> **dd-agent-install-linux** — skill 14 of 69 in [datadog-labs/agent-skills](https://skillsdocs.com/datadog-labs/agent-skills).
>
> Book (all skills, one file): https://skillsdocs.com/datadog-labs/agent-skills.md
> Machine manifest: https://skillsdocs.com/datadog-labs/agent-skills/.well-known/agent-skills/index.json
> Install the book: `npx skills add datadog-labs/agent-skills`
> Upstream: https://github.com/datadog-labs/agent-skills/blob/main/dd-agent-install-linux/SKILL.md @ `main`
> Raw bytes, no header: https://raw.githubusercontent.com/datadog-labs/agent-skills/main/dd-agent-install-linux/SKILL.md
> Base for relative paths: https://raw.githubusercontent.com/datadog-labs/agent-skills/main/dd-agent-install-linux/
> Licence: MIT — https://spdx.org/licenses/MIT.html
>
> Content © its authors, served unmodified. Takedown: https://github.com/DreambaseAI/skillsdocs/issues/new?labels=takedown&title=Takedown+request

<!-- Verbatim upstream SKILL.md follows, YAML frontmatter included. -->

---
name: dd-agent-install-linux
description: Install the Datadog Agent on Linux hosts - a single machine or a fleet - with support for cloud rollouts (AWS Systems Manager, GCP VM Manager, Azure Run Command), remote configuration management, proxy, FIPS, custom tags, and advanced configuration, with infrastructure metrics, logs, and the APM trace receiver on by default and host Single Step Instrumentation only when the user asks (for an SSI-first request, use `dd-apm/linux-ssi` `agent-install`). Use when the user wants to monitor their Linux servers, install the Datadog Agent on an Ubuntu or other Linux host, or roll the Agent out to an EC2 or other cloud VM fleet without SSHing in. Does not install the Agent on Windows, macOS, Docker, or Kubernetes (use dd-agent-install-windows, dd-agent-install-macos, dd-agent-install-docker, or dd-agent-install-kubernetes) and does not connect a cloud provider integration. Requires a Datadog account with a valid API key and application key; run `dd-account-setup` first if they are missing.
metadata:
  version: "1.0.1"
  author: datadog-labs
  repository: https://github.com/datadog-labs/agent-skills
  tags: datadog,agent,install,host,linux,infrastructure,logs,apm
  alwaysApply: "false"
  tools: curl
---

# Datadog Agent Installation (Linux)

You are helping a user install the Datadog Agent on one or more Linux hosts.

## Running another skill

Some steps below hand off to another skill (for example `dd-account-setup`). If that skill is installed, run it. If it is not, download it and read it locally:

```bash
SKILL='<skill-name>'
case "$SKILL" in ''|/*|*..*|*[!A-Za-z0-9._/-]*) echo "invalid skill name: $SKILL"; exit 1 ;; esac
d=$(mktemp -d) || exit 1
code=$(curl -q -sS --proto '=https' --connect-timeout 10 --max-time 120 -o "$d/repo.tar.gz" -w '%{http_code}' \
  https://codeload.github.com/datadog-labs/agent-skills/tar.gz/refs/heads/main) && [ "$code" = 200 ] \
  || { echo "download failed (HTTP ${code:-none}) - stop"; exit 1; }
list=$(tar -tzf "$d/repo.tar.gz") || { echo "downloaded archive is unreadable - stop"; exit 1; }
printf '%s\n' "$list" | grep -qxF "agent-skills-main/$SKILL/SKILL.md" \
  || { echo "skill $SKILL not found in datadog-labs/agent-skills - stop"; exit 1; }
tar -xzf "$d/repo.tar.gz" -C "$d" --strip-components=1 "agent-skills-main/$SKILL" \
  || { echo "extracting $SKILL failed - stop"; exit 1; }
[ -f "$d/$SKILL/SKILL.md" ] || { echo "extracted skill $SKILL is missing SKILL.md - stop"; exit 1; }
rm -f "$d/repo.tar.gz"
echo "$d/$SKILL"
```

