debuginfod: balance redirect & reverse-proxy better

Our ansible default ansible scripts don't like multiple /suburls being
individually proxied, so we ended up losing /buildid/* and keeping
/metrics.

Switch to using single /-level reverse-proxying AND wiki-redirection
clauses, and use a new template .conf file to break the tie with a
"ProxyPass / !"  directive.

playbooks/include/proxies-redirects.yml

@@ -873,7 +873,7 @@
     path: /
     target: https://fedoraproject.org/wiki/QA
 
-  # redirects for debuginfod main page
+  # redirects for debuginfod main page; subdirs are reverse-proxied
   - role: httpd/redirect
     shortname: debuginfod
     website: debuginfod.fedoraproject.org
@@ -881,11 +881,4 @@
     target: https://fedoraproject.org/wiki/Debuginfod
     tags:
     - debuginfod
-
-  - role: httpd/redirect
-    shortname: debuginfod
-    website: debuginfod.fedoraproject.org
-    regex: ^/index.html$
-    target: https://fedoraproject.org/wiki/Debuginfod
-    tags:
-    - debuginfod
+    

playbooks/include/proxies-reverseproxy.yml

@@ -751,18 +751,8 @@
   - role: httpd/reverseproxy
     website: debuginfod.fedoraproject.org
     destname: debuginfod
-    remotepath: /buildid/
-    localpath: /buildid/
+    # manage non-trivial reverse-proxy specs in template
     proxyurl: http://debuginfod01:8002
     proxyopts: "connectiontimeout=600 timeout=600 keepalive=on"
-    tags: debuginfod
-
-  - role: httpd/reverseproxy
-    website: debuginfod.fedoraproject.org
-    destname: debuginfod
-    remotepath: /metrics
-    localpath: /metrics
-    proxyurl: http://debuginfod01:8002
-    proxyopts: "connectiontimeout=600 timeout=600 keepalive=on"
-    tags: debuginfod
-
+    tags:
+    - debuginfod

roles/httpd/reverseproxy/templates/reversepassproxy.debuginfod.conf

@@ -0,0 +1,10 @@
+
+# Broadly reverse-proxy
+ProxyPassMatch "^(.*)$" "{{proxyurl}}$1" {{proxyopts}}
+ProxyPassReverse / {{proxyurl}}/
+
+# ... but not the top level, which is instead redirected
+ProxyPass / !
+
+# ... configure this redirect in playbooks/include/proxies-redirects.yml
+# Redirect permanent / https://sourceware.org/elfutils/Debuginfod.html