root: fix missing go client in dockerfile

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

Dockerfile

@@ -11,7 +11,7 @@ RUN pip install pipenv && \
     pipenv lock -r --dev-only > requirements-dev.txt
 
 # Stage 2: Build web API
-FROM openapitools/openapi-generator-cli as api-builder
+FROM openapitools/openapi-generator-cli as web-api-builder
 
 COPY ./schema.yml /local/schema.yml
 
@@ -21,16 +21,31 @@ RUN	docker-entrypoint.sh generate \
     -o /local/web/api \
     --additional-properties=typescriptThreePlus=true,supportsES6=true,npmName=authentik-api,npmVersion=1.0.0
 
-# Stage 3: Build webui
+# Stage 3: Generate API Client
+FROM openapitools/openapi-generator-cli as go-api-builder
+
+COPY ./schema.yml /local/schema.yml
+
+RUN	docker-entrypoint.sh generate \
+    --git-host goauthentik.io \
+    --git-repo-id outpost \
+    --git-user-id api \
+    -i /local/schema.yml \
+    -g go \
+    -o /local/api \
+    --additional-properties=packageName=api,enumClassPrefix=true,useOneOfDiscriminatorLookup=true && \
+    rm -f /local/api/go.mod /local/api/go.sum
+
+# Stage 4: Build webui
 FROM node as npm-builder
 
 COPY ./web /static/
-COPY --from=api-builder /local/web/api /static/api
+COPY --from=web-api-builder /local/web/api /static/api
 
 ENV NODE_ENV=production
 RUN cd /static && npm i && npm run build
 
-# Stage 4: Build go proxy
+# Stage 5: Build go proxy
 FROM golang:1.16.5 AS builder
 
 WORKDIR /work
@@ -40,6 +55,7 @@ COPY --from=npm-builder /static/security.txt /work/web/security.txt
 COPY --from=npm-builder /static/dist/ /work/web/dist/
 COPY --from=npm-builder /static/authentik/ /work/web/authentik/
 
+COPY --from=go-api-builder /local/api api
 COPY ./cmd /work/cmd
 COPY ./web/static.go /work/web/static.go
 COPY ./internal /work/internal
@@ -48,7 +64,7 @@ COPY ./go.sum /work/go.sum
 
 RUN go build -o /work/authentik ./cmd/server/main.go
 
-# Stage 5: Run
+# Stage 6: Run
 FROM python:3.9-slim-buster
 
 WORKDIR /