standardize upstream version-check comments across roles

Reword and reposition the lookup comment above each upstream _version
var to a single greppable "# version-check: <url>" marker, matching the
convention adopted in ansible-roles: always directly above the version
line, one grep finds every instance.

Covers bitcoind, bitcoind-prometheus-exporter, lnd (lnd_version and
lndconnect_version, the latter had no lookup comment before), and
lnurld/build, which points at the upstream commits page since
lnurld_version pins a commit hash rather than a release tag.

Document the convention in the README.

5 files changed, 22 insertions, 4 deletions

diff --git a/README.md b/README.md
index 17befca..007b0e0 100644
--- a/README.md
+++ b/README.md
@@ -3,3 +3,20 @@
 https://src.nth.io/bitcoin-ansible-roles/file
 
 bitcoind node without a wallet with an lnd node with wallet.
+
+## Dependency Version Checks
+
+Roles that pin an upstream dependency's version carry a comment directly above the `_version`
+variable in `defaults/main.yaml`, pointing at the page where the current upstream version can be
+confirmed:
+
+```yaml
+# version-check: https://github.com/lightningnetwork/lnd/releases
+lnd_version: "0.20.2-beta"
+```
+
+Find every instance across the repo with:
+
+```sh
+grep -rn "# version-check:" --include="*.yaml" .
+```
diff --git a/bitcoind-prometheus-exporter/defaults/main.yaml b/bitcoind-prometheus-exporter/defaults/main.yaml
index e8a6607..9a2e3aa 100644
--- a/bitcoind-prometheus-exporter/defaults/main.yaml
+++ b/bitcoind-prometheus-exporter/defaults/main.yaml
@@ -1,7 +1,7 @@
 ---
 
 bitcoind_prometheus_exporter_conf: "/home/bitcoin/.bitcoin/bitcoin.conf"
+# version-check: https://github.com/jvstein/bitcoin-prometheus-exporter/releases
 bitcoind_prometheus_exporter_version: "0.9.0"
-# https://github.com/jvstein/bitcoin-prometheus-exporter/releases
 bitcoind_prometheus_exporter_url: "https://github.com/jvstein/bitcoin-prometheus-exporter/archive/v{{bitcoind_prometheus_exporter_version}}.tar.gz"
 bitcoind_prometheus_exporter_tar_name: "bitcoin-prometheus-exporter-{{bitcoind_prometheus_exporter_version}}"
diff --git a/bitcoind/defaults/main.yaml b/bitcoind/defaults/main.yaml
index 82202c8..e2ac8bf 100644
--- a/bitcoind/defaults/main.yaml
+++ b/bitcoind/defaults/main.yaml
@@ -1,7 +1,7 @@
 ---
 
 bitcoind_user: "bitcoin"
-# https://bitcoincore.org/bin
+# version-check: https://bitcoincore.org/bin
 bitcoind_version: "31.1"
 bitcoind_arch: "{{ansible_facts['architecture']}}"
 bitcoind_url: "https://bitcoincore.org/bin/bitcoin-core-{{bitcoind_version}}/bitcoin-{{bitcoind_version}}-{{bitcoind_arch}}-linux-gnu.tar.gz"
diff --git a/lnd/defaults/main.yaml b/lnd/defaults/main.yaml
index bbdb43e..d095f0e 100644
--- a/lnd/defaults/main.yaml
+++ b/lnd/defaults/main.yaml
@@ -1,7 +1,7 @@
 ---
 
 lnd_user: "{{node_user}}"
-# https://github.com/lightningnetwork/lnd/releases
+# version-check: https://github.com/lightningnetwork/lnd/releases
 lnd_version: "0.20.2-beta"
 lnd_arch: "arm64"
 lnd_tar_name: "lnd-linux-{{lnd_arch}}-v{{lnd_version}}"
@@ -16,6 +16,7 @@ lnd_sha256:
   amd64: "bcec401ae34ad15fbd1970e9836ba8334a1a466bcfbf587dff6aae2a0c220206"
 
 lndconnect_user: "{{node_user}}"
+# version-check: https://github.com/LN-Zap/lndconnect/releases
 lndconnect_version: "0.2.0"
 lndconnect_tar_name: "lndconnect-linux-{{lnd_arch}}-v{{lndconnect_version}}"
 lndconnect_tar: "{{lndconnect_tar_name}}.tar.gz"
diff --git a/lnurld/build/defaults/main.yaml b/lnurld/build/defaults/main.yaml
index c638550..fa0a2a6 100644
--- a/lnurld/build/defaults/main.yaml
+++ b/lnurld/build/defaults/main.yaml
@@ -1,7 +1,7 @@
 ---
 
+# version-check: https://github.com/yanascz/lnurld/commits
 lnurld_version: "0bf1955"
-# https://github.com/yanascz/lnurld/commits
 lnurld_git: "https://github.com/yanascz/lnurld.git"
 lnurld_build_dir: "{{build_work_dir}}/lnurld"
 lnurld_srv_dir: "{{build_srv_dir}}"