Add template process to serve bash file

Unfortunately, a static file can't really be used to serve the
connection - the host address is needed to link back to the server.
Only a light library is needed to handle the template file though,
and if more are needed in the future it should be a non-trivial
task to add them to the process.

By default I'm configuring this to work with drone.io, since that
is the CI that I personally will be using (most likely). It should
be non-trivial to configure other CI to handle the script as well.

1 files changed, 30 insertions, 0 deletions

diff --git a/src/templates.ts b/src/templates.ts
new file mode 100644
index 0000000..2ffd0dd
--- /dev/null
+++ b/src/templates.ts
@@ -0,0 +1,30 @@
+import winston from "winston";
+import handlebars from "handlebars";
+import path from "path";
+import fs from "fs";
+
+import loggerConfig from "./util/logger";
+import { configOrError } from "./util/config";
+
+const logger = winston.createLogger(loggerConfig("TEMPLATE"));
+
+const HOST_DIR = configOrError("HOST_DIR");
+const TARGET_URL = process.env.TARGET_URL || "http://localhost:3000";
+
+fs.promises
+  .readFile(path.join(__dirname, "..", "public", "bash.template"), "utf-8")
+  .then(buffer => {
+    const translate = handlebars.compile(buffer);
+
+    return {
+      name: "bash",
+      data: translate({ TARGET_URL })
+    };
+  })
+  .then(file =>
+    fs.promises
+      .writeFile(path.join(HOST_DIR, file.name), file.data)
+      .then(() => file)
+  )
+  .then(file => logger.debug("Generated '%s' from template file", file.name))
+  .catch(err => logger.error("Error while generating template file: %s", err));