fix: make challenge toggle actually work end-to-end (5 root-cause bugs)

Found by testing a real enable/disable cycle (art, fjb, gift-card):

1. compose_gen always swapped build->image, so a never-built challenge
   produced 'pull access denied for services-<name>'. Now it only reuses
   the image when it exists locally, otherwise keeps build: so
   'docker compose up --build' builds it.
2. Canonical templates use 'build: context: .' (written for the shared
   services/ tree). In the per-team compose that resolves to the team dir
   which has no Dockerfile -> 'failed to read dockerfile'. The renderer
   now rewrites the main service's context to ./<name>.
3. Teams created before the XVI/XVII import had no xvi/xvii subpackages
   under their local challenges/ dir, so the regenerated receiver main.py
   crash-looped on import. gen_receiver_main now mirrors ALL shared
   checkers (native + xvi + xvii) into every team receiver on each sync.
4. systemd Environment= keys can't contain hyphens, so
   CHALLENGE_PORT_GIFT-CARD was silently dropped. Keys are now
   normalized to underscores on both the writer and reader side.
5. Several checkers called 'docker exec' with no timeout; against a
   container with accumulated chall.py zombies that blocks forever and
   stalls the whole SLA loop. Added mandatory timeouts (Phew, Sheesh,
   Carbeat, Poke, Warmup).

Also: enabling a challenge now copies its source tree into each team's
services/ dir (team dirs only held challenges enabled at create_team
time), and the XVII checkers were rewritten to be protocol-aware
(gift-card/gift-voucher are socat TCP, not HTTP) with strict timeouts.

panel/compose_gen.py

@@ -18,6 +18,7 @@ anti-alchemy, tempest-poc) keep their sidecar services.
 """
 import json
 import re
+import subprocess
 from pathlib import Path
 
 BASE = Path("/opt/gemastik18-final")
@@ -47,6 +48,18 @@ def read_template(name: str) -> str:
         raise FileNotFoundError(f"Tidak ada template compose untuk {name} di {p}")
     return p.read_text()
 
+def _image_exists(image_name: str) -> bool:
+    """True if the docker image is already present locally.
+
+    The renderer only swaps a service's `build:` block for `image: services-<name>`
+    when that image actually exists. Otherwise compose would try to PULL a local
+    build artifact and fail with "pull access denied for services-<name>".
+    """
+    r = subprocess.run(["docker", "image", "inspect", image_name],
+                       capture_output=True, text=True, timeout=30)
+    return r.returncode == 0
+
+
 def _parse_services(text: str):
     names = []
     for line in text.splitlines():
@@ -93,10 +106,12 @@ def render_team_compose(idx: int, state: dict) -> str:
         text = re.sub(rf'"({org}):', f'"{tc}:', text)
         text = re.sub(rf'"({org + 22}):', f'"{ts}:', text)
 
-        # --- build: -> image for MAIN only ---
-        # Replace the main service's build block with image: services-<name>.
-        # NB we process by service names, not generic removal, so sidecar
-        # builds survive.
+        # --- build: -> image for MAIN only (only when the image exists) ---
+        # Replace the main service's build block with image: services-<name> so
+        # teams share one image. If that image was never built, KEEP the build
+        # block so `docker compose up --build` builds it instead of trying to
+        # pull a nonexistent local image.
+        use_image = _image_exists(f"services-{name}")
         lines = text.splitlines()
         i = 0
         in_main = False
@@ -112,7 +127,7 @@ def render_team_compose(idx: int, state: dict) -> str:
                 i += 1
                 continue
             # inside a service block
-            if in_main and line.strip() == "build:":
+            if in_main and use_image and line.strip() == "build:":
                 # skip build block (context/args/dockerfile...) until next key at same indent
                 out.append(f"    image: services-{name}")
                 i += 1
@@ -127,6 +142,15 @@ def render_team_compose(idx: int, state: dict) -> str:
         text = re.sub(r"\$PASSWORD_" + str(org) + r"\b", passwords[name], text)
         text = re.sub(r"PASSWORD_" + str(org) + r"\b", passwords[name], text)
 
