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Azure DNS API - support for ACME v2 and reliability improvments
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support adding 2 txt records
Adding retry logic for REST API calls
Reusing bearer token removes 50% of required REST calls
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@martgras
martgras committed Feb 22, 2018
1 parent 9ad7ac6 commit 83b1a98
Showing 1 changed file with 124 additions and 34 deletions.
158 changes: 124 additions & 34 deletions dnsapi/dns_azure.sh
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Original file line number Diff line number Diff line change
@@ -1,5 +1,7 @@
#!/usr/bin/env sh

WIKI="https://github.com/Neilpang/acme.sh/wiki/How-to-use-Azure-DNS"

######## Public functions #####################

# Usage: add _acme-challenge.www.domain.com "XKrxpRBosdIKFzxW_CT3KLZNf6q0HG9i01zxXp5CPBs"
Expand Down Expand Up @@ -69,12 +71,36 @@ dns_azure_add() {

acmeRecordURI="https://management.azure.com$(printf '%s' "$_domain_id" | sed 's/\\//g')/TXT/$_sub_domain?api-version=2017-09-01"
_debug "$acmeRecordURI"
body="{\"properties\": {\"TTL\": 3600, \"TXTRecords\": [{\"value\": [\"$txtvalue\"]}]}}"
# Get existing TXT record
_azure_rest GET "$acmeRecordURI" "" "$accesstoken"
values="{\"value\":[\"$txtvalue\"]}"
timestamp="$(_time)"
if [ "$_code" = "200" ]; then
vlist="$(echo "$response" | _egrep_o "\"value\"\s*:\s*\[\s*\"[^\"]*\"\s*]" | cut -d : -f 2 | tr -d "[]\"")"
_debug "existing TXT found"
_debug "$vlist"
existingts="$(echo "$response" | _egrep_o "\"acmetscheck\"\s*:\s*\"[^\"]*\"" | _head_n 1 | cut -d : -f 2 | tr -d "\"")"
if [ -z "$existingts" ]; then
# the record was not created by acme.sh. Copy the exisiting entires
existingts=$timestamp
fi
_diff="$(_math "$timestamp - $existingts")"
_debug "existing txt age: $_diff"
# only use recently added records and discard if older than 2 hours because they are probably orphaned
if [ "$_diff" -lt 7200 ]; then
_debug "existing txt value: $vlist"
for v in $vlist; do
values="$values ,{\"value\":[\"$v\"]}"
done
fi
fi
# Add the txtvalue TXT Record
body="{\"properties\":{\"metadata\":{\"acmetscheck\":\"$timestamp\"},\"TTL\":10, \"TXTRecords\":[$values]}}"
_azure_rest PUT "$acmeRecordURI" "$body" "$accesstoken"
if [ "$_code" = "200" ] || [ "$_code" = '201' ]; then
_info "validation record added"
_info "validation value added"
else
_err "error adding validation record ($_code)"
_err "error adding validation value ($_code)"
return 1
fi
}
Expand Down Expand Up @@ -141,13 +167,38 @@ dns_azure_rm() {

acmeRecordURI="https://management.azure.com$(printf '%s' "$_domain_id" | sed 's/\\//g')/TXT/$_sub_domain?api-version=2017-09-01"
_debug "$acmeRecordURI"
body="{\"properties\": {\"TTL\": 3600, \"TXTRecords\": [{\"value\": [\"$txtvalue\"]}]}}"
_azure_rest DELETE "$acmeRecordURI" "" "$accesstoken"
if [ "$_code" = "200" ] || [ "$_code" = '204' ]; then
_info "validation record removed"
else
_err "error removing validation record ($_code)"
return 1
# Get existing TXT record
_azure_rest GET "$acmeRecordURI" "" "$accesstoken"
timestamp="$(_time)"
if [ "$_code" = "200" ]; then
vlist="$(echo "$response" | _egrep_o "\"value\"\s*:\s*\[\s*\"[^\"]*\"\s*]" | cut -d : -f 2 | tr -d "[]\"" | grep -v "$txtvalue")"
values=""
comma=""
for v in $vlist; do
values="$values$comma{\"value\":[\"$v\"]}"
comma=","
done
if [ -z "$values" ]; then
# No values left remove record
_debug "removing validation record completely $acmeRecordURI"
_azure_rest DELETE "$acmeRecordURI" "" "$accesstoken"
if [ "$_code" = "200" ] || [ "$_code" = '204' ]; then
_info "validation record removed"
else
_err "error removing validation record ($_code)"
return 1
fi
else
# Remove only txtvalue from the TXT Record
body="{\"properties\":{\"metadata\":{\"acmetscheck\":\"$timestamp\"},\"TTL\":10, \"TXTRecords\":[$values]}}"
_azure_rest PUT "$acmeRecordURI" "$body" "$accesstoken"
if [ "$_code" = "200" ] || [ "$_code" = '201' ]; then
_info "validation value removed"
else
_err "error removing validation value ($_code)"
return 1
fi
fi
fi
}

Expand All @@ -159,52 +210,92 @@ _azure_rest() {
data="$3"
accesstoken="$4"

export _H1="authorization: Bearer $accesstoken"
export _H2="accept: application/json"
export _H3="Content-Type: application/json"

_debug "$ep"
if [ "$m" != "GET" ]; then
_debug data "$data"
response="$(_post "$data" "$ep" "" "$m")"
else
response="$(_get "$ep")"
fi
_debug2 response "$response"

