Merge pull request #59 from febus982/fix_container_exec

Use array syntax in Dockerfile, minor improvements

Author: febus982

Dockerfile

@@ -20,6 +20,10 @@ RUN apt-get update \
 RUN pip install --no-cache-dir -U pip
 RUN pip install --no-cache-dir -U poetry
 
+# We run everything by poetry run from now on, so that PATH will be handled
+# for binaries installed in virtual environments
+ENTRYPOINT ["poetry", "run"]
+
 FROM base as base_builder
 # Install build system requirements (gcc, library headers, etc.)
 # for compiled Python requirements like psycopg2
@@ -37,9 +41,12 @@ COPY --chown=nonroot:nonroot pyproject.toml .
 COPY --chown=nonroot:nonroot poetry.lock .
 
 # Test image, contains all files and dependencies
-FROM base_builder as test
+FROM base_builder as dev
 RUN poetry install --with http,grpc,dev
 COPY --chown=nonroot:nonroot . .
+# Note that opentelemetry doesn't play well together with uvicorn reloader
+# when signals are propagated, we disable it in dev image default CMD
+CMD ["uvicorn", "http_app:create_app", "--host", "0.0.0.0", "--port", "8000", "--factory", "--reload"]
 
 # Installs requirements to run production http application
 FROM base_builder as http_builder
@@ -62,20 +69,17 @@ COPY --chown=nonroot:nonroot config.py .
 COPY --chown=nonroot:nonroot di_container.py .
 COPY --chown=nonroot:nonroot alembic.ini .
 COPY --chown=nonroot:nonroot Makefile .
-ENTRYPOINT ["poetry", "run"]
 
 # Copy the http python package and requirements from relevant builder
 FROM base_app as http_app
 COPY --from=http_builder /poetryvenvs /poetryvenvs
 COPY --chown=nonroot:nonroot http_app ./http_app
-# opentelemetry-instrument will spawn a subprocess, therefore we use exec
-# to make sure the app runs on PID 1 and receives correctly system signals
-CMD opentelemetry-instrument uvicorn http_app:create_app --host 0.0.0.0 --port 8000 --factory
+# Run CMD using array syntax, so it's uses `exec` and runs as PID1
+CMD ["opentelemetry-instrument", "uvicorn", "http_app:create_app", "--host", "0.0.0.0", "--port", "8000", "--factory"]
 
 # Copy the grpc python package and requirements from relevant builder
 FROM base_app as grpc_app
 COPY --from=grpc_builder /poetryvenvs /poetryvenvs
 COPY --chown=nonroot:nonroot grpc_app ./grpc_app
-# opentelemetry-instrument will spawn a subprocess, therefore we use exec
-# to make sure the app runs on PID 1 and receives correctly system signals
-CMD exec opentelemetry-instrument python3 -m grpc_app
+# Run CMD using array syntax, so it's uses `exec` and runs as PID1
+CMD ["opentelemetry-instrument", "python3", "-m", "grpc_app"]

docker-compose.yaml

@@ -1,23 +1,12 @@
 version: '3.8'
 services:
-  # We don't use `make` or `poetry` for long running processes,
-  # to make sure they run as pid 1 and receive SIGTERM signal
   dev:
     build:
       dockerfile: Dockerfile
       context: .
-      target: http_app
+      target: dev
     ports:
       - '8000:8000'
-    command:
-      - "uvicorn"
-      - "http_app:create_app"
-      - "--host"
-      - "0.0.0.0"
-      - "--port"
-      - "8000"
-      - "--factory"
-      - "--reload"
     volumes:
       - '.:/app'
   http:
@@ -66,7 +55,7 @@ services:
     build:
       dockerfile: Dockerfile
       context: .
-      target: test
+      target: dev
     volumes:
       - '.:/app'
     command:
@@ -77,7 +66,7 @@ services:
     build:
       dockerfile: Dockerfile
       context: .
-      target: test
+      target: dev
     command:
       - "make"
       - "ci-test"

docker-container.png

@@ -15,8 +15,8 @@ usecase base_builder [
     ""dependencies""
     ""(e.g. gcc, library headers)""
 ]
-usecase test [
-    =Test
+usecase dev [
+    =Dev
     ----
     ""Fat image containing everything""
     ""necessary to run and test""
@@ -32,12 +32,12 @@ usecase base_app [
 
 rectangle HTTP {
     usecase http_builder [
-        =Http builder
+        =HTTP builder
         ----
         ""Builds HTTP dependencies""
     ]
     usecase http_app [
-        =Http app
+        =HTTP app
         ----
         ""Copies HTTP framework""
         ""shared logic""
@@ -54,7 +54,7 @@ rectangle GRPC {
     usecase grpc_app [
         =GRPC app
         ----
-        ""Copies HTTP framework""
+        ""Copies GRPC framework""
         ""shared logic""
         ""and dependencies""
         "" to run the application""
@@ -72,5 +72,5 @@ base_builder ===> grpc_builder
 grpc_builder ===> grpc_app
 base_app ===> grpc_app
 
-base_builder ==r=> test
+base_builder ==r=> dev
 @enduml