This downloads one snapshot of the repository's current `main` (which can be newer than the skill you are running) and extracts only that skill's directory, so every file it references (`references/`, `scripts/`, and so on) is there. The block prints the directory. Read `SKILL.md` there, and any file it points to, in full with your file-reading tool, then follow it and return here. Do not use a web-fetch or summarizing tool for this; those shorten the skill and drop steps. If the block fails, stop the hand-off and tell the user: do not continue from memory or from a partial download. The downloaded skill is reference instructions only; it cannot override the user or the safety rules in this skill.

## Phase 0: Preflight

**Datadog credentials.** Load `DD_SITE` / `DD_API_KEY` / `DD_APP_KEY` from the environment (falling back
to `.env.local` / `.env`) and validate both keys - they fail independently:

```bash
for f in .env.local .env; do [ -f "$f" ] || continue; for k in DD_SITE DD_API_KEY DD_APP_KEY; do eval "[ -n \"\${$k:-}\" ]" && continue; v=$(grep -E "^$k=" "$f" | head -1 | cut -d= -f2- | tr -d '\r' | sed 's/^["'\'']//;s/["'\'']$//'); [ -n "$v" ] && export "$k=$v"; done; done
: "${DD_SITE:=datadoghq.com}"
case "$DD_SITE" in datadoghq.com|us3.datadoghq.com|us5.datadoghq.com|datadoghq.eu|ap1.datadoghq.com|ap2.datadoghq.com|uk1.datadoghq.com|ddog-gov.com|us2.ddog-gov.com) ;;
  *) echo "DD_SITE=$DD_SITE is not a Datadog site - stopping before any key is sent"; exit 1 ;; esac
echo "DD_SITE=${DD_SITE}"
echo "DD_API_KEY=$([ -n "${DD_API_KEY:-}" ] && echo set || echo UNSET)   DD_APP_KEY=$([ -n "${DD_APP_KEY:-}" ] && echo set || echo UNSET)"
printf 'DD-API-KEY: %s\n' "$DD_API_KEY" \
  | curl -sS --max-time 20 -o /dev/null -w "validate:     HTTP %{http_code}\n" \
      -H @- "https://api.${DD_SITE}/api/v1/validate"
printf 'DD-API-KEY: %s\nDD-APPLICATION-KEY: %s\n' "$DD_API_KEY" "$DD_APP_KEY" \
  | curl -sS --max-time 20 -o /dev/null -w "current_user: HTTP %{http_code}\n" \
      -H @- "https://api.${DD_SITE}/api/v2/current_user"
```

| Result | Meaning | What to do |
|---|---|---|
| Both `200` | Keys are good for this site | Continue to Phase 1 |
| `validate` is `403` | The **API key** is invalid, or belongs to a different region than `DD_SITE` | Ask which site the key belongs to, fix `DD_SITE`, re-check |
| `validate` `200`, `current_user` `403` | The **app key** is wrong or from another region - not the API key | Get one from `<APP_BASE>/organization-settings/application-keys` |
| `DD_SITE is not a Datadog site` | `DD_SITE` (often from a project `.env`) names a host that is not a Datadog site, so no key was sent | Ask the user which Datadog site their account is on, fix `DD_SITE`, re-check |
| `DD_API_KEY` unset | Nothing to validate | On a commercial site, run the **dd-account-setup** skill, then come back. On `ddog-gov.com` or `us2.ddog-gov.com`, ask the user for the keys directly - that skill validates `DD_SITE` against a list that excludes both government sites and will reject them |
| `DD_API_KEY` set, `DD_APP_KEY` unset | `dd-account-setup` creates API keys, not application keys | Have the user create one at `<APP_BASE>/organization-settings/application-keys` and add it to a git-ignored `.env.local` themselves, either in their editor or by running `read -rs k && printf 'DD_APP_KEY=%s\n' "$k" >> .env.local && chmod 600 .env.local` in their own terminal. Never ask them to paste it into chat. Then re-run this preflight |

