docker: Add docker-compose.yml and modify Dockerfile

Dockerfile

@@ -1,24 +1,35 @@
 # Build Pinger binary
 
+# Use the golang image for building the binary
 FROM golang:1.16.0-alpine3.13 AS builder
 
+# Set the work directory
 WORKDIR /go/src/github.com/sdslabs/pinger
 
+# Copy over the source code to the container
 COPY . .
 
-ARG vers
-
+# Install bash and make
 RUN apk update && \
   apk add make && \
   apk add bash
-RUN make build VERSION=$vers
+
+# Build the actual binary
+RUN make build VERSION=1.0
 
 # Copy binary into actual image
 
-FROM alpine:3.12.0
+# Use the alpine image for running the binary
+FROM alpine:3.13
 
+# Set the work directory
 WORKDIR /go/bin
 
+# Copy over the binary from Builder image
 COPY --from=builder /go/src/github.com/sdslabs/pinger/pinger .
 
+# Copy over the agent.yml from Builder image
+# COPY --from=builder /go/src/github.com/sdslabs/pinger/agent.yml .
+
+# Final command to run pinger
 CMD [ "./pinger", "version" ]

build/docker.sh

@@ -15,6 +15,6 @@ fi
 VERSION=$(echo $TAG | cut -d':' -f 2)
 
 # Build the image using the tag.
-docker build -t "${TAG}" --build-arg vers="${VERSION}" .
+docker build -t "${TAG}" .
 
 finally "Built image with tag '${TAG}'"

docker-compose.yml

@@ -0,0 +1,29 @@
+version: "3"
+
+services:
+  # Timescale DB is used to store the metrics
+  timescale:
+    image: timescale/timescaledb:2.0.0-pg12
+    # Setting environment variables for Timescale
+    environment:
+      POSTGRES_PASSWORD: "password"
+      POSTGRES_DB: "pinger"
+    # Healthcheck conditions are defined since pinger service needs to know if Timescale has started
+    # pg_isready is a binary that is available with the postgres image(timescale is built upon postgres)
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U postgres"]
+      interval: 5s
+      timeout: 5s
+      retries: 5
+    # Mapping the volume to make it persistent
+    volumes:
+      - ./pinger_data:/var/lib/postgresql/data
+  pinger:
+    # Depends on timescale and condition will be true when timescale can accept connections
+    depends_on:
+      timescale:
+        condition: service_healthy
+    build: ./
+    # PINGER_PORT is the port on the host machine where the service will be available. Set it through .env
+    ports:
+      - "${PINGER_PORT:-9010}:9010"