Configure from env vars at run time

In both local developent, and production.  Also, vendor the `envsubst`
binary from https://github.com/a8m/envsubst, as it supports default
values, which the gnu envsubst (from gettext-base) does not.

services/git-bridge/.dockerignore

@@ -6,3 +6,4 @@
 !/pom.xml
 !/Makefile
 !/LICENSE
+!/vendor

services/git-bridge/.gitignore

@@ -48,3 +48,6 @@ com_crashlytics_export_strings.xml
 crashlytics.properties
 crashlytics-build.properties
 fabric.properties
+
+# Local configuration files
+conf/runtime.json

services/git-bridge/Dockerfile

@@ -2,16 +2,20 @@
 
 FROM maven:3-jdk-8 as base
 
-RUN apt-get update && apt-get install -y make \
+RUN apt-get update && apt-get install -y make git \
  && rm -rf /var/lib/apt/lists
 
+COPY vendor/envsubst /opt/envsubst
+RUN chmod +x /opt/envsubst
+
 RUN useradd --create-home node
 
 FROM base as builder
 
+COPY . /app
+
 WORKDIR /app
 
-COPY . /app
 RUN make package \
 # The name of the created jar contains the current version tag.
 # Rename it to a static path that can be used for copying.
@@ -21,15 +25,16 @@ RUN make package \
 
 FROM openjdk:8-jre
 
-RUN apt-get update && apt-get install -y git gettext-base\
+RUN apt-get update && apt-get install -y git \
  && rm -rf /var/lib/apt/lists
 
 RUN useradd --create-home node
 
-CMD ["/start.sh"]
-
 COPY --from=builder /git-bridge.jar /
 
+COPY vendor/envsubst /opt/envsubst
+RUN chmod +x /opt/envsubst
+
 COPY conf/envsubst_template.json envsubst_template.json
 COPY start.sh start.sh
 
@@ -37,3 +42,5 @@ RUN mkdir conf
 RUN chown node:node conf
 
 USER node
+
+ENTRYPOINT ["/start.sh"]

services/git-bridge/Makefile

@@ -2,8 +2,14 @@
 
 MVN_OPTS := "--no-transfer-progress"
 
-run: package
-	java -jar target/writelatex-git-bridge-1.0-SNAPSHOT-jar-with-dependencies.jar conf/local.json
+runtime-conf:
+	/opt/envsubst < conf/envsubst_template.json > conf/runtime.json
+
+
+run: package runtime-conf
+	java -jar \
+	target/writelatex-git-bridge-1.0-SNAPSHOT-jar-with-dependencies.jar \
+	conf/runtime.json
 
 
 build:
@@ -22,4 +28,4 @@ package: clean
 	mvn $(MVN_OPTS) package -DskipTests
 
 
-.PHONY: run package build clean test
+.PHONY: run package build clean test runtime-conf

services/git-bridge/conf/envsubst_template.json

@@ -1,32 +1,32 @@
 {
-    "port": 8080,
-    "rootGitDirectory": "/tmp/wlgb",
-    "apiBaseUrl": "https://localhost/api/v0",
-    "username": "$GITBRIDGE_USERNAME",
-    "password": "$GITBRIDGE_PASSWORD",
-    "postbackBaseUrl": "https://localhost",
-    "serviceName": "Overleaf",
+  "port": ${GIT_BRIDGE_PORT:-8000},
+    "rootGitDirectory": "${GIT_BRIDGE_ROOT_DIR:-/tmp/wlgb}",
+    "apiBaseUrl": "${GIT_BRIDGE_API_BASE_URL:-https://localhost/api/v0}",
+    "username": "${GIT_BRIDGE_USERNAME}",
+    "password": "${GIT_BRIDGE_PASSWORD}",
+    "postbackBaseUrl": "${GIT_BRIDGE_POSTBACK_BASE_URL:-https://localhost}",
+    "serviceName": "${GIT_BRIDGE_SERVICE_NAME:-Overleaf}",
     "oauth2": {
-        "oauth2ClientID": "$GITBRIDGE_OAUTH2_CLIENT_ID",
-        "oauth2ClientSecret": "$GITBRIDGE_OAUTH2_CLIENT_SECRET",
-        "oauth2Server": "https://localhost"
+      "oauth2ClientID": "${GITBRIDGE_OAUTH2_CLIENT_ID}",
+      "oauth2ClientSecret": "${GITBRIDGE_OAUTH2_CLIENT_SECRET}",
+      "oauth2Server": "${GIT_BRIDGE_OAUTH2_SERVER:-https://localhost}"
     },
     "repoStore": {
-        "maxFileNum": 2000,
-        "maxFileSize": 52428800
+      "maxFileNum": ${GIT_BRIDGE_REPOSTORE_MAX_FILE_NUM:-2000},
+      "maxFileSize": ${GIT_BRIDGE_REPOSTORE_MAX_FILE_SIZE:-52428800}
     },
     "swapStore": {
-        "type": "s3",
-        "awsAccessKey": "asdf",
-        "awsSecret": "asdf",
-        "s3BucketName": "com.overleaf.testbucket",
-        "awsRegion": "us-east-1"
+      "type": "${GIT_BRIDGE_SWAPSTORE_TYPE:-noop}",
+      "awsAccessKey": "${GIT_BRIDGE_SWAPSTORE_AWS_ACCESS_KEY}",
+      "awsSecret": "${GIT_BRIDGE_SWAPSTORE_AWS_ACCESS_KEY}",
+      "s3BucketName": "${GIT_BRIDGE_SWAPSTORE_S3_BUCKET_NAME}",
+      "awsRegion": "${GIT_BRIDGE_SWAPSTORE_AWS_REGION:-us-east-1}"
     },
     "swapJob": {
-        "minProjects": 50,
-        "lowGiB": 128,
-        "highGiB": 256,
-        "intervalMillis": 3600000,
-        "compressionMethod": "gzip"
+      "minProjects": ${GIT_BRIDGE_SWAPJOB_MIN_PROJECTS:-50},
+      "lowGiB": ${GIT_BRIDGE_SWAPJOB_LOW_GIB:-128},
+      "highGiB": ${GIT_BRIDGE_SWAPJOB_HIGH_GIB:-256},
+      "intervalMillis": ${GIT_BRIDGE_SWAPJOB_INTERVAL_MILLIS:-3600000},
+      "compressionMethod": "${GIT_BRIDGE_SWAPJOB_COMPRESSION_METHOD:-gzip}"
     }
 }

services/git-bridge/start.sh

@@ -1,3 +1,3 @@
 #!/bin/bash
-envsubst < /envsubst_template.json > /conf/runtime.json
-java -jar /git-bridge.jar /conf/runtime.json
+/opt/envsubst < /envsubst_template.json > /conf/runtime.json
+exec java -jar /git-bridge.jar /conf/runtime.json