protected virtual async Task InitializeAsync(ILambdaConfigSource envSource, ILambdaContext context)
{
// read configuration from environment variables
DeploymentTier = envSource.Read("TIER");
ModuleName = envSource.Read("MODULE");
_deadLetterQueueUrl = envSource.Read("DEADLETTERQUEUE");
_loggingTopicArn = envSource.Read("LOGGINGTOPIC");
var framework = envSource.Read("LAMBDARUNTIME");
LogInfo($"TIER = {DeploymentTier}");
LogInfo($"MODULE = {ModuleName}");
LogInfo($"DEADLETTERQUEUE = {_deadLetterQueueUrl ?? "NONE"}");
LogInfo($"LOGGINGTOPIC = {_loggingTopicArn ?? "NONE"}");
// read optional git-sha file
var gitsha = File.Exists("gitsha.txt") ? File.ReadAllText("gitsha.txt") : null;
LogInfo($"GITSHA = {gitsha ?? "NONE"}");
// convert environment variables to lambda parameters
_appConfig = new LambdaConfig(new LambdaDictionarySource(await ReadParametersFromEnvironmentVariables()));
// initialize rollbar
var rollbarAccessToken = _appConfig.ReadText("RollbarToken", defaultValue: null);
const string proxy = "";
const string platform = "lambda";
_rollbarClient = RollbarClient.Create(new RollbarConfiguration(
// NOTE (2018-08-06, bjorg): the rollbar access token determines the rollbar project
// the error report is associated with; when rollbar intergration is disabled,
// use the module name instead so the logging recipient can determine the module
// the log entry belongs to.
rollbarAccessToken ?? ModuleName,
proxy,
DeploymentTier,
platform,
framework,
gitsha
));
_rollbarEnabled = (rollbarAccessToken != null);
LogInfo($"ROLLBAR = {(_rollbarEnabled ? "ENABLED" : "DISABLED")}");
}
private LambdaConfig(LambdaConfig parent, string key, ILambdaConfigSource source)
{
_parent = parent ?? throw new ArgumentNullException(nameof(parent));
_key = key ?? throw new ArgumentNullException(nameof(key));
_source = source ?? throw new ArgumentNullException(nameof(source));
}
public static TimeSpan ReadTimeSpan(this LambdaConfig config, string key, TimeSpan defaultValue, Action <TimeSpan> validate = null) => config.Read(key, fallback: _ => defaultValue, convert: value => TimeSpan.FromSeconds(float.Parse(value)), validate: validate);
public static int ReadInt(this LambdaConfig config, string key, int defaultValue, Action <int> validate = null) => config.Read(key, fallback: _ => defaultValue, convert: int.Parse, validate: validate);
public static string ReadText(this LambdaConfig config, string key, string defaultValue, Action <string> validate = null) => config.Read(key, fallback: _ => defaultValue, convert: v => v, validate: validate);
//--- Abstract Methods --- public abstract Task InitializeAsync(LambdaConfig config);
protected virtual async Task InitializeAsync(ILambdaConfigSource envSource, ILambdaContext context)
{
// read configuration from environment variables
DeploymentTier = envSource.Read("TIER");
ModuleName = envSource.Read("MODULE");
_deadLetterQueueUrl = envSource.Read("DEADLETTERQUEUE");
_loggingTopicArn = envSource.Read("LOGGINGTOPIC");
var framework = envSource.Read("LAMBDARUNTIME");
LogInfo($"TIER = {DeploymentTier}");
LogInfo($"MODULE = {ModuleName}");
LogInfo($"DEADLETTERQUEUE = {_deadLetterQueueUrl ?? "NONE"}");
LogInfo($"LOGGINGTOPIC = {_loggingTopicArn ?? "NONE"}");
// read optional git-sha file
var gitsha = File.Exists("gitsha.txt") ? File.ReadAllText("gitsha.txt") : null;
LogInfo($"GITSHA = {gitsha ?? "NONE"}");
// read module parameter values from parameters file
var parameters = await ParseParameters("/", File.ReadAllText("parameters.json"));
// create config where environment variables take precedence over those found in the parameter file
_appConfig = new LambdaConfig(new LambdaMultiSource(new[] {
envSource,
new LambdaDictionarySource("", parameters)
}));
// initialize rollbar
var rollbarAccessToken = _appConfig.ReadText("RollbarToken", defaultValue: null);
const string proxy = "";
const string platform = "lambda";
_rollbarClient = RollbarClient.Create(new RollbarConfiguration(
// NOTE (2018-08-06, bjorg): the rollbar access token determines the rollbar project
// the error report is associated with; when rollbar intergration is disabled,
// use the module name instead so the logging recipient can determine the module
// the log entry belongs to.
rollbarAccessToken ?? ModuleName,
proxy,
DeploymentTier,
platform,
framework,
gitsha
));
_rollbarEnabled = (rollbarAccessToken != null);
LogInfo($"ROLLBAR = {(_rollbarEnabled ? "ENABLED" : "DISABLED")}");
// local functions
async Task <Dictionary <string, string> > ParseParameters(string parameterPrefix, string json)
{
var functionParameters = JsonConvert.DeserializeObject <Dictionary <string, LambdaFunctionParameter> >(json);
var flatten = new Dictionary <string, string>();
await Flatten(functionParameters, parameterPrefix, "STACK_", flatten);
return(flatten);
// local functions
async Task Flatten(Dictionary <string, LambdaFunctionParameter> source, string prefix, string envPrefix, Dictionary <string, string> target)
{
foreach (var kv in source)
{
var value = kv.Value.Value;
switch (kv.Value.Type)
{
case LambdaFunctionParameterType.Collection:
await Flatten((Dictionary <string, LambdaFunctionParameter>) value, prefix + kv.Key + "/", envPrefix + kv.Key.ToUpperInvariant() + "_", target);
break;
case LambdaFunctionParameterType.Secret: {
var secret = (string)value;
var plaintextStream = (await _kmsClient.DecryptAsync(new DecryptRequest {
CiphertextBlob = new MemoryStream(Convert.FromBase64String(secret)),
EncryptionContext = kv.Value.EncryptionContext
})).Plaintext;
target.Add(prefix + kv.Key, Encoding.UTF8.GetString(plaintextStream.ToArray()));
break;
}
case LambdaFunctionParameterType.Stack:
target.Add(prefix + kv.Key, envSource.Read(envPrefix + kv.Key.ToUpperInvariant()));
break;
case LambdaFunctionParameterType.Text:
target.Add(prefix + kv.Key, (string)value);
break;
default:
throw new NotSupportedException($"unsupported parameter type: '{kv.Value.Type.ToString()}'");
}
}
}
}
}