Monitor Fly.io with SigNoz

Fly.io is an app hosting platform that lets you run full-stack apps close to your users. SigNoz supports two signals from Fly.io:

Logs — forwarded via fly-log-shipper, a Vector-based log draining app. SigNoz is a named provider in fly-log-shipper.
Metrics — scraped from Fly's Prometheus federation endpoint using the OpenTelemetry Collector. See the full Fly.io Metrics guide.

If using self-hosted SigNoz, most steps are identical. To adapt this guide, update the endpoint and remove the ingestion key header as shown in Cloud → Self-Hosted.

Prerequisites

A SigNoz Cloud (or self-hosted) workspace
Fly CLI installed and a Fly.io account

Forward Logs

Fly.io logs are forwarded to SigNoz using fly-log-shipper — a Fly app that runs Vector and drains logs from your entire Fly.io organisation.

Step 1: Clone fly-log-shipper

git clone https://github.com/superfly/fly-log-shipper.git
cd fly-log-shipper

Step 2: Create the shipper app (without deploying yet)

fly launch --no-deploy

This creates a new Fly app in your organisation without starting it.

Step 3: Create a read-only access token

fly tokens create readonly personal

Save the token value — you will set it as a secret in the next step.

Step 4: Set the required secrets

fly secrets set \
  ACCESS_TOKEN="<your-readonly-fly-token>" \
  SIGNOZ_INGESTION_KEY="<your-signoz-ingestion-key>" \
  SIGNOZ_INGESTION_URL="https://ingest.<region>.signoz.cloud:443"

Replace:

<your-readonly-fly-token> — the token from Step 3
<your-signoz-ingestion-key> — your SigNoz ingestion key
<region> — your SigNoz Cloud region (e.g. us, eu). See regions.

Step 5: Deploy

fly deploy

Once deployed, fly-log-shipper begins draining logs from all apps in the organisation and forwarding them to SigNoz.

Step 6: Verify logs in SigNoz

Open Logs Explorer in SigNoz. Within a minute you should see log entries with Fly.io-specific attributes such as app, region, and instance_id.

Troubleshooting

fly-log-shipper not running — run fly status inside the fly-log-shipper directory and confirm the app is in a running state.
Wrong secrets — re-check ACCESS_TOKEN, SIGNOZ_INGESTION_KEY, and SIGNOZ_INGESTION_URL with fly secrets list. Update them with fly secrets set and redeploy.
Token scope — ensure the token was created with fly tokens create readonly personal, not a deploy token.

Collect Metrics

Fly.io exposes application and infrastructure metrics via a Prometheus federation endpoint. The OpenTelemetry Collector scrapes this endpoint and forwards metrics to SigNoz. For the full reference, see Fly.io Metrics.

Step 1: Create an org metrics token

Generate a token at the org scope:

fly tokens create org --org <your-org-slug>

This prints a value beginning with FlyV1 .... Save only the raw part after FlyV1 to a file (do not include the prefix):

# Save the raw token (without the "FlyV1 " prefix)
echo '<RAW_TOKEN_AFTER_FlyV1>' > fly_federate_token

Step 2: Configure the OpenTelemetry Collector

Follow instructions here to install OpenTelemetry Binary as an agent

Update config.yaml in the otelcol-contrib folder with the following:

receivers:
  prometheus:
    config:
      scrape_configs:
        - job_name: fly-federate
          scheme: https
          metrics_path: /prometheus/<your-org-slug>/federate   # e.g., /prometheus/personal/federate
          params:
            match[]: ['{__name__=~"fly_.*"}']
          static_configs:
            - targets: ["api.fly.io"]
          authorization:
            type: FlyV1
            credentials_file: /etc/otel/secret/fly_federate_token

Replace <your-org-slug> with your actual organization slug. Then add the prometheus receiver to your receivers configuration.

processors:
  transform/fly_metrics:
    error_mode: ignore
    metric_statements:
      - context: datapoint
        statements:
          - 'convert_gauge_to_sum("cumulative", true) where IsMatch(metric.name, "^fly_.*_count$") or metric.name == "fly_instance_cpu" or metric.name == "fly_instance_net_sent_bytes" or metric.name == "fly_instance_net_recv_bytes"'

Add the transform/fly_metrics processor to your processors configuration.

exporters:
  otlphttp:
    endpoint: "https://ingest.{region}.signoz.cloud:443"
    headers:
      signoz-access-token: <YOUR_SIGNOZ_API_KEY>

Replace {region} with your SigNoz Cloud region and <YOUR_SIGNOZ_API_KEY> with your Ingestion Key.

service:
  telemetry:
    logs:
      level: debug
  pipelines:
    metrics:
      receivers: [prometheus]
      processors: [transform/fly_metrics, batch]
      exporters: [otlphttp]

Step 3: Run the Collector

./otelcol-contrib --config ./config.yaml

Install the OpenTelemetry Collector for Docker.