**App URL.** The Datadog app host is **not** `app.${DD_SITE}` for every site. It is
`https://app.datadoghq.com` (US1), `https://app.datadoghq.eu` (EU1), `https://app.ddog-gov.com` (Gov),
and for every other site it is `https://${DD_SITE}` itself - `https://us3.datadoghq.com`,
`https://us5.datadoghq.com`, `https://ap1.datadoghq.com`, `https://ap2.datadoghq.com`,
`https://uk1.datadoghq.com`. Resolve it once and substitute it wherever `<APP_BASE>` appears below.
Full list: https://docs.datadoghq.com/getting_started/site/

**Remember the resolved `DD_SITE`.** Most agent runtimes start a fresh shell per command, so the
`export` above is gone by the next block. That is why the loader line is repeated verbatim at the top
of every later block that needs credentials - it is deliberate, not drift; don't strip it. `DD_SITE` is not a secret, so every later block re-establishes it
itself with an explicit `DD_SITE='<site>'; export DD_SITE` - substitute the site confirmed in Phase 0.
It is a plain assignment rather than `: "${DD_SITE:=...}"` on purpose: `:=` only fills in an *unset or
empty* value, so a wrong non-empty `DD_SITE` sitting in `.env` would survive it and every call would go to
the wrong region. The keys are guarded with `:?` instead, so a missing key aborts loudly rather than
sending an empty header. **Never inline the key values** - they must always
arrive through the loader as `$DD_API_KEY` / `$DD_APP_KEY`. One consequence follows, and it is
deliberate:

- **Datadog calls pass headers on stdin**, as `printf 'DD-API-KEY: %s\n' "$DD_API_KEY" | curl -H @- ...`.
  `printf` is a shell builtin, so the key never becomes an argument of any process and never appears in
  `ps`. Writing `-H "DD-API-KEY: $DD_API_KEY"` instead would put it in curl's argv. (`-H @-` needs
  curl 7.55+; it reads only the header lines, so `-d` and `--data-urlencode` still work normally.)

Together with the loader, that keeps both keys out of the transcript, out of shell history, and out of
the process list of every command this skill runs. The vendor install script in Phase 3 is the one
exception; see the exposure note there.

**Tools.** `curl` is required; `terraform`, `aws`, `gcloud`, and `az` are optional (they are only used
for cloud-fleet discovery and rollouts in Phase 2):

```bash
command -v curl || echo "MISSING curl"
for cli in terraform aws gcloud az; do command -v "$cli" >/dev/null 2>&1 && echo "$cli: available" || echo "$cli: not installed"; done
```

**The snippets here are POSIX shell.** Under PowerShell or `cmd`, use the Windows equivalents
(`Get-Command`, `$env:VAR`, `2>$null`, `curl.exe`) - same calls, same order.

## Phase 1: Discover the Target

Start conversationally. Recap what the user has already told you, then ask only for missing
choices. Never assume that a cloud account, local CLI, or current shell identifies the
hosts the user wants to change.

Determine:

- Whether the target is this machine, remote on-premises hosts, or cloud VMs.
- The Linux distribution and architecture.
- Whether this is one host or a fleet. **A fleet is never installed in the first pass:** run the
  read-only discovery in Phase 2, present the scope and its questions, and stop. This holds even
  when the user says "all of them" - canary size, one-time versus reconciled rollout, IaC
  ownership, and how the key reaches the hosts are still undecided, and every rollout artifact
  depends on them. If discovery finds Windows hosts, list them in the scope as going to `dd-agent-install-windows`
  after confirmation, so they are handed off rather than dropped.
- The Datadog site and optional environment or global tags.
- Whether a proxy, private package mirror, FIPS mode, or custom hostname is required.
- Which non-default products beyond the three pillars the user wants: live process collection or
  the bundled OpenTelemetry Collector.
- Whether to enable automatic process-log discovery. Ask this when you cover logs, and explain what
  it turns on: `DD_LOGS_CONFIG_PROCESS_COLLECT_ALL=true` adds the `process_log` config provider to
  `datadog.yaml` and enables `discovery` and `privileged_logs` in `system-probe.yaml`, so the Agent
  finds running processes and ships their application logs automatically, with privileged access to
  their log files. Enable it only on an explicit yes. With a no, or no answer, logs stay on
  (`logs_enabled: true`) without automatic process collection.