+        # --- build context -> per-team challenge subdir ---
+        # Canonical templates are written for the SHARED services/ tree where a
+        # challenge's files sit in services/<name>/. The per-team compose lives in
+        # teamN/services/, so a bare `context: .` would resolve to the team dir
+        # (no Dockerfile). Point the MAIN service's build at ./<name>.
+        if re.search(r"^    build:$", text, re.M):
+            text = re.sub(r"^    build:\n      context: \.$",
+                          f"    build:\n      context: ./{name}", text, count=1, flags=re.M)
+
         # --- flag volume normalization ---
         # Replace any ./flag.txt / ../receiver/flags/<name>.txt with the per-team flag mount
         text = re.sub(r"\./flag\.txt(:\w+)?", f"../receiver/flags/{name}.txt", text)

panel/gen_receiver_main.py

@@ -11,6 +11,7 @@ from three packages:
 from __future__ import annotations
 
 import json
+import shutil
 from pathlib import Path
 
 from teams import TEAMS_DIR, load_registry
@@ -98,26 +99,33 @@ app = FastAPI()
 security = HTTPBasic()
 settings = get_settings()
 
+def _envkey(name: str) -> str:
+    # systemd Environment= keys can't contain hyphens; gen_receiver_services
+    # writes CHALLENGE_PORT_GIFT_CARD for the challenge "gift-card".
+    return name.upper().replace("-", "_")
+
 def _ch_port(name: str, default: int) -> int:
     # read from .env manually (pydantic settings has fixed fields)
-    val = os.environ.get(f"CHALLENGE_PORT_{{name.upper()}}")
+    key = _envkey(name)
+    val = os.environ.get(f"CHALLENGE_PORT_{{key}}")
     if not val:
         try:
             with open(os.path.join(os.path.dirname(__file__), ".env")) as f:
                 for line in f:
-                    if line.startswith(f"CHALLENGE_PORT_{{name.upper()}}="):
+                    if line.startswith(f"CHALLENGE_PORT_{{key}}="):
                         val = line.strip().split("=", 1)[1]
         except Exception:
             pass
     return int(val) if val else default
 
 def _ch_container(name: str, default: str) -> str:
-    val = os.environ.get(f"CHALLENGE_CONTAINER_{{name.upper()}}")
+    key = _envkey(name)
+    val = os.environ.get(f"CHALLENGE_CONTAINER_{{key}}")
     if not val:
         try:
             with open(os.path.join(os.path.dirname(__file__), ".env")) as f:
                 for line in f:
-                    if line.startswith(f"CHALLENGE_CONTAINER_{{name.upper()}}="):
+                    if line.startswith(f"CHALLENGE_CONTAINER_{{key}}="):
                         val = line.strip().split("=", 1)[1]
         except Exception:
             pass
@@ -253,6 +261,32 @@ def validate(credentials, challenge):
 """
 
 
+def _sync_checker_packages(recv_dir) -> None:
+    """Mirror the shared receiver's challenge checkers into a team receiver.
+
+    Two reasons this must run on every sync, not just at create_team time:
+      1. Teams created before the XVI/XVII import have no xvi/xvii subpackages,
+         so a regenerated main.py that imports them would crash-loop the receiver.
+      2. Native checkers (Blogpost/Phew/...) get bug fixes (e.g. mandatory
+         subprocess timeouts); a team copy made earlier keeps the stale version.
+    """
+    shared_challenges = Path("/opt/gemastik18-final/receiver/challenges")
+    dst_root = recv_dir / "challenges"
+    dst_root.mkdir(parents=True, exist_ok=True)
+    for src_file in sorted(shared_challenges.glob("*.py")):
+        if src_file.name == "__init__.py":
+            continue
+        shutil.copy2(src_file, dst_root / src_file.name)
+    for pkg in ("xvi", "xvii"):
+        src = shared_challenges / pkg
+        if not src.exists():
+            continue
+        dst = dst_root / pkg
+        if dst.exists():
+            shutil.rmtree(dst)
+        shutil.copytree(src, dst, ignore=shutil.ignore_patterns("__pycache__", "*.pyc"))
+
+
 def sync_team_receivers() -> None:
     """Regenerate main.py for every existing team from its state + registry."""
     for d in sorted(TEAMS_DIR.glob("team*")):
@@ -262,6 +296,7 @@ def sync_team_receivers() -> None:
         st = json.loads(sf.read_text())
         idx = st["index"]
         enabled = [c for c in load_registry()["challenges"] if c.get("enabled")]
+        _sync_checker_packages(d / "receiver")
         text = render_receiver_main(enabled, {c["name"]: st["ports"][c["name"]]["chall"] for c in enabled})
         (d / "receiver" / "main.py").write_text(text)
         print(f"team{idx}: receiver main.py regenerated ({len(enabled)} challenges)")

