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The following guide deploys the Minimus Redis image together with custom certificates generated with OpenSSL to help you get started. Run the code to try it for yourself.

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Components

  • Redis image: Redis container configured with to require secure connections via TLS.
  • certgen.sh script: Generates a custom CA, server, and client certificates using OpenSSL.
  • Minidebug image: A Minimus dev toolkit that provides a shell, OpenSSL, and other utilities used to generate the certificates.

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What this guide demonstrates

  • TLS handshake validation
  • Server/client certificate trust
  • Basic auth and Redis operations
  • Image compatibility

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Directory Structure

.
├── certgen.sh             # Certificate generation script
├── create-certs.yml       # Compose file to run certgen container
└── docker-compose.yml     # Compose file to run Redis

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Deploy Redis with TLS certificates

1

Save certgen.sh

Save the following script to a file named certgen.sh. The script is used to generate the TLS certificates and store them in a certs folder on the host.
certgen.sh
#!/bin/sh
set -e
cd /certs

cat > openssl.cnf <<EOF
[ req ]
default_bits       = 2048
distinguished_name = req_distinguished_name
prompt             = no

[ req_distinguished_name ]
CN = redis

[ v3_ca ]
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid:always,issuer
basicConstraints = critical, CA:true
keyUsage = critical, keyCertSign, cRLSign

[ v3_server ]
basicConstraints = CA:false
keyUsage = digitalSignature, keyEncipherment
extendedKeyUsage = serverAuth
subjectAltName = @alt_names

[ v3_client ]
basicConstraints = CA:false
keyUsage = digitalSignature, keyEncipherment
extendedKeyUsage = clientAuth

[ alt_names ]
DNS.1 = redis
DNS.2 = localhost
IP.1  = 127.0.0.1
IP.2  = 192.168.10.0
IP.3  = 192.168.10.2
IP.4  = 192.168.10.3
EOF

# Optional: clean old stuff so we don't mix CAs
rm -f ca*.pem ca.srl server-*.pem client-*.pem

# ----- CA -----
openssl genrsa -out ca-key.pem 2048
openssl req -x509 -new -nodes -key ca-key.pem \
  -sha256 -days 365 -out ca.pem \
  -subj "/CN=Test CA" \
  -extensions v3_ca -config openssl.cnf

# ----- Server cert (with SAN + serverAuth) -----
openssl genrsa -out server-key.pem 2048
openssl req -new -key server-key.pem -out server.csr -config openssl.cnf
openssl x509 -req -in server.csr -CA ca.pem -CAkey ca-key.pem -CAcreateserial \
  -out server-cert.pem -days 365 -sha256 \
  -extensions v3_server -extfile openssl.cnf

# ----- Client cert (clientAuth only) -----
openssl genrsa -out client-key.pem 2048
openssl req -new -key client-key.pem -out client.csr -subj "/CN=root"
openssl x509 -req -in client.csr -CA ca.pem -CAkey ca-key.pem -CAcreateserial \
  -out client-cert.pem -days 365 -sha256 \
  -extensions v3_client -extfile openssl.cnf

# Permissions / ownership (as you had)
chmod 600 *.pem || true
chown -R 1000:1000 /certs/*.pem || true
chmod 644 /certs/*.pem || true
2

Save create-certs.yml

Save the following YAML file to run with Docker Compose. It uses the Minimus minidebug image to generate the certificates with the certgen.shshell script. Minidebug is a Minimus dev toolkit that provides a shell, OpenSSL, and other utilities.The certificates will be persisted in the certs volume on the host.
create-certs.yml
services:
  certgen:
    image: reg.mini.dev/minidebug:latest
    container_name: redis_certgen
    volumes:
    - ./certs:/certs
    - ./certgen.sh:/certgen.sh:ro
    entrypoint: ["/bin/sh", "/certgen.sh"]
3

Generate certificates

Run the following to generate the certificates:
docker compose -f create-certs.yml up

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TLS certificates

The script certgen.sh generates the following self-signed certificates:
  • Self-signed CA certificate (ca.pem)
  • Server certificates (server-cert.pem, server-key.pem) with SANs: Redis, localhost, and 192.168.20.3
  • Client certificates for testuser(client.csr, client-key.pem)
Certificate permissions are adjusted to support non-root containers. The certificates will be mounted into the Redis container.
4

Save Docker Compose script

Save the following Docker Compose script to a file nameddocker-compose.yml. This script sets up the Redis service with a healthcheck, mounts a volume with the certificates, and maps port 6379. The container is configured with "--tls-auth-clients", "yes" to require client certificates.
docker-compose.yml
services:
  redis:
    image: reg.mini.dev/redis:latest
    command: [
      "redis-server",
      "--tls-port", "6379",
      "--port", "0",
      "--tls-cert-file", "/certs/server-cert.pem",
      "--tls-key-file", "/certs/server-key.pem",
      "--tls-ca-cert-file", "/certs/ca.pem",
      "--requirepass", "testpass",
      "--tls-auth-clients", "yes"
    ]
    volumes:
      - ./certs:/certs:ro
    ports:
      - "6379:6379"
5

Run Redis

Start the Redis container:
docker compose -f docker-compose.yml up
6

Run tests over redis-cli

We will use redis-cli to connect over TLS and run tests. For example, here are a few commands you can try out:
  1. Check sever info and health: 
    redis-cli \
  -h 127.0.0.1 \
  -p 6379 \
  --tls \
  --cacert ./certs/ca.pem \
  --cert  ./certs/client-cert.pem  \
  --key   ./certs/client-key.pem \
  -a testpass \
  info
  2. Add test key to a database: 
    redis-cli \
  -h 127.0.0.1 \
  -p 6379 \
  --tls \
  --cacert ./certs/ca.pem \
  --cert  ./certs/client-cert.pem  \
  --key   ./certs/client-key.pem \
  -a testpass \
  -n 1 \
  set mykey "Hello from Minimus"
    Redis has numbered logical databases (default 0–15) rather than named databases.
    Verify the key: 
    redis-cli \
  -h 127.0.0.1 \
  -p 6379 \
  --tls \
  --cacert ./certs/ca.pem \
  --cert  ./certs/client-cert.pem  \
  --key   ./certs/client-key.pem \
  -a testpass \
  -n 1 \
  get mykey
  3. Test data persistence:
    Save data
    redis-cli \
  -h 127.0.0.1 \
  -p 6379 \
  --tls \
  --cacert ./certs/ca.pem \
  --cert  ./certs/client-cert.pem  \
  --key   ./certs/client-key.pem \
  -a testpass \
  save
    Stop the container, then restart it: 
    docker ps 
docker stop {Redis container ID}
docker restart {Redis container ID}
    Check the key you added in the previous step:
    Get key
    redis-cli \
  -h 127.0.0.1 \
  -p 6379 \
  --tls \
  --cacert ./certs/ca.pem \
  --cert  ./certs/client-cert.pem  \
  --key   ./certs/client-key.pem \
  -a testpass \
  -n 1 \
  get mykey
  4. Delete the key: 
    redis-cli \
  -h 127.0.0.1 \
  -p 6379 \
  --tls \
  --cacert ./certs/ca.pem \
  --cert  ./certs/client-cert.pem  \
  --key   ./certs/client-key.pem \
  -a testpass \
  -n 1 \
  del mykey