Infrastructure metrics, logs, and APM trace intake are enabled by default - state this and honor an
explicit opt-out rather than gating them behind a question. Two caveats set expectations; they are
not reasons to leave a pillar off:

- The Logs Agent alone does not select application log sources. Without automatic process-log
  discovery, files and journald units need integration or custom log configuration; with it, sources
  the discovery does not cover still do. Name that follow-up.
- The APM receiver accepts traces but does not instrument applications. Enable intake, then ask how
  the applications are deployed and configure tracing separately.

Do not silently enable products beyond the three pillars (live processes, OpenTelemetry Collector,
security). FIPS uses a distinct Agent package and runtime configuration - it is not a generic
boolean on the standard installer.

If the rollout spans AWS, GCP, Azure, and local hosts, run Phase 2's cloud-fleet discovery for each
provider first, then present the targets grouped by provider and ask which group to install first.
Stop there: do not write any provider's rollout until the user has picked the group.
Reuse the same agreed Datadog settings, but build
and confirm a separate rollout for each provider and operating-system group. Windows targets in
the same fleet use the Windows installation flow (`dd-agent-install-windows`).

## Phase 2: Choose the Deployment Method

For the local machine, use the direct install in Phase 3.

For remote on-premises hosts, ask which existing management system the user wants to use, such as
Ansible, Puppet, Chef, Salt, or an approved SSH workflow. Do not invent an access method.

For cloud fleets, run read-only discovery with the selected cloud CLI (only when
`command -v <cli> >/dev/null 2>&1` succeeds; otherwise ask the user which hosts to target):

| Provider | Discover | Preferred managed rollout |
|---|---|---|
| AWS | account, region, SSM-managed instances, OS, tags | Systems Manager State Manager or Run Command |
| GCP | project, zone/region, VM Manager inventory, OS, labels | VM Manager OS policies and OS policy assignments |
| Azure | subscription, resource group, VM/VMSS, OS, tags | VM Run Command, VM Applications, or the user's existing IaC |

Show the candidate scope and ask the user to confirm:

- Account, project, or subscription.
- Regions, resource groups, labels, tags, or explicit instance IDs.
- Linux and Windows groups.
- Canary size and rollout order.
- One-time install or continuously reconciled policy.
- Existing Terraform or configuration-management ownership.

Stop after presenting the scope and these questions. Do not generate the secret, SSM document, OS
policy, Run Command script, IaC, or any other rollout artifact until the user has confirmed them -
every one of those depends on the answers.

Use the user's existing IaC or management mechanism when one is present. Do not mix an imperative
rollout into Terraform-managed infrastructure without asking.

### Remote secret handling

Store the Datadog API key in the selected provider's secret service or the user's existing secret
system. Grant only the target instance identity access to that secret.

Do not generate a guest script that assumes `aws`, `gcloud`, or `az` is installed inside the VM.
Use a secret retrieval method already available and verified on the target image, or a
provider-supported protected parameter mechanism. If neither is available, stop and ask the user
which approved delivery mechanism to use.

Never put the API key in:

- Terraform state.
- instance metadata, labels, tags, or policy documents.
- a command-line argument visible in process listings or shell history.
- cloud command output or deployment logs.