Update otel.yaml with the following:

receivers:
  prometheus:
    config:
      scrape_configs:
        - job_name: fly-federate
          scheme: https
          metrics_path: /prometheus/<your-org-slug>/federate
          params:
            match[]: ['{__name__=~"fly_.*"}']
          static_configs:
            - targets: ["api.fly.io"]
          authorization:
            type: FlyV1
            credentials_file: /etc/otel/secret/fly_federate_token

Replace <your-org-slug> with your actual organization slug.

processors:
  transform/fly_metrics:
    error_mode: ignore
    metric_statements:
      - context: datapoint
        statements:
          - 'convert_gauge_to_sum("cumulative", true) where IsMatch(metric.name, "^fly_.*_count$") or metric.name == "fly_instance_cpu" or metric.name == "fly_instance_net_sent_bytes" or metric.name == "fly_instance_net_recv_bytes"'

exporters:
  otlphttp:
    endpoint: "https://ingest.{region}.signoz.cloud:443"
    headers:
      signoz-access-token: <YOUR_SIGNOZ_API_KEY>

Replace {region} with your SigNoz Cloud region and <YOUR_SIGNOZ_API_KEY> with your Ingestion Key.

service:
  telemetry:
    logs:
      level: debug
  pipelines:
    metrics:
      receivers: [prometheus]
      processors: [transform/fly_metrics, batch]
      exporters: [otlphttp]

Step 3: Run the Collector

docker run --rm -it \
  -v "$(pwd)/otel.yaml:/etc/otel/config.yaml" \
  -v "$(pwd)/fly_federate_token:/etc/otel/secret/fly_federate_token:ro" \
  otel/opentelemetry-collector-contrib:0.103.1 \
  --config /etc/otel/config.yaml

Install the SigNoz K8s Infra chart.

Create the namespace (if needed):

kubectl create namespace signoz

Create the secret for the Fly token:

kubectl create secret generic fly-federate-token \
  --from-file=fly_federate_token=./fly_federate_token \
  -n signoz

Update override-values.yaml:

global:
  cloud: others
  clusterName: <CLUSTER_NAME>
  deploymentEnvironment: <DEPLOYMENT_ENVIRONMENT>
otelCollectorEndpoint: ingest.{region}.signoz.cloud:443
otelInsecure: false
signozApiKey: <your-ingestion-key>
 
otelAgent:
  image:
    repository: otel/opentelemetry-collector-contrib
    tag: 0.103.1
  config:
    receivers:
      prometheus:
        config:
          scrape_configs:
            - job_name: fly-federate
              scheme: https
              metrics_path: /prometheus/<your-org-slug>/federate
              params:
                match[]: ['{__name__=~"fly_.*"}']
              static_configs:
                - targets: ["api.fly.io"]
              authorization:
                type: FlyV1
                credentials_file: /etc/otel/secret/fly_federate_token
    processors:
      transform/fly_metrics:
        error_mode: ignore
        metric_statements:
          - context: datapoint
            statements:
              - 'convert_gauge_to_sum("cumulative", true) where IsMatch(metric.name, "^fly_.*_count$") or metric.name == "fly_instance_cpu" or metric.name == "fly_instance_net_sent_bytes" or metric.name == "fly_instance_net_recv_bytes"'
    exporters:
      otlphttp:
        endpoint: https://ingest.{region}.signoz.cloud:443
        headers:
          signoz-access-token: <your-ingestion-key>
    service:
      pipelines:
        metrics:
          receivers: [prometheus]
          processors: [transform/fly_metrics, batch]
          exporters: [otlphttp]
  extraVolumes:
    - name: fly-token
      secret:
        secretName: fly-federate-token
  extraVolumeMounts:
    - name: fly-token
      mountPath: /etc/otel/secret/fly_federate_token
      subPath: fly_federate_token
      readOnly: true

Step 3: Deploy the chart

helm install my-release signoz/k8s-infra -f override-values.yaml

Fly's /federate endpoint doesn't expose metric types, so all metrics are mapped as Gauge by default. The transform/fly_metrics processor converts the relevant metrics to Sum (counter) type. Add any additional metric names to the processor statements as needed.

Verify the federation endpoint

Generate some traffic and confirm metrics are returned:

curl -sS -i -G \
  -H "Authorization: FlyV1 $(cat fly_federate_token)" \
  --data-urlencode 'match[]={__name__=~"fly_.*"}' \
  https://api.fly.io/prometheus/<your-org-slug>/federate | head -n 40

You should see lines like fly_instance_cpu_user_seconds_total, fly_instance_memory_resident, etc.

Troubleshooting

Wrong org slug — confirm <your-org-slug> in metrics_path matches the output of fly orgs list.
Token format — the token file must contain only the raw value after FlyV1 (no prefix, no trailing newline).
Gauge vs counter — Fly's federation endpoint does not expose metric types; all metrics default to Gauge. Use the transform/fly_metrics processor to convert counters. See Fly.io Metrics for details.

Pre-built Dashboard

A pre-built Fly.io Prometheus dashboard is available to import directly into SigNoz:

Dashboard JSON

Recommended. Uses the V2 dashboard schema and needs SigNoz v0.135.0 or newer.

Import it in SigNoz with Dashboards → + New dashboard → Import JSON. Import guide

Fly.io pre-built Prometheus dashboard in SigNoz — *Fly.io Prometheus dashboard in SigNoz*

Next Steps

Set up metric-based alerts on Fly.io app metrics.
Set up log-based alerts to get notified on error patterns in Fly.io logs.
Create a dashboard to combine Fly.io metrics and logs in a single view.

Get Help

If you need help with the steps in this topic, please reach out to us on SigNoz Community Slack. If you are a SigNoz Cloud user, please use in product chat support located at the bottom right corner of your SigNoz instance or contact us at cloud-support@signoz.io.

Monitor Fly.io with SigNoz

Prerequisites

Forward Logs

Step 1: Clone fly-log-shipper

Step 2: Create the shipper app (without deploying yet)

Step 3: Create a read-only access token

Step 4: Set the required secrets

Step 5: Deploy

Step 6: Verify logs in SigNoz

Troubleshooting

Collect Metrics

Step 1: Create an org metrics token

Step 2: Configure the OpenTelemetry Collector

Step 3: Run the Collector

Step 3: Run the Collector

Step 3: Deploy the chart

Verify the federation endpoint

Troubleshooting

Pre-built Dashboard

Next Steps

Get Help

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