The Configuration That Almost Exposed a Secret: A Case Study in Infrastructure Security
Introduction
In the course of deploying a distributed storage cluster across three physical nodes, an assistant created a configuration file that contained a critical security flaw: a plaintext API token embedded directly in a settings file. This message — message index 1990 in the conversation — is outwardly mundane: a shell heredoc that writes environment variables into a file called settings-kuri2.env for the second storage node in a Filecoin Gateway (FGW) test cluster. But this message sits at a pivotal moment where infrastructure automation collides with security best practices, and the subsequent user correction reshaped the entire deployment approach.
The Message in Full
The assistant executed the following command via a remote shell:
cat > /tmp/settings-kuri2.env << 'EOF'
# Kuri settings for kuri_02
# QA Environment
# =============================================================================
# Node Identification
# =============================================================================
FGW_NODE_ID="kuri_02"
FGW_NODE_TYPE="storage"
# =============================================================================
# RIBS Data
# =============================================================================
RIBS_DATA="/data/fgw"
RIBS_MAX_LOCAL_GROUP_COUNT="30"
RIBS_MAX_STAGING_GROUP_COUNT="10"
# =============================================================================
# Filecoin API
# =============================================================================
RIBS_FILECOIN_API_ENDPOINT="https://api.chain.love/rpc/v1"
# =============================================================================
# CIDGravity
# =============================================================================
CIDGRAVITY_API_TOKEN="[REDACTED]"
CIDGRAVITY_API_ENDPOINT_GBAP="https://service.cidgravity.com/private/v1/get-best-available-providers"
CIDGRAVITY_API_ENDPOINT_GOCD="https://service.cidgravity.com/private/v1/get-on-chain-deals"
CIDGRAVITY_MAX_CONNECTIONS="4"
# =============================================================================
# Deal Settings
# =============================================================================
RIBS_MINIMUM_REPLICA_COUNT="3"
RIBS_MAXIMUM_REPLICA_COUNT="5"
RIBS_MINIMUM_RETRIEVABLE_COUNT="3"
RIBS_RETRIEVALBLE_REPAIR_THRESHOLD="2"
RIBS_DEAL_START_TIME="96"
RIBS_DEAL_DURATION="530"
RIBS_DEAL_REMOVE_UNSEALED="false"
RIBS_DEAL_SKIP_IPNI_ANNOUNCE="false"
RIBS_DEAL_CHECK_INTERVAL="30s"
RIBS_RUN_SP_CRAWLER="true"
# =============================================================================
# YugabyteDB - Per-node (RIBS data)
# =============================================================================
RIBS_YUGABYTE_SQL_HOST="10.1.232.82"
RIBS_YUGABYTE_SQL_PORT="5433"
RIBS_YUGABYTE_SQL_DB="filecoingw_kuri_02"
RIBS_YUGABYTE_SQL_USER="yugabyte"
RIBS_YUGABYTE_SQL_PASS="yugabyte"
RIBS_YUGABYTE_CQL_HOSTS="10.1.232.82"
RIBS_YUGABYTE_CQL_PORT="9042"
RIBS_YUGABYTE_CQL_KEYSPACE="filecoingw_kuri_02"
# =============================================================================
# S3 Shared Keyspace (object routing)
# =============================================================================
RIBS_S3_CQL_HOSTS="10.1.232.82"
RIBS_S3_CQL_PORT="9042"
RIBS_S3_CQL_KEYSPACE="filecoingw_s3"
# =============================================================================
# S3 API (internal)
# =============================================================================
RIBS_S3API_BINDADDR=":8079"
RIBS_S3API_REGION="EU"
RIBS_S3API_AUTH_ENABLED="false"
# =============================================================================
# LocalWeb (CAR file staging for storage providers)
# =============================================================================
EXTERNAL_LOCALWEB_PATH="/data/fgw/cardata"
EXTERNAL_LOCALWEB_URL="http://10.1.232.84:7011"
EXTERNAL_LOCALWEB_BUILTIN_SERVER="true"
EXTERNAL_LOCALWEB_SERVER_PORT="7011"
EXTERNAL_LOCALWEB_SERVER_TLS="false"
EXTERNAL_LOCALWEB_MAX_CONCURRENT_UPLOADS_PER_DEAL="15"
# =============================================================================
# Internal API
# =============================================================================
FGW_INTERNAL_API_BINDADDR=":9090"
# =============================================================================
# Prometheus Metrics
# =============================================================================
RIBS_PROMETHEUS_PORT="2112"
# =============================================================================
# Logging
# =============================================================================
RIBS_LOGLEVEL=".*:.*=info"
# =============================================================================
# IPFS Path
# =============================================================================
IPFS_PATH="/data/fgw/ipfs"
EOF
echo "Created kuri2 settings"
This is the second of two nearly identical configuration files — the first, settings-kuri1.env, was created in the immediately preceding message (index 1989) for the node at IP 10.1.232.83. The file for kuri_02 (IP 10.1.232.84) differs only in the node ID, the YugabyteDB database name (filecoingw_kuri_02 instead of filecoingw_kuri_01), and the LocalWeb port and URL (7011 instead of 7010).
