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@rezan
Last active November 7, 2019 16:56
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Varnish: validate JSON, if invalid, refetch
varnishtest "Validate JSON, if invalid, refetch"
server s1 {
rxreq
txresp -hdr "Content-Type: application/json" -body {
{
"some": "field",
"error...bad json
}
}
rxreq
txresp -hdr "Content-Type: application/json" -body {
{
"some": "field",
"valid": true
}
}
} -start
varnish v1 -vcl+backend {
import edgestash;
import json;
sub vcl_recv {
# Should we attempt to refetch and reinsert a JSON request?
if (req.restarts > 0 && req.http.refetch-json) {
set req.hash_always_miss = true;
}
unset req.http.refetch-json;
}
sub vcl_backend_response {
# Setup JSON parsing
if (beresp.http.Content-Type ~ "json") {
edgestash.index_json();
}
}
sub vcl_deliver {
# Do we have valid JSON?
if (resp.http.Content-Type ~ "json") {
json.parse_resp_index();
# We don't, refetch
if (!json.is_valid()) {
set req.http.refetch-json = "true";
return (restart);
}
set resp.http.json = json.is_object();
}
}
} -start
client c1 {
txreq
rxresp
expect resp.status == 200
expect resp.http.json == "true"
} -run
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