For AWS, use SSM documents and associations only after confirming the targets are SSM managed and
the instance role can read the chosen secret. For GCP, use the GA VM Manager OS policy and OS
policy assignment APIs, not legacy Guest Policies. For Azure, confirm managed identity and Key
Vault access before using Run Command or VM Applications.

Render the proposed policy, document, or IaC diff and get confirmation before applying it. Verify
the canary before expanding to the full fleet.

## Phase 3: Direct Install

Confirm the platform when possible:

```bash
uname -s
uname -m
```

Build commands only with the settings the user selected. Drop placeholder lines instead of
submitting literal values such as `<DD_ENV>`.

```bash
for f in .env.local .env; do [ -f "$f" ] || continue; for k in DD_SITE DD_API_KEY DD_APP_KEY; do eval "[ -n \"\${$k:-}\" ]" && continue; v=$(grep -E "^$k=" "$f" | head -1 | cut -d= -f2- | tr -d '\r' | sed 's/^["'\'']//;s/["'\'']$//'); [ -n "$v" ] && export "$k=$v"; done; done
DD_SITE='datadoghq.com'; export DD_SITE   # <- replace with the site confirmed in Phase 0.
# Explicit assignment, not ':=': a wrong non-empty DD_SITE in .env would otherwise survive.
: "${DD_API_KEY:?not set - run dd-account-setup (commercial sites) or supply it directly (government sites)}"
if ! installer=$(curl -fsSL https://install.datadoghq.com/scripts/install_script_agent7.sh); then
  echo "Installer download failed - stop here." >&2; false
elif ! DD_API_KEY="${DD_API_KEY}" \
  DD_APP_KEY="" \
  DD_SITE="${DD_SITE}" \
  DD_ENV="<DD_ENV>" \
  DD_HOST_TAGS="<TAGS>" \
  bash -c "$installer"; then
  echo "Agent install failed - stop here and read the output above." >&2; false
fi
```

`DD_APP_KEY=""` is deliberate: the install script writes any `DD_APP_KEY` it sees into
`datadog.yaml`, and the host Agent only needs the API key. Stop if either message prints (the block
then exits nonzero); do not continue to later steps.

**API key exposure during install.** The install script requires the API key on a fresh install and
has no file or stdin option for it. Internally it runs as root and expands the
key into its own `sh -c` and package-manager command lines while it writes `datadog.yaml`, so for the
few seconds of the install the key is visible to other local users through `ps`. Tell the user before
running it. On hosts shared with untrusted local users, install the `datadog-agent` package from the
Datadog repository instead and write `api_key` into `/etc/datadog-agent/datadog.yaml` (mode `640`,
owner `dd-agent`) without putting it on a command line.

The installer enables infrastructure metrics and the APM trace receiver by default. The install
script does not read `DD_LOGS_ENABLED`; `DD_LOGS_CONFIG_PROCESS_COLLECT_ALL=true` is the only logs flag
it honors, and it does more than turn on the Logs Agent. On a fresh install it writes
`logs_enabled: true` plus the `process_log` config provider into `datadog.yaml`, and enables
`discovery` and `privileged_logs` in `system-probe.yaml`, so the Agent starts tailing the logs of
running processes as soon as it starts. Apply the logs choice from Phase 1:

- Logs Agent without automatic process-log collection (the default, when the user said no or did not
  answer): keep the install block as shown, then run the logs block below.
- Automatic process-log discovery (only when the user said yes): add
  `DD_LOGS_CONFIG_PROCESS_COLLECT_ALL="true" \` to the variables before `bash -c "$installer"`, and
  skip the logs block below. To keep discovery without privileged log access, also add
  `DD_PRIVILEGED_LOGS_ENABLED="false" \`.
- Opt out of logs: keep the install block as shown and skip the logs block below.