panel/gen_receiver_services.py

@@ -19,12 +19,16 @@ def write_unit(idx: int, st: dict):
     port = st["ports"]["receiver"]
     recv_dir = TEAMS_DIR / f"team{idx}" / "receiver"
     env = {}
-    # ports/containers for challenge classes
+    # ports/containers for challenge classes.
+    # NOTE: systemd Environment= keys must be [A-Za-z0-9_]+ — a hyphen in the
+    # challenge name (gift-card) would make systemd silently drop the line, so
+    # normalize the name to underscores here. main.py looks up the same key.
     for ch in st["ports"]:
         if ch in ("receiver", "panel"):
             continue
-        env[f"CHALLENGE_PORT_{ch.upper()}"] = str(st["ports"][ch]["chall"])
-        env[f"CHALLENGE_CONTAINER_{ch.upper()}"] = f"{ch}_container_team{idx}"
+        key = ch.upper().replace("-", "_")
+        env[f"CHALLENGE_PORT_{key}"] = str(st["ports"][ch]["chall"])
+        env[f"CHALLENGE_CONTAINER_{key}"] = f"{ch}_container_team{idx}"
         # SSH passwords: checker Challenge.credentials() reads PASSWORD_<self.port>
         # where self.port is the team challenge port.
         pwd = st.get("chall_passwords", {}).get(ch)

panel/teams.py

@@ -116,6 +116,20 @@ def sync_challenge_runtime(name: str, enabled: bool) -> dict:
                     name) or f"chall{idx}_{name}_{secrets.token_hex(4)}"
                 # write state BEFORE rendering (render needs ports[name])
                 (sf).write_text(json.dumps(st, indent=2))
+                # Copy the challenge source into the team's services tree so a
+                # `build: context: .` resolves (team dirs only hold challenges
+                # that were enabled at create_team time).
+                team_svc_src = svc_dir / name
+                if not team_svc_src.exists():
+                    src = SERVICES_SRC / name
+                    if not src.exists():
+                        raise FileNotFoundError(f"sumber service tidak ada: {src}")
+                    shutil.copytree(src, team_svc_src,
+                                    ignore=shutil.ignore_patterns("__pycache__", "*.pyc", ".git"))
+                # apt-insecure.conf is needed by every challenge build
+                shared_apt = SERVICES_SRC / "apt-insecure.conf"
+                if shared_apt.exists() and not (team_svc_src / "apt-insecure.conf").exists():
+                    shutil.copy2(shared_apt, team_svc_src / "apt-insecure.conf")
                 # regenerate whole compose (so enabled challenge included),
                 # then bring up just this service
                 new_text = compose_gen.render_team_compose(idx, st)

receiver/challenges/Carbeat.py

@@ -26,8 +26,9 @@ class Carbeat(Challenge):
 
 
     def _read_container_flag(self) -> str:
+        # timeout is mandatory: docker exec can block forever on a saturated container
         out = subprocess.run(["docker", "exec", self._CONTAINER, "cat", "/flag.txt"],
-                             capture_output=True, text=True)
+                             capture_output=True, text=True, timeout=30)
         if out.returncode != 0 or not out.stdout.strip():
             raise FileNotFoundError("Flag not found in container (/flag.txt)")
         return out.stdout.strip()

receiver/challenges/Phew.py

@@ -14,8 +14,14 @@ class Phew(Challenge):
     _HEX_RE      = re.compile(r'^[0-9a-fA-F]+$')
 
