Add Docker support to improve reproducibility

Signed-off-by: Benoit Donneaux <[email protected]>

.gitignore

@@ -1,3 +1,4 @@
+/.gocache
 accessor/mock_gitea
 accessor/mock_trac
 mock_markdown

README.md

@@ -187,3 +187,16 @@ Missing dependencies can be fetched using:
 ```lang-none
 make deps
 ```
+
+## Docker
+
+In order to improve the reproducibility, one can leverage Docker:
+
+```
+docker compose build
+docker compose run --rm go-shell
+go version
+...
+make
+...
+```

docker-compose.yml

@@ -0,0 +1,29 @@
+# Docker compose file to provide a reproducable Go environment
+version: '3'
+services:
+  go-shell:
+    build:
+      context: docker/go
+      dockerfile: Dockerfile
+      args:
+        user: appuser
+        group: appgroup
+        uid: "${_UID:-1000}"
+        gid: "${_GID:-1000}"
+    environment:
+      - GOCACHE=/var/lib/appdata/.gocache
+    volumes:
+      - .:/var/lib/appdata
+    working_dir: /var/lib/appdata
+    stdin_open: true
+    tty: true
+    hostname: go-shell.local
+    container_name: go-shell.local
+    network_mode: "bridge"
+    # Prevents container to hang the host
+    # Requires `... --compatibility run ...`
+    deploy:
+      resources:
+        limits:
+          cpus: '1.5'
+          memory: 512M

docker/go/Dockerfile

@@ -0,0 +1,34 @@
+# Start from the official Go image based on Alpine
+FROM golang:1.19.3-alpine
+
+LABEL Description="Trac2Gitea migration tool"
+
+RUN apk --no-cache add gcc git libc-dev make
+
+# Parameters for default user:group
+ARG uid=1000
+ARG user=appuser
+ARG gid=1000
+ARG group=appgroup
+
+# Add user and group for build and runtime
+RUN id ${user} > /dev/null 2>&1 || \
+    { addgroup -g "${gid}" "${group}" && adduser -D -h /home/${user} -s /bin/bash -G "${group}" -u "${uid}" "${user}"; }
+
+# Prepare directories
+RUN DIRS="/src /app" && \
+    mkdir -p ${DIRS} && \
+    chown -R ${user}:${group} $DIRS
+
+# Switch to non-root user
+USER ${user}
+
+# Install mockgen
+#RUN go install go.uber.org/mock/[email protected]
+#RUN ln -s /go /home/${user}/go
+
+# Install pinned dependencies
+#COPY go.mod go.sum /src
+#WORKDIR /src
+#RUN go mod download && \
+#    go mod verify