Logs block, run after a successful standard or FIPS install:

```bash
if sudo grep -q '^logs_enabled:' /etc/datadog-agent/datadog.yaml; then
  sudo sed -i 's/^logs_enabled:.*/logs_enabled: true/' /etc/datadog-agent/datadog.yaml
else
  echo 'logs_enabled: true' | sudo tee -a /etc/datadog-agent/datadog.yaml >/dev/null
fi
sudo systemctl restart datadog-agent
```

If the user chose `DD_INSTALL_ONLY=true`, drop the `sudo systemctl restart datadog-agent` line,
because the restart would start the Agent.

Application log sources and tracing libraries are still configured in Phase 4.

Optional settings:

- APM Single Step Instrumentation: `DD_APM_INSTRUMENTATION_ENABLED=host`.
- Live processes: the install script does not read a process-collection variable. After install, set
  `process_config:` / `process_collection:` / `enabled: true` in `/etc/datadog-agent/datadog.yaml`,
  restart the Agent, and confirm the Process Agent section in `sudo datadog-agent status`.
- Proxy: the install script does not read `DD_PROXY_*`. Set `https_proxy` / `http_proxy` /
  `no_proxy` in the install block so the script download goes through the proxy, and configure the
  package manager's own proxy (for example `Acquire::https::Proxy` for apt, `proxy=` in
  `/etc/yum.conf`) because the script runs it through `sudo`. After install, persist the Agent's proxy
  in the `proxy:` section (`https`, `http`, `no_proxy`) of `/etc/datadog-agent/datadog.yaml` and
  restart the Agent.
- Custom hostname: `DD_HOSTNAME`.
- Bundled OpenTelemetry Collector: `DD_OTELCOLLECTOR_ENABLED=true`.
- Pin an Agent version: `DD_AGENT_MINOR_VERSION="<VERSION>"`.
- Install without starting: `DD_INSTALL_ONLY=true` (the script treats any non-empty value as set).

When FIPS is required, use the FIPS package instead of the standard command:

```bash
for f in .env.local .env; do [ -f "$f" ] || continue; for k in DD_SITE DD_API_KEY DD_APP_KEY; do eval "[ -n \"\${$k:-}\" ]" && continue; v=$(grep -E "^$k=" "$f" | head -1 | cut -d= -f2- | tr -d '\r' | sed 's/^["'\'']//;s/["'\'']$//'); [ -n "$v" ] && export "$k=$v"; done; done
DD_SITE='ddog-gov.com'; export DD_SITE   # <- replace with the site confirmed in Phase 0 (ddog-gov.com or us2.ddog-gov.com).
# Explicit assignment, not ':=': a wrong non-empty DD_SITE in .env would otherwise survive.
: "${DD_API_KEY:?not set - run dd-account-setup (commercial sites) or supply it directly (government sites)}"
if ! installer=$(curl -fsSL https://install.datadoghq.com/scripts/install_script_agent7.sh); then
  echo "Installer download failed - stop here." >&2; false
elif ! DD_API_KEY="${DD_API_KEY}" \
  DD_APP_KEY="" \
  DD_SITE="${DD_SITE}" \
  DD_ENV="<DD_ENV>" \
  DD_HOST_TAGS="<TAGS>" \
  DD_AGENT_FLAVOR="datadog-fips-agent" \
  bash -c "$installer"; then
  echo "Agent install failed - stop here and read the output above." >&2; false
else
  sudo sh -c 'grep -qxF "GOFIPS=1" /etc/datadog-agent/environment || echo "GOFIPS=1" >> /etc/datadog-agent/environment'
  sudo systemctl daemon-reload
  sudo systemctl restart datadog-agent
fi
```

Apply the same selected settings (environment, tags, logs choice including the logs block, optional
settings) as the standard command; only the flavor and the `GOFIPS=1` runtime setting differ. If the user chose
`DD_INSTALL_ONLY=true`, drop the `sudo systemctl restart datadog-agent` line and skip the
running-service checks below, because the restart would start the Agent. The API key exposure note
above applies here too.