_code="$(grep "^HTTP" "$HTTP_HEADER" | _tail_n 1 | cut -d " " -f 2 | tr -d "\r\n")"
_debug2 "http response code $_code"

if [ "$?" != "0" ]; then
_err "error $ep"
MAX_REQUEST_RETRY_TIMES=5
_request_retry_times=0
while [ "${_request_retry_times}" -lt "$MAX_REQUEST_RETRY_TIMES" ]; do
_debug3 _request_retry_times "$_request_retry_times"
export _H1="authorization: Bearer $accesstoken"
export _H2="accept: application/json"
export _H3="Content-Type: application/json"
# clear headers from previous request to avoid getting wrong http code on timeouts
:>"$HTTP_HEADER"
_debug "$ep"
if [ "$m" != "GET" ]; then
_secure_debug2 "data $data"
response="$(_post "$data" "$ep" "" "$m")"
else
response="$(_get "$ep")"
fi
_secure_debug2 "response $response"
_code="$(grep "^HTTP" "$HTTP_HEADER" | _tail_n 1 | cut -d " " -f 2 | tr -d "\r\n")"
_debug "http response code $_code"
if [ "$_code" = "401" ]; then
# we have an invalid access token set to expired
_saveaccountconf_mutable AZUREDNS_TOKENVALIDTO "0"
_err "access denied make sure your Azure settings are correct. See $WIKI"
return 1
fi
# See https://docs.microsoft.com/en-us/azure/architecture/best-practices/retry-service-specific#general-rest-and-retry-guidelines for retryable HTTP codes
if [ "$?" != "0" ] || [ -z "$_code" ] || [ "$_code" = "408" ] || [ "$_code" = "500" ] || [ "$_code" = "503" ] || [ "$_code" = "504" ]; then
_request_retry_times="$(_math "$_request_retry_times" + 1)"
_info "REST call error $_code retrying $ep in $_request_retry_times s"
_sleep "$_request_retry_times"
continue
fi
break
done
if [ "$_request_retry_times" = "$MAX_REQUEST_RETRY_TIMES" ]; then
_err "Error Azure REST called was retried $MAX_REQUEST_RETRY_TIMES times."
_err "Calling $ep failed."
return 1
fi
response="$(echo "$response" | _normalizeJson)"
return 0
}

## Ref: https://docs.microsoft.com/en-us/azure/active-directory/develop/active-directory-protocols-oauth-service-to-service#request-an-access-token
_azure_getaccess_token() {
TENANTID=$1
tenantID=$1
clientID=$2
clientSecret=$3

accesstoken="${AZUREDNS_BEARERTOKEN:-$(_readaccountconf_mutable AZUREDNS_BEARERTOKEN)}"
expires_on="${AZUREDNS_TOKENVALIDTO:-$(_readaccountconf_mutable AZUREDNS_TOKENVALIDTO)}"

# can we reuse the bearer token?
if [ -n "$accesstoken" ] && [ -n "$expires_on" ]; then
if [ "$(_time)" -lt "$expires_on" ]; then
# brearer token is still valid - reuse it
_debug "reusing bearer token"
printf "%s" "$accesstoken"
return 0
else
_debug "bearer token expired"
fi
fi
_debug "getting new bearer token"

export _H1="accept: application/json"
export _H2="Content-Type: application/x-www-form-urlencoded"

body="resource=$(printf "%s" 'https://management.core.windows.net/' | _url_encode)&client_id=$(printf "%s" "$clientID" | _url_encode)&client_secret=$(printf "%s" "$clientSecret" | _url_encode)&grant_type=client_credentials"
_debug data "$body"
response="$(_post "$body" "https://login.windows.net/$TENANTID/oauth2/token" "" "POST")"
_secure_debug2 "data $body"
response="$(_post "$body" "https://login.microsoftonline.com/$tenantID/oauth2/token" "" "POST")"
_secure_debug2 "response $response"
response="$(echo "$response" | _normalizeJson)"
accesstoken=$(echo "$response" | _egrep_o "\"access_token\":\"[^\"]*\"" | _head_n 1 | cut -d : -f 2 | tr -d \")
_debug2 "response $response"
expires_on=$(echo "$response" | _egrep_o "\"expires_on\":\"[^\"]*\"" | _head_n 1 | cut -d : -f 2 | tr -d \")

if [ -z "$accesstoken" ]; then
_err "no acccess token received"
_err "no acccess token received. Check your Azure settings see $WIKI"
return 1
fi
if [ "$?" != "0" ]; then
_err "error $response"
return 1
fi
_saveaccountconf_mutable AZUREDNS_BEARERTOKEN "$accesstoken"
_saveaccountconf_mutable AZUREDNS_TOKENVALIDTO "$expires_on"
printf "%s" "$accesstoken"
return 0
}
Expand All @@ -222,7 +313,6 @@ _get_root() {
## Per https://docs.microsoft.com/en-us/azure/azure-subscription-service-limits#dns-limits you are limited to 100 Zone/subscriptions anyways
##
_azure_rest GET "https://management.azure.com/subscriptions/$subscriptionId/providers/Microsoft.Network/dnszones?api-version=2017-09-01" "" "$accesstoken"

# Find matching domain name is Json response
while true; do
h=$(printf "%s" "$domain" | cut -d . -f $i-100)
Expand Down

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