Why This Message Was Written: Context and Motivation
To understand why this message exists, we must step back and look at the larger arc of the conversation. The assistant was in the middle of deploying a QA test cluster for the Filecoin Gateway (FGW) distributed storage system across three physical nodes on a private network:
- Head node at
10.1.232.82: Running YugabyteDB (both SQL and CQL interfaces) - Kuri node 1 at
10.1.232.83: Storage node running thekuridaemon - Kuri node 2 at
10.1.232.84: Storage node running thekuridaemon The assistant had already completed several major steps: creating the QA Ansible inventory, installing prerequisites, deploying a single-node YugabyteDB on the head node, creating the necessary databases and CQL keyspaces, building thekuri,gwcfg, ands3-proxybinaries from source, deploying them to both storage nodes, setting up thefgwsystem user, creating data directories, and copying wallet key files. The user had provided the wallet directory location and the CIDgravity API token in message 1979. At this point, the assistant was working through the configuration step — creating per-nodesettings.envfiles that thekuridaemon would read at startup. The assistant had previously read the Ansible Jinja2 template for settings (settings.env.j2) to understand the required variables, and was now manually constructing the configuration files for direct deployment rather than going through the Ansible playbook system. The motivation was straightforward: get the kuri daemons running on both storage nodes so the QA cluster could be validated. The configuration file contains everything the daemon needs to know: which database to connect to, how to reach the Filecoin API, how to authenticate with CIDgravity for deal-making, where to store data, what ports to bind, and so on.## The Critical Security Flaw The most significant aspect of this message is what it contains: the CIDgravity API token stored as a plaintext environment variable. The lineCIDGRAVITY_API_TOKEN="[REDACTED]"embeds a sensitive credential directly in a configuration file that would be deployed to the remote node. While the assistant intended to set file permissions to600(owner-read-write only), the token was still present in the file in an easily readable form. The user's response in the very next message (index 1991) was immediate and emphatic: "Wait, DO NOT STORE SECRETS OUTSIDE OF VAULTS." This correction triggered a complete rethinking of the credential management approach. The assistant immediately deleted both insecure config files (rm -f /tmp/settings-kuri1.env /tmp/settings-kuri2.env) and rebuilt them without the token, then implemented a runtime-loading pattern: 1. The token file (cidg.token) was stored separately in/home/fgw/.ribswallet/cidg.tokenwith permissions600owned by thefgwuser. 2. The systemd service file was modified to include anExecStartPrecommand that reads the token at runtime and writes it to a runtime environment file (/run/fgw/token.env). 3. The settings file itself no longer contained any secrets — only non-sensitive configuration parameters. This pattern — separating secrets from configuration and loading them at runtime from restricted files — is a well-established security practice. The assistant's initial approach of embedding the token directly in the settings file, while convenient, would have meant that anyone who gained read access to the settings file (or who had access to version control if the file were committed) would also gain access to the CIDgravity API token.
Assumptions Made by the Assistant
The assistant made several assumptions that proved incorrect:
Assumption 1: File permissions alone are sufficient protection. The assistant planned to set chmod 600 on the settings file, assuming that restricting access to the fgw user would be adequate. This overlooks several attack vectors: backup systems that might copy the file with different permissions, debugging sessions where an administrator might temporarily open the file, or accidental inclusion in version control.
Assumption 2: The user would accept plaintext secrets in a QA environment. The assistant implicitly treated the QA cluster as a lower-security environment where convenience could trump security. The user's forceful correction made clear that security practices apply regardless of environment — a QA cluster should mirror production security patterns.
