cat error.log | grep 'Not found.'
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
     - name: backup strategy for deleting month backup exceeding 36 months(3 years)
+      before_install: *before_install_aws
       install:
-        - docker-compose --file tests/postgres15/docker-compose.yml up --detach
-        - docker-compose --file tests/s3/docker-compose-localstack.yml up --detach
-        - docker-compose --file tests/docker-compose-backup-strategy.yml build
+        - docker compose --file tests/postgres15/docker-compose.yml up --detach --quiet-pull
+        - docker compose --file tests/s3/docker-compose-localstack.yml up --detach --quiet-pull
+        - docker compose --file tests/docker-compose-backup-strategy.yml build --quiet
         - sleep 10
         - awslocal s3api create-bucket --bucket "${BUCKET_NAME}"
       before_script:
         - TARGET_TIME=`date "+%Y-%m-01" --date '3 years ago 1 months ago'`
         - DATE=`date "+%Y-%m-%d" --date "${TARGET_TIME}"`
         - TIME=`date "+%Y%m%dT%H%M" --date "${TARGET_TIME}"`
-        - OLD_BACKUP="postgres15_postgres_1/${DATE}/postgres15_postgres_1_${TIME}.sql.gz"
+        - OLD_BACKUP="postgres15-postgres-1/${DATE}/postgres15-postgres-1_${TIME}.sql.gz"
       script:
         - echo '# SQL' | gzip > test.sql.gz
         - awslocal s3api put-object --bucket "${BUCKET_NAME}" --key "${OLD_BACKUP}" --body test.sql.gz
-        - docker-compose --file tests/docker-compose-backup-strategy.yml run --rm backup
+        - docker compose --file tests/docker-compose-backup-strategy.yml run --rm backup
         - awslocal s3api get-object --bucket "${BUCKET_NAME}" --key "${OLD_BACKUP}" postgres15.sql.gz || (echo 'Not found.' | tee error.log)
         - cat error.log | grep 'Not found.'
         - awslocal s3api list-objects --bucket "${BUCKET_NAME}"
diff --git a/Dockerfile b/Dockerfile
index d095583..81224dd 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,29 +1,28 @@
-FROM ubuntu:latest
+FROM ubuntu:24.04
+# https://github.com/aws/aws-cli/blob/v2/CHANGELOG.rst?plain=1
 
+RUN groupadd --system --gid 138 docker
 ARG DEBIAN_FRONTEND=noninteractive
-
 RUN apt update && \
-  apt install -y \
-    ca-certificates \
-    curl \
-    gnupg \
-    lsb-release && \
-  mkdir -m 0755 -p /etc/apt/keyrings && \
-  curl -fsSL https://download.docker.com/linux/ubuntu/gpg \
-    | gpg --dearmor -o /etc/apt/keyrings/docker.gpg && \
-  echo \
-    "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \
-    $(lsb_release -cs) stable" | tee /etc/apt/sources.list.d/docker.list > /dev/null && \
-  apt-get update && \
-  apt install -y docker-ce-cli cron gnupg jq
-
-RUN apt install -y unzip && \
+  apt install --no-install-recommends -y \
+    docker.io cron gnupg jq \
+    curl ca-certificates unzip && \
+  apt-get clean && \
   mkdir /aws_build/ && \
-  curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "/aws_build/awscliv2.zip" && \
+  update-ca-certificates && \
+  curl -sSf "https://awscli.amazonaws.com/awscli-exe-linux-x86_64-2.22.35.zip" -o "/aws_build/awscliv2.zip" && \
   unzip -q /aws_build/awscliv2.zip -d /aws_build/ && \
   /aws_build/aws/install && \
   rm -rf /aws_build/
 
+RUN useradd --uid 1001 nonroot --user-group && \
+  usermod -aG docker nonroot && \
+  touch /etc/environment && \
+  chown nonroot:nonroot /etc/environment && \
+  chmod u+s /usr/sbin/cron
+
+WORKDIR /app/
 COPY scripts/ /app/
 
-CMD bash /app/start.sh
+USER nonroot
+CMD ["bash", "/app/start.sh"]
diff --git a/README.md b/README.md
index 79bd7ef..732500a 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ Backup databases from dockerized PostgresSQL to any S3-compatible storage with a
 
 ## Quick Start
 
-```
+```yaml
 version: '3'
 services:
   postgres:
@@ -46,7 +46,7 @@ services:
 
 ### Backup Multiple Databases Simultaneously
 
-To backup multiple databases simultaneously, you can label the database containers that require backup with the `backup.postgres=true` label. The backup script will then identify all containers with this label and execute the backup command for each of them. 
+To backup multiple databases simultaneously, you can label the database containers that require backup with the `backup.postgres=true` label. The backup script will then identify all containers with this label and execute the backup command for each of them.
 
