From 999c5032941ec108ba36cd293bdb334ad0db05a3 Mon Sep 17 00:00:00 2001
From: Andy Bunce <bunce.andy@gmail.com>
Date: Wed, 21 May 2025 16:12:37 +0100
Subject: [PATCH] [add] graphviz

---
 graphviz/Dockerfile       | 10 +++++++
 graphviz/compose.yml      |  7 +++++
 graphviz/readme.md        |  7 +++++
 graphviz/requirements.txt |  3 ++
 graphviz/server.py        | 60 +++++++++++++++++++++++++++++++++++++++
 graphviz/test.dot         | 11 +++++++
 6 files changed, 98 insertions(+)
 create mode 100644 graphviz/Dockerfile
 create mode 100644 graphviz/compose.yml
 create mode 100644 graphviz/readme.md
 create mode 100644 graphviz/requirements.txt
 create mode 100644 graphviz/server.py
 create mode 100644 graphviz/test.dot

diff --git a/graphviz/Dockerfile b/graphviz/Dockerfile
new file mode 100644
index 0000000..a8030f2
--- /dev/null
+++ b/graphviz/Dockerfile
@@ -0,0 +1,10 @@
+FROM alpine:3
+
+RUN apk add --no-cache \
+	graphviz python3 py-pip
+
+ADD requirements.txt ./
+RUN pip3 install -r requirements.txt --break-system-packages
+
+ADD server.py ./
+CMD hug -f server.py
diff --git a/graphviz/compose.yml b/graphviz/compose.yml
new file mode 100644
index 0000000..c1ee058
--- /dev/null
+++ b/graphviz/compose.yml
@@ -0,0 +1,7 @@
+name: graphviz
+services:
+    graphviz:
+        ports:
+            - 8000:8000
+        image: graphviz
+        restart: unless-stopped
\ No newline at end of file
diff --git a/graphviz/readme.md b/graphviz/readme.md
new file mode 100644
index 0000000..408485d
--- /dev/null
+++ b/graphviz/readme.md
@@ -0,0 +1,7 @@
+
+
+```
+docker build -t graphviz .
+docker run -p8000:8000 graphviz
+```
+Based on https://github.com/sseemayer/docker-graphviz
diff --git a/graphviz/requirements.txt b/graphviz/requirements.txt
new file mode 100644
index 0000000..846c5ad
--- /dev/null
+++ b/graphviz/requirements.txt
@@ -0,0 +1,3 @@
+hug==2.6.1
+hug-middleware-cors==1.0.0
+six==1.16.0
\ No newline at end of file
diff --git a/graphviz/server.py b/graphviz/server.py
new file mode 100644
index 0000000..62b1033
--- /dev/null
+++ b/graphviz/server.py
@@ -0,0 +1,60 @@
+import hug
+from hug.middleware import CORSMiddleware
+from six import BytesIO
+import subprocess
+import logging
+from tempfile import NamedTemporaryFile as ntf
+
+logging.basicConfig()
+api = hug.API(__name__)
+api.http.add_middleware(CORSMiddleware(api, allow_credentials=True))
+
+@hug.not_found()
+def not_found_handler():
+    return "Not Found"
+
+@hug.get_post('/viz.svg', output=hug.output_format.image("svg+xml"))
+@hug.get_post('/viz.png', output=hug.output_format.image("png"))
+@hug.get_post('/viz.dot', output=hug.output_format.text)
+@hug.get_post('/viz.xdot', output=hug.output_format.text)
+def demo(
+    dot: 'A Graphviz dot document',
+    request,
+    response,
+    algorithm: hug.types.one_of(['dot', 'neato', 'twopi', 'circo', 'fdp', 'sfdp', 'patchwork', 'osage'])='dot',
+):
+
+    suffix = request.path.split(".")[-1]
+
+    # Enforce unicode strings
+    try:
+        dot = dot.decode("utf-8")
+    except AttributeError:
+        pass
+
+    with ntf(suffix=".dot", mode="w") as f_dot, ntf(mode="r+b") as f_out, ntf(mode="r") as f_err:
+        f_dot.write(dot)
+        f_dot.flush()
+
+        cmd = [
+            algorithm,
+            '-T',
+            suffix,
+            f_dot.name,
+            '-o',
+            f_out.name
+        ]
+
+        proc = subprocess.Popen(cmd, stdout=f_err, stderr=subprocess.STDOUT)
+
+        ret = proc.wait()
+
+        if ret != 0:
+            response.status = hug.HTTP_500
+            f_err.seek(0)
+            return {"status_code": ret, "message": f_err.read()}
+
+        f_out.seek(0)
+        out_data = f_out.read()
+
+    return BytesIO(out_data)
diff --git a/graphviz/test.dot b/graphviz/test.dot
new file mode 100644
index 0000000..024f822
--- /dev/null
+++ b/graphviz/test.dot
@@ -0,0 +1,11 @@
+
+
+digraph D {
+
+    node [fontname="Arial"];
+
+    node_A [shape=record    label="shape=record|{above|middle|below}|right"];
+    node_B [shape=plaintext label="shape=plaintext|{curly|braces and|bars without}|effect"];
+
+
+}