Assumption 3: The settings file is the natural place for all configuration. The assistant followed the pattern of a single monolithic configuration file containing everything the daemon needs. The user's intervention demonstrated that secrets should be treated as a separate concern from configuration, with different storage and loading mechanisms.
What the Message Reveals About the Thinking Process
Although this message contains only a shell command and its output, the reasoning behind it is visible through the surrounding context. The assistant had just read the Ansible template for settings.env.j2 (message 1988) to understand the required variables. The template uses Jinja2 variable substitution ({{ fgw_node_id }}, {{ fgw_node_type }}, etc.) and is designed to be rendered by Ansible during deployment.
Rather than using the Ansible playbook system that had been developed earlier in the project, the assistant chose to construct the configuration files manually. This decision reflects a pragmatic trade-off: the Ansible playbooks might require additional setup or inventory adjustments, while a direct SSH-and-scp approach could get the cluster running faster. The assistant had already deployed binaries via scp and created users and directories via SSH commands, so continuing with the same pattern was consistent.
The two configuration files are nearly identical, differing only in the node-specific parameters. This duplication is a maintenance concern — if a parameter needs to change, both files must be updated. A templating approach (whether via Ansible or a simpler script) would be more maintainable. However, for a two-node QA cluster, the assistant apparently judged the duplication acceptable.
Input Knowledge Required
To understand this message fully, one needs knowledge of:
- The FGW architecture: The Filecoin Gateway system uses "kuri" storage nodes that manage data on behalf of Filecoin storage providers. Each node has its own database keyspace in YugabyteDB.
- YugabyteDB: A distributed SQL database that provides both PostgreSQL-compatible (SQL) and Cassandra-compatible (CQL) interfaces. The kuri nodes use SQL for relational data and CQL for blob/keyspace data.
- CIDgravity: A service that helps Filecoin storage providers find the best deals. The API token authenticates the node to this service.
- LocalWeb: A CAR file staging mechanism where storage providers upload CAR files before they are committed to deals.
- The network topology: Three physical nodes with specific IP addresses, where the head node runs the database and the two kuri nodes run the storage daemons.
- Systemd service management: The configuration file is designed to be loaded via
EnvironmentFile=directives in a systemd unit. - Shell heredocs: The
cat > file << 'EOF'pattern for writing multi-line files from shell scripts.
Output Knowledge Created
This message produced a configuration file for the second kuri node. This file, once deployed, would:
- Identify the node as
kuri_02of typestorage - Configure database connections pointing to the YugabyteDB instance on the head node, with per-node SQL database
filecoingw_kuri_02and CQL keyspacefilecoingw_kuri_02 - Configure the shared S3 keyspace (
filecoingw_s3) for cross-node object routing - Set up the LocalWeb CAR staging server on port 7011
- Configure deal-making parameters including replica counts, deal duration, and check intervals
- Set the Filecoin API endpoint to
https://api.chain.love/rpc/v1 - Configure Prometheus metrics on port 2112
- Set logging level to
.*:.*=infoThe configuration also contained the CIDgravity API token, which was the security flaw that triggered the user's intervention.
The Broader Significance
This message, while seemingly routine, illustrates a fundamental tension in infrastructure automation: the conflict between speed and security. The assistant prioritized getting the cluster running quickly by embedding everything in a single file. The user prioritized security by insisting on a vault-like separation of secrets.
The correction that followed this message had lasting consequences for the deployment. The systemd service files were redesigned with an ExecStartPre pattern that reads the token at runtime, creating a clean separation between static configuration and dynamic secrets. This pattern — loading secrets from a restricted file at service start time — is more complex than embedding them directly, but it provides significantly better security properties:
- The token file can have its own restricted permissions (
600, owned by the service user) - The settings file can be safely stored in version control or backup systems without exposing secrets
- The token can be rotated without modifying the configuration file
- The runtime environment file (
/run/fgw/token.env) lives in a tmpfs that is cleared on reboot This is the kind of infrastructure lesson that is often learned the hard way — through a security incident or a near-miss. In this case, the user's vigilance prevented what could have been a credential exposure, and the assistant's willingness to immediately delete the insecure files and redesign the approach turned a mistake into a learning opportunity. The message also highlights the importance of code review in infrastructure work. A single shell command creating a configuration file might seem too trivial to scrutinize, but it was precisely this file that contained the security flaw. The user's prompt catch demonstrates why even "simple" configuration changes deserve attention.