From bf87b3fb010813e97784e898abbaab818b05fc1c Mon Sep 17 00:00:00 2001
From: Fabian Schindler <fabian.schindler.strauss@gmail.com>
Date: Wed, 6 Sep 2023 10:40:08 +0200
Subject: [PATCH] Runtime config in Docker (#349)

Co-authored-by: Matthias Mohr <m.mohr@uni-muenster.de>
---
 Dockerfile                  | 18 +++++---
 docker/docker-entrypoint.sh | 91 +++++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+), 6 deletions(-)
 create mode 100755 docker/docker-entrypoint.sh

diff --git a/Dockerfile b/Dockerfile
index 4694d6f8e..ce6973ac0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,21 +1,27 @@
 FROM node:lts-alpine3.18 AS build-step
-
-ARG catalogURL
+ARG DYNAMIC_CONFIG=true
 
 WORKDIR /app
 COPY package*.json ./
 RUN npm install
 COPY . .
-RUN npm run build -- --catalogUrl=$catalogURL
+RUN \[ "${DYNAMIC_CONFIG}" == "true" \] && sed -i 's/<!-- <script defer="defer" src=".\/config.js"><\/script> -->/<script defer="defer" src=".\/config.js"><\/script>/g' public/index.html
+RUN npm run build
+
+
+FROM nginx:1-alpine-slim
 
-FROM nginx:1-alpine
 COPY --from=build-step /app/dist /usr/share/nginx/html
+COPY ./config.schema.json /etc/nginx/conf.d/config.schema.json
 
 # change default port to 8080
-RUN sed -i 's/\s*listen\s*80;/    listen 8080;/' /etc/nginx/conf.d/default.conf
+RUN apk add jq pcre-tools && \
+    sed -i 's/\s*listen\s*80;/    listen 8080;/' /etc/nginx/conf.d/default.conf && \
+    sed -i 's/\s*location \/ {/    location \/ {\n        try_files $uri $uri\/ \/index.html;/' /etc/nginx/conf.d/default.conf
 
 EXPOSE 8080
 
 STOPSIGNAL SIGTERM
 
-CMD ["nginx", "-g", "daemon off;"]
\ No newline at end of file
+# override entrypoint, which calls nginx-entrypoint underneath
+ADD docker/docker-entrypoint.sh /docker-entrypoint.d/40-stac-browser-entrypoint.sh
diff --git a/docker/docker-entrypoint.sh b/docker/docker-entrypoint.sh
new file mode 100755
index 000000000..d38acc133
--- /dev/null
+++ b/docker/docker-entrypoint.sh
@@ -0,0 +1,91 @@
+# echo a string, handling different types
+safe_echo() {
+    local value="$1"
+    if [ -z "$value" ]; then
+        echo -n "null"
+    elif printf '%s\n' "$value" | grep -qE '\n.+\n$'; then
+        echo -n "\`$value\`"
+    else
+        echo -n "'$value'"
+    fi
+}
+
+#  handle boolean
+bool() {
+    case "$1" in
+        true | TRUE | yes | t | True)
+            echo -n true ;;
+        false | FALSE | no | n | False)
+            echo -n false ;;
+        *)
+            echo "Err: Unknown boolean value \"$1\"" >&2
+            exit 1 ;;
+    esac
+}
+
+# handle array values
+array() {
+    local value="$1"
+    local arraytype="$2"
+    if [ -z "$value" ]; then
+        echo -n "[]"
+    else
+        case "$arraytype" in
+            string)
+                echo -n "['$(echo "$value" | sed "s/,/', '/g")']"
+                ;;
+            *)
+                echo -n "[$value]"
+                ;;
+        esac
+    fi
+}
+
+# handle object values
+object() {
+    local value="$1"
+    if [ -z "$value" ]; then
+        echo -n "null"
+    else
+        echo -n "$value"
+    fi
+}
+
+config_schema=$(cat /etc/nginx/conf.d/config.schema.json)
+
+# Iterate over environment variables with "SB_" prefix
+env -0 | cut -f1 -d= | tr '\0' '\n' | grep "^SB_" | {
+    echo "window.STAC_BROWSER_CONFIG = {"
+    while IFS='=' read -r name; do
+        # Strip the prefix
+        argname="${name#SB_}"
+        # Read the variable's value
+        value="$(eval "echo \"\$$name\"")"
+
+        # Get the argument type from the schema
+        argtype="$(echo "$config_schema" | jq -r ".properties.$argname.type[0]")"
+        arraytype="$(echo "$config_schema" | jq -r ".properties.$argname.items.type[0]")"
+
+        # Encode key/value
+        echo -n "  $argname: "
+        case "$argtype" in
+            string)
+                safe_echo "$value"
+                ;;
+            boolean)
+                bool "$value"
+                ;;
+            integer | number)
+                object "$value"
+                ;;
+            array)
+                array "$value" "$arraytype"
+                ;;
+            *)
+                safe_echo "$value"
+                ;;
+        esac
+        echo ","
+    done
+    echo "}"
+} > /usr/share/nginx/html/config.js