ad-hock runner install template with cache support

sample-gitea-cache.tmlp

#!/bin/bash

set -e
set -o pipefail

{{- if .EnableBootDebug }}
set -x
{{- end }}

CALLBACK_URL="{{ .CallbackURL }}"
METADATA_URL="{{ .MetadataURL }}"
BEARER_TOKEN="{{ .CallbackToken }}"

RUN_HOME="/home/{{.RunnerUsername}}/gitea-runner"

if [ -z "$METADATA_URL" ];then
	echo "no token is available and METADATA_URL is not set"
	exit 1
fi

function call() {
	PAYLOAD="$1"
	[[ $CALLBACK_URL =~ ^(.*)/status(/)?$ ]] || CALLBACK_URL="${CALLBACK_URL}/status"
	curl --retry 5 --retry-delay 5 --retry-connrefused --fail -s -X POST -d "${PAYLOAD}" -H 'Accept: application/json' -H "Authorization: Bearer ${BEARER_TOKEN}" "${CALLBACK_URL}" || echo "failed to call home: exit code ($?)"
}

function systemInfo() {
	if [ -f "/etc/os-release" ];then
		. /etc/os-release
	fi
	OS_NAME=${NAME:-""}
	OS_VERSION=${VERSION_ID:-""}
	AGENT_ID=${1:-null}
	# strip status from the callback url
	[[ $CALLBACK_URL =~ ^(.*)/status(/)?$ ]] && CALLBACK_URL="${BASH_REMATCH[1]}" || true
	SYSINFO_URL="${CALLBACK_URL}/system-info/"
	PAYLOAD="{\"os_name\": \"$OS_NAME\", \"os_version\": \"$OS_VERSION\", \"agent_id\": $AGENT_ID}"
	curl --retry 5 --retry-delay 5 --retry-connrefused --fail -s -X POST -d "${PAYLOAD}" -H 'Accept: application/json' -H "Authorization: Bearer ${BEARER_TOKEN}" "${SYSINFO_URL}" || true
}

function sendStatus() {
	MSG="$1"
	call "{\"status\": \"installing\", \"message\": \"$MSG\"}"
}

function success() {
	MSG="$1"
	ID=${2:-null}
	call "{\"status\": \"idle\", \"message\": \"$MSG\", \"agent_id\": $ID}"
}

function fail() {
	MSG="$1"
	call "{\"status\": \"failed\", \"message\": \"$MSG\"}"
	exit 1
}

function downloadAndExtractRunner() {
	sendStatus "downloading tools from {{ .DownloadURL }}"
	mkdir -p "$RUN_HOME" || fail "failed to create actions-runner folder"
	curl --retry 5 --retry-delay 5 --retry-connrefused --fail -L -o "$RUN_HOME/gitea-runner" "{{ .DownloadURL }}" || fail "failed to download tools"
	chown {{ .RunnerUsername }}:{{ .RunnerGroup }} -R "$RUN_HOME"/ || fail "failed to change owner"
	chmod +x "$RUN_HOME/gitea-runner" || fail "failed to set executable flag"
}

if [ ! -d "$RUN_HOME" ];then
	downloadAndExtractRunner
else
	sendStatus "using cached runner found in $RUN_HOME"
fi

cd "$RUN_HOME"
HAS_CACHE=0
{{- $addr := index .ExtraContext "gitea_cache_address" -}}
{{- $secret := index .ExtraContext "gitea_cache_secret" -}}
{{- if and $addr $secret }}
HAS_CACHE=1
cat > "$RUN_HOME/config.yaml" << 'EOF'
cache:
  external_server: "{{ $addr }}"
  external_secret: "{{ $secret }}"
EOF
{{- end }}


{{- if .AgentMode }}
AGENT_MODE="true"
{{- else }}
AGENT_MODE=""
{{- end }}

if [ "$AGENT_MODE" == "true" ]; then
	sendStatus "Agent mode is enabled; setting up agent"
	DOWNLOAD_URL="{{ .AgentDownloadURL }}"
	AGENT_URL="{{ .AgentURL }}"
	AGENT_TOKEN="{{ .AgentToken }}"
	AGENT_SHELL={{ .AgentShell }}
	sendStatus "Downloading agent from $DOWNLOAD_URL"
	sudo curl --retry 5 \
		--retry-delay 5 \
		--retry-connrefused \
		--fail -L \
		-H "Authorization: Bearer ${BEARER_TOKEN}" \
		-o /usr/local/bin/garm-agent "$DOWNLOAD_URL" || fail "failed to download garm-agent"
	sudo chmod +x /usr/local/bin/garm-agent || fail "failed to make garm-agent executable"
	sudo mkdir -p /var/log/garm-agent || fail "failed to create /var/log/garm-agent"
	sudo chown {{ .RunnerUsername }}:{{ .RunnerUsername }} /var/log/garm-agent || fail "failed to chown /var/log/garm-agent"
	sudo mkdir -p /etc/garm-agent || fail "failed to create /etc/garm"
	sudo chown {{ .RunnerUsername }}:{{ .RunnerUsername }} /etc/garm-agent || fail "failed to change owner on /etc/garm-agent"