 ### Easy Configuration
 
@@ -75,6 +75,7 @@ The codebase undergoes automatic testing using Travis CI, which covers backup sc
 ## Configuration
 
 ### S3 Storage Configurations
+
 - `S3_ENDPOINT_URL` (required): The S3 endpoint URL in the form of `http://<hostname>/` or `https://<hostname>/
 `. Note that the scheme should be included.
 - `S3_REGION`: The name of the S3 region (eg. `eu-west-1`). This may be optional depending on your storage vendor.
@@ -86,7 +87,6 @@ The codebase undergoes automatic testing using Travis CI, which covers backup sc
 
 - `SCHEDULE`: The backup schedule specified in a string following [crontab syntax](https://www.man7.org/linux/man-pages/man5/crontab.5.html) where the five fields are minute, hour, day of month, month and day of week. If set to a blank string, the script will perform a instant backup and exit. The default value is a blank string.
 
-
 ### GPG Key
 
 - `GPG_PUBLIC_KEY`: Base64-encoded GPG public key used in the encryption process. If not set, backup files will be uploaded and saved un-encrypted.
@@ -95,11 +95,14 @@ The codebase undergoes automatic testing using Travis CI, which covers backup sc
 
 1. [Generate a new GPG key](https://docs.github.com/en/authentication/managing-commit-signature-verification/generating-a-new-gpg-key) if there is not any existing GPG key.
 2. Encode GPG public key in base64 format and write it into the `.env` file.
+
 ```bash
 GPG_PUBLIC_KEY=`gpg --armor --export <GPG key ID> | base64 --wrap 0`
 echo "GPG_PUBLIC_KEY=${GPG_PUBLIC_KEY}" > .env
 ```
+
 3. Export the private key and store it securely. The private key is needed when decrypting a backup file.
+
 ```bash
 gpg --export-secret-keys --armor <GPG key ID> > <gpg-private-key.asc>
 ```
@@ -107,10 +110,13 @@ gpg --export-secret-keys --armor <GPG key ID> > <gpg-private-key.asc>
 #### Decrypt a Backup File
 
 1. Import the gpg private key if it hasn't been imported yet.
+
 ```bash
 gpg --import <gpg-private-key.asc>
 ```
+
 2. Decrypt the backup file to get the original SQL.
+
 ```bash
 gpg --decrypt <postgres15.sql.gz.gpg> | zcat
 ```
diff --git a/requirements_travisci.in b/requirements_travisci.in
new file mode 100644
index 0000000..d13a290
--- /dev/null
+++ b/requirements_travisci.in
@@ -0,0 +1,4 @@
+awscli
+boto3~=1.35.0
+
+awscli-local
diff --git a/requirements_travisci.txt b/requirements_travisci.txt
new file mode 100644
index 0000000..5f37f7e
--- /dev/null
+++ b/requirements_travisci.txt
@@ -0,0 +1,45 @@
+#
+# This file is autogenerated by pip-compile with Python 3.10
+# by the following command:
+#
+#    pip-compile requirements_travisci.in
+#
+awscli==1.36.40
+    # via -r requirements_travisci.in
+awscli-local==0.22.0
+    # via -r requirements_travisci.in
+boto3==1.35.99
+    # via
+    #   -r requirements_travisci.in
+    #   localstack-client
+botocore==1.35.99
+    # via
+    #   awscli
+    #   boto3
+    #   s3transfer
+colorama==0.4.6
+    # via awscli
+docutils==0.16
+    # via awscli
+jmespath==1.0.1
+    # via
+    #   boto3
+    #   botocore
+localstack-client==2.10
+    # via awscli-local
+pyasn1==0.6.1
+    # via rsa
+python-dateutil==2.9.0.post0
+    # via botocore
+pyyaml==6.0.2
+    # via awscli
+rsa==4.7.2
+    # via awscli
+s3transfer==0.10.4
+    # via
+    #   awscli
+    #   boto3
+six==1.17.0
+    # via python-dateutil
+urllib3==2.5.0
+    # via botocore
diff --git a/scripts/backup.sh b/scripts/backup.sh
index 64eabd8..15a09a1 100755
--- a/scripts/backup.sh
+++ b/scripts/backup.sh
@@ -23,7 +23,7 @@ all_containers=`docker container list \
 for postgres_container_name in $all_containers
 do
   >&2 echo "Backuping ${postgres_container_name} is starting."
-  FILE_PATH=$(filepath ${postgres_container_name} 'now')
+  FILE_PATH=$(filepath "${postgres_container_name}" 'now')
   docker exec "${postgres_container_name}" pg_dump -U postgres \
     | gzip \
     | ${ENCRYPT_COMMAND} \
diff --git a/scripts/cleanup.sh b/scripts/cleanup.sh
index ebff041..f9a3901 100755
--- a/scripts/cleanup.sh
+++ b/scripts/cleanup.sh
@@ -5,7 +5,7 @@ source /app/filepath.sh
 