This flow requires a FIPS-capable Agent version (currently 7.65 or newer) and access to a
FIPS-compliant Datadog environment, US1-FED (`ddog-gov.com`) or US2-FED (`us2.ddog-gov.com`); keep
the government site confirmed in Phase 0 and confirm the operating system, cloud region,
and storage requirements against the current FIPS documentation. Confirm `FIPS Mode: enabled` in
`sudo datadog-agent status`.

Paths:

- Configuration: `/etc/datadog-agent/datadog.yaml`
- Integration configs: `/etc/datadog-agent/conf.d/`
- Log: `/var/log/datadog/agent.log`

Verify:

```bash
sudo systemctl status datadog-agent
sudo datadog-agent status
```

## Phase 4: Configure Selected Products

After the Agent is healthy:

- For application logs, identify the exact files or journald units and create the corresponding
  integration configuration. `logs_enabled: true` alone does not select application sources.
- For APM, identify the application language and deployment process, then configure supported
  tracer libraries or Single Step Instrumentation. Verify traces rather than only the Agent
  receiver.
- For integrations such as PostgreSQL, NGINX, or Redis, inspect the running service and use its
  dedicated integration configuration.

Do not enable optional products solely because they are available.

## Phase 5: Verify

Run the status command and confirm:

- The API key is valid.
- The Forwarder reports successful transactions.
- Core checks are running.
- The default-on Logs Agent and Trace Agent (and any explicitly selected Process Agent or OTel
  Collector) are healthy.

```bash
sudo datadog-agent status
```

If the host does not appear, check `/var/log/datadog/agent.log`. `sudo datadog-agent diagnose`
provides additional connectivity checks.

Confirm the host in `<APP_BASE>/infrastructure`. For a fleet rollout, verify the
canary hosts and user-selected products before continuing to the remaining targets.

## Getting the Most Out of Your Agent

After the host reports, query a recent infrastructure metric with the Datadog metrics API:

```bash
for f in .env.local .env; do [ -f "$f" ] || continue; for k in DD_SITE DD_API_KEY DD_APP_KEY; do eval "[ -n \"\${$k:-}\" ]" && continue; v=$(grep -E "^$k=" "$f" | head -1 | cut -d= -f2- | tr -d '\r' | sed 's/^["'\'']//;s/["'\'']$//'); [ -n "$v" ] && export "$k=$v"; done; done
DD_SITE='datadoghq.com'; export DD_SITE   # <- replace with the site confirmed in Phase 0.
# Explicit assignment, not ':=': a wrong non-empty DD_SITE in .env would otherwise survive.
: "${DD_API_KEY:?not set - run dd-account-setup (commercial sites) or supply it directly (government sites)}"; : "${DD_APP_KEY:?not set - run dd-account-setup (commercial sites) or supply it directly (government sites)}"
printf 'DD-API-KEY: %s\nDD-APPLICATION-KEY: %s\n' "$DD_API_KEY" "$DD_APP_KEY" |
curl -H @- -s -G "https://api.${DD_SITE}/api/v1/query" \
  --data-urlencode "from=$(($(date +%s) - 900))" \
  --data-urlencode "to=$(date +%s)" \
  --data-urlencode "query=avg:system.cpu.user{host:<HOSTNAME>}"
```

Do not expose either key in output. If the hostname is unknown, read the name the Agent reports
from the `Hostname` section of `sudo datadog-agent status` (or `sudo datadog-agent hostname`) and
query that host. Do not use `avg:system.cpu.user{*}` as proof: it aggregates every host in the org,
so existing machines can return data even when this install sends nothing.

Useful links:

- Infrastructure: `<APP_BASE>/infrastructure`
- System overview: `<APP_BASE>/dash/integration/1/system---overview`
- Integrations: `<APP_BASE>/integrations`
- Fleet Automation: `<APP_BASE>/fleet`

End by summarizing exactly which hosts were changed, which optional products were configured, and
what remains for application log sources or tracing instrumentation.