    cmdline="[\"$RUN_HOME/gitea-runner\", \"daemon\", \"--once\"]"
    if [ $HAS_CACHE -gt 0 ];then
        cmdline="[\"$RUN_HOME/gitea-runner\", \"daemon\", \"--once\", \"--config\", \"$RUN_HOME/config.yaml\"]"
    fi
	sendStatus "Creating config and systemd unit"
	cat > /etc/garm-agent/garm-agent.toml << EOF
server_url = "$AGENT_URL"
log_file = "/var/log/garm-agent/garm-agent.log"
work_dir = "$RUN_HOME"
enable_shell = $AGENT_SHELL
{{- if .ForceInsecureGARMAgent }}
force_insecure = true
{{- end }}
token = "$AGENT_TOKEN"
runner_cmdline = $cmdline
state_db_path = "/etc/garm-agent/agent-state.db"
EOF

	cat > /tmp/garm-agent.service << EOF
[Unit]
Description=GARM agent
After=multi-user.target

[Service]
Type=simple
ExecStart=/usr/local/bin/garm-agent daemon --config /etc/garm-agent/garm-agent.toml
ExecReload=/bin/kill -HUP $MAINPID
Restart=always
RestartSec=5s
User={{ .RunnerUsername }}
Environment=TERM=xterm-256color
Environment=LANG=en_US.UTF-8

[Install]
WantedBy=multi-user.target
EOF

	sudo mv /tmp/garm-agent.service /etc/systemd/system/garm-agent.service || fail "failed to create /etc/systemd/system/garm-agent.service"
	sudo chown root:root /etc/systemd/system/garm-agent.service || fail "failed to change owner on /etc/systemd/system/garm-agent.service"
	sendStatus "Reloading systemd unit"
	sudo systemctl daemon-reload || fail "failed to reload systemd"
fi

sendStatus "configuring runner"
function getRunnerFile() {
	curl --retry 5 --retry-delay 5 \
		--retry-connrefused --fail -s \
		-X GET -H 'Accept: application/json' \
		-H "Authorization: Bearer ${BEARER_TOKEN}" \
		"${METADATA_URL}/$1" -o "$2"
}

GITHUB_TOKEN=$(curl --retry 5 --retry-delay 5 --retry-connrefused --fail -s -X GET -H 'Accept: application/json' -H "Authorization: Bearer ${BEARER_TOKEN}" "${METADATA_URL}/runner-registration-token/")

set +e
attempt=1
while true; do
	ERROUT=$(mktemp)
	./gitea-runner register --ephemeral --no-interactive --instance "{{ .RepoURL }}" --token "$GITHUB_TOKEN" --name "{{ .RunnerName }}" --labels "{{ .RunnerLabels }}" 2>$ERROUT
	if [ $? -eq 0 ]; then
		rm $ERROUT || true
		sendStatus "runner successfully configured after $attempt attempt(s)"
		break
	fi
	LAST_ERR=$(cat $ERROUT)
	echo "$LAST_ERR"

	if [ $attempt -gt 5 ];then
		rm $ERROUT || true
		fail "failed to configure runner: $LAST_ERR"
	fi

	sendStatus "failed to configure runner (attempt $attempt): $LAST_ERR (retrying in 5 seconds)"
	attempt=$((attempt+1))
	rm $ERROUT || true
	sleep 5
done
set -e

getRunnerFile "system/service-name" ""$RUN_HOME"/.service" || fail "failed to get service name file"
sed -i 's/$/\.service/' "$RUN_HOME"/.service
SVC_NAME=$(cat "$RUN_HOME"/.service)

AGENT_ID=""
sendStatus "starting service"
if [ "$AGENT_MODE" == "true" ]; then
	sendStatus "Enabling garm-agent service"
	sudo systemctl enable --now garm-agent
else
	sendStatus "generating systemd unit file"
	getRunnerFile "systemd/unit-file?runAsUser={{ .RunnerUsername }}" "$SVC_NAME" || fail "failed to get service file"
	sudo mv $SVC_NAME /etc/systemd/system/ || fail "failed to move service file"
	sudo chown root:root /etc/systemd/system/$SVC_NAME || fail "failed to change owner"
	if [ -e "/sys/fs/selinux" ];then
		sudo chcon -h system_u:object_r:systemd_unit_file_t:s0 /etc/systemd/system/$SVC_NAME || fail "failed to change selinux context"
		sudo chcon -R -h user_u:object_r:bin_t:s0 /home/runner/ || fail "failed to change selinux context"
	fi
    if [ $HAS_CACHE -gt 0 ];then
        sudo sed -i '/gitea-runner daemon --once/ s@$@ --config '$RUN_HOME'/config.yaml@' /etc/systemd/system/$SVC_NAME
    fi
	sudo systemctl daemon-reload || fail "failed to reload systemd"
	sudo systemctl enable --now $SVC_NAME
fi

set +e
AGENT_ID=$(grep '"id"' "$RUN_HOME"/.runner |  tr -d -c 0-9)
if [ $? -ne 0 ];then
	fail "failed to get agent ID"
fi
set -e

systemInfo $AGENT_ID
success "runner successfully installed" $AGENT_ID

Do not use this template for anything other than an example. It is simply a cloned version of the build-in GARM template, with some added handling of cache server config past in using exta_specs --> extra_context.