     def _read_container_flag(self) -> str:
-        out = subprocess.run(["docker", "exec", self._CONTAINER, "cat", "/flag.txt"],
-                             capture_output=True, text=True)
+        # NB: a timeout is mandatory here. `docker exec` against a container
+        # whose process table is saturated (accumulated chall.py zombies) can
+        # block forever and take the whole SLA check loop down with it.
+        try:
+            out = subprocess.run(["docker", "exec", self._CONTAINER, "cat", "/flag.txt"],
+                                 capture_output=True, text=True, timeout=30)
+        except subprocess.TimeoutExpired:
+            raise TimeoutError("docker exec cat /flag.txt timed out (container overloaded?)")
         if out.returncode != 0 or not out.stdout.strip():
             raise FileNotFoundError("Flag not found in container (/flag.txt)")
         return out.stdout.strip()

receiver/challenges/Poke.py

@@ -52,7 +52,8 @@ class Poke(Challenge):
             container_flag = subprocess.run(
                 ["docker", "exec", "poke_container", "cat", "/flag.txt"],
                 capture_output=True,
-                text=True
+                text=True,
+                timeout=30
             ).stdout.strip()
             
             assert host_flag == container_flag, 'Flag mismatch between host and container'

receiver/challenges/Sheesh.py

@@ -15,9 +15,10 @@ class Sheesh(Challenge):
     _HEX_RE      = re.compile(r'^[0-9a-fA-F]+$')
 
     def _read_container_flag(self) -> str:
+        # timeout is mandatory: docker exec can block forever on a saturated container
         out = subprocess.run(
             ["docker", "exec", self._CONTAINER, "cat", "/flag.txt"],
-            capture_output=True, text=True
+            capture_output=True, text=True, timeout=30
         )
         if out.returncode != 0 or not out.stdout.strip():
             raise FileNotFoundError("Flag not found in container (/flag.txt)")

receiver/challenges/Warmup.py

@@ -32,7 +32,7 @@ class Warmup(Challenge):
                 host_flag = f.read().strip()
             container_flag = subprocess.run([
                 "docker", "exec", os.environ.get("CHALLENGE_CONTAINER_WARMUP", "warmup_container"), "cat", "/flag.txt"
-            ], capture_output=True, text=True).stdout.strip()
+            ], capture_output=True, text=True, timeout=30).stdout.strip()
             assert host_flag == container_flag, 'Flag mismatch between host and container'
 
             self.logger.info('Check passed for warmup')

receiver/challenges/xvii/checkers.py

@@ -1,10 +1,17 @@
 """SLA checkers for GEMASTIK XVII challenges (imported from
 github.com/vidner/gemastik-xvii-final — no upstream receiver was provided).
 
-Each checker validates liveness + flag presence in the container.  Protocols:
-  - TCP/netcat   : asmr, bit-canvas, go-green (xinetd banner) & ticketer (socat)
-  - HTTP GET     : anti-alchemy, fjb, gift-card, gift-voucher, gleam-drive,
-                   kode-viewer, more-less, tempest-poc
+Each checker validates liveness (+ flag presence where the flag is a file) with
+STRICT timeouts so a wedged service can never hang the receiver's check loop.
+
+Protocol classes:
+  - WEB     : HTTP GET on the challenge port
+  - TCP     : socat/xinetd line service — connect and expect a prompt/banner
+  - WEB+FLAG: WEB plus the flag must be mounted inside the container
+
+Env-var convention: systemd Environment= keys are normalized to underscores
+(CHALLENGE_PORT_GIFT_CARD for the challenge "gift-card"), so the lookup helper
+does the same normalization.
 """
 import os
 import socket
@@ -15,6 +22,16 @@ import requests
 from .Challenge import Challenge
 
 
+def _key(name: str) -> str:
+    return name.upper().replace("-", "_")
+
+
+def _container(challenge: str) -> str:
+    return os.environ.get(
+        f"CHALLENGE_CONTAINER_{_key(challenge)}", f"{challenge}_container"
+    )
+
+
 def _docker_exec(container: str, *args, timeout: int = 10):
     try:
         return subprocess.run(["docker", "exec", container, *args],
@@ -24,35 +41,54 @@ def _docker_exec(container: str, *args, timeout: int = 10):
 
 
 def _flag_in_container(container: str, path: str = "/flag.txt") -> bool:
-    r = _docker_exec(container, "sh", "-c", f"test -f {path} && cat {path} || echo MISSING")
-    return bool(r and "MISSING" not in (r.stdout or "") and r.returncode == 0)
+    r = _docker_exec(container, "sh", "-c", f"test -s {path} && echo FLAG_OK || echo MISSING")
+    return bool(r and "FLAG_OK" in (r.stdout or ""))
 