 CONTAINER_NAME=$1
 
-FILE_PATH=$(filepath ${CONTAINER_NAME} "${MAX_PERIOD_IN_HOURS_TO_KEEP_EVERY_BACKUPS} hours ago")
+FILE_PATH=$(filepath "${CONTAINER_NAME}" "${MAX_PERIOD_IN_HOURS_TO_KEEP_EVERY_BACKUPS} hours ago")
 
 temp_dir=$(mktemp -d)
 ALL_FILES="${temp_dir}/all.list"
@@ -29,7 +29,7 @@ aws s3api list-objects-v2 \
 for day in $(seq 1 "${MAX_PERIOD_IN_DAYS_TO_KEEP_DAILY_BACKUPS}")
 do
   TARGET_DAY=`date "+%Y-%m-%d" --date "${day} days ago"`
-  FILE_PATH=$(filepath ${CONTAINER_NAME} "${TARGET_DAY}")
+  FILE_PATH=$(filepath "${CONTAINER_NAME}" "${TARGET_DAY}")
   aws s3api list-objects-v2 \
       --endpoint-url "${S3_ENDPOINT_URL}" \
       --bucket "${S3_BUCKET}" \
@@ -43,7 +43,7 @@ done
 for month in $(seq 1 "${MAX_PERIOD_IN_MONTHS_TO_KEEP_MONTHLY_BACKUPS}")
 do
   TARGET_DAY=`date "+%Y-%m-01" --date "${month} months ago"`
-  FILE_PATH=$(filepath ${CONTAINER_NAME} "${TARGET_DAY}")
+  FILE_PATH=$(filepath "${CONTAINER_NAME}" "${TARGET_DAY}")
   aws s3api list-objects-v2 \
       --endpoint-url "${S3_ENDPOINT_URL}" \
       --bucket "${S3_BUCKET}" \
@@ -54,14 +54,18 @@ do
     >> "${PRESERVE_FILES}"
 done
 
-for filename in `cat "${ALL_FILES}" \
-  | grep --invert-match --line-regexp --file "${PRESERVE_FILES}" \
-  | sed 's/^"\(.*\)"$/\1/g'`
+sort -u "${ALL_FILES}" > "${temp_dir}/tmp.list"
+mv "${temp_dir}/tmp.list" "${ALL_FILES}"
+sort -u "${PRESERVE_FILES}" > "${temp_dir}/tmp.list"
+mv "${temp_dir}/tmp.list" "${PRESERVE_FILES}"
+comm -23 "${ALL_FILES}" "${PRESERVE_FILES}" \
+  | sed 's/^[[:space:]]*"\(.*\)"$/\1/g' \
+  | while IFS= read -r filename
 do
   aws s3api delete-object \
     --endpoint-url "${S3_ENDPOINT_URL}" \
     --bucket "${S3_BUCKET}" \
-    --key ${filename}
+    --key "${filename}"
 done
 
 rm -rf "${temp_dir}"
diff --git a/scripts/crontab.sh b/scripts/crontab.sh
index dd67cf5..abaedb4 100644
--- a/scripts/crontab.sh
+++ b/scripts/crontab.sh
@@ -2,7 +2,7 @@
 set -euo pipefail
 
 echo "PATH=${PATH}
-${SCHEDULE} bash /app/backup.sh >> /var/log/cron.log 2>> /var/log/cron.error.log" \
+${SCHEDULE} bash /app/backup.sh" \
   | crontab -
 
 cron -f -L 15
diff --git a/scripts/filepath.sh b/scripts/filepath.sh
index 5690506..0f06e02 100644
--- a/scripts/filepath.sh
+++ b/scripts/filepath.sh
@@ -3,9 +3,13 @@ set -euo pipefail
 
