Reliability-Security on StackOnward

Go Live with Payments: From Sandbox Keys to the First Real Order

Fri, 11 Sep 2026 05:24:00 +0800

The checkout page already uses a live key, but the subscription still cites a test Price. After the customer pays, the production webhook fails signature checks because it still uses the sandbox secret. Mixed config does not fail together: some errors stop before payment, others wait until money has moved, then order, entitlements, and finance stop in different states.

The cutover order is: fence entries that create captures and refunds; attach account, keys, Price, webhook, domain, workers, and finance to live together; use read-only requests, test events, and return-URL checks to catch environment errors; then open the first real order under provider rules. If that first order fails, close new transactions. Webhooks, lookups, and reconciliation keep running.

How to Configure Docker Volume Permissions and Secrets

Fri, 11 Sep 2026 05:12:00 +0800

How to configure Docker volume permissions starts with a numeric UID and GID match, not a matching username. Put database files and other container-generated state on a named volume, bind-mount host-managed config read-only, and grant each secret only to the service that reads it as a file. Recreate the container to prove the mount. Restore a backup in a separate environment to prove the backup.

Named volumes hold writable state. Bind mounts hold host-managed config. Secret files are granted per service.

Choose a named volume, bind mount, or tmpfs

Type	What belongs there	Why	Main risk
Named volume	Databases, queues, application state	Docker manages the lifecycle; the path is not tied to one host layout	Host backup and migration must name the volume and its driver
Bind mount	Caddyfile, explicit data directories, host scripts	The path is visible to existing backup and permission tools	The host path, owner, and SELinux or AppArmor labels all have to match
tmpfs	Short-lived sensitive files or fast scratch data that must not persist	Nothing is written to durable disk	A restart drops the files; the size counts against container memory

Docker storage(opens in a new tab) treats volumes(opens in a new tab) as the default for data a container generates. Bind mounts(opens in a new tab) are for files the host already owns. tmpfs(opens in a new tab) stays in host memory and is gone when the container stops. The image writable layer is the wrong place for runtime data: deleting the container deletes that layer.

How to Expose Docker Ports: 127.0.0.1, 0.0.0.0, Firewalls

Fri, 11 Sep 2026 04:14:00 +0800

How to expose Docker ports depends on the process listen address inside the container, the host publish bind, and the firewall or cloud security group in front of the host. Listening on 0.0.0.0 inside a container does not put that port on the public internet.

The app and database stay on the Docker network. The public internet reaches only the ports the proxy publishes.

How to expose Docker ports at each network layer

Where it is set	Example	What it means
App process listen	`0.0.0.0:8080`	Accept 8080 on every interface in this container
App process listen	`127.0.0.1:8080`	Accept 8080 only on this container’s loopback
Docker port publish	`127.0.0.1:8080:8080`	Host-local processes can reach container 8080 on host 8080
Docker port publish	`0.0.0.0:8080:8080`	Every IPv4 address on the host publishes 8080; the public internet may reach it
Compose internal access	`http://app:8080`	A peer on the same network uses the service name and the container port

The two uses of 0.0.0.0 are not the same action. Listening on every interface inside the container lets a proxy on the same Docker network connect. Publishing the port onto every host interface widens the host entry.