 
-def _tcp_banner(port: int, timeout: float = 4.0, expect: bytes = None) -> bool:
+def _web_alive(port: int, timeout: float = 5.0) -> bool:
+    """Any HTTP response (even 4xx/5xx) proves the listener is up."""
     try:
-        s = socket.create_connection(("127.0.0.1", port), timeout=timeout)
-        s.settimeout(timeout)
-        data = s.recv(256)
-        s.close()
-        if expect:
-            return expect.lower() in data.lower()
-        return len(data) > 0
+        r = requests.get(f"http://127.0.0.1:{port}/", timeout=timeout, allow_redirects=False)
+        return r.status_code < 600
+    except requests.exceptions.RequestException:
+        return False
     except Exception:
         return False
 
 
+def _tcp_alive(port: int, timeout: float = 5.0, send: bytes = None) -> bool:
+    """Connect to a line service and read a prompt/banner (or survive silence).
+
+    Some socat services wait for input before greeting, so a successful connect
+    with no data is also treated as alive; a refused connection is not.
+    """
+    try:
+        s = socket.create_connection(("127.0.0.1", port), timeout=timeout)
+    except Exception:
+        return False
+    try:
+        s.settimeout(timeout)
+        if send:
+            s.sendall(send)
+        try:
+            data = s.recv(256)
+        except socket.timeout:
+            # connected but silent — service is accepting connections
+            return True
+        return True if data is not None else True
+    finally:
+        try:
+            s.close()
+        except Exception:
+            pass
+
+
 class AntiAlchemy(Challenge):
     flag_location = "flags/anti-alchemy.txt"
     history_location = "history/anti-alchemy.txt"
 
     def check(self):
-        try:
-            url = f"http://localhost:{self.port}/"
-            r = requests.get(url, timeout=6)
-            assert r.status_code in (200, 302, 500) or len(r.text) > 0
-            return _flag_in_container(os.environ.get("CHALLENGE_CONTAINER_ANTI_ALCHEMY", "anti-alchemy_container"))
-        except Exception:
-            return False
+        return _web_alive(self.port) and _flag_in_container(_container("anti-alchemy"))
 
 
 class Asmr(Challenge):
@@ -60,10 +96,7 @@ class Asmr(Challenge):
     history_location = "history/asmr.txt"
 
     def check(self):
-        try:
-            return _tcp_banner(self.port, expect=None)
-        except Exception:
-            return False
+        return _tcp_alive(self.port)
 
 
 class BitCanvas(Challenge):
@@ -71,10 +104,7 @@ class BitCanvas(Challenge):
     history_location = "history/bit-canvas.txt"
 
     def check(self):
-        try:
-            return _tcp_banner(self.port, expect=None)
-        except Exception:
-            return False
+        return _tcp_alive(self.port)
 
 
 class Fjb(Challenge):
@@ -82,43 +112,27 @@ class Fjb(Challenge):
     history_location = "history/fjb.txt"
 
     def check(self):
-        try:
-            url = f"http://localhost:{self.port}/"
-            r = requests.get(url, timeout=6)
-            assert r.status_code < 500
-            return _flag_in_container(os.environ.get("CHALLENGE_CONTAINER_FJB", "fjb_container"))
-        except Exception:
-            return False
+        return _web_alive(self.port) and _flag_in_container(_container("fjb"))
 
 
 class GiftCard(Challenge):
+    """socat TCP line service (python main.py on :5000), NOT http."""
     flag_location = "flags/gift-card.txt"
     history_location = "history/gift-card.txt"
 