 function filepath()
 {
-    local container_name="$1"
-    local target_time="$2"
-    local DATE=`date "+%Y-%m-%d" --date "${target_time}"`
-    local TIME=`date "+%Y%m%dT%H%M" --date "${target_time}"`
+    local container_name
+    local target_time
+    local DATE
+    local TIME
+    container_name="$1"
+    target_time="$2"
+    DATE=`date "+%Y-%m-%d" --date "${target_time}"`
+    TIME=`date "+%Y%m%dT%H%M" --date "${target_time}"`
     echo "${container_name}/${DATE}/${container_name}_${TIME}"
 }
diff --git a/scripts/start.sh b/scripts/start.sh
index ad3b5bb..daf05e0 100644
--- a/scripts/start.sh
+++ b/scripts/start.sh
@@ -31,7 +31,7 @@ if [ -z "${GPG_PUBLIC_KEY}" ]; then
   >&2 echo 'There is not a GPG_PUBLIC_KEY, all backup files will not be encrypted.'
 else
   >&2 echo 'There is the GPG_PUBLIC_KEY, all backup files will be encrypted.'
-  echo ${GPG_PUBLIC_KEY} | base64 -d  > ${GPG_PUBLIC_KEY_PATH}
+  echo "${GPG_PUBLIC_KEY}" | base64 -d  > ${GPG_PUBLIC_KEY_PATH}
 fi
 if [ -z "${SCHEDULE}" ]; then
   >&2 echo "multiple-databases-backup is starting."
diff --git a/shellcheck.sh b/shellcheck.sh
new file mode 100644
index 0000000..7542ba1
--- /dev/null
+++ b/shellcheck.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+exit_code=0
+shellcheck --severity=info scripts/*;
+tsitkai="$?"
+exit_code=$(( tsitkai != 0 ? tsitkai : exit_code))
+while IFS= read -r -d '' file
+do
+    shellcheck --severity=info "$file";
+    tsitkai="$?"
+    exit_code=$(( tsitkai != 0 ? tsitkai : exit_code))
+done <   <(find . -type f -name '*.sh' -not -path './venv/*' -not -path './scripts/*' -print0)
+exit $(( exit_code == 0 ? 0 : 1))
diff --git a/tests/docker-compose-backup-encrypt.yml b/tests/docker-compose-backup-encrypt.yml
index 72cc381..1b019a0 100644
--- a/tests/docker-compose-backup-encrypt.yml
+++ b/tests/docker-compose-backup-encrypt.yml
@@ -1,5 +1,4 @@
 ---
-version: '3'
 services:
   backup:
     build: ../
diff --git a/tests/docker-compose-backup-minute.yml b/tests/docker-compose-backup-minute.yml
index 57cf0ca..70c2f41 100644
--- a/tests/docker-compose-backup-minute.yml
+++ b/tests/docker-compose-backup-minute.yml
@@ -1,5 +1,4 @@
 ---
-version: '3'
 services:
   backup:
     build: ../
diff --git a/tests/docker-compose-backup-strategy.yml b/tests/docker-compose-backup-strategy.yml
index 538c2ec..2dc45fc 100644
--- a/tests/docker-compose-backup-strategy.yml
+++ b/tests/docker-compose-backup-strategy.yml
@@ -1,5 +1,4 @@
 ---
-version: '3'
 services:
   backup:
     build: ../
diff --git a/tests/docker-compose-backup.yml b/tests/docker-compose-backup.yml
index e23213a..c88b876 100644
--- a/tests/docker-compose-backup.yml
+++ b/tests/docker-compose-backup.yml
@@ -1,5 +1,4 @@
 ---
-version: '3'
 services:
   backup:
     build: ../
diff --git a/tests/postgres15/docker-compose.yml b/tests/postgres15/docker-compose.yml
index 3a2393f..b8587c5 100644
--- a/tests/postgres15/docker-compose.yml
+++ b/tests/postgres15/docker-compose.yml
@@ -1,5 +1,4 @@
 ---
-version: '3'
 services:
   postgres:
     image: postgres:15
diff --git a/tests/s3/docker-compose-localstack.yml b/tests/s3/docker-compose-localstack.yml
index c7cde06..4c04a9e 100644
--- a/tests/s3/docker-compose-localstack.yml
+++ b/tests/s3/docker-compose-localstack.yml
@@ -1,5 +1,4 @@
 ---
-version: '3'
 services:
   localstack:
     container_name: "${LOCALSTACK_DOCKER_NAME-localstack_main}"
diff --git a/tox.ini b/tox.ini
new file mode 100644
index 0000000..559d66c
--- /dev/null
+++ b/tox.ini
@@ -0,0 +1,36 @@
+[tox]
+skipsdist = True
+
+[flake8]
+max-line-length = 79
+exclude =
+    .git
+    .tox
+    venv
+
+[testenv:yamllint]
+deps =
+    yamllint
+commands =
+    yamllint .
+
+[testenv:flake8]
+deps =
+    flake8
+commands =
+    flake8 . --show-source --count
+
+[testenv:pymarkdown]
+deps =
+    pymarkdownlnt
+commands =
+    pymarkdown \
+        --strict-config \
+        --disable-rules md013,md029 \
+        scan .
+
+[testenv:shellcheck]
+allowlist_externals =
+    bash
+commands =
+    bash shellcheck.sh