From c55e6b986eaea38543851dc407cc0fa4485c9fe1 Mon Sep 17 00:00:00 2001
From: Volker Theile <vtheile@suse.com>
Date: Fri, 2 Feb 2024 10:34:02 +0100
Subject: [PATCH] Add infra + documentation to remote debug harvester-installer

Signed-off-by: Volker Theile <vtheile@suse.com>
---
 Dockerfile.dapper |  2 +-
 README.md         | 32 ++++++++++++++++++++++++++++++--
 scripts/build     |  9 +++++++--
 3 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/Dockerfile.dapper b/Dockerfile.dapper
index 3bd624f42..d318ac636 100644
--- a/Dockerfile.dapper
+++ b/Dockerfile.dapper
@@ -40,7 +40,7 @@ RUN mkdir /usr/tmp && \
     mv /usr/tmp/helm /usr/bin/helm
 
 # You cloud defined your own rke2 url by setup `RKE2_IMAGE_REPO`
-ENV DAPPER_ENV REPO TAG DRONE_TAG DRONE_BRANCH CROSS RKE2_IMAGE_REPO USE_LOCAL_IMAGES BUILD_QCOW DRONE_BUILD_EVENT
+ENV DAPPER_ENV REPO TAG DRONE_TAG DRONE_BRANCH CROSS RKE2_IMAGE_REPO USE_LOCAL_IMAGES BUILD_QCOW DRONE_BUILD_EVENT REMOTE_DEBUG
 ENV DAPPER_SOURCE /go/src/github.com/harvester/harvester-installer/
 ENV DAPPER_OUTPUT ./bin ./dist
 ENV DAPPER_DOCKER_SOCKET true
diff --git a/README.md b/README.md
index 15076b155..f31f698d7 100644
--- a/README.md
+++ b/README.md
@@ -64,7 +64,7 @@ Either way (ISO or PXE), the installer writes the final config out to
 a temporary file which is passed to [harv-install](https://github.com/harvester/harvester-installer/blob/master/package/harvester-os/files/usr/sbin/harv-install)
 which in turn calls `elemental install` to provision the system.
 The harv-install script also preloads all the container images.
-Finally the system is rebooted.
+Finally, the system is rebooted.
 
 On the newly installed system, `harvester-installer` remains active
 on the console in order to show the cluster management URL along with
@@ -72,7 +72,7 @@ the current node's hostname and IP address.
 
 ## Hacking the Interactive Part of `harvester-installer`
 
-Ordinarily `harvester-installer` needs to be run from a booted ISO
+Ordinarily `harvester-installer` needs to be run from a booted ISO,
 so it can actually install a system.  But, if you're only working
 on changes to the interactive part of the installer (e.g. adding
 or changing fields, or altering the workflow) and don't actually
@@ -92,6 +92,34 @@ screen.  To break out of the installer, hit CTRL-C.  If you rebuild
 the binary it can be sync'd back to a running vagrant box with
 `vagrant rsync`.
 
+To remote debug the `harvester-installer` in your IDE, you need to
+install the `delve` package in your Vagrant box first.
+
+```sh
+ $ zypper addrepo https://download.opensuse.org/repositories/devel:languages:go/15.4/devel:languages:go.repo
+ $ zypper refresh
+ $ zypper install delve
+```
+
+Then rebuild the `harvester-installer` app and start it in the
+Vagrant box.
+
+```sh
+ $ REMOTE_DEBUG=true USE_LOCAL_IMAGES=true make build
+ $ vagrant rsync
+ $ vagrant ssh
+ > sudo DEBUG=true TTY=/dev/tty dlv --listen=:2345 --headless=true --api-version=2 --accept-multiclient exec /vagrant/harvester-installer
+```
+
+The `harvester-installer` app will now listen for remote connections
+on port `2345`.
+
+Run `vagrant ssh-config` on your host to get the IP address that is 
+needed to connect the IDE debugger to the `harvester-installer` app.
+If you are using the Goland IDE, check out their [documentation](https://www.jetbrains.com/help/go/go-remote.html)
+how to attach to the `harvester-installer` process on the remote
+Vagrant box.
+
 ## License
 Copyright (c) 2024 [Rancher Labs, Inc.](http://rancher.com)
 
diff --git a/scripts/build b/scripts/build
index 83cbf0cf3..5633c7914 100755
--- a/scripts/build
+++ b/scripts/build
@@ -40,10 +40,15 @@ LINKFLAGS="-X github.com/harvester/harvester-installer/pkg/config.RKE2Version=$R
            $LINKFLAGS"
 
 if [ "$(uname)" = "Linux" ]; then
-    OTHER_LINKFLAGS="-extldflags -static -s"
+    if [ -n "${REMOTE_DEBUG}" ]; then
+        OTHER_COMPILERFLAGS="all=-N -l"
+        OTHER_LINKFLAGS="-extldflags -static"
+    else
+        OTHER_LINKFLAGS="-extldflags -static -s"
+    fi
 fi
 
-CGO_ENABLED=0 go build -ldflags "$LINKFLAGS $OTHER_LINKFLAGS" -o bin/harvester-installer .
+CGO_ENABLED=0 go build -gcflags "${OTHER_COMPILERFLAGS}" -ldflags "$LINKFLAGS $OTHER_LINKFLAGS" -o bin/harvester-installer .
 
 # Copy to harvester package folder
 mkdir -p ${PACKAGE_HARVESTER_OS_DIR}/files/usr/bin