Include smart agent bundle in docker image (#241)

Makefile

@@ -191,7 +191,7 @@ delete-tag:
 docker-otelcol:
 	GOOS=linux $(MAKE) otelcol
 	cp ./bin/otelcol_linux_amd64 ./cmd/otelcol/otelcol
-	docker build -t otelcol ./cmd/otelcol/
+	docker build -t otelcol --build-arg SMART_AGENT_RELEASE=$(SMART_AGENT_RELEASE) ./cmd/otelcol/
 	rm ./cmd/otelcol/otelcol
 
 .PHONY: binaries-all-sys

cmd/otelcol/Dockerfile

@@ -1,16 +1,37 @@
-FROM alpine:3.12 as certs
+ARG SMART_AGENT_RELEASE=v5.9.1
+ARG ALPINE_VERSION=3.12
+
+FROM alpine:${ALPINE_VERSION} as certs
 RUN apk --update add ca-certificates
 
-FROM alpine:3.12 AS otelcol
+FROM alpine:${ALPINE_VERSION} AS otelcol
 COPY otelcol /
 # Note that this shouldn't be necessary, but in some cases the file seems to be
 # copied with the execute bit lost (see #1317)
 RUN chmod 755 /otelcol
 
+FROM alpine:${ALPINE_VERSION} AS smartagent
+ARG SMART_AGENT_RELEASE
+RUN mkdir -p "$(dirname "/usr/lib/splunk-otel-collector/agent-bundle")" && \
+    SMART_AGENT=signalfx-agent-${SMART_AGENT_RELEASE#v}.tar.gz && \
+    URL=https://github.com/signalfx/signalfx-agent/releases/download/${SMART_AGENT_RELEASE}/$SMART_AGENT && \
+    wget "$URL" && tar -xzf $SMART_AGENT && mv signalfx-agent /usr/lib/splunk-otel-collector/agent-bundle && \
+    # Absolute path of interpreter in smart agent dir is set in dependent binaries
+    # requiring the interpreter location not to change.
+    /usr/lib/splunk-otel-collector/agent-bundle/bin/patch-interpreter /usr/lib/splunk-otel-collector/agent-bundle && \
+    rm -f /usr/lib/splunk-otel-collector/agent-bundle/bin/signalfx-agent \
+          /usr/lib/splunk-otel-collector/agent-bundle/bin/agent-status \
+          $SMART_AGENT
+
 FROM scratch
+ENV SPLUNK_BUNDLE_DIR=/usr/lib/splunk-otel-collector/agent-bundle
+ENV SPLUNK_COLLECTD_DIR=$SIGNALFX_BUNDLE_DIR/run/collectd
 COPY --from=certs /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
 COPY --from=otelcol /otelcol /
-COPY config/collector/gateway_config.yaml /etc/otel/collector/gateway_config.yaml
+# Maintaining interpreter location as required.
+COPY --from=smartagent /usr/lib/splunk-otel-collector/agent-bundle /usr/lib/splunk-otel-collector/agent-bundle
+COPY config/collector/gateway_config.yaml    /etc/otel/collector/gateway_config.yaml
 COPY config/collector/otlp_config_linux.yaml /etc/otel/collector/otlp_config_linux.yaml
+COPY config/collector/agent_config.yaml      /etc/otel/collector/agent_config.yaml
 ENTRYPOINT ["/otelcol"]
 EXPOSE 13133 14250 14268 55680 4317 6060 7276 8888 9411 9443