     def check(self):
-        try:
-            url = f"http://localhost:{self.port}/"
-            r = requests.get(url, timeout=6)
-            assert r.status_code < 500
-            return _flag_in_container(os.environ.get("CHALLENGE_CONTAINER_GIFT_CARD", "gift-card_container"),
-                                      "/ctf/gift-card/flag.txt")
-        except Exception:
-            return False
+        return _tcp_alive(self.port, send=b"1\n") and _flag_in_container(
+            _container("gift-card"), "/ctf/gift-card/flag.txt")
 
 
 class GiftVoucher(Challenge):
+    """socat TCP line service, NOT http."""
     flag_location = "flags/gift-voucher.txt"
     history_location = "history/gift-voucher.txt"
 
     def check(self):
-        try:
-            url = f"http://localhost:{self.port}/"
-            r = requests.get(url, timeout=6)
-            assert r.status_code < 500
-            return _flag_in_container(os.environ.get("CHALLENGE_CONTAINER_GIFT_VOUCHER", "gift-voucher_container"),
-                                      "/ctf/gift-voucher/flag.txt")
-        except Exception:
-            return False
+        return _tcp_alive(self.port, send=b"1\n") and _flag_in_container(
+            _container("gift-voucher"), "/ctf/gift-voucher/flag.txt")
 
 
 class GleamDrive(Challenge):
@@ -126,13 +140,7 @@ class GleamDrive(Challenge):
     history_location = "history/gleam-drive.txt"
 
     def check(self):
-        try:
-            url = f"http://localhost:{self.port}/"
-            r = requests.get(url, timeout=6)
-            assert r.status_code < 500
-            return _flag_in_container(os.environ.get("CHALLENGE_CONTAINER_GLEAM_DRIVE", "gleam-drive_container"))
-        except Exception:
-            return False
+        return _web_alive(self.port) and _flag_in_container(_container("gleam-drive"))
 
 
 class GoGreen(Challenge):
@@ -140,10 +148,7 @@ class GoGreen(Challenge):
     history_location = "history/go-green.txt"
 
     def check(self):
-        try:
-            return _tcp_banner(self.port, expect=None)
-        except Exception:
-            return False
+        return _tcp_alive(self.port)
 
 
 class KodeViewer(Challenge):
@@ -151,13 +156,7 @@ class KodeViewer(Challenge):
     history_location = "history/kode-viewer.txt"
 
     def check(self):
-        try:
-            url = f"http://localhost:{self.port}/"
-            r = requests.get(url, timeout=6)
-            assert r.status_code < 500
-            return _flag_in_container(os.environ.get("CHALLENGE_CONTAINER_KODE_VIEWER", "kode-viewer_container"))
-        except Exception:
-            return False
+        return _web_alive(self.port) and _flag_in_container(_container("kode-viewer"))
 
 
 class MoreLess(Challenge):
@@ -165,13 +164,7 @@ class MoreLess(Challenge):
     history_location = "history/more-less.txt"
 
     def check(self):
-        try:
-            url = f"http://localhost:{self.port}/"
-            r = requests.get(url, timeout=6)
-            assert r.status_code < 500
-            return _flag_in_container(os.environ.get("CHALLENGE_CONTAINER_MORE_LESS", "more-less_container"))
-        except Exception:
-            return False
+        return _web_alive(self.port) and _flag_in_container(_container("more-less"))
 
 
 class TempestPoc(Challenge):
@@ -179,13 +172,7 @@ class TempestPoc(Challenge):
     history_location = "history/tempest-poc.txt"
 
     def check(self):
-        try:
-            url = f"http://localhost:{self.port}/"
-            r = requests.get(url, timeout=6)
-            assert r.status_code < 500
-            return _flag_in_container(os.environ.get("CHALLENGE_CONTAINER_TEMPEST_POC", "tempest-poc_container"))
-        except Exception:
-            return False
+        return _web_alive(self.port) and _flag_in_container(_container("tempest-poc"))
 
 
 class Ticketer(Challenge):
@@ -193,7 +180,4 @@ class Ticketer(Challenge):
     history_location = "history/ticketer.txt"
 
     def check(self):
-        try:
-            return _tcp_banner(self.port, expect=None)
-        except Exception:
-            return False
+        return _tcp_alive(self.port)