Fix large GitHub release JSON handling

README.md

@@ -57,3 +57,11 @@ At 09:00 server-local time:
 ```
 
 Run the monitor under a dedicated user where possible. Keep `.env` private and do not commit it. Use `./monitor.sh --test-telegram` to verify Telegram and proxy connectivity.
+
+### Large release histories
+
+GitHub response pages are processed through temporary files, rather than passed
+through command-line arguments. The state file is read directly by `jq`.
+This prevents `Argument list too long` for repositories with large release notes.
+
+Run `bash -n monitor.sh` and `./monitor.sh --dry-run --verbose` to verify.

monitor.sh

@@ -93,29 +93,48 @@ test_telegram() {
     if send_telegram "$message"; then log INFO 'Test notification sent'; else log ERROR 'Test notification failed'; return 1; fi
 }
 fetch_releases() {
-    local repo="$1" page response count result='[]'
+    local repo="$1" page count response_file releases_file
+    response_file="$(mktemp)" || return 1
+    releases_file="$(mktemp)" || { rm -f "$response_file"; return 1; }
+
     for ((page=1; page<=GITHUB_MAX_PAGES; page++)); do
         debug "Fetching $repo page=$page"
-        response="$(curl "${CURL_OPTIONS[@]}" "${GITHUB_HEADERS[@]}" \
-            "${GITHUB_API}/repos/${repo}/releases?per_page=${GITHUB_PER_PAGE}&page=${page}")" || return 1
-        jq -e 'type == "array"' <<< "$response" >/dev/null || return 1
-        count="$(jq 'length' <<< "$response")"
-        result="$(jq -cn --argjson old "$result" --argjson new "$response" '$old + $new')" || return 1
+        if ! curl "${CURL_OPTIONS[@]}" "${GITHUB_HEADERS[@]}" \
+            --output "$response_file" \
+            "${GITHUB_API}/repos/${repo}/releases?per_page=${GITHUB_PER_PAGE}&page=${page}"; then
+            rm -f "$response_file" "$releases_file"
+            return 1
+        fi
+        if ! count="$(jq -er 'if type == "array" then length else error("Invalid releases response") end' "$response_file")"; then
+            rm -f "$response_file" "$releases_file"
+            return 1
+        fi
+        if ! jq -c --argjson prereleases "$INCLUDE_PRERELEASES" '
+            .[] | select(.draft == false) |
+            select($prereleases or (.prerelease == false)) |
+            {id: (.id | tostring), tag: .tag_name, name: .name,
+             url: .html_url, published: .published_at, prerelease: .prerelease}
+        ' "$response_file" >> "$releases_file"; then
+            rm -f "$response_file" "$releases_file"
+            return 1
+        fi
         if (( count < GITHUB_PER_PAGE )); then break; fi
     done
-    jq -c --argjson prereleases "$INCLUDE_PRERELEASES" '
-        [.[] | select(.draft == false) | select($prereleases or (.prerelease == false)) |
-        {id: (.id | tostring), tag: .tag_name, name: .name, url: .html_url,
-         published: .published_at, prerelease: .prerelease}]
-    ' <<< "$result"
+
+    local status=0
+    jq -sc '.' "$releases_file" || status=$?
+    rm -f "$response_file" "$releases_file"
+    return "$status"
 }
+
 write_state() {
     local repo="$1" ids="$2" mode="$3" temp
     temp="$(mktemp "${STATE_FILE}.tmp.XXXXXX")" || return 1
-    if ! jq --arg repo "$repo" --argjson ids "$ids" --arg mode "$mode" '
-        if $mode == "replace" then .[$repo] = $ids
-        else .[$repo] = ((.[$repo] // []) + $ids | unique) end
-    ' "$STATE_FILE" > "$temp"; then rm -f "$temp"; return 1; fi
+    if ! jq --arg repo "$repo" --arg mode "$mode" --slurpfile ids /dev/stdin '
+        ($ids[0] // []) as $new_ids |
+        if $mode == "replace" then .[$repo] = $new_ids
+        else .[$repo] = ((.[$repo] // []) + $new_ids | unique) end
+    ' "$STATE_FILE" <<< "$ids" > "$temp"; then rm -f "$temp"; return 1; fi
     if ! mv -f "$temp" "$STATE_FILE"; then rm -f "$temp"; return 1; fi
 }
 format_message() {
@@ -151,7 +170,13 @@ process_repo() {
         log INFO "Baseline initialized: $repo ($count releases)"
         return 0
     fi
-    new_releases="$(jq -c --argjson seen "$previous" '[.[] | select(.id as $id | $seen | index($id) | not)] | reverse' <<< "$releases")" || return 1
+    # Read the existing state from a file, not from argv (ARG_MAX).
+    local state_source="$STATE_FILE"
+    [[ -f "$state_source" ]] || state_source=/dev/null
+    new_releases="$(jq -c --slurpfile state "$state_source" --arg repo "$repo" '
+        ($state[0][$repo] // []) as $seen |
+        [.[] | select(.id as $id | $seen | index($id) | not)] | reverse
+    ' <<< "$releases")" || return 1
     count="$(jq 'length' <<< "$new_releases")"
     if (( count == 0 )); then log INFO "No new releases: $repo"; return 0; fi
     log INFO "Found $count new releases: $repo"