Docker agent configuration

The Middleware.io Host Agent can be extensively configured using environment variables. These variables allow you to fine-tune data collection, logging, and integration behavior.

Environment Variables

The following table lists the most commonly used environment variables for configuring the Middleware.io Host Agent.

Environment Variable	Description	Default Value	Example Usage
`MW_API_KEY`	(Required) Your unique Middleware.io API key for authenticating the agent.	`(None)`	`-e MW_API_KEY="your_api_key_here"`
`MW_TARGET`	(Required) The ingestion URL for your Middleware.io instance where the agent should send data.	`(None)`	`-e MW_TARGET="https://ingest.middleware.io/v1/"`
`MW_HOST_TAGS`	Comma-separated list of custom tags to apply to the host and all metrics/logs collected from it. Useful for filtering and organizing data.	`(None)`	`-e MW_HOST_TAGS="env:prod,location:us-east-1"`
`MW_LOG_LEVEL`	Sets the logging verbosity for the agent. Useful for debugging.	`info`	`-e MW_LOG_LEVEL="debug"` (Options: `error`, `warn`, `info`, `debug`, `trace`)
`MW_COLLECT_METRICS`	Enables or disables metric collection. Set to `false` to disable.	`true`	`-e MW_COLLECT_METRICS="false"`
`MW_COLLECT_LOGS`	Enables or disables log collection. Set to `false` to disable.	`true`	`-e MW_COLLECT_LOGS="false"`
`MW_COLLECT_TRACES`	Enables or disables trace collection. Note: This primarily controls the agent's ability to receive traces from language-specific APM agents. Individual APM agents need to be configured separately.	`true`	`-e MW_COLLECT_TRACES="false"`
`MW_AGENT_SERVICE`	A custom name for the agent service. This can help differentiate agents in your dashboard if you have multiple running.	`mw-host-agent`	`-e MW_AGENT_SERVICE="my-docker-host-agent"`
`MW_AGENT_LOG_PATHS`	Comma-separated list of additional host log file paths (full paths) that the agent should monitor and collect.	`(None)`	`-e MW_AGENT_LOG_PATHS="/var/log/nginx/error.log,/opt/app/logs/server.log"`
`HTTP_PROXY`	HTTP proxy to use for outbound connections.	`(None)`	`-e HTTP_PROXY="http://proxy.example.com:8080"`
`HTTPS_PROXY`	HTTPS proxy to use for outbound connections.	`(None)`	`-e HTTPS_PROXY="https://proxy.example.com:8080"`
`NO_PROXY`	Comma-separated list of hosts or domains that should bypass the proxy.	`localhost,127.0.0.1`	`-e NO_PROXY="localhost,10.0.0.0/8"`
`MW_HOSTNAME`	Overrides the hostname reported by the agent. By default, it uses the container's hostname or the host's actual hostname if `--hostname $(hostname)` is used.	`(System hostname)`	`-e MW_HOSTNAME="my-custom-docker-host"`
`MW_CONTAINER_EXCLUDE_LIST`	Comma-separated list of container names or image names to exclude from monitoring. Wildcards (``) are supported. Example: `^nginx.,my-app-v2` or `nginx*,redis`	`(None)`	`-e MW_CONTAINER_EXCLUDE_LIST="^monitoring-,^kube-"`
`MW_CONTAINER_INCLUDE_LIST`	Comma-separated list of container names or image names to explicitly include for monitoring. If provided, only containers matching this list will be monitored. Wildcards (``) are supported. Example: `^app-,my-database`	`(None - all included)`	`-e MW_CONTAINER_INCLUDE_LIST="^my-web-app-,^my-api-service-"`
`MW_COLLECT_PROCESSES`	Enables or disables process metric collection on the host.	`true`	`-e MW_COLLECT_PROCESSES="false"`
`MW_METRIC_INTERVAL_SECONDS`	Interval (in seconds) at which metrics are collected.	`10`	`-e MW_METRIC_INTERVAL_SECONDS="30"`
`MW_LOG_BUFFER_SIZE`	Maximum number of log lines to buffer before sending.	`1000`	`-e MW_LOG_BUFFER_SIZE="2000"`

Volume Mounts

Proper volume mounts are critical for the agent to access the necessary host and Docker resources. Ensure these are correctly configured as shown in the installation examples:

/var/run/docker.sock:/var/run/docker.sock:ro: Essential for the agent to communicate with the Docker daemon and discover containers.
/proc:/proc:ro: Provides access to host process and system information for metrics.
/sys:/sys:ro: Provides access to system-level information.
/etc/os-release:/etc/os-release:ro: Helps the agent identify the host's operating system.
/var/lib/docker/containers:/var/lib/docker/containers:ro: Required for the agent to read container logs from their respective log files.
/var/log:/var/log:ro: (Optional) For collecting general host logs, such as system logs or application logs residing outside of Docker containers.

Important Note on Permissions: Ensure the user running the Docker daemon (and thus the agent container) has appropriate permissions to access these host paths. The :ro (read-only) mode is recommended for security where applicable.

Network Configuration

Host Network Mode: For some advanced scenarios, or if you need the agent to bind directly to host network interfaces, you might consider using network_mode: host in Docker Compose or --network host with docker run. However, the default bridge network mode is generally sufficient for basic data collection as long as the agent can reach the Middleware.io ingestion endpoint.
- Caution: Using host network mode bypasses Docker's network isolation, which has security implications. Only use if strictly necessary and understood.
Firewall Rules: Ensure that your host's firewall (e.g., ufw, firewalld, iptables) allows outbound connections from the Docker host to the MW_TARGET URL (typically port 443 for HTTPS).

Integrations (Containerized Applications)

The Middleware.io Host Agent primarily collects infrastructure and container-level data. To get Application Performance Monitoring (APM) traces from your applications running inside Docker containers, you'll need to instrument your application code with language-specific Middleware.io APM agents.

These APM agents automatically detect the running Middleware.io Host Agent and send traces to it, which are then forwarded to your Middleware.io dashboard.

Java APM Agent: [Link to Java APM Agent Docs]
Node.js APM Agent: [Link to Node.js APM Agent Docs]
Python APM Agent: [Link to Python APM Agent Docs]
... (and so on for other supported languages)

Refer to the respective APM agent documentation for detailed installation and configuration instructions for your